HONEYCOMB-130: Separate v3po plugin from HC infra

Creating folders:
- common/
- infra/
- v3po/
- vpp-common/

Change-Id: I2c39e1b17e39e7c0f0628f44aa5fe08563fa06e4
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

43 files changed, 4256 insertions, 0 deletions

diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/AbstractSubtreeManagerRegistryBuilderBuilder.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/AbstractSubtreeManagerRegistryBuilderBuilder.java
new file mode 100644
index 000000000..23a66337f
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/AbstractSubtreeManagerRegistryBuilderBuilder.java
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
+import io.fd.honeycomb.v3po.translate.ModifiableSubtreeManagerRegistryBuilder;
+import io.fd.honeycomb.v3po.translate.SubtreeManager;
+import io.fd.honeycomb.v3po.translate.SubtreeManagerRegistryBuilder;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import javax.annotation.Nonnull;
+import org.jgrapht.experimental.dag.DirectedAcyclicGraph;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public abstract class AbstractSubtreeManagerRegistryBuilderBuilder<S extends SubtreeManager<? extends DataObject>, R>
+        implements ModifiableSubtreeManagerRegistryBuilder<S>, SubtreeManagerRegistryBuilder<R>, AutoCloseable {
+
+    // Using directed acyclic graph to represent the ordering relationships between writers
+    private final DirectedAcyclicGraph<InstanceIdentifier<?>, Order>
+            handlersRelations = new DirectedAcyclicGraph<>((sourceVertex, targetVertex) -> new Order());
+    private final Map<InstanceIdentifier<?>, S> handlersMap = new HashMap<>();
+
+    /**
+     * Add handler without any special relationship to any other type.
+     */
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> add(@Nonnull final S handler) {
+        // Make IID wildcarded just in case
+        // + the way InstanceIdentifier.create + equals work for Identifiable items is unexpected, meaning updates would
+        // not be matched to writers in registry
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(handler.getManagedDataObjectType());
+        checkWriterNotPresentYet(targetType);
+        handlersRelations.addVertex(targetType);
+        handlersMap.put(targetType, handler);
+        return this;
+    }
+
+    /**
+     * Add handler without any special relationship to any other type.
+     */
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> subtreeAdd(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                                         @Nonnull final S handler) {
+        add(getSubtreeHandler(handledChildren, handler));
+        return this;
+    }
+
+    private void checkWriterNotPresentYet(final InstanceIdentifier<?> targetType) {
+        Preconditions.checkArgument(!handlersMap.containsKey(targetType),
+                "Writer for type: %s already present: %s", targetType, handlersMap.get(targetType));
+    }
+
+    /**
+     * Add handler with relationship: to be executed before handler handling relatedType.
+     */
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> addBefore(@Nonnull final S handler,
+                                                                        @Nonnull final InstanceIdentifier<?> relatedType) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(handler.getManagedDataObjectType());
+        final InstanceIdentifier<?> wildcardedRelatedType = RWUtils.makeIidWildcarded(relatedType);
+        checkWriterNotPresentYet(targetType);
+        handlersRelations.addVertex(targetType);
+        handlersRelations.addVertex(wildcardedRelatedType);
+        addEdge(targetType, wildcardedRelatedType);
+        handlersMap.put(targetType, handler);
+        return this;
+    }
+
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> addBefore(@Nonnull final S handler,
+                                                                        @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(handler.getManagedDataObjectType());
+        checkWriterNotPresentYet(targetType);
+        handlersRelations.addVertex(targetType);
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(handlersRelations::addVertex);
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(type -> addEdge(targetType, type));
+        handlersMap.put(targetType, handler);
+        return this;
+    }
+
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> subtreeAddBefore(
+            @Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+            @Nonnull final S handler,
+            @Nonnull final InstanceIdentifier<?> relatedType) {
+        return addBefore(getSubtreeHandler(handledChildren, handler), relatedType);
+    }
+
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> subtreeAddBefore(
+            @Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+            @Nonnull final S handler,
+            @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        return addBefore(getSubtreeHandler(handledChildren, handler), relatedTypes);
+    }
+
+    protected abstract S getSubtreeHandler(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                           @Nonnull final S handler);
+
+    /**
+     * Add handler with relationship: to be executed after handler handling relatedType.
+     */
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> addAfter(@Nonnull final S handler,
+                                                                       @Nonnull final InstanceIdentifier<?> relatedType) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(handler.getManagedDataObjectType());
+        final InstanceIdentifier<?> wildcardedRelatedType = RWUtils.makeIidWildcarded(relatedType);
+        checkWriterNotPresentYet(targetType);
+        handlersRelations.addVertex(targetType);
+        handlersRelations.addVertex(wildcardedRelatedType);
+        // set edge to indicate before relationship, just reversed
+        addEdge(wildcardedRelatedType, targetType);
+        handlersMap.put(targetType, handler);
+        return this;
+    }
+
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> addAfter(@Nonnull final S handler,
+                                                                       @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(handler.getManagedDataObjectType());
+        checkWriterNotPresentYet(targetType);
+        handlersRelations.addVertex(targetType);
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(handlersRelations::addVertex);
+        // set edge to indicate before relationship, just reversed
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(type -> addEdge(type, targetType));
+        handlersMap.put(targetType, handler);
+        return this;
+    }
+
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> subtreeAddAfter(
+            @Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+            @Nonnull final S handler,
+            @Nonnull final InstanceIdentifier<?> relatedType) {
+        return addAfter(getSubtreeHandler(handledChildren, handler), relatedType);
+    }
+
+    @Override
+    public AbstractSubtreeManagerRegistryBuilderBuilder<S, R> subtreeAddAfter(
+            @Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+            @Nonnull final S handler,
+            @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        return addAfter(getSubtreeHandler(handledChildren, handler), relatedTypes);
+    }
+
+
+    private void addEdge(final InstanceIdentifier<?> targetType,
+                         final InstanceIdentifier<?> relatedType) {
+        try {
+            handlersRelations.addDagEdge(targetType, relatedType);
+        } catch (DirectedAcyclicGraph.CycleFoundException e) {
+            throw new IllegalArgumentException(String.format(
+                    "Unable to add writer with relation: %s -> %s. Loop detected", targetType, relatedType), e);
+        }
+    }
+
+    protected ImmutableMap<InstanceIdentifier<?>, S> getMappedHandlers() {
+        final ImmutableMap.Builder<InstanceIdentifier<?>, S> builder = ImmutableMap.builder();
+        // Iterate writer types according to their relationships from graph
+        handlersRelations.iterator()
+                .forEachRemaining(writerType -> {
+                    // There might be types stored just for relationship sake, no real writer, ignoring those
+                    if (handlersMap.containsKey(writerType)) {
+                        builder.put(writerType, handlersMap.get(writerType));
+                    }
+                });
+
+        // TODO we could optimize subtree handlers, if there is a dedicated handler for a node managed by a subtree
+        // handler, recreate the subtree handler with a subset of handled child nodes
+        // This way it is not necessary to change the configuration of subtree writer, just to add a dedicated child
+        // writer. This will be needed if we ever switch to annotations for reader/writer hierarchy initialization
+
+        return builder.build();
+    }
+
+    @Override
+    public void close() throws Exception {
+        handlersMap.clear();
+        // Wrap sets into another set to avoid concurrent modification ex in graph
+        handlersRelations.removeAllEdges(Sets.newHashSet(handlersRelations.edgeSet()));
+        handlersRelations.removeAllVertices(Sets.newHashSet(handlersRelations.vertexSet()));
+    }
+
+    // Represents edges in graph
+    private class Order {}
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/JsonUtils.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/JsonUtils.java
new file mode 100644
index 000000000..d9798d07d
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/JsonUtils.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import com.google.common.base.Charsets;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
+import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
+import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
+import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
+import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
+import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
+import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
+import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
+import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
+import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.DataContainerNodeAttrBuilder;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import org.opendaylight.yangtools.yang.model.api.SchemaPath;
+
+public final class JsonUtils {
+
+    private JsonUtils() {}
+
+    /**
+     * Serialize normalized node root structure into provided output stream
+     *
+     * @throws IOException if serialized data cannot be written into provided output stream
+     */
+    public static void writeJsonRoot(@Nonnull final NormalizedNode<?, ?> rootData,
+                                     @Nonnull final SchemaContext schemaContext,
+                                     @Nonnull final OutputStream outputStream) throws IOException {
+        final JsonWriter
+            jsonWriter = createJsonWriter(outputStream, true);
+        final NormalizedNodeStreamWriter streamWriter = JSONNormalizedNodeStreamWriter
+            .createNestedWriter(JSONCodecFactory.create(schemaContext), SchemaPath.ROOT, null, jsonWriter);
+        final NormalizedNodeWriter normalizedNodeWriter =
+            NormalizedNodeWriter.forStreamWriter(streamWriter, true);
+        jsonWriter.beginObject();
+        writeChildren(normalizedNodeWriter,(ContainerNode) rootData);
+        jsonWriter.endObject();
+        jsonWriter.flush();
+    }
+
+    /**
+     * Read json serialized normalized node root structure and parse them into normalized nodes
+     *
+     * @return artificial normalized node holding all the top level nodes from provided stream as children. In case
+     *         the stream is empty, empty artificial normalized node is returned
+     *
+     * @throws IllegalArgumentException if content in the provided input stream is not restore-able
+     */
+    public static ContainerNode readJsonRoot(@Nonnull final SchemaContext schemaContext,
+                                             @Nonnull final InputStream stream) {
+        final DataContainerNodeAttrBuilder<YangInstanceIdentifier.NodeIdentifier, ContainerNode> builder =
+            Builders.containerBuilder().withNodeIdentifier(new YangInstanceIdentifier.NodeIdentifier(schemaContext.getQName()));
+        final NormalizedNodeStreamWriter writer = ImmutableNormalizedNodeStreamWriter.from(builder);
+
+        final JsonParserStream jsonParser = JsonParserStream.create(writer, schemaContext);
+        final JsonReader reader = new JsonReader(new InputStreamReader(stream, Charsets.UTF_8));
+        jsonParser.parse(reader);
+
+        return builder.build();
+    }
+
+    private static void writeChildren(final NormalizedNodeWriter nnWriter, final ContainerNode data) throws IOException {
+        for(final DataContainerChild<? extends YangInstanceIdentifier.PathArgument, ?> child : data.getValue()) {
+            nnWriter.write(child);
+        }
+    }
+
+    private static JsonWriter createJsonWriter(final OutputStream entityStream, boolean prettyPrint) {
+        if (prettyPrint) {
+            return JsonWriterFactory.createJsonWriter(new OutputStreamWriter(entityStream, Charsets.UTF_8), 2);
+        } else {
+            return JsonWriterFactory.createJsonWriter(new OutputStreamWriter(entityStream, Charsets.UTF_8));
+        }
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/RWUtils.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/RWUtils.java
new file mode 100644
index 000000000..2a565d9f2
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/RWUtils.java
@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import com.google.common.base.Function;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Maps;
+import io.fd.honeycomb.v3po.translate.SubtreeManager;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.Augmentation;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.Identifiable;
+import org.opendaylight.yangtools.yang.binding.Identifier;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public final class RWUtils {
+
+    private RWUtils() {}
+
+    /**
+     * Collector expecting only a single resulting item from a stream
+     */
+    public static<T> Collector<T,?,T> singleItemCollector() {
+        return Collectors.collectingAndThen(
+                Collectors.toList(),
+                list -> {
+                    if (list.size() != 1) {
+                        throw new IllegalStateException("Unexpected size of list: " + list + ". Single item expected");
+                    }
+                    return list.get(0);
+                }
+        );
+    }
+
+    /**
+     * Find next item in ID after provided type
+     */
+    @Nonnull
+    public static InstanceIdentifier.PathArgument getNextId(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                                            @Nonnull final InstanceIdentifier<? extends DataObject> type) {
+        // TODO this is inefficient(maybe, depending on actual Iterable type)
+        final Iterable<InstanceIdentifier.PathArgument> pathArguments = id.getPathArguments();
+        final int i = Iterables.indexOf(pathArguments, new Predicate<InstanceIdentifier.PathArgument>() {
+            @Override
+            public boolean apply(final InstanceIdentifier.PathArgument input) {
+                return input.getType().isAssignableFrom(type.getTargetType());
+            }
+        });
+        Preconditions.checkArgument(i >= 0, "Unable to find %s type in %s", type.getTargetType(), id);
+        return Iterables.get(pathArguments, i + 1);
+    }
+
+    /**
+     * Replace last item in ID with a provided IdentifiableItem of the same type
+     */
+    @SuppressWarnings("unchecked")
+    @Nonnull
+    public static <D extends DataObject & Identifiable<K>, K extends Identifier<D>> InstanceIdentifier<D> replaceLastInId(
+        @Nonnull final InstanceIdentifier<D> id, final InstanceIdentifier.IdentifiableItem<D, K> currentBdItem) {
+
+        final Iterable<InstanceIdentifier.PathArgument> pathArguments = id.getPathArguments();
+        final Iterable<InstanceIdentifier.PathArgument> withoutCurrent =
+            Iterables.limit(pathArguments, Iterables.size(pathArguments) - 1);
+        final Iterable<InstanceIdentifier.PathArgument> concat =
+            Iterables.concat(withoutCurrent, Collections.singleton(currentBdItem));
+        return (InstanceIdentifier<D>) InstanceIdentifier.create(concat);
+    }
+
+    /**
+     * Create IdentifiableItem from target type of provided ID with provided key
+     */
+    @Nonnull
+    public static <D extends DataObject & Identifiable<K>, K extends Identifier<D>> InstanceIdentifier.IdentifiableItem<D, K> getCurrentIdItem(
+        @Nonnull final InstanceIdentifier<D> id, final K key) {
+        return new InstanceIdentifier.IdentifiableItem<>(id.getTargetType(), key);
+    }
+
+    /**
+     * Trim InstanceIdentifier at indexOf(type)
+     */
+    @SuppressWarnings("unchecked")
+    @Nonnull
+    public static <D extends DataObject> InstanceIdentifier<D> cutId(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                                                     @Nonnull final InstanceIdentifier<D> type) {
+        final Iterable<InstanceIdentifier.PathArgument> pathArguments = id.getPathArguments();
+        final int i = Iterables.indexOf(pathArguments, new Predicate<InstanceIdentifier.PathArgument>() {
+            @Override
+            public boolean apply(final InstanceIdentifier.PathArgument input) {
+                return input.getType().equals(type.getTargetType());
+            }
+        });
+        Preconditions.checkArgument(i >= 0, "ID %s does not contain %s", id, type);
+        return (InstanceIdentifier<D>) InstanceIdentifier.create(Iterables.limit(pathArguments, i + 1));
+    }
+
+    /**
+     * Create an ordered map from a collection, checking for duplicity in the process.
+     */
+    @Nonnull
+    public static <K, V> Map<K, V> uniqueLinkedIndex(@Nonnull final Collection<V> values, @Nonnull final Function<? super V, K> keyFunction) {
+        final Map<K, V> objectObjectLinkedHashMap = Maps.newLinkedHashMap();
+        for (V value : values) {
+            final K key = keyFunction.apply(value);
+            Preconditions.checkArgument(objectObjectLinkedHashMap.put(key, value) == null,
+                "Duplicate key detected : %s", key);
+        }
+        return objectObjectLinkedHashMap;
+    }
+
+    public static final Function<SubtreeManager<? extends DataObject>, Class<? extends DataObject>>
+        MANAGER_CLASS_FUNCTION = new Function<SubtreeManager<? extends DataObject>, Class<? extends DataObject>>() {
+        @Override
+        public Class<? extends DataObject> apply(final SubtreeManager<? extends DataObject> input) {
+            return input.getManagedDataObjectType().getTargetType();
+        }
+    };
+
+    public static final Function<SubtreeManager<? extends Augmentation<?>>, Class<? extends DataObject>>
+        MANAGER_CLASS_AUG_FUNCTION = new Function<SubtreeManager<? extends Augmentation<?>>, Class<? extends DataObject>>() {
+
+        @Override
+        @SuppressWarnings("unchecked")
+        public Class<? extends DataObject> apply(final SubtreeManager<? extends Augmentation<?>> input) {
+            final Class<? extends Augmentation<?>> targetType = input.getManagedDataObjectType().getTargetType();
+            Preconditions.checkArgument(DataObject.class.isAssignableFrom(targetType));
+            return (Class<? extends DataObject>) targetType;
+        }
+    };
+
+    /**
+     * Transform a keyed instance identifier into a wildcarded one.
+     * <p/>
+     * ! This has to be called also for wildcarded List instance identifiers
+     * due to weird behavior of equals in InstanceIdentifier !
+     */
+    @SuppressWarnings("unchecked")
+    public static <D extends DataObject> InstanceIdentifier<D> makeIidWildcarded(final InstanceIdentifier<D> id) {
+        final List<InstanceIdentifier.PathArgument> transformedPathArguments =
+                StreamSupport.stream(id.getPathArguments().spliterator(), false)
+                        .map(RWUtils::cleanPathArgumentFromKeys)
+                        .collect(Collectors.toList());
+        return (InstanceIdentifier<D>) InstanceIdentifier.create(transformedPathArguments);
+    }
+
+    /**
+     * Transform a keyed instance identifier into a wildcarded one, keeping keys except the last item.
+     */
+    @SuppressWarnings("unchecked")
+    public static <D extends DataObject> InstanceIdentifier<D> makeIidLastWildcarded(final InstanceIdentifier<D> id) {
+        final InstanceIdentifier.Item<D> wildcardedItem = new InstanceIdentifier.Item<>(id.getTargetType());
+        final Iterable<InstanceIdentifier.PathArgument> pathArguments = id.getPathArguments();
+        return (InstanceIdentifier<D>) InstanceIdentifier.create(
+                Iterables.concat(
+                        Iterables.limit(pathArguments, Iterables.size(pathArguments) - 1),
+                        Collections.singleton(wildcardedItem)));
+    }
+
+    private static InstanceIdentifier.PathArgument cleanPathArgumentFromKeys(final InstanceIdentifier.PathArgument pathArgument) {
+        return pathArgument instanceof InstanceIdentifier.IdentifiableItem<?, ?>
+                ? new InstanceIdentifier.Item<>(pathArgument.getType())
+                : pathArgument;
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/ReflectionUtils.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/ReflectionUtils.java
new file mode 100644
index 000000000..728c4f80d
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/ReflectionUtils.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import com.google.common.base.Optional;
+import java.lang.reflect.Method;
+import java.util.List;
+import javax.annotation.Nonnull;
+
+/**
+ * Reflection based utilities
+ */
+public final class ReflectionUtils {
+
+    private ReflectionUtils() {}
+
+    /**
+     * Find a specific method using reflection
+     *
+     * @param managedType Class object to find method in
+     * @param prefix Method name prefix used when finding the method. Case does not matter.
+     * @param paramTypes List of input argument types
+     * @param retType Return type
+     *
+     * @return Found method or Optional.absent() if there's no such method
+     */
+    @Nonnull
+    public static Optional<Method> findMethodReflex(@Nonnull final Class<?> managedType,
+                                                    @Nonnull final String prefix,
+                                                    @Nonnull final List<Class<?>> paramTypes,
+                                                    @Nonnull final Class<?> retType) {
+        for (Method method : managedType.getMethods()) {
+            if (isMethodMatch(prefix, paramTypes, retType, method)) {
+                return Optional.of(method);
+            }
+        }
+
+        return Optional.absent();
+    }
+
+    private static boolean isMethodMatch(final @Nonnull String prefix,
+                                         final @Nonnull List<Class<?>> paramTypes,
+                                         final @Nonnull Class<?> retType, final Method method) {
+        if (!method.getName().toLowerCase().startsWith(prefix.toLowerCase())) {
+            return false;
+        }
+
+        final Class<?>[] parameterTypes = method.getParameterTypes();
+        if (parameterTypes.length != paramTypes.size()) {
+            return false;
+        }
+
+        for (int i = 0; i < parameterTypes.length; i++) {
+            if (!parameterTypes[i].isAssignableFrom(paramTypes.get(i))) {
+                return false;
+            }
+        }
+
+        if (!method.getReturnType().equals(retType)) {
+            return false;
+        }
+
+        return true;
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/TransactionMappingContext.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/TransactionMappingContext.java
new file mode 100644
index 000000000..6abc3b1eb
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/TransactionMappingContext.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.CheckedFuture;
+import io.fd.honeycomb.v3po.translate.MappingContext;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.binding.api.ReadWriteTransaction;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Binding Transaction backed mapping context.
+ */
+public class TransactionMappingContext implements MappingContext {
+
+    private final ReadWriteTransaction readWriteTransaction;
+
+    // TODO make async
+
+    public TransactionMappingContext(final ReadWriteTransaction readWriteTransaction) {
+        this.readWriteTransaction = readWriteTransaction;
+    }
+
+    @Override
+    public <T extends DataObject> Optional<T> read(@Nonnull final InstanceIdentifier<T> currentId) {
+        try {
+            return readWriteTransaction.read(LogicalDatastoreType.OPERATIONAL, currentId).checkedGet();
+        } catch (ReadFailedException e) {
+            throw new IllegalStateException("Unable to perform read", e);
+        }
+    }
+
+    @Override
+    public void delete(final InstanceIdentifier<?> path) {
+        readWriteTransaction.delete(LogicalDatastoreType.OPERATIONAL, path);
+    }
+
+    @Override
+    public <T extends DataObject> void merge(final InstanceIdentifier<T> path, T data) {
+        readWriteTransaction.merge(LogicalDatastoreType.OPERATIONAL, path, data, true);
+    }
+
+    @Override
+    public <T extends DataObject> void put(final InstanceIdentifier<T> path, T data) {
+        readWriteTransaction.put(LogicalDatastoreType.OPERATIONAL, path, data, true);
+    }
+
+    public CheckedFuture<Void, TransactionCommitFailedException> submit() {
+        return readWriteTransaction.submit();
+    }
+
+    @Override
+    public void close() {
+        readWriteTransaction.cancel();
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/AbstractGenericReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/AbstractGenericReader.java
new file mode 100644
index 000000000..9bfbc2450
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/AbstractGenericReader.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Beta
+public abstract class AbstractGenericReader<D extends DataObject, B extends Builder<D>> implements Reader<D, B> {
+
+    private static final Logger LOG = LoggerFactory.getLogger(AbstractGenericReader.class);
+
+    private final InstanceIdentifier<D> instanceIdentifier;
+
+    protected AbstractGenericReader(final InstanceIdentifier<D> managedDataObjectType) {
+        this.instanceIdentifier = RWUtils.makeIidWildcarded(managedDataObjectType);
+    }
+
+    @Nonnull
+    @Override
+    public final InstanceIdentifier<D> getManagedDataObjectType() {
+        return instanceIdentifier;
+    }
+
+    /**
+     * @param id {@link InstanceIdentifier} pointing to current node. In case of keyed list, key must be present.
+     *
+     */
+    protected Optional<D> readCurrent(@Nonnull final InstanceIdentifier<D> id,
+                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
+        LOG.debug("{}: Reading current: {}", this, id);
+        final B builder = getBuilder(id);
+        // Cache empty value to determine if anything has changed later TODO cache in a field
+        final D emptyValue = builder.build();
+
+        LOG.trace("{}: Reading current attributes", this);
+        readCurrentAttributes(id, builder, ctx);
+
+        // Need to check whether anything was filled in to determine if data is present or not.
+        final D built = builder.build();
+        final Optional<D> read = built.equals(emptyValue)
+            ? Optional.absent()
+            : Optional.of(built);
+
+        LOG.debug("{}: Current node read successfully. Result: {}", this, read);
+        return read;
+    }
+
+    @Nonnull
+    @Override
+    @SuppressWarnings("unchecked")
+    public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                               @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        LOG.trace("{}: Reading : {}", this, id);
+        checkArgument(id.getTargetType().equals(getManagedDataObjectType().getTargetType()));
+        return readCurrent((InstanceIdentifier<D>) id, ctx);
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Reader[%s]", getManagedDataObjectType().getTargetType().getSimpleName());
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/BindingBrokerReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/BindingBrokerReader.java
new file mode 100644
index 000000000..68aa3956e
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/BindingBrokerReader.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.CheckedFuture;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.binding.api.DataBroker;
+import org.opendaylight.controller.md.sal.binding.api.ReadOnlyTransaction;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Simple DataBroker backed reader allowing to delegate reads to different brokers.
+ */
+public final class BindingBrokerReader<D extends DataObject, B extends Builder<D>>
+        implements Reader<D, B>, AutoCloseable {
+
+    private final InstanceIdentifier<D> instanceIdentifier;
+    private final DataBroker dataBroker;
+    private final LogicalDatastoreType datastoreType;
+    private final ReflexiveReaderCustomizer<D, B> reflexiveReaderCustomizer;
+
+    public BindingBrokerReader(final InstanceIdentifier<D> instanceIdentifier,
+                               final DataBroker dataBroker,
+                               final LogicalDatastoreType datastoreType,
+                               final Class<B> builderClass) {
+        this.reflexiveReaderCustomizer = new ReflexiveReaderCustomizer<>(instanceIdentifier.getTargetType(), builderClass);
+        this.instanceIdentifier = instanceIdentifier;
+        this.dataBroker = dataBroker;
+        this.datastoreType = datastoreType;
+    }
+
+    @Nonnull
+    @Override
+    public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                               @Nonnull final ReadContext ctx) throws ReadFailedException {
+        try (final ReadOnlyTransaction readOnlyTransaction = dataBroker.newReadOnlyTransaction()) {
+            final CheckedFuture<? extends Optional<? extends DataObject>, org.opendaylight.controller.md.sal.common.api.data.ReadFailedException>
+                read = readOnlyTransaction.read(datastoreType, id);
+            try {
+                return read.checkedGet();
+            } catch (org.opendaylight.controller.md.sal.common.api.data.ReadFailedException e) {
+                throw new ReadFailedException(id, e);
+            }
+        }
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue) {
+        reflexiveReaderCustomizer.merge(parentBuilder, readValue);
+    }
+
+    @Nonnull
+    @Override
+    public B getBuilder(final InstanceIdentifier<D> id) {
+        return reflexiveReaderCustomizer.getBuilder(id);
+    }
+
+    @Override
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id,
+                                      @Nonnull final B builder,
+                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
+        throw new UnsupportedOperationException("Not supported");
+    }
+
+    @Nonnull
+    @Override
+    public InstanceIdentifier<D> getManagedDataObjectType() {
+        return instanceIdentifier;
+    }
+
+    @Override
+    public void close() throws Exception {
+        // Noop
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/KeepaliveReaderWrapper.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/KeepaliveReaderWrapper.java
new file mode 100644
index 000000000..d782bcc7f
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/KeepaliveReaderWrapper.java
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import io.fd.honeycomb.v3po.translate.MappingContext;
+import io.fd.honeycomb.v3po.translate.ModificationCache;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import java.io.Closeable;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Nonnegative;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Reader wrapper that periodically invokes a read to determine whether reads are still fully functional.
+ * In case a specific error occurs, Keep-alive failure listener gets notified.
+ */
+public final class KeepaliveReaderWrapper<D extends DataObject, B extends Builder<D>> implements Reader<D, B>, Runnable, Closeable {
+
+    private static final Logger LOG = LoggerFactory.getLogger(KeepaliveReaderWrapper.class);
+
+    private static final NoopReadContext CTX = new NoopReadContext();
+
+    private final Reader<D, B> delegate;
+    private final Class<? extends Exception> exceptionType;
+    private final KeepaliveFailureListener failureListener;
+    private final ScheduledFuture<?> scheduledFuture;
+
+    /**
+     * Create new Keepalive wrapper
+     *
+     * @param delegate underlying reader performing actual reads
+     * @param executor scheduled executor service to schedule keepalive calls
+     * @param exception type of exception used to differentiate keepalive exception from other exceptions
+     * @param delayInSeconds number of seconds to wait between keepalive calls
+     * @param failureListener listener to be called whenever a keepalive failure is detected
+     */
+    public KeepaliveReaderWrapper(@Nonnull final Reader<D, B> delegate,
+                                  @Nonnull final ScheduledExecutorService executor,
+                                  @Nonnull final Class<? extends Exception> exception,
+                                  @Nonnegative final int delayInSeconds,
+                                  @Nonnull final KeepaliveFailureListener failureListener) {
+        this.delegate = delegate;
+        this.exceptionType = exception;
+        this.failureListener = failureListener;
+        Preconditions.checkArgument(delayInSeconds > 0, "Delay cannot be < 0");
+        LOG.debug("Starting keep-alive execution on top of: {} with delay of: {} seconds", delegate, delayInSeconds);
+        scheduledFuture = executor.scheduleWithFixedDelay(this, delayInSeconds, delayInSeconds, TimeUnit.SECONDS);
+    }
+
+    @Nonnull
+    public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier id,
+                                               @Nonnull final ReadContext ctx) throws ReadFailedException {
+        return delegate.read(id, ctx);
+    }
+
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id,
+                                      @Nonnull final B builder,
+                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
+        delegate.readCurrentAttributes(id, builder, ctx);
+    }
+
+    @Nonnull
+    public B getBuilder(final InstanceIdentifier<D> id) {
+        return delegate.getBuilder(id);
+    }
+
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder,
+                      @Nonnull final D readValue) {
+        delegate.merge(parentBuilder, readValue);
+    }
+
+    @Nonnull
+    @Override
+    public InstanceIdentifier<D> getManagedDataObjectType() {
+        return delegate.getManagedDataObjectType();
+    }
+
+    @Override
+    public void run() {
+        LOG.trace("Invoking keepalive");
+        try {
+            final Optional<? extends DataObject> read = read(delegate.getManagedDataObjectType(), CTX);
+            LOG.debug("Keepalive executed successfully with data: {}", read);
+        } catch (Exception e) {
+            if (exceptionType.isAssignableFrom(e.getClass())) {
+                LOG.warn("Keepalive failed. Notifying listener", e);
+                failureListener.onKeepaliveFailure();
+            }
+            LOG.warn("Keepalive failed unexpectedly", e);
+            throw new IllegalArgumentException("Unexpected failure during keep-alive execution", e);
+        }
+    }
+
+    @Override
+    public void close() {
+        // Do not interrupt, it's not our executor
+        scheduledFuture.cancel(false);
+    }
+
+    /**
+     * Listener that gets called whenever keepalive fails as expected
+     */
+    public interface KeepaliveFailureListener {
+
+        void onKeepaliveFailure();
+    }
+
+    private static final class NoopMappingContext implements MappingContext {
+        @Override
+        public <T extends DataObject> Optional<T> read(@Nonnull final InstanceIdentifier<T> currentId) {
+            return Optional.absent();
+        }
+
+        @Override
+        public void delete(final InstanceIdentifier<?> path) {}
+
+        @Override
+        public <T extends DataObject> void merge(final InstanceIdentifier<T> path, final T data) {}
+
+        @Override
+        public <T extends DataObject> void put(final InstanceIdentifier<T> path, final T data) {}
+
+        @Override
+        public void close() {}
+    }
+
+    private static class NoopReadContext implements ReadContext {
+
+        private final ModificationCache modificationCache = new ModificationCache();
+
+        @Nonnull
+        @Override
+        public ModificationCache getModificationCache() {
+            return modificationCache;
+        }
+
+        @Nonnull
+        @Override
+        public MappingContext getMappingContext() {
+            return new NoopMappingContext();
+        }
+
+        @Override
+        public void close() {
+
+        }
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/NoopReaderCustomizer.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/NoopReaderCustomizer.java
new file mode 100644
index 000000000..a4de9febb
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/NoopReaderCustomizer.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.spi.read.ReaderCustomizer;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public abstract class NoopReaderCustomizer<C extends DataObject, B extends Builder<C>> implements
+        ReaderCustomizer<C, B> {
+
+    @Override
+    public void readCurrentAttributes(InstanceIdentifier<C> id, final B builder, final ReadContext context) throws
+        ReadFailedException {
+        // Noop
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveListReaderCustomizer.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveListReaderCustomizer.java
new file mode 100644
index 000000000..8ad323cc3
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveListReaderCustomizer.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Optional;
+import io.fd.honeycomb.v3po.translate.spi.read.ListReaderCustomizer;
+import io.fd.honeycomb.v3po.translate.util.ReflectionUtils;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Collections;
+import java.util.List;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.Identifiable;
+import org.opendaylight.yangtools.yang.binding.Identifier;
+
+/**
+ * Might be slow !
+ */
+public abstract class ReflexiveListReaderCustomizer<C extends DataObject & Identifiable<K>, K extends Identifier<C>, B extends Builder<C>>
+        extends ReflexiveReaderCustomizer<C, B>
+        implements ListReaderCustomizer<C, K, B> {
+
+
+    public ReflexiveListReaderCustomizer(final Class<C> typeClass, final Class<B> builderClass) {
+        super(typeClass, builderClass);
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final C readValue) {
+        merge(parentBuilder, Collections.singletonList(readValue));
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final List<C> readData) {
+        final Optional<Method> method =
+                ReflectionUtils.findMethodReflex(parentBuilder.getClass(), "set" + getTypeClass().getSimpleName(),
+                        Collections.singletonList(List.class), parentBuilder.getClass());
+
+        checkArgument(method.isPresent(), "Unable to set %s to %s", readData, parentBuilder);
+
+        try {
+            method.get().invoke(parentBuilder, readData);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new IllegalArgumentException("Unable to set " + readData + " to " + parentBuilder, e);
+        }
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveReader.java
new file mode 100644
index 000000000..2b2d9300b
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveReader.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Reader that performs no read operation on its own, just fills in the hierarchy.
+ * <p/>
+ * Might be slow due to reflection !
+ */
+public class ReflexiveReader<C extends DataObject, B extends Builder<C>> extends AbstractGenericReader<C, B> {
+
+    private final ReflexiveReaderCustomizer<C, B> customizer;
+
+    public ReflexiveReader(final InstanceIdentifier<C> identifier, final Class<B> builderClass) {
+        super(identifier);
+        this.customizer = new ReflexiveReaderCustomizer<>(identifier.getTargetType(), builderClass);
+    }
+
+    @Override
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<C> id, @Nonnull final B builder,
+                                      @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        customizer.readCurrentAttributes(id, builder, ctx);
+    }
+
+    @Nonnull
+    @Override
+    public B getBuilder(final InstanceIdentifier<C> id) {
+        return customizer.getBuilder(id);
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final C readValue) {
+        customizer.merge(parentBuilder, readValue);
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveReaderCustomizer.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveReaderCustomizer.java
new file mode 100644
index 000000000..a6b9bf08e
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/ReflexiveReaderCustomizer.java
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.Lists;
+import io.fd.honeycomb.v3po.translate.util.ReflectionUtils;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Collections;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.Augmentation;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Might be slow !
+ */
+class ReflexiveReaderCustomizer<C extends DataObject, B extends Builder<C>> extends NoopReaderCustomizer<C, B> {
+
+    private final Class<C> typeClass;
+    private final Class<B> builderClass;
+
+    public ReflexiveReaderCustomizer(final Class<C> typeClass, final Class<B> builderClass) {
+        this.typeClass = typeClass;
+        this.builderClass = builderClass;
+    }
+
+    protected Class<C> getTypeClass() {
+        return typeClass;
+    }
+
+    protected Class<B> getBuilderClass() {
+        return builderClass;
+    }
+
+    @Nonnull
+    @Override
+    public B getBuilder(@Nonnull InstanceIdentifier<C> id) {
+        try {
+            return builderClass.newInstance();
+        } catch (InstantiationException | IllegalAccessException e) {
+            throw new IllegalStateException("Unable to instantiate " + builderClass, e);
+        }
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final C readValue) {
+        if (Augmentation.class.isAssignableFrom(typeClass)) {
+            mergeAugmentation(parentBuilder, (Class<? extends Augmentation<?>>) typeClass, readValue);
+        } else {
+            mergeRegular(parentBuilder, readValue);
+        }
+    }
+
+    private static void mergeRegular(@Nonnull final Builder<? extends DataObject> parentBuilder,
+                                     @Nonnull final DataObject readValue) {
+        final Optional<Method> method =
+                ReflectionUtils.findMethodReflex(parentBuilder.getClass(), "set",
+                        Collections.singletonList(readValue.getClass()), parentBuilder.getClass());
+
+        checkArgument(method.isPresent(), "Unable to set %s to %s", readValue, parentBuilder);
+
+        try {
+            method.get().invoke(parentBuilder, readValue);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new IllegalArgumentException("Unable to set " + readValue + " to " + parentBuilder, e);
+        }
+    }
+
+    private static void mergeAugmentation(@Nonnull final Builder<? extends DataObject> parentBuilder,
+                                          @Nonnull final Class<? extends Augmentation<?>> typeClass,
+                                          @Nonnull final DataObject readValue) {
+        final Optional<Method> method =
+                ReflectionUtils.findMethodReflex(parentBuilder.getClass(), "addAugmentation",
+                        Lists.newArrayList(Class.class, Augmentation.class), parentBuilder.getClass());
+
+        checkArgument(method.isPresent(), "Not possible to add augmentations to builder: %s", parentBuilder);
+        try {
+            method.get().invoke(parentBuilder, typeClass, readValue);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new IllegalArgumentException("Unable to set " + readValue + " to " + parentBuilder, e);
+        }
+    }
+
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReader.java
new file mode 100644
index 000000000..aa9b2dc92
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReader.java
@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Iterables;
+import io.fd.honeycomb.v3po.translate.read.ListReader;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.util.read.AbstractGenericReader;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.Identifiable;
+import org.opendaylight.yangtools.yang.binding.Identifier;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+class CompositeReader<D extends DataObject, B extends Builder<D>> extends AbstractGenericReader<D, B> {
+
+    private static final Logger LOG = LoggerFactory.getLogger(CompositeReader.class);
+
+    private final Reader<D, B> delegate;
+    private final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders;
+
+    private CompositeReader(final Reader<D, B> reader,
+                            final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders) {
+        super(reader.getManagedDataObjectType());
+        this.delegate = reader;
+        this.childReaders = childReaders;
+    }
+
+    @VisibleForTesting
+    ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> getChildReaders() {
+        return childReaders;
+    }
+
+    @SuppressWarnings("unchecked")
+    public static <D extends DataObject> InstanceIdentifier<D> appendTypeToId(
+        final InstanceIdentifier<? extends DataObject> parentId, final InstanceIdentifier<D> type) {
+        final InstanceIdentifier.PathArgument t = new InstanceIdentifier.Item<>(type.getTargetType());
+        return (InstanceIdentifier<D>) InstanceIdentifier.create(Iterables.concat(
+            parentId.getPathArguments(), Collections.singleton(t)));
+    }
+
+    @Nonnull
+    @Override
+    public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                               @Nonnull final ReadContext ctx) throws ReadFailedException {
+        if (shouldReadCurrent(id)) {
+            LOG.trace("{}: Reading current: {}", this, id);
+            return readCurrent((InstanceIdentifier<D>) id, ctx);
+        } else if (shouldDelegateToChild(id)) {
+            LOG.trace("{}: Reading child: {}", this, id);
+            return readSubtree(id, ctx);
+        } else {
+            // Fallback
+            LOG.trace("{}: Delegating read: {}", this, id);
+            return delegate.read(id, ctx);
+        }
+    }
+
+    private boolean shouldReadCurrent(@Nonnull final InstanceIdentifier<? extends DataObject> id) {
+        return id.getTargetType().equals(getManagedDataObjectType().getTargetType());
+    }
+
+    private boolean shouldDelegateToChild(@Nonnull final InstanceIdentifier<? extends DataObject> id) {
+        return childReaders.containsKey(RWUtils.getNextId(id, getManagedDataObjectType()).getType());
+    }
+
+    private Optional<? extends DataObject> readSubtree(final InstanceIdentifier<? extends DataObject> id,
+                                                       final ReadContext ctx) throws ReadFailedException {
+        final InstanceIdentifier.PathArgument nextId = RWUtils.getNextId(id, getManagedDataObjectType());
+        final Reader<?, ? extends Builder<?>> nextReader = childReaders.get(nextId.getType());
+        checkArgument(nextReader != null, "Unable to read: %s. No delegate present, available readers at next level: %s",
+                id, childReaders.keySet());
+        return nextReader.read(id, ctx);
+    }
+
+    @SuppressWarnings("unchecked")
+    private void readChildren(final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx, final B builder)
+            throws ReadFailedException {
+        LOG.debug("{}: Reading children: {}", this, childReaders.keySet());
+        for (Reader child : childReaders.values()) {
+            final InstanceIdentifier childId = appendTypeToId(id, child.getManagedDataObjectType());
+
+            LOG.debug("{}: Reading child from: {}", this, child);
+            if (child instanceof ListReader) {
+                final List<? extends DataObject> list = ((ListReader) child).readList(childId, ctx);
+                ((ListReader) child).merge(builder, list);
+            } else {
+                final Optional<? extends DataObject> read = child.read(childId, ctx);
+                if (read.isPresent()) {
+                    child.merge(builder, read.get());
+                }
+            }
+        }
+    }
+
+    @Override
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id, @Nonnull final B builder,
+                                      @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        delegate.readCurrentAttributes(id, builder, ctx);
+        readChildren(id, ctx, builder);
+    }
+
+    @Nonnull
+    @Override
+    public B getBuilder(final InstanceIdentifier<D> id) {
+        return delegate.getBuilder(id);
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue) {
+        delegate.merge(parentBuilder, readValue);
+    }
+
+    /**
+     * Wrap a Reader as a Composite Reader.
+     */
+    static <D extends DataObject, B extends Builder<D>> Reader<D, B> createForReader(
+            @Nonnull final Reader<D, B> reader,
+            @Nonnull final ImmutableMap<Class<?>, Reader<?, ? extends Builder<?>>> childReaders) {
+
+        return (reader instanceof ListReader)
+                ? new CompositeListReader<>((ListReader) reader, childReaders)
+                : new CompositeReader<>(reader, childReaders);
+    }
+
+    private static class CompositeListReader<D extends DataObject & Identifiable<K>, B extends Builder<D>, K extends Identifier<D>>
+            extends CompositeReader<D, B>
+            implements ListReader<D, K, B> {
+
+        private final ListReader<D, K, B> delegate;
+
+        private CompositeListReader(final ListReader<D, K, B> reader,
+                                    final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders) {
+            super(reader, childReaders);
+            this.delegate = reader;
+        }
+
+        @Nonnull
+        @Override
+        public List<D> readList(@Nonnull final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx)
+                throws ReadFailedException {
+            LOG.trace("{}: Reading all list entries", this);
+            final List<K> allIds = delegate.getAllIds(id, ctx);
+            LOG.debug("{}: Reading list entries for: {}", this, allIds);
+
+            // Override read list in order to perform readCurrent + readChildren here
+            final ArrayList<D> allEntries = new ArrayList<>(allIds.size());
+            for (K key : allIds) {
+                final InstanceIdentifier.IdentifiableItem<D, K> currentBdItem = RWUtils.getCurrentIdItem(id, key);
+                final InstanceIdentifier<D> keyedId = RWUtils.replaceLastInId(id, currentBdItem);
+                final Optional<D> read = readCurrent(keyedId, ctx);
+                if (read.isPresent()) {
+                    final DataObject singleItem = read.get();
+                    checkArgument(getManagedDataObjectType().getTargetType().isAssignableFrom(singleItem.getClass()));
+                    allEntries.add(getManagedDataObjectType().getTargetType().cast(singleItem));
+                }
+            }
+            return allEntries;
+        }
+
+        @Override
+        public void merge(@Nonnull final Builder<? extends DataObject> builder, @Nonnull final List<D> readData) {
+            delegate.merge(builder, readData);
+        }
+
+        @Override
+        public List<K> getAllIds(@Nonnull final InstanceIdentifier<D> id,
+                                 @Nonnull final ReadContext ctx) throws ReadFailedException {
+            return delegate.getAllIds(id, ctx);
+        }
+    }
+
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistry.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistry.java
new file mode 100644
index 000000000..a9f606ae2
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistry.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.LinkedListMultimap;
+import com.google.common.collect.Multimap;
+import io.fd.honeycomb.v3po.translate.read.ListReader;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.read.registry.ReaderRegistry;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Simple reader registry able to perform and aggregated read (ROOT read) on top of all provided readers. Also able to
+ * delegate a specific read to one of the delegate readers.
+ * <p/>
+ * This could serve as a utility to hold & hide all available readers in upper layers.
+ */
+public final class CompositeReaderRegistry implements ReaderRegistry {
+
+    private static final Logger LOG = LoggerFactory.getLogger(CompositeReaderRegistry.class);
+
+    private final Map<Class<? extends DataObject>, Reader<? extends DataObject, ? extends Builder<?>>> rootReaders;
+
+    /**
+     * Create new {@link CompositeReaderRegistry}.
+     *
+     * @param rootReaders List of delegate readers
+     */
+    public CompositeReaderRegistry(@Nonnull final List<Reader<? extends DataObject, ? extends Builder<?>>> rootReaders) {
+        this.rootReaders = RWUtils.uniqueLinkedIndex(checkNotNull(rootReaders), RWUtils.MANAGER_CLASS_FUNCTION);
+    }
+
+    @VisibleForTesting
+    Map<Class<? extends DataObject>, Reader<? extends DataObject, ? extends Builder<?>>> getRootReaders() {
+        return rootReaders;
+    }
+
+    @Override
+    @Nonnull
+    public Multimap<InstanceIdentifier<? extends DataObject>, ? extends DataObject> readAll(
+        @Nonnull final ReadContext ctx) throws ReadFailedException {
+
+        LOG.debug("Reading from all delegates: {}", this);
+        LOG.trace("Reading from all delegates: {}", rootReaders.values());
+
+        final Multimap<InstanceIdentifier<? extends DataObject>, DataObject> objects = LinkedListMultimap.create();
+        for (Reader<? extends DataObject, ? extends Builder<?>> rootReader : rootReaders.values()) {
+            LOG.debug("Reading from delegate: {}", rootReader);
+
+            if (rootReader instanceof ListReader) {
+                final List<? extends DataObject> listEntries =
+                        ((ListReader) rootReader).readList(rootReader.getManagedDataObjectType(), ctx);
+                if (!listEntries.isEmpty()) {
+                    objects.putAll(rootReader.getManagedDataObjectType(), listEntries);
+                }
+            } else {
+                final Optional<? extends DataObject> read = rootReader.read(rootReader.getManagedDataObjectType(), ctx);
+                if (read.isPresent()) {
+                    objects.putAll(rootReader.getManagedDataObjectType(), Collections.singletonList(read.get()));
+                }
+            }
+        }
+
+        return objects;
+    }
+
+    @Nonnull
+    @Override
+    public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                               @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        final InstanceIdentifier.PathArgument first = checkNotNull(
+                Iterables.getFirst(id.getPathArguments(), null), "Empty id");
+        final Reader<? extends DataObject, ? extends Builder<?>> reader = rootReaders.get(first.getType());
+        checkNotNull(reader,
+                "Unable to read %s. Missing reader. Current readers for: %s", id, rootReaders.keySet());
+        LOG.debug("Reading from delegate: {}", reader);
+        return reader.read(id, ctx);
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getSimpleName()
+                + rootReaders.keySet().stream().map(Class::getSimpleName).collect(Collectors.toList());
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistryBuilder.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistryBuilder.java
new file mode 100644
index 000000000..3adda713d
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistryBuilder.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import com.google.common.collect.ImmutableMap;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.read.registry.ModifiableReaderRegistryBuilder;
+import io.fd.honeycomb.v3po.translate.read.registry.ReaderRegistry;
+import io.fd.honeycomb.v3po.translate.read.registry.ReaderRegistryBuilder;
+import io.fd.honeycomb.v3po.translate.util.AbstractSubtreeManagerRegistryBuilderBuilder;
+import io.fd.honeycomb.v3po.translate.util.read.ReflexiveReader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.concurrent.NotThreadSafe;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@NotThreadSafe
+public final class CompositeReaderRegistryBuilder
+        extends AbstractSubtreeManagerRegistryBuilderBuilder<Reader<? extends DataObject, ? extends Builder<?>>, ReaderRegistry>
+        implements ModifiableReaderRegistryBuilder, ReaderRegistryBuilder {
+
+    private static final Logger LOG = LoggerFactory.getLogger(CompositeReaderRegistryBuilder.class);
+
+    @Override
+    protected Reader<? extends DataObject, ? extends Builder<?>> getSubtreeHandler(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                                                   @Nonnull final Reader<? extends DataObject, ? extends Builder<?>> reader) {
+        return SubtreeReader.createForReader(handledChildren, reader);
+    }
+
+    @Override
+    public <D extends DataObject> void addStructuralReader(@Nonnull InstanceIdentifier<D> id,
+                                                           @Nonnull Class<? extends Builder<D>> builderType) {
+        add(new ReflexiveReader<>(id, builderType));
+    }
+
+    /**
+     * Create {@link CompositeReaderRegistry} with Readers ordered according to submitted relationships.
+     * <p/>
+     * Note: The ordering only applies between nodes on the same level, inter-level and inter-subtree relationships are
+     * ignored.
+     */
+    @Override
+    public ReaderRegistry build() {
+        ImmutableMap<InstanceIdentifier<?>, Reader<? extends DataObject, ? extends Builder<?>>> mappedReaders =
+                getMappedHandlers();
+        LOG.debug("Building Reader registry with Readers: {}",
+                mappedReaders.keySet().stream()
+                        .map(InstanceIdentifier::getTargetType)
+                        .map(Class::getSimpleName)
+                        .collect(Collectors.joining(", ")));
+
+        LOG.trace("Building Reader registry with Readers: {}", mappedReaders);
+        final List<InstanceIdentifier<?>> readerOrder = new ArrayList<>(mappedReaders.keySet());
+
+        // Wrap readers into composite readers recursively, collect roots and create registry
+        final TypeHierarchy typeHierarchy = TypeHierarchy.create(mappedReaders.keySet());
+        final List<Reader<? extends DataObject, ? extends Builder<?>>> orderedRootReaders =
+                typeHierarchy.getRoots().stream()
+                        .map(rootId -> toCompositeReader(rootId, mappedReaders, typeHierarchy))
+                        .collect(Collectors.toList());
+
+        // We are violating the ordering from mappedReaders, since we are forming a composite structure
+        // but at least order root writers
+        orderedRootReaders.sort((reader1, reader2) -> readerOrder.indexOf(reader1.getManagedDataObjectType())
+                - readerOrder.indexOf(reader2.getManagedDataObjectType()));
+
+        return new CompositeReaderRegistry(orderedRootReaders);
+    }
+
+    private Reader<? extends DataObject, ? extends Builder<?>> toCompositeReader(
+            final InstanceIdentifier<?> instanceIdentifier,
+            final ImmutableMap<InstanceIdentifier<?>, Reader<? extends DataObject, ? extends Builder<?>>> mappedReaders,
+            final TypeHierarchy typeHierarchy) {
+
+        // Order child readers according to the mappedReadersCollection
+        final ImmutableMap.Builder<Class<?>, Reader<?, ? extends Builder<?>>> childReadersMapB = ImmutableMap.builder();
+        for (InstanceIdentifier<?> childId : mappedReaders.keySet()) {
+            if (typeHierarchy.getDirectChildren(instanceIdentifier).contains(childId)) {
+                childReadersMapB.put(childId.getTargetType(), toCompositeReader(childId, mappedReaders, typeHierarchy));
+            }
+        }
+
+        final ImmutableMap<Class<?>, Reader<?, ? extends Builder<?>>> childReadersMap = childReadersMapB.build();
+        return childReadersMap.isEmpty()
+                ? mappedReaders.get(instanceIdentifier)
+                : CompositeReader.createForReader(mappedReaders.get(instanceIdentifier), childReadersMap);
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/SubtreeReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/SubtreeReader.java
new file mode 100644
index 000000000..50a20656e
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/SubtreeReader.java
@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+import io.fd.honeycomb.v3po.translate.read.ListReader;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.util.ReflectionUtils;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.Identifiable;
+import org.opendaylight.yangtools.yang.binding.Identifier;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Simple Reader delegate for subtree Readers (Readers handling also children nodes) providing a list of all the
+ * children nodes being handled.
+ */
+class SubtreeReader<D extends DataObject, B extends Builder<D>> implements Reader<D, B> {
+
+    private static final Logger LOG = LoggerFactory.getLogger(SubtreeReader.class);
+
+    private final Reader<D, B> delegate;
+    private final Set<InstanceIdentifier<?>> handledChildTypes = new HashSet<>();
+
+    private SubtreeReader(final Reader<D, B> delegate, Set<InstanceIdentifier<?>> handledTypes) {
+        this.delegate = delegate;
+        for (InstanceIdentifier<?> handledType : handledTypes) {
+            // Iid has to start with Reader's handled root type
+            checkArgument(delegate.getManagedDataObjectType().getTargetType().equals(
+                    handledType.getPathArguments().iterator().next().getType()),
+                    "Handled node from subtree has to be identified by an instance identifier starting from: %s."
+                            + "Instance identifier was: %s", getManagedDataObjectType().getTargetType(), handledType);
+            checkArgument(Iterables.size(handledType.getPathArguments()) > 1,
+                    "Handled node from subtree identifier too short: %s", handledType);
+            handledChildTypes.add(InstanceIdentifier.create(Iterables.concat(
+                    getManagedDataObjectType().getPathArguments(), Iterables.skip(handledType.getPathArguments(), 1))));
+        }
+    }
+
+    /**
+     * Return set of types also handled by this Reader. All of the types are children of the type managed by this Reader
+     * excluding the type of this Reader.
+     */
+    Set<InstanceIdentifier<?>> getHandledChildTypes() {
+        return handledChildTypes;
+    }
+
+    @Override
+    @Nonnull
+    public Optional<? extends DataObject> read(
+            @Nonnull final InstanceIdentifier<? extends DataObject> id,
+            @Nonnull final ReadContext ctx) throws ReadFailedException {
+        final InstanceIdentifier<?> wildcarded = RWUtils.makeIidWildcarded(id);
+
+        // Reading entire subtree and filtering if is current reader responsible
+        if (getHandledChildTypes().contains(wildcarded)) {
+            LOG.debug("{}: Subtree node managed by this writer requested: {}. Reading current and filtering", this, id);
+            // If there's no dedicated reader, use read current
+            final InstanceIdentifier<D> currentId = RWUtils.cutId(id, getManagedDataObjectType());
+            final Optional<? extends DataObject> current = delegate.read(currentId, ctx);
+            // then perform post-reading filtering (return only requested sub-node)
+            final Optional<? extends DataObject> readSubtree = current.isPresent()
+                ? filterSubtree(current.get(), id, getManagedDataObjectType().getTargetType())
+                : current;
+
+            LOG.debug("{}: Subtree: {} read successfully. Result: {}", this, id, readSubtree);
+            return readSubtree;
+
+        // Fallback solution, try delegate, maybe it can read the ID
+        } else {
+            return delegate.read(id, ctx);
+        }
+    }
+
+    @Override
+    public void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id, @Nonnull final B builder,
+                                      @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        delegate.readCurrentAttributes(id, builder, ctx);
+    }
+
+    @Nonnull
+    @Override
+    public B getBuilder(final InstanceIdentifier<D> id) {
+        return delegate.getBuilder(id);
+    }
+
+    @Override
+    public void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue) {
+        delegate.merge(parentBuilder, readValue);
+    }
+
+    @Nonnull
+    private static Optional<? extends DataObject> filterSubtree(@Nonnull final DataObject parent,
+                                                                @Nonnull final InstanceIdentifier<? extends DataObject> absolutPath,
+                                                                @Nonnull final Class<?> managedType) {
+        final InstanceIdentifier.PathArgument nextId =
+                RWUtils.getNextId(absolutPath, InstanceIdentifier.create(parent.getClass()));
+
+        final Optional<? extends DataObject> nextParent = findNextParent(parent, nextId, managedType);
+
+        if (Iterables.getLast(absolutPath.getPathArguments()).equals(nextId)) {
+            return nextParent; // we found the dataObject identified by absolutePath
+        } else if (nextParent.isPresent()) {
+            return filterSubtree(nextParent.get(), absolutPath, nextId.getType());
+        } else {
+            return nextParent; // we can't go further, return Optional.absent()
+        }
+    }
+
+    private static Optional<? extends DataObject> findNextParent(@Nonnull final DataObject parent,
+                                                                 @Nonnull final InstanceIdentifier.PathArgument nextId,
+                                                                 @Nonnull final Class<?> managedType) {
+        // TODO is there a better way than reflection ? e.g. convert into NN and filter out with a utility
+        Optional<Method> method = ReflectionUtils.findMethodReflex(managedType, "get",
+                Collections.emptyList(), nextId.getType());
+
+        if (method.isPresent()) {
+            return Optional.fromNullable(filterSingle(parent, nextId, method.get()));
+        } else {
+            // List child nodes
+            method = ReflectionUtils.findMethodReflex(managedType,
+                    "get" + nextId.getType().getSimpleName(), Collections.emptyList(), List.class);
+
+            if (method.isPresent()) {
+                return filterList(parent, nextId, method.get());
+            } else {
+                throw new IllegalStateException(
+                        "Unable to filter " + nextId + " from " + parent + " getters not found using reflexion");
+            }
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private static Optional<? extends DataObject> filterList(final DataObject parent,
+                                                             final InstanceIdentifier.PathArgument nextId,
+                                                             final Method method) {
+        final List<? extends DataObject> invoke = (List<? extends DataObject>) invoke(method, nextId, parent);
+
+        checkArgument(nextId instanceof InstanceIdentifier.IdentifiableItem<?, ?>,
+                "Unable to perform wildcarded read for %s", nextId);
+        final Identifier key = ((InstanceIdentifier.IdentifiableItem) nextId).getKey();
+        // TODO replace with stream().filter().findFirst() when we switch to using java's Optional instead of Guava's
+        // because now we would have to do awkward Optional transformation since findFirstReturns guava's optional
+        return Iterables.tryFind(invoke, new Predicate<DataObject>() {
+
+            @Override
+            public boolean apply(@Nullable final DataObject input) {
+                final Optional<Method> keyGetter = ReflectionUtils.findMethodReflex(nextId.getType(), "get",
+                                Collections.emptyList(), key.getClass());
+                final Object actualKey;
+                actualKey = invoke(keyGetter.get(), nextId, input);
+                return key.equals(actualKey);
+            }
+        });
+    }
+
+    private static DataObject filterSingle(final DataObject parent,
+                                           final InstanceIdentifier.PathArgument nextId, final Method method) {
+        return nextId.getType().cast(invoke(method, nextId, parent));
+    }
+
+    private static Object invoke(final Method method,
+                                 final InstanceIdentifier.PathArgument nextId, final DataObject parent) {
+        try {
+            return method.invoke(parent);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new IllegalArgumentException("Unable to get " + nextId + " from " + parent, e);
+        }
+    }
+
+    @Override
+    @Nonnull
+    public InstanceIdentifier<D> getManagedDataObjectType() {
+        return delegate.getManagedDataObjectType();
+    }
+
+    /**
+     * Wrap a Reader as a subtree Reader.
+     */
+    static <D extends DataObject, B extends Builder<D>> Reader<D, B> createForReader(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                                                     @Nonnull final Reader<D, B> reader) {
+        return (reader instanceof ListReader)
+                ? new SubtreeListReader<>((ListReader) reader, handledChildren)
+                : new SubtreeReader<>(reader, handledChildren);
+    }
+
+    private static final class SubtreeListReader<D extends DataObject & Identifiable<K>, B extends Builder<D>, K extends Identifier<D>>
+            extends SubtreeReader<D, B> implements ListReader<D, K, B> {
+
+        private final ListReader<D, K, B> delegate;
+
+        private SubtreeListReader(final ListReader<D, K, B> delegate,
+                                  final Set<InstanceIdentifier<?>> handledTypes) {
+            super(delegate, handledTypes);
+            this.delegate = delegate;
+        }
+
+        @Nonnull
+        @Override
+        public List<D> readList(@Nonnull final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx)
+                throws ReadFailedException {
+            return delegate.readList(id, ctx);
+        }
+
+        @Override
+        public void merge(@Nonnull final Builder<? extends DataObject> builder, @Nonnull final List<D> readData) {
+            delegate.merge(builder, readData);
+        }
+
+        @Override
+        public List<K> getAllIds(@Nonnull final InstanceIdentifier<D> id,
+                                 @Nonnull final ReadContext ctx) throws ReadFailedException {
+            return delegate.getAllIds(id, ctx);
+        }
+    }
+
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/TypeHierarchy.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/TypeHierarchy.java
new file mode 100644
index 000000000..005e3bc8d
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/read/registry/TypeHierarchy.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.collect.Iterables;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import org.jgrapht.experimental.dag.DirectedAcyclicGraph;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+final class TypeHierarchy {
+    private final DirectedAcyclicGraph<InstanceIdentifier<?>, Parent> hierarchy;
+
+    private TypeHierarchy(@Nonnull final DirectedAcyclicGraph<InstanceIdentifier<?>, Parent> hierarchy) {
+        this.hierarchy = hierarchy;
+    }
+
+    Set<InstanceIdentifier<?>> getAllChildren(InstanceIdentifier<?> id) {
+        final HashSet<InstanceIdentifier<?>> instanceIdentifiers = new HashSet<>();
+        for (InstanceIdentifier<?> childId : getDirectChildren(id)) {
+            instanceIdentifiers.add(childId);
+            instanceIdentifiers.addAll(getAllChildren(childId));
+        }
+        return instanceIdentifiers;
+    }
+
+    Set<InstanceIdentifier<?>> getDirectChildren(InstanceIdentifier<?> id) {
+        checkArgument(hierarchy.vertexSet().contains(id),
+                "Unknown reader: %s. Known readers: %s", id, hierarchy.vertexSet());
+
+        return hierarchy.outgoingEdgesOf(id).stream()
+                .map(hierarchy::getEdgeTarget)
+                .collect(Collectors.toSet());
+    }
+
+    Set<InstanceIdentifier<?>> getRoots() {
+        return hierarchy.vertexSet().stream()
+                .filter(vertex -> hierarchy.incomingEdgesOf(vertex).size() == 0)
+                .collect(Collectors.toSet());
+    }
+
+    /**
+     * Create reader hierarchy from a flat set of instance identifiers.
+     *
+     * @param allIds Set of unkeyed instance identifiers
+     */
+    static TypeHierarchy create(@Nonnull Set<InstanceIdentifier<?>> allIds) {
+        final DirectedAcyclicGraph<InstanceIdentifier<?>, Parent>
+                readersHierarchy = new DirectedAcyclicGraph<>((sourceVertex, targetVertex) -> new Parent());
+
+        for (InstanceIdentifier<?> allId : allIds) {
+            checkArgument(!Iterables.isEmpty(allId.getPathArguments()), "Empty ID detected");
+
+            if (Iterables.size(allId.getPathArguments()) == 1) {
+                readersHierarchy.addVertex(allId);
+            }
+
+            List<InstanceIdentifier.PathArgument> pathArgs = new LinkedList<>();
+            pathArgs.add(allId.getPathArguments().iterator().next());
+
+            for (InstanceIdentifier.PathArgument pathArgument : Iterables.skip(allId.getPathArguments(), 1)) {
+                final InstanceIdentifier<?> previous = InstanceIdentifier.create(pathArgs);
+                pathArgs.add(pathArgument);
+                final InstanceIdentifier<?> current = InstanceIdentifier.create(pathArgs);
+
+                readersHierarchy.addVertex(previous);
+                readersHierarchy.addVertex(current);
+
+                try {
+                    readersHierarchy.addDagEdge(previous, current);
+                } catch (DirectedAcyclicGraph.CycleFoundException e) {
+                    throw new IllegalArgumentException("Loop in hierarchy detected", e);
+                }
+            }
+        }
+
+        return new TypeHierarchy(readersHierarchy);
+    }
+
+    private static final class Parent{}
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/AbstractGenericWriter.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/AbstractGenericWriter.java
new file mode 100644
index 000000000..44b36edae
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/AbstractGenericWriter.java
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public abstract class AbstractGenericWriter<D extends DataObject> implements Writer<D> {
+
+    private static final Logger LOG = LoggerFactory.getLogger(AbstractGenericWriter.class);
+
+    private final InstanceIdentifier<D> instanceIdentifier;
+
+    protected AbstractGenericWriter(final InstanceIdentifier<D> type) {
+        this.instanceIdentifier = RWUtils.makeIidWildcarded(type);
+    }
+
+    protected void writeCurrent(final InstanceIdentifier<D> id, final D data, final WriteContext ctx)
+        throws WriteFailedException {
+        LOG.debug("{}: Writing current: {} data: {}", this, id, data);
+        writeCurrentAttributes(id, data, ctx);
+        LOG.debug("{}: Current node written successfully", this);
+    }
+
+    protected void updateCurrent(final InstanceIdentifier<D> id, final D dataBefore, final D dataAfter,
+                                 final WriteContext ctx) throws WriteFailedException {
+        LOG.debug("{}: Updating current: {} dataBefore: {}, datAfter: {}", this, id, dataBefore, dataAfter);
+
+        if (dataBefore.equals(dataAfter)) {
+            LOG.debug("{}: Skipping current(no update): {}", this, id);
+            // No change, ignore
+            return;
+        }
+        updateCurrentAttributes(id, dataBefore, dataAfter, ctx);
+        LOG.debug("{}: Current node updated successfully", this);
+    }
+
+    protected void deleteCurrent(final InstanceIdentifier<D> id, final D dataBefore, final WriteContext ctx)
+        throws WriteFailedException {
+        LOG.debug("{}: Deleting current: {} dataBefore: {}", this, id, dataBefore);
+        deleteCurrentAttributes(id, dataBefore, ctx);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public void update(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                       @Nullable final DataObject dataBefore,
+                       @Nullable final DataObject dataAfter,
+                       @Nonnull final WriteContext ctx) throws WriteFailedException {
+        LOG.debug("{}: Updating : {}", this, id);
+        LOG.trace("{}: Updating : {}, from: {} to: {}", this, id, dataBefore, dataAfter);
+
+        checkArgument(idPointsToCurrent(id), "Cannot handle data: %s. Only: %s can be handled by writer: %s",
+                id, getManagedDataObjectType(), this);
+
+        if (isWrite(dataBefore, dataAfter)) {
+            writeCurrent((InstanceIdentifier<D>) id, castToManaged(dataAfter), ctx);
+        } else if (isDelete(dataBefore, dataAfter)) {
+            deleteCurrent((InstanceIdentifier<D>) id, castToManaged(dataBefore), ctx);
+        } else {
+            checkArgument(dataBefore != null && dataAfter != null, "No data to process");
+            updateCurrent((InstanceIdentifier<D>) id, castToManaged(dataBefore), castToManaged(dataAfter), ctx);
+        }
+    }
+
+    private void checkDataType(@Nonnull final DataObject dataAfter) {
+        checkArgument(getManagedDataObjectType().getTargetType().isAssignableFrom(dataAfter.getClass()));
+    }
+
+    private D castToManaged(final DataObject data) {
+        checkDataType(data);
+        return getManagedDataObjectType().getTargetType().cast(data);
+    }
+
+    private static boolean isWrite(final DataObject dataBefore,
+                                    final DataObject dataAfter) {
+        return dataBefore == null && dataAfter != null;
+    }
+
+    private static boolean isDelete(final DataObject dataBefore,
+                                    final DataObject dataAfter) {
+        return dataAfter == null && dataBefore != null;
+    }
+
+    private boolean idPointsToCurrent(final @Nonnull InstanceIdentifier<? extends DataObject> id) {
+        return id.getTargetType().equals(getManagedDataObjectType().getTargetType());
+    }
+
+    protected abstract void writeCurrentAttributes(@Nonnull final InstanceIdentifier<D> id,
+                                                   @Nonnull final D data,
+                                                   @Nonnull final WriteContext ctx) throws WriteFailedException;
+
+    protected abstract void deleteCurrentAttributes(@Nonnull final InstanceIdentifier<D> id,
+                                                    @Nonnull final D dataBefore,
+                                                    @Nonnull final WriteContext ctx) throws WriteFailedException;
+
+    protected abstract void updateCurrentAttributes(@Nonnull final InstanceIdentifier<D> id,
+                                                    @Nonnull final D dataBefore,
+                                                    @Nonnull final D dataAfter,
+                                                    @Nonnull final WriteContext ctx) throws WriteFailedException;
+
+    @Nonnull
+    @Override
+    public InstanceIdentifier<D> getManagedDataObjectType() {
+        return instanceIdentifier;
+    }
+
+
+    @Override
+    public String toString() {
+        return String.format("Writer[%s]", getManagedDataObjectType().getTargetType().getSimpleName());
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/NoopWriterRegistry.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/NoopWriterRegistry.java
new file mode 100644
index 000000000..7c45fcd82
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/NoopWriterRegistry.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write;
+
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistry;
+import javax.annotation.Nonnull;
+
+/**
+ * Empty registry that does not perform any changes. Can be used in data layer, if we want to disable passing data to
+ * translation layer.
+ */
+public class NoopWriterRegistry implements WriterRegistry, AutoCloseable {
+
+    @Override
+    public void update(@Nonnull final DataObjectUpdates updates,
+                       @Nonnull final WriteContext ctx) throws TranslationException {
+        // NOOP
+    }
+
+    @Override
+    public void close() throws Exception {
+        // NOOP
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/TransactionWriteContext.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/TransactionWriteContext.java
new file mode 100644
index 000000000..47498f594
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/TransactionWriteContext.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.CheckedFuture;
+import io.fd.honeycomb.v3po.translate.MappingContext;
+import io.fd.honeycomb.v3po.translate.ModificationCache;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadOnlyTransaction;
+import org.opendaylight.yangtools.binding.data.codec.api.BindingNormalizedNodeSerializer;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+
+/**
+ * Transaction based WriteContext
+ */
+public final class TransactionWriteContext implements WriteContext {
+
+    private final DOMDataReadOnlyTransaction beforeTx;
+    private final DOMDataReadOnlyTransaction afterTx;
+    private final ModificationCache ctx;
+    private final BindingNormalizedNodeSerializer serializer;
+    private final MappingContext mappingContext;
+
+    public TransactionWriteContext(final BindingNormalizedNodeSerializer serializer,
+                                   final DOMDataReadOnlyTransaction beforeTx,
+                                   final DOMDataReadOnlyTransaction afterTx,
+                                   final MappingContext mappingContext) {
+        this.serializer = serializer;
+        // TODO do we have a BA transaction adapter ? If so, use it here and don't pass serializer
+        this.beforeTx = beforeTx;
+        this.afterTx = afterTx;
+        this.mappingContext = mappingContext;
+        this.ctx = new ModificationCache();
+    }
+
+    // TODO make this asynchronous
+
+    @Override
+    public <T extends DataObject> Optional<T> readBefore(@Nonnull final InstanceIdentifier<T> currentId) {
+        return read(currentId, beforeTx);
+    }
+
+    @Override
+    public <T extends DataObject> Optional<T> readAfter(@Nonnull final InstanceIdentifier<T> currentId) {
+        return read(currentId, afterTx);
+    }
+
+
+    private <T extends DataObject> Optional<T> read(final InstanceIdentifier<T> currentId,
+                                                    final DOMDataReadOnlyTransaction tx) {
+        final YangInstanceIdentifier path = serializer.toYangInstanceIdentifier(currentId);
+
+        final CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read =
+                tx.read(LogicalDatastoreType.CONFIGURATION, path);
+
+        try {
+            // TODO once the APIs are asynchronous use just Futures.transform
+            final Optional<NormalizedNode<?, ?>> optional = read.checkedGet();
+
+            if (!optional.isPresent()) {
+                return Optional.absent();
+            }
+
+            final NormalizedNode<?, ?> data = optional.get();
+            final Map.Entry<InstanceIdentifier<?>, DataObject> entry = serializer.fromNormalizedNode(path, data);
+
+            final Class<T> targetType = currentId.getTargetType();
+            checkState(targetType.isAssignableFrom(entry.getValue().getClass()),
+                "Unexpected data object type, should be: %s, but was: %s", targetType, entry.getValue().getClass());
+            return Optional.of(targetType.cast(entry.getValue()));
+        } catch (ReadFailedException e) {
+            throw new IllegalStateException("Unable to perform read", e);
+        }
+    }
+
+    @Nonnull
+    @Override
+    public ModificationCache getModificationCache() {
+        return ctx;
+    }
+
+    @Nonnull
+    @Override
+    public MappingContext getMappingContext() {
+        return mappingContext;
+    }
+
+    /**
+     * Does not close the transactions
+     */
+    @Override
+    public void close() {
+        ctx.close();
+        beforeTx.close();
+        afterTx.close();
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistry.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistry.java
new file mode 100644
index 000000000..7433de813
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistry.java
@@ -0,0 +1,315 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Sets;
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.write.DataObjectUpdate;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistry;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Flat writer registry, delegating updates to writers in the order writers were submitted.
+ */
+@ThreadSafe
+final class FlatWriterRegistry implements WriterRegistry {
+
+    private static final Logger LOG = LoggerFactory.getLogger(FlatWriterRegistry.class);
+
+    // All types handled by writers directly or as children
+    private final ImmutableSet<InstanceIdentifier<?>> handledTypes;
+
+    private final Set<InstanceIdentifier<?>> writersOrderReversed;
+    private final Set<InstanceIdentifier<?>> writersOrder;
+    private final Map<InstanceIdentifier<?>, Writer<?>> writers;
+
+    /**
+     * Create flat registry instance.
+     *
+     * @param writers immutable, ordered map of writers to use to process updates. Order of the writers has to be
+     *                one in which create and update operations should be handled. Deletes will be handled in reversed
+     *                order. All deletes are handled before handling all the updates.
+     */
+    FlatWriterRegistry(@Nonnull final ImmutableMap<InstanceIdentifier<?>, Writer<?>> writers) {
+        this.writers = writers;
+        this.writersOrderReversed = Sets.newLinkedHashSet(Lists.reverse(Lists.newArrayList(writers.keySet())));
+        this.writersOrder = writers.keySet();
+        this.handledTypes = getAllHandledTypes(writers);
+    }
+
+    private static ImmutableSet<InstanceIdentifier<?>> getAllHandledTypes(
+            @Nonnull final ImmutableMap<InstanceIdentifier<?>, Writer<?>> writers) {
+        final ImmutableSet.Builder<InstanceIdentifier<?>> handledTypesBuilder = ImmutableSet.builder();
+        for (Map.Entry<InstanceIdentifier<?>, Writer<?>> writerEntry : writers.entrySet()) {
+            final InstanceIdentifier<?> writerType = writerEntry.getKey();
+            final Writer<?> writer = writerEntry.getValue();
+            handledTypesBuilder.add(writerType);
+            if (writer instanceof SubtreeWriter) {
+                handledTypesBuilder.addAll(((SubtreeWriter<?>) writer).getHandledChildTypes());
+            }
+        }
+        return handledTypesBuilder.build();
+    }
+
+    @Override
+    public void update(@Nonnull final DataObjectUpdates updates,
+                       @Nonnull final WriteContext ctx) throws TranslationException {
+        if (updates.isEmpty()) {
+            return;
+        }
+
+        // Optimization
+        if (updates.containsOnlySingleType()) {
+            // First process delete
+            singleUpdate(updates.getDeletes(), ctx);
+            // Next is update
+            singleUpdate(updates.getUpdates(), ctx);
+        } else {
+            // First process deletes
+            bulkUpdate(updates.getDeletes(), ctx, true, writersOrderReversed);
+            // Next are updates
+            bulkUpdate(updates.getUpdates(), ctx, true, writersOrder);
+        }
+
+        LOG.debug("Update successful for types: {}", updates.getTypeIntersection());
+        LOG.trace("Update successful for: {}", updates);
+    }
+
+    private void singleUpdate(@Nonnull final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates,
+                              @Nonnull final WriteContext ctx) throws WriteFailedException {
+        if (updates.isEmpty()) {
+            return;
+        }
+
+        final InstanceIdentifier<?> singleType = updates.keySet().iterator().next();
+        LOG.debug("Performing single type update for: {}", singleType);
+        Collection<? extends DataObjectUpdate> singleTypeUpdates = updates.get(singleType);
+        Writer<?> writer = getWriter(singleType);
+
+        if (writer == null) {
+            // This node must be handled by a subtree writer, find it and call it or else fail
+            checkArgument(handledTypes.contains(singleType), "Unable to process update. Missing writers for: %s",
+                    singleType);
+            writer = getSubtreeWriterResponsible(singleType);
+            singleTypeUpdates = getParentDataObjectUpdate(ctx, updates, writer);
+        }
+
+        LOG.trace("Performing single type update with writer: {}", writer);
+        for (DataObjectUpdate singleUpdate : singleTypeUpdates) {
+            writer.update(singleUpdate.getId(), singleUpdate.getDataBefore(), singleUpdate.getDataAfter(), ctx);
+        }
+    }
+
+    private Writer<?> getSubtreeWriterResponsible(final InstanceIdentifier<?> singleType) {
+        final Writer<?> writer;// This is slow ( minor TODO-perf )
+        writer = writers.values().stream()
+                .filter(w -> w instanceof SubtreeWriter)
+                .filter(w -> ((SubtreeWriter<?>) w).getHandledChildTypes().contains(singleType))
+                .findFirst()
+                .get();
+        return writer;
+    }
+
+    private Collection<DataObjectUpdate> getParentDataObjectUpdate(final WriteContext ctx,
+                                                                   final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates,
+                                                                   final Writer<?> writer) {
+        // Now read data for subtree reader root, but first keyed ID is needed and that ID can be cut from updates
+        InstanceIdentifier<?> firstAffectedChildId = ((SubtreeWriter<?>) writer).getHandledChildTypes().stream()
+                .filter(updates::containsKey)
+                .map(unkeyedId -> updates.get(unkeyedId))
+                .flatMap(doUpdates -> doUpdates.stream())
+                .map(DataObjectUpdate::getId)
+                .findFirst()
+                .get();
+
+        final InstanceIdentifier<?> parentKeyedId =
+                RWUtils.cutId(firstAffectedChildId, writer.getManagedDataObjectType());
+
+        final Optional<? extends DataObject> parentBefore = ctx.readBefore(parentKeyedId);
+        final Optional<? extends DataObject> parentAfter = ctx.readAfter(parentKeyedId);
+        return Collections.singleton(
+                DataObjectUpdate.create(parentKeyedId, parentBefore.orNull(), parentAfter.orNull()));
+    }
+
+    private void bulkUpdate(@Nonnull final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates,
+                            @Nonnull final WriteContext ctx,
+                            final boolean attemptRevert,
+                            @Nonnull final Set<InstanceIdentifier<?>> writersOrder) throws BulkUpdateException {
+        if (updates.isEmpty()) {
+            return;
+        }
+
+        LOG.debug("Performing bulk update with revert attempt: {} for: {}", attemptRevert, updates.keySet());
+
+        // Check that all updates can be handled
+        checkAllTypesCanBeHandled(updates);
+
+        // Capture all changes successfully processed in case revert is needed
+        final Set<InstanceIdentifier<?>> processedNodes = new HashSet<>();
+
+        // Iterate over all writers and call update if there are any related updates
+        for (InstanceIdentifier<?> writerType : writersOrder) {
+            Collection<? extends DataObjectUpdate> writersData = updates.get(writerType);
+            final Writer<?> writer = getWriter(writerType);
+
+            if (writersData.isEmpty()) {
+                // If there are no data for current writer, but it is a SubtreeWriter and there are updates to
+                // its children, still invoke it with its root data
+                if (writer instanceof SubtreeWriter<?> && isAffected(((SubtreeWriter<?>) writer), updates)) {
+                    // Provide parent data for SubtreeWriter for further processing
+                    writersData = getParentDataObjectUpdate(ctx, updates, writer);
+                } else {
+                    // Skipping unaffected writer
+                    // Alternative to this would be modification sort according to the order of writers
+                    continue;
+                }
+            }
+
+            LOG.debug("Performing update for: {}",  writerType);
+            LOG.trace("Performing update with writer: {}", writer);
+
+            for (DataObjectUpdate singleUpdate : writersData) {
+                try {
+                    writer.update(singleUpdate.getId(), singleUpdate.getDataBefore(), singleUpdate.getDataAfter(), ctx);
+                    processedNodes.add(singleUpdate.getId());
+                    LOG.trace("Update successful for type: {}", writerType);
+                    LOG.debug("Update successful for: {}", singleUpdate);
+                } catch (Exception e) {
+                    LOG.error("Error while processing data change of: {} (updates={})", writerType, writersData, e);
+
+                    final Reverter reverter = attemptRevert
+                            ? new ReverterImpl(processedNodes, updates, writersOrder, ctx)
+                            : () -> {}; // NOOP reverter
+
+                    // Find out which changes left unprocessed
+                    final Set<InstanceIdentifier<?>> unprocessedChanges = updates.values().stream()
+                            .map(DataObjectUpdate::getId)
+                            .filter(id -> !processedNodes.contains(id))
+                            .collect(Collectors.toSet());
+                    throw new BulkUpdateException(unprocessedChanges, reverter, e);
+                }
+            }
+        }
+    }
+
+    private void checkAllTypesCanBeHandled(
+            @Nonnull final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates) {
+        if (!handledTypes.containsAll(updates.keySet())) {
+            final Sets.SetView<InstanceIdentifier<?>> missingWriters = Sets.difference(updates.keySet(), handledTypes);
+            LOG.warn("Unable to process update. Missing writers for: {}", missingWriters);
+            throw new IllegalArgumentException("Unable to process update. Missing writers for: " + missingWriters);
+        }
+    }
+
+    /**
+     * Check whether {@link SubtreeWriter} is affected by the updates.
+     *
+     * @return true if there are any updates to SubtreeWriter's child nodes (those marked by SubtreeWriter
+     *         as being taken care of)
+     * */
+    private static boolean isAffected(final SubtreeWriter<?> writer,
+                               final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates) {
+        return !Sets.intersection(writer.getHandledChildTypes(), updates.keySet()).isEmpty();
+    }
+
+    @Nullable
+    private Writer<?> getWriter(@Nonnull final InstanceIdentifier<?> singleType) {
+        return writers.get(singleType);
+    }
+
+    // FIXME unit test
+    private final class ReverterImpl implements Reverter {
+
+        private final Collection<InstanceIdentifier<?>> processedNodes;
+        private final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates;
+        private final Set<InstanceIdentifier<?>> revertDeleteOrder;
+        private final WriteContext ctx;
+
+        ReverterImpl(final Collection<InstanceIdentifier<?>> processedNodes,
+                     final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates,
+                     final Set<InstanceIdentifier<?>> writersOrderOriginal,
+                     final WriteContext ctx) {
+            this.processedNodes = processedNodes;
+            this.updates = updates;
+            // Use opposite ordering when executing revert
+            this.revertDeleteOrder =  writersOrderOriginal == FlatWriterRegistry.this.writersOrder
+                    ? FlatWriterRegistry.this.writersOrderReversed
+                    : FlatWriterRegistry.this.writersOrder;
+            this.ctx = ctx;
+        }
+
+        @Override
+        public void revert() throws RevertFailedException {
+            Multimap<InstanceIdentifier<?>, DataObjectUpdate> updatesToRevert =
+                    filterAndRevertProcessed(updates, processedNodes);
+
+            LOG.info("Attempting revert for changes: {}", updatesToRevert);
+            try {
+                // Perform reversed bulk update without revert attempt
+                bulkUpdate(updatesToRevert, ctx, true, revertDeleteOrder);
+                LOG.info("Revert successful");
+            } catch (BulkUpdateException e) {
+                LOG.error("Revert failed", e);
+                throw new RevertFailedException(e.getFailedIds(), e);
+            }
+        }
+
+        /**
+         * Create new updates map, but only keep already processed changes. Switching before and after data for each
+         * update.
+         */
+        private Multimap<InstanceIdentifier<?>, DataObjectUpdate> filterAndRevertProcessed(
+                final Multimap<InstanceIdentifier<?>, ? extends DataObjectUpdate> updates,
+                final Collection<InstanceIdentifier<?>> processedNodes) {
+            final Multimap<InstanceIdentifier<?>, DataObjectUpdate> filtered = HashMultimap.create();
+            for (InstanceIdentifier<?> processedNode : processedNodes) {
+                final InstanceIdentifier<?> wildcardedIid = RWUtils.makeIidWildcarded(processedNode);
+                if (updates.containsKey(wildcardedIid)) {
+                    updates.get(wildcardedIid).stream()
+                            .filter(dataObjectUpdate -> processedNode.contains(dataObjectUpdate.getId()))
+                            .forEach(dataObjectUpdate -> filtered.put(processedNode, dataObjectUpdate.reverse()));
+                }
+            }
+            return filtered;
+        }
+    }
+
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilder.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilder.java
new file mode 100644
index 000000000..bfac2eedd
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilder.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableMap;
+import io.fd.honeycomb.v3po.translate.util.AbstractSubtreeManagerRegistryBuilderBuilder;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import io.fd.honeycomb.v3po.translate.write.registry.ModifiableWriterRegistryBuilder;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistry;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistryBuilder;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.concurrent.NotThreadSafe;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Builder for {@link FlatWriterRegistry} allowing users to specify inter-writer relationships.
+ */
+@NotThreadSafe
+public final class FlatWriterRegistryBuilder
+        extends AbstractSubtreeManagerRegistryBuilderBuilder<Writer<? extends DataObject>, WriterRegistry>
+        implements ModifiableWriterRegistryBuilder, WriterRegistryBuilder {
+
+    private static final Logger LOG = LoggerFactory.getLogger(FlatWriterRegistryBuilder.class);
+
+    @Override
+    protected Writer<? extends DataObject> getSubtreeHandler(final @Nonnull Set<InstanceIdentifier<?>> handledChildren,
+                                                             final @Nonnull Writer<? extends DataObject> writer) {
+        return SubtreeWriter.createForWriter(handledChildren, writer);
+    }
+
+    /**
+     * Create FlatWriterRegistry with writers ordered according to submitted relationships.
+     */
+    @Override
+    public WriterRegistry build() {
+        final ImmutableMap<InstanceIdentifier<?>, Writer<?>> mappedWriters = getMappedHandlers();
+        LOG.debug("Building writer registry with writers: {}",
+                mappedWriters.keySet().stream()
+                        .map(InstanceIdentifier::getTargetType)
+                        .map(Class::getSimpleName)
+                        .collect(Collectors.joining(", ")));
+        LOG.trace("Building writer registry with writers: {}", mappedWriters);
+        return new FlatWriterRegistry(mappedWriters);
+    }
+
+    @VisibleForTesting
+    @Override
+    protected ImmutableMap<InstanceIdentifier<?>, Writer<? extends DataObject>> getMappedHandlers() {
+        return super.getMappedHandlers();
+    }
+}
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/SubtreeWriter.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/SubtreeWriter.java
new file mode 100644
index 000000000..e395b29da
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/SubtreeWriter.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.collect.Iterables;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.WriteFailedException;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import java.util.HashSet;
+import java.util.Set;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Simple writer delegate for subtree writers (writers handling also children nodes) providing a list of all the
+ * children nodes being handled.
+ */
+final class SubtreeWriter<D extends DataObject> implements Writer<D> {
+
+    private final Writer<D> delegate;
+    private final Set<InstanceIdentifier<?>> handledChildTypes = new HashSet<>();
+
+    private SubtreeWriter(final Writer<D> delegate, Set<InstanceIdentifier<?>> handledTypes) {
+        this.delegate = delegate;
+        for (InstanceIdentifier<?> handledType : handledTypes) {
+            // Iid has to start with writer's handled root type
+            checkArgument(delegate.getManagedDataObjectType().getTargetType().equals(
+                    handledType.getPathArguments().iterator().next().getType()),
+                    "Handled node from subtree has to be identified by an instance identifier starting from: %s."
+                    + "Instance identifier was: %s", getManagedDataObjectType().getTargetType(), handledType);
+            checkArgument(Iterables.size(handledType.getPathArguments()) > 1,
+                    "Handled node from subtree identifier too short: %s", handledType);
+            handledChildTypes.add(InstanceIdentifier.create(Iterables.concat(
+                    getManagedDataObjectType().getPathArguments(), Iterables.skip(handledType.getPathArguments(), 1))));
+        }
+    }
+
+    /**
+     * Return set of types also handled by this writer. All of the types are children of the type managed by this
+     * writer excluding the type of this writer.
+     */
+    Set<InstanceIdentifier<?>> getHandledChildTypes() {
+        return handledChildTypes;
+    }
+
+    @Override
+    public void update(
+            @Nonnull final InstanceIdentifier<? extends DataObject> id,
+            @Nullable final DataObject dataBefore,
+            @Nullable final DataObject dataAfter, @Nonnull final WriteContext ctx) throws WriteFailedException {
+        delegate.update(id, dataBefore, dataAfter, ctx);
+    }
+
+    @Override
+    @Nonnull
+    public InstanceIdentifier<D> getManagedDataObjectType() {
+        return delegate.getManagedDataObjectType();
+    }
+
+    /**
+     * Wrap a writer as a subtree writer.
+     */
+    static Writer<?> createForWriter(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                     @Nonnull final Writer<? extends DataObject> writer) {
+        return new SubtreeWriter<>(writer, handledChildren);
+    }
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingReaderRegistryModule.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingReaderRegistryModule.java
new file mode 100644
index 000000000..e1f04ebe2
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingReaderRegistryModule.java
@@ -0,0 +1,25 @@
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+
+import io.fd.honeycomb.v3po.translate.util.read.registry.CompositeReaderRegistryBuilder;
+
+public class DelegatingReaderRegistryModule extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractDelegatingReaderRegistryModule {
+    public DelegatingReaderRegistryModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver) {
+        super(identifier, dependencyResolver);
+    }
+
+    public DelegatingReaderRegistryModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver, org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.DelegatingReaderRegistryModule oldModule, java.lang.AutoCloseable oldInstance) {
+        super(identifier, dependencyResolver, oldModule, oldInstance);
+    }
+
+    @Override
+    public void customValidation() {
+        // add custom validation form module attributes here.
+    }
+
+    @Override
+    public java.lang.AutoCloseable createInstance() {
+        final CompositeReaderRegistryBuilder flatReaderRegistryBuilder = new CompositeReaderRegistryBuilder();
+        getReaderFactoryDependency().forEach(readerFactory -> readerFactory.init(flatReaderRegistryBuilder));
+        return flatReaderRegistryBuilder;
+    }
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingReaderRegistryModuleFactory.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingReaderRegistryModuleFactory.java
new file mode 100644
index 000000000..24d6c50b8
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingReaderRegistryModuleFactory.java
@@ -0,0 +1,20 @@
+/*
+* Generated file
+*
+* Generated from: yang module name: translate-utils yang module local name: delegating-reader-registry
+* Generated by: org.opendaylight.controller.config.yangjmxgenerator.plugin.JMXGenerator
+* Generated at: Wed Apr 06 12:32:43 CEST 2016
+*
+* Do not modify this file unless it is present under src/main directory
+*/
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+
+import org.opendaylight.controller.config.api.DynamicMBeanWithInstance;
+
+public class DelegatingReaderRegistryModuleFactory extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractDelegatingReaderRegistryModuleFactory {
+
+    @Override
+    public DelegatingReaderRegistryModule handleChangedClass(final DynamicMBeanWithInstance old) throws Exception {
+        return super.handleChangedClass(old);
+    }
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingWriterRegistryModule.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingWriterRegistryModule.java
new file mode 100644
index 000000000..7eadde80e
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingWriterRegistryModule.java
@@ -0,0 +1,26 @@
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+
+import io.fd.honeycomb.v3po.translate.util.write.registry.FlatWriterRegistryBuilder;
+
+public class DelegatingWriterRegistryModule extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractDelegatingWriterRegistryModule {
+    public DelegatingWriterRegistryModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver) {
+        super(identifier, dependencyResolver);
+    }
+
+    public DelegatingWriterRegistryModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver, org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.DelegatingWriterRegistryModule oldModule, java.lang.AutoCloseable oldInstance) {
+        super(identifier, dependencyResolver, oldModule, oldInstance);
+    }
+
+    @Override
+    public void customValidation() {
+        // add custom validation form module attributes here.
+    }
+
+    @Override
+    public java.lang.AutoCloseable createInstance() {
+        final FlatWriterRegistryBuilder flatWriterRegistryBuilder = new FlatWriterRegistryBuilder();
+        getWriterFactoryDependency().forEach(writerFactory -> writerFactory.init(flatWriterRegistryBuilder));
+        return flatWriterRegistryBuilder;
+    }
+
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingWriterRegistryModuleFactory.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingWriterRegistryModuleFactory.java
new file mode 100644
index 000000000..ab3b820d3
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/DelegatingWriterRegistryModuleFactory.java
@@ -0,0 +1,13 @@
+/*
+* Generated file
+*
+* Generated from: yang module name: translate-utils yang module local name: delegating-writer-registry
+* Generated by: org.opendaylight.controller.config.yangjmxgenerator.plugin.JMXGenerator
+* Generated at: Wed Apr 06 16:32:08 CEST 2016
+*
+* Do not modify this file unless it is present under src/main directory
+*/
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+public class DelegatingWriterRegistryModuleFactory extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractDelegatingWriterRegistryModuleFactory {
+
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/NoopWriterRegistryModule.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/NoopWriterRegistryModule.java
new file mode 100644
index 000000000..0f72df9da
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/NoopWriterRegistryModule.java
@@ -0,0 +1,38 @@
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+
+import io.fd.honeycomb.v3po.translate.util.write.NoopWriterRegistry;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistry;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistryBuilder;
+
+public class NoopWriterRegistryModule extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractNoopWriterRegistryModule {
+    public NoopWriterRegistryModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver) {
+        super(identifier, dependencyResolver);
+    }
+
+    public NoopWriterRegistryModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver, org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.NoopWriterRegistryModule oldModule, java.lang.AutoCloseable oldInstance) {
+        super(identifier, dependencyResolver, oldModule, oldInstance);
+    }
+
+    @Override
+    public void customValidation() {
+        // add custom validation form module attributes here.
+    }
+
+    @Override
+    public java.lang.AutoCloseable createInstance() {
+        return new NoopWriterRegistryBuilder();
+    }
+
+    private static final class NoopWriterRegistryBuilder implements AutoCloseable, WriterRegistryBuilder {
+
+        @Override
+        public WriterRegistry build() {
+            return new NoopWriterRegistry();
+        }
+
+        @Override
+        public void close() throws Exception {
+            // Noop
+        }
+    }
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/NoopWriterRegistryModuleFactory.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/NoopWriterRegistryModuleFactory.java
new file mode 100644
index 000000000..57b6859f3
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/NoopWriterRegistryModuleFactory.java
@@ -0,0 +1,13 @@
+/*
+* Generated file
+*
+* Generated from: yang module name: translate-utils yang module local name: noop-writer-registry
+* Generated by: org.opendaylight.controller.config.yangjmxgenerator.plugin.JMXGenerator
+* Generated at: Tue Apr 12 08:41:08 CEST 2016
+*
+* Do not modify this file unless it is present under src/main directory
+*/
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+public class NoopWriterRegistryModuleFactory extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractNoopWriterRegistryModuleFactory {
+
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/RealtimeMappingContextModule.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/RealtimeMappingContextModule.java
new file mode 100644
index 000000000..99cf4b4e1
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/RealtimeMappingContextModule.java
@@ -0,0 +1,84 @@
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+
+import com.google.common.base.Optional;
+import io.fd.honeycomb.v3po.translate.MappingContext;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.binding.api.ReadOnlyTransaction;
+import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class RealtimeMappingContextModule extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractRealtimeMappingContextModule {
+    public RealtimeMappingContextModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver) {
+        super(identifier, dependencyResolver);
+    }
+
+    public RealtimeMappingContextModule(org.opendaylight.controller.config.api.ModuleIdentifier identifier, org.opendaylight.controller.config.api.DependencyResolver dependencyResolver, org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.RealtimeMappingContextModule oldModule, java.lang.AutoCloseable oldInstance) {
+        super(identifier, dependencyResolver, oldModule, oldInstance);
+    }
+
+    @Override
+    public void customValidation() {
+        // add custom validation form module attributes here.
+    }
+
+    @Override
+    public java.lang.AutoCloseable createInstance() {
+        // Provides real time CRUD on top of Context data broker
+        return new MappingContext() {
+
+            @Override
+            public <T extends DataObject> Optional<T> read(@Nonnull final InstanceIdentifier<T> currentId) {
+                try(ReadOnlyTransaction tx = getContextBindingBrokerDependency().newReadOnlyTransaction()) {
+                    try {
+                        return tx.read(LogicalDatastoreType.OPERATIONAL, currentId).checkedGet();
+                    } catch (ReadFailedException e) {
+                        throw new IllegalStateException("Unable to perform read of " + currentId, e);
+                    }
+                }
+            }
+
+            @Override
+            public void delete(final InstanceIdentifier<?> path) {
+                final WriteTransaction writeTx = getContextBindingBrokerDependency().newWriteOnlyTransaction();
+                writeTx.delete(LogicalDatastoreType.OPERATIONAL, path);
+                try {
+                    writeTx.submit().checkedGet();
+                } catch (TransactionCommitFailedException e) {
+                    throw new IllegalStateException("Unable to perform delete of " + path, e);
+                }
+            }
+
+            @Override
+            public <T extends DataObject> void merge(final InstanceIdentifier<T> path, final T data) {
+                final WriteTransaction writeTx = getContextBindingBrokerDependency().newWriteOnlyTransaction();
+                writeTx.merge(LogicalDatastoreType.OPERATIONAL, path, data);
+                try {
+                    writeTx.submit().checkedGet();
+                } catch (TransactionCommitFailedException e) {
+                    throw new IllegalStateException("Unable to perform merge of " + path, e);
+                }
+            }
+
+            @Override
+            public <T extends DataObject> void put(final InstanceIdentifier<T> path, final T data) {
+                final WriteTransaction writeTx = getContextBindingBrokerDependency().newWriteOnlyTransaction();
+                writeTx.put(LogicalDatastoreType.OPERATIONAL, path, data);
+                try {
+                    writeTx.submit().checkedGet();
+                } catch (TransactionCommitFailedException e) {
+                    throw new IllegalStateException("Unable to perform put of " + path, e);
+                }
+            }
+
+            @Override
+            public void close() {
+                // Noop
+            }
+        };
+    }
+
+}
diff --git a/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/RealtimeMappingContextModuleFactory.java b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/RealtimeMappingContextModuleFactory.java
new file mode 100644
index 000000000..76647eace
--- /dev/null
+++ b/infra/translate-utils/src/main/java/org/opendaylight/yang/gen/v1/urn/honeycomb/params/xml/ns/yang/translate/utils/rev160406/RealtimeMappingContextModuleFactory.java
@@ -0,0 +1,13 @@
+/*
+* Generated file
+*
+* Generated from: yang module name: translate-utils yang module local name: realtime-mapping-context
+* Generated by: org.opendaylight.controller.config.yangjmxgenerator.plugin.JMXGenerator
+* Generated at: Fri Jun 03 16:04:29 CEST 2016
+*
+* Do not modify this file unless it is present under src/main directory
+*/
+package org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406;
+public class RealtimeMappingContextModuleFactory extends org.opendaylight.yang.gen.v1.urn.honeycomb.params.xml.ns.yang.translate.utils.rev160406.AbstractRealtimeMappingContextModuleFactory {
+
+}
diff --git a/infra/translate-utils/src/main/yang/translate-utils.yang b/infra/translate-utils/src/main/yang/translate-utils.yang
new file mode 100644
index 000000000..b543bba0d
--- /dev/null
+++ b/infra/translate-utils/src/main/yang/translate-utils.yang
@@ -0,0 +1,95 @@
+module translate-utils {
+    yang-version 1;
+    namespace "urn:honeycomb:params:xml:ns:yang:translate:utils";
+    prefix "tutils";
+
+    import config { prefix config; revision-date 2013-04-05; }
+    import translate-api { prefix tapi; revision-date 2016-04-06; }
+    import opendaylight-md-sal-binding { prefix md-sal-binding; revision-date 2013-10-28;}
+
+    description
+        "This module contains translation layer utilities";
+
+    revision "2016-04-06" {
+        description
+            "Initial revision.";
+    }
+
+    identity delegating-reader-registry {
+        base config:module-type;
+        config:provided-service tapi:honeycomb-reader-registry;
+        config:provided-service tapi:honeycomb-reader-registry-builder;
+        config:java-name-prefix DelegatingReaderRegistry;
+    }
+
+    augment "/config:modules/config:module/config:configuration" {
+        case delegating-reader-registry {
+            when "/config:modules/config:module/config:type = 'delegating-reader-registry'";
+
+                list reader-factory {
+                    uses config:service-ref {
+                        refine type {
+                            mandatory true;
+                            config:required-identity tapi:honeycomb-reader-factory;
+                        }
+                    }
+                }
+
+        }
+    }
+
+    identity delegating-writer-registry {
+        base config:module-type;
+        config:provided-service tapi:honeycomb-writer-registry;
+        config:provided-service tapi:honeycomb-writer-registry-builder;
+        config:java-name-prefix DelegatingWriterRegistry;
+    }
+
+    augment "/config:modules/config:module/config:configuration" {
+        case delegating-writer-registry {
+            when "/config:modules/config:module/config:type = 'delegating-writer-registry'";
+
+                list writer-factory {
+                    uses config:service-ref {
+                        refine type {
+                            mandatory true;
+                            config:required-identity tapi:honeycomb-writer-factory;
+                        }
+                    }
+                }
+
+        }
+    }
+
+    identity noop-writer-registry-builder {
+        base config:module-type;
+        config:provided-service tapi:honeycomb-writer-registry-builder;
+        config:java-name-prefix NoopWriterRegistry;
+    }
+
+    augment "/config:modules/config:module/config:configuration" {
+        case noop-writer-registry-builder {
+            when "/config:modules/config:module/config:type = 'noop-writer-registry-builder'";
+        }
+    }
+
+    identity realtime-mapping-context {
+        base config:module-type;
+        config:provided-service tapi:honeycomb-mapping-context;
+    }
+
+    augment "/config:modules/config:module/config:configuration" {
+        case realtime-mapping-context {
+            when "/config:modules/config:module/config:type = 'realtime-mapping-context'";
+
+            container context-binding-broker {
+                uses config:service-ref {
+                    refine type {
+                        mandatory true;
+                        config:required-identity md-sal-binding:binding-async-data-broker;
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/impl/write/util/TransactionWriteContextTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/impl/write/util/TransactionWriteContextTest.java
new file mode 100644
index 000000000..7c93e992a
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/impl/write/util/TransactionWriteContextTest.java
@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.impl.write.util;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.Futures;
+import io.fd.honeycomb.v3po.translate.MappingContext;
+import io.fd.honeycomb.v3po.translate.ModificationCache;
+import io.fd.honeycomb.v3po.translate.util.DataObjects;
+import io.fd.honeycomb.v3po.translate.util.write.TransactionWriteContext;
+import java.util.Map;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadOnlyTransaction;
+import org.opendaylight.yangtools.binding.data.codec.api.BindingNormalizedNodeSerializer;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+
+public class TransactionWriteContextTest {
+
+    @Mock
+    private BindingNormalizedNodeSerializer serializer;
+    @Mock
+    private DOMDataReadOnlyTransaction beforeTx;
+    @Mock
+    private DOMDataReadOnlyTransaction afterTx;
+    @Mock
+    private Map.Entry entry;
+    @Mock
+    private MappingContext contextBroker;
+
+    private TransactionWriteContext transactionWriteContext;
+
+    @Before
+    public void setUp() {
+        initMocks(this);
+        transactionWriteContext = new TransactionWriteContext(serializer, beforeTx, afterTx, contextBroker);
+    }
+
+    @Test
+    public void testReadBeforeNoData() throws Exception {
+        when(beforeTx.read(eq(LogicalDatastoreType.CONFIGURATION), any(YangInstanceIdentifier.class))).thenReturn(
+                Futures.immediateCheckedFuture(Optional.absent()));
+
+        final InstanceIdentifier<DataObjects.DataObject1> instanceId =
+                InstanceIdentifier.create(DataObjects.DataObject1.class);
+
+        final Optional<DataObjects.DataObject1> dataObjects = transactionWriteContext.readBefore(instanceId);
+        assertNotNull(dataObjects);
+        assertFalse(dataObjects.isPresent());
+
+        verify(serializer).toYangInstanceIdentifier(instanceId);
+        verify(serializer, never()).fromNormalizedNode(any(YangInstanceIdentifier.class), any(NormalizedNode.class));
+    }
+
+    @Test
+    public void testReadBefore() throws Exception {
+        when(beforeTx.read(eq(LogicalDatastoreType.CONFIGURATION), any(YangInstanceIdentifier.class))).thenReturn(
+                Futures.immediateCheckedFuture(Optional.of(mock(NormalizedNode.class))));
+
+        final InstanceIdentifier<DataObjects.DataObject1> instanceId =
+                InstanceIdentifier.create(DataObjects.DataObject1.class);
+        final YangInstanceIdentifier yangId = YangInstanceIdentifier.builder().node(QName.create("n", "d")).build();
+        when(serializer.toYangInstanceIdentifier(any(InstanceIdentifier.class))).thenReturn(yangId);
+        when(serializer.fromNormalizedNode(eq(yangId), any(NormalizedNode.class))).thenReturn(entry);
+        when(entry.getValue()).thenReturn(mock(DataObjects.DataObject1.class));
+
+        final Optional<DataObjects.DataObject1> dataObjects = transactionWriteContext.readBefore(instanceId);
+        assertNotNull(dataObjects);
+        assertTrue(dataObjects.isPresent());
+
+        verify(serializer).toYangInstanceIdentifier(instanceId);
+        verify(serializer).fromNormalizedNode(eq(yangId), any(NormalizedNode.class));
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testReadBeforeFailed() throws Exception {
+        when(beforeTx.read(eq(LogicalDatastoreType.CONFIGURATION), any(YangInstanceIdentifier.class))).thenReturn(
+                Futures.immediateFailedCheckedFuture(mock(ReadFailedException.class)));
+        transactionWriteContext.readBefore(mock(InstanceIdentifier.class));
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testReadAfterFailed() throws Exception {
+        when(afterTx.read(eq(LogicalDatastoreType.CONFIGURATION), any(YangInstanceIdentifier.class))).thenReturn(
+                Futures.immediateFailedCheckedFuture(mock(ReadFailedException.class)));
+        transactionWriteContext.readAfter(mock(InstanceIdentifier.class));
+    }
+
+    @Test
+    public void testGetContext() throws Exception {
+        assertNotNull(transactionWriteContext.getModificationCache());
+    }
+
+    @Test
+    public void testClose() throws Exception {
+        final ModificationCache context = transactionWriteContext.getModificationCache();
+        transactionWriteContext.close();
+        // TODO verify context was closed
+    }
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/DataObjects.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/DataObjects.java
new file mode 100644
index 000000000..d823465bd
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/DataObjects.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import org.opendaylight.yangtools.yang.binding.ChildOf;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class DataObjects {
+    public interface DataObject1 extends DataObject {
+        InstanceIdentifier<DataObject1> IID = InstanceIdentifier.create(DataObject1.class);
+    }
+
+    public interface DataObject2 extends DataObject {
+        InstanceIdentifier<DataObject2> IID = InstanceIdentifier.create(DataObject2.class);
+    }
+
+    public interface DataObject3 extends DataObject {
+        InstanceIdentifier<DataObject3> IID = InstanceIdentifier.create(DataObject3.class);
+        interface DataObject31 extends DataObject, ChildOf<DataObject3> {
+            InstanceIdentifier<DataObject31> IID = DataObject3.IID.child(DataObject31.class);
+        }
+    }
+
+    public interface DataObject4 extends DataObject {
+        InstanceIdentifier<DataObject4> IID = InstanceIdentifier.create(DataObject4.class);
+        interface DataObject41 extends DataObject, ChildOf<DataObject4> {
+            InstanceIdentifier<DataObject41> IID = DataObject4.IID.child(DataObject41.class);
+            interface DataObject411 extends DataObject, ChildOf<DataObject41> {
+                InstanceIdentifier<DataObject411> IID = DataObject41.IID.child(DataObject411.class);
+            }
+        }
+
+        interface DataObject42 extends DataObject, ChildOf<DataObject4> {
+            InstanceIdentifier<DataObject42> IID = DataObject4.IID.child(DataObject42.class);
+        }
+    }
+}
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/JsonUtilsTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/JsonUtilsTest.java
new file mode 100644
index 000000000..bd48cb446
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/JsonUtilsTest.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.google.common.io.ByteStreams;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.MockitoAnnotations;
+import org.opendaylight.yangtools.yang.common.QName;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
+import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
+import org.opendaylight.yangtools.yang.parser.stmt.reactor.CrossSourceStatementReactor;
+import org.opendaylight.yangtools.yang.parser.stmt.rfc6020.YangInferencePipeline;
+import org.opendaylight.yangtools.yang.parser.stmt.rfc6020.YangStatementSourceImpl;
+import org.opendaylight.yangtools.yang.parser.stmt.rfc6020.effective.EffectiveSchemaContext;
+
+public class JsonUtilsTest {
+
+    public static final String NAMESPACE = "urn:opendaylight:params:xml:ns:yang:test:persistence";
+
+    private static final QName ROOT_QNAME = QName.create("urn:ietf:params:xml:ns:netconf:base:1.0",  "data");
+    private static final QName TOP_CONTAINER_NAME = QName.create(NAMESPACE, "2015-01-05", "top-container");
+    private static final QName TOP_CONTAINER2_NAME = QName.create(NAMESPACE, "2015-01-05", "top-container2");
+    private static final QName STRING_LEAF_QNAME = QName.create(TOP_CONTAINER_NAME, "string");
+
+    private Path tmpPersistFile;
+    private EffectiveSchemaContext effectiveSchemaContext;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        tmpPersistFile = Files.createTempFile("testing-hc-persistence", "json");
+
+        final CrossSourceStatementReactor.BuildAction buildAction = YangInferencePipeline.RFC6020_REACTOR.newBuild();
+        buildAction.addSource(new YangStatementSourceImpl(getClass().getResourceAsStream("/test-persistence.yang")));
+        effectiveSchemaContext = buildAction.buildEffective();
+    }
+
+    @Test
+    public void testPersist() throws Exception {
+
+        NormalizedNode<?, ?> data = getData("testing");
+        JsonUtils.writeJsonRoot(data, effectiveSchemaContext, Files.newOutputStream(tmpPersistFile, StandardOpenOption.CREATE));
+        assertTrue(Files.exists(tmpPersistFile));
+
+        String persisted = new String(Files.readAllBytes(tmpPersistFile));
+        String expected =
+            new String(ByteStreams.toByteArray(getClass().getResourceAsStream("/expected-persisted-output.txt")));
+
+        assertEquals(expected, persisted);
+
+        data = getData("testing2");
+        JsonUtils.writeJsonRoot(data, effectiveSchemaContext, Files.newOutputStream(tmpPersistFile, StandardOpenOption.CREATE));
+        persisted = new String(Files.readAllBytes(tmpPersistFile));
+        assertEquals(expected.replace("testing", "testing2"), persisted);
+
+        // File has to stay even after close
+        assertTrue(Files.exists(tmpPersistFile));
+    }
+
+    @Test
+    public void testRestore() throws Exception {
+        final ContainerNode normalizedNodeOptional = JsonUtils
+            .readJsonRoot(effectiveSchemaContext, getClass().getResourceAsStream("/expected-persisted-output.txt"));
+        assertEquals(getData("testing"), normalizedNodeOptional);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testRestoreInvalidFile() throws Exception {
+        JsonUtils.readJsonRoot(effectiveSchemaContext, getClass().getResourceAsStream("/test-persistence.yang"));
+    }
+
+    private ContainerNode getData(final String stringValue) {
+        return Builders.containerBuilder()
+            .withNodeIdentifier(new YangInstanceIdentifier.NodeIdentifier(ROOT_QNAME))
+            .withChild(Builders.containerBuilder()
+                .withNodeIdentifier(new YangInstanceIdentifier.NodeIdentifier(TOP_CONTAINER_NAME))
+                .withChild(ImmutableNodes.leafNode(STRING_LEAF_QNAME, stringValue))
+                .build())
+            .withChild(Builders.containerBuilder()
+                .withNodeIdentifier(new YangInstanceIdentifier.NodeIdentifier(TOP_CONTAINER2_NAME))
+                .withChild(ImmutableNodes.leafNode(STRING_LEAF_QNAME, stringValue))
+                .build())
+            .build();
+    }
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistryBuilderTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistryBuilderTest.java
new file mode 100644
index 000000000..e57dcee43
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/CompositeReaderRegistryBuilderTest.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.when;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.read.registry.ReaderRegistry;
+import io.fd.honeycomb.v3po.translate.util.DataObjects;
+import java.util.List;
+import java.util.Map;
+import org.junit.Test;
+import org.mockito.Mockito;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class CompositeReaderRegistryBuilderTest {
+
+    private Reader<DataObjects.DataObject1, Builder<DataObjects.DataObject1>> reader1 =
+            mock(DataObjects.DataObject1.class);
+    private Reader<DataObjects.DataObject2, Builder<DataObjects.DataObject2>> reader2 =
+            mock(DataObjects.DataObject2.class);
+    private Reader<DataObjects.DataObject3, Builder<DataObjects.DataObject3>> reader3 =
+            mock(DataObjects.DataObject3.class);
+    private Reader<DataObjects.DataObject3.DataObject31, Builder<DataObjects.DataObject3.DataObject31>> reader31 =
+            mock(DataObjects.DataObject3.DataObject31.class);
+
+    private Reader<DataObjects.DataObject4, Builder<DataObjects.DataObject4>> reader4 =
+            mock(DataObjects.DataObject4.class);
+    private Reader<DataObjects.DataObject4.DataObject41, Builder<DataObjects.DataObject4.DataObject41>> reader41 =
+            mock(DataObjects.DataObject4.DataObject41.class);
+    private Reader<DataObjects.DataObject4.DataObject41.DataObject411, Builder<DataObjects.DataObject4.DataObject41.DataObject411>> reader411 =
+            mock(DataObjects.DataObject4.DataObject41.DataObject411.class);
+    private Reader<DataObjects.DataObject4.DataObject42, Builder<DataObjects.DataObject4.DataObject42>> reader42 =
+            mock(DataObjects.DataObject4.DataObject42.class);
+
+    @SuppressWarnings("unchecked")
+    private <D extends DataObject> Reader<D, Builder<D>> mock(final Class<D> dataObjectType) {
+        final Reader<D, Builder<D>> mock = Mockito.mock(Reader.class);
+        try {
+            when(mock.getManagedDataObjectType())
+                    .thenReturn(((InstanceIdentifier<D>) dataObjectType.getDeclaredField("IID").get(null)));
+        } catch (IllegalAccessException | NoSuchFieldException e) {
+            throw new RuntimeException(e);
+        }
+        return mock;
+    }
+
+    @Test
+    public void testCompositeStructure() throws Exception {
+        final CompositeReaderRegistryBuilder compositeReaderRegistryBuilder = new CompositeReaderRegistryBuilder();
+        /*
+            Composite reader structure ordered left from right
+
+            1,      2,      3,      4
+                            31      42, 41
+                                        411
+         */
+        compositeReaderRegistryBuilder.add(reader1);
+        compositeReaderRegistryBuilder.addAfter(reader2, reader1.getManagedDataObjectType());
+        compositeReaderRegistryBuilder.addAfter(reader3, reader2.getManagedDataObjectType());
+        compositeReaderRegistryBuilder.addAfter(reader31, reader1.getManagedDataObjectType());
+        compositeReaderRegistryBuilder.addAfter(reader4, reader3.getManagedDataObjectType());
+        compositeReaderRegistryBuilder.add(reader41);
+        compositeReaderRegistryBuilder.addBefore(reader42, reader41.getManagedDataObjectType());
+        compositeReaderRegistryBuilder.add(reader411);
+
+        final ReaderRegistry build = compositeReaderRegistryBuilder.build();
+
+        final Map<Class<? extends DataObject>, Reader<? extends DataObject, ? extends Builder<?>>> rootReaders =
+                ((CompositeReaderRegistry) build).getRootReaders();
+        final List<Class<? extends DataObject>> rootReaderOrder = Lists.newArrayList(rootReaders.keySet());
+
+        assertEquals(reader1.getManagedDataObjectType().getTargetType(), rootReaderOrder.get(0));
+        assertEquals(reader2.getManagedDataObjectType().getTargetType(), rootReaderOrder.get(1));
+        assertEquals(reader3.getManagedDataObjectType().getTargetType(), rootReaderOrder.get(2));
+        assertEquals(reader4.getManagedDataObjectType().getTargetType(), rootReaderOrder.get(3));
+
+        assertFalse(rootReaders.get(DataObjects.DataObject1.class) instanceof CompositeReader);
+        assertFalse(rootReaders.get(DataObjects.DataObject2.class) instanceof CompositeReader);
+        assertTrue(rootReaders.get(DataObjects.DataObject3.class) instanceof CompositeReader);
+        assertTrue(rootReaders.get(DataObjects.DataObject4.class) instanceof CompositeReader);
+
+        final ImmutableMap<Class<?>, Reader<? extends DataObject, ? extends Builder<?>>> childReaders =
+                ((CompositeReader<? extends DataObject, ? extends Builder<?>>) rootReaders
+                        .get(DataObjects.DataObject4.class)).getChildReaders();
+        final List<Class<?>> orderedChildReaders = Lists.newArrayList(childReaders.keySet());
+
+        assertEquals(reader42.getManagedDataObjectType().getTargetType(), orderedChildReaders.get(0));
+        assertEquals(reader41.getManagedDataObjectType().getTargetType(), orderedChildReaders.get(1));
+        assertTrue(childReaders.get(DataObjects.DataObject4.DataObject41.class) instanceof CompositeReader);
+        assertFalse(childReaders.get(DataObjects.DataObject4.DataObject42.class) instanceof CompositeReader);
+    }
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/SubtreeReaderTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/SubtreeReaderTest.java
new file mode 100644
index 000000000..324d71daa
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/SubtreeReaderTest.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.mockito.Mockito.atLeastOnce;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.Sets;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import io.fd.honeycomb.v3po.translate.util.DataObjects;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.ChildOf;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class SubtreeReaderTest {
+
+    @Mock
+    private Reader<DataObjects.DataObject4, Builder<DataObjects.DataObject4>> delegate;
+    @Mock
+    private Reader<DataObject1, Builder<DataObject1>> delegateLocal;
+    @Mock
+    private ReadContext ctx;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        doReturn(DataObjects.DataObject4.IID).when(delegate).getManagedDataObjectType();
+        doReturn(DataObject1.IID).when(delegateLocal).getManagedDataObjectType();
+    }
+
+    @Test
+    public void testCreate() throws Exception {
+        final Reader<DataObjects.DataObject4, Builder<DataObjects.DataObject4>> subtreeR =
+                SubtreeReader.createForReader(Sets.newHashSet(DataObjects.DataObject4.DataObject41.IID), delegate);
+
+        subtreeR.getBuilder(DataObjects.DataObject4.IID);
+        verify(delegate).getBuilder(DataObjects.DataObject4.IID);
+
+        subtreeR.getManagedDataObjectType();
+        verify(delegate, atLeastOnce()).getManagedDataObjectType();
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateInvalid() throws Exception {
+        SubtreeReader.createForReader(Sets.newHashSet(DataObjects.DataObject1.IID), delegate);
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testReadOnlySubtreeCannotFilter() throws Exception {
+        final Reader<DataObjects.DataObject4, Builder<DataObjects.DataObject4>> subtreeR =
+                SubtreeReader.createForReader(Sets.newHashSet(DataObjects.DataObject4.DataObject41.IID), delegate);
+
+        doReturn(Optional.fromNullable(mock(DataObjects.DataObject4.class))).when(delegate).read(DataObjects.DataObject4.IID, ctx);
+        subtreeR.read(DataObjects.DataObject4.DataObject41.IID, ctx);
+    }
+
+    @Test
+    public void testReadOnlySubtreeNotPresent() throws Exception {
+        final Reader<DataObjects.DataObject4, Builder<DataObjects.DataObject4>> subtreeR =
+                SubtreeReader.createForReader(Sets.newHashSet(DataObjects.DataObject4.DataObject41.IID), delegate);
+
+        doReturn(Optional.absent()).when(delegate).read(DataObjects.DataObject4.IID, ctx);
+        assertFalse(subtreeR.read(DataObjects.DataObject4.DataObject41.IID, ctx).isPresent());
+    }
+
+    @Test
+    public void testReadOnlySubtreeChild() throws Exception {
+        final Reader<DataObject1, Builder<DataObject1>> subtreeR =
+                SubtreeReader.createForReader(Sets.newHashSet(DataObject1.DataObject11.IID), delegateLocal);
+
+        final DataObject1 mock = mock(DataObject1.class);
+        final DataObject1.DataObject11 mock11 = mock(DataObject1.DataObject11.class);
+        doReturn(mock11).when(mock).getDataObject11();
+        doReturn(Optional.fromNullable(mock)).when(delegateLocal).read(DataObject1.IID, ctx);
+        assertEquals(mock11, subtreeR.read(DataObject1.DataObject11.IID, ctx).get());
+    }
+
+    @Test
+    public void testReadEntireSubtree() throws Exception {
+        final Reader<DataObject1, Builder<DataObject1>> subtreeR =
+                SubtreeReader.createForReader(Sets.newHashSet(DataObject1.DataObject11.IID), delegateLocal);
+
+        final DataObject1 mock = mock(DataObject1.class);
+        final DataObject1.DataObject11 mock11 = mock(DataObject1.DataObject11.class);
+        doReturn(mock11).when(mock).getDataObject11();
+        doReturn(Optional.fromNullable(mock)).when(delegateLocal).read(DataObject1.IID, ctx);
+        assertEquals(mock, subtreeR.read(DataObject1.IID, ctx).get());
+    }
+
+    public abstract static class DataObject1 implements DataObject {
+        public static InstanceIdentifier<DataObject1> IID = InstanceIdentifier.create(DataObject1.class);
+
+        public abstract DataObject11 getDataObject11();
+
+        public abstract static class DataObject11 implements DataObject, ChildOf<DataObject1> {
+            public static InstanceIdentifier<DataObject11> IID = DataObject1.IID.child(DataObject11.class);
+        }
+    }
+}
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/TypeHierarchyTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/TypeHierarchyTest.java
new file mode 100644
index 000000000..7a664eef1
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/read/registry/TypeHierarchyTest.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.read.registry;
+
+import static org.hamcrest.CoreMatchers.hasItem;
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+import com.google.common.collect.Sets;
+import io.fd.honeycomb.v3po.translate.util.DataObjects.DataObject1;
+import io.fd.honeycomb.v3po.translate.util.DataObjects.DataObject3;
+import io.fd.honeycomb.v3po.translate.util.DataObjects.DataObject4;
+import org.junit.Test;
+
+public class TypeHierarchyTest {
+
+    @Test
+    public void testHierarchy() throws Exception {
+        final TypeHierarchy typeHierarchy = TypeHierarchy.create(Sets.newHashSet(
+                DataObject4.DataObject41.DataObject411.IID,
+                DataObject4.DataObject41.IID,/* Included in previous already */
+                DataObject1.IID,
+                DataObject3.DataObject31.IID));
+
+        // Roots
+        assertThat(typeHierarchy.getRoots().size(), is(3));
+        assertThat(typeHierarchy.getRoots(), hasItems(DataObject1.IID, DataObject3.IID, DataObject4.IID));
+
+        // Leaves
+        assertThat(typeHierarchy.getDirectChildren(DataObject1.IID).size(), is(0));
+        assertThat(typeHierarchy.getDirectChildren(DataObject3.DataObject31.IID).size(), is(0));
+        assertThat(typeHierarchy.getDirectChildren(DataObject4.DataObject41.DataObject411.IID).size(), is(0));
+
+        // Intermediate leaves
+        assertThat(typeHierarchy.getDirectChildren(DataObject3.IID).size(), is(1));
+        assertThat(typeHierarchy.getDirectChildren(DataObject3.IID), hasItem(DataObject3.DataObject31.IID));
+        assertEquals(typeHierarchy.getDirectChildren(DataObject3.IID), typeHierarchy.getAllChildren(DataObject3.IID));
+
+        assertThat(typeHierarchy.getDirectChildren(DataObject4.DataObject41.IID).size(), is(1));
+        assertThat(typeHierarchy.getDirectChildren(DataObject4.DataObject41.IID), hasItem(
+                DataObject4.DataObject41.DataObject411.IID));
+        assertEquals(typeHierarchy.getDirectChildren(DataObject4.DataObject41.IID), typeHierarchy.getAllChildren(
+                DataObject4.DataObject41.IID));
+
+        assertThat(typeHierarchy.getDirectChildren(DataObject4.IID).size(), is(1));
+        assertThat(typeHierarchy.getDirectChildren(DataObject4.IID), hasItem(DataObject4.DataObject41.IID));
+        assertThat(typeHierarchy.getAllChildren(DataObject4.IID).size(), is(2));
+        assertTrue(typeHierarchy.getAllChildren(DataObject4.IID).contains(DataObject4.DataObject41.IID));
+        assertTrue(typeHierarchy.getAllChildren(DataObject4.IID).contains(DataObject4.DataObject41.DataObject411.IID));
+    }
+}
+
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilderTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilderTest.java
new file mode 100644
index 000000000..743d84cbf
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilderTest.java
@@ -0,0 +1,131 @@
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import static org.hamcrest.CoreMatchers.anyOf;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import io.fd.honeycomb.v3po.translate.util.DataObjects;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.Test;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class FlatWriterRegistryBuilderTest {
+
+
+    @Test
+    public void testRelationsBefore() throws Exception {
+        final FlatWriterRegistryBuilder flatWriterRegistryBuilder = new FlatWriterRegistryBuilder();
+        /*
+            1   ->  2   ->  3
+                        ->  4
+         */
+        flatWriterRegistryBuilder.add(mockWriter(DataObjects.DataObject3.class));
+        flatWriterRegistryBuilder.add(mockWriter(DataObjects.DataObject4.class));
+        flatWriterRegistryBuilder.addBefore(mockWriter(DataObjects.DataObject2.class),
+                Lists.newArrayList(DataObjects.DataObject3.IID, DataObjects.DataObject4.IID));
+        flatWriterRegistryBuilder.addBefore(mockWriter(DataObjects.DataObject1.class), DataObjects.DataObject2.IID);
+        final ImmutableMap<InstanceIdentifier<?>, Writer<?>> mappedWriters =
+                flatWriterRegistryBuilder.getMappedHandlers();
+
+        final ArrayList<InstanceIdentifier<?>> typesInList = Lists.newArrayList(mappedWriters.keySet());
+        assertEquals(DataObjects.DataObject1.IID, typesInList.get(0));
+        assertEquals(DataObjects.DataObject2.IID, typesInList.get(1));
+        assertThat(typesInList.get(2), anyOf(equalTo(DataObjects.DataObject3.IID), equalTo(DataObjects.DataObject4.IID)));
+        assertThat(typesInList.get(3), anyOf(equalTo(DataObjects.DataObject3.IID), equalTo(DataObjects.DataObject4.IID)));
+    }
+
+    @Test
+    public void testRelationsAfter() throws Exception {
+        final FlatWriterRegistryBuilder flatWriterRegistryBuilder = new FlatWriterRegistryBuilder();
+        /*
+            1   ->  2   ->  3
+                        ->  4
+         */
+        flatWriterRegistryBuilder.add(mockWriter(DataObjects.DataObject1.class));
+        flatWriterRegistryBuilder.addAfter(mockWriter(DataObjects.DataObject2.class), DataObjects.DataObject1.IID);
+        flatWriterRegistryBuilder.addAfter(mockWriter(DataObjects.DataObject3.class), DataObjects.DataObject2.IID);
+        flatWriterRegistryBuilder.addAfter(mockWriter(DataObjects.DataObject4.class), DataObjects.DataObject2.IID);
+        final ImmutableMap<InstanceIdentifier<?>, Writer<?>> mappedWriters =
+                flatWriterRegistryBuilder.getMappedHandlers();
+
+        final List<InstanceIdentifier<?>> typesInList = Lists.newArrayList(mappedWriters.keySet());
+        assertEquals(DataObjects.DataObject1.IID, typesInList.get(0));
+        assertEquals(DataObjects.DataObject2.IID, typesInList.get(1));
+        assertThat(typesInList.get(2), anyOf(equalTo(DataObjects.DataObject3.IID), equalTo(DataObjects.DataObject4.IID)));
+        assertThat(typesInList.get(3), anyOf(equalTo(DataObjects.DataObject3.IID), equalTo(DataObjects.DataObject4.IID)));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testRelationsLoop() throws Exception {
+        final FlatWriterRegistryBuilder flatWriterRegistryBuilder = new FlatWriterRegistryBuilder();
+        /*
+            1   ->  2   ->  1
+         */
+        flatWriterRegistryBuilder.add(mockWriter(DataObjects.DataObject1.class));
+        flatWriterRegistryBuilder.addAfter(mockWriter(DataObjects.DataObject2.class), DataObjects.DataObject1.IID);
+        flatWriterRegistryBuilder.addAfter(mockWriter(DataObjects.DataObject1.class), DataObjects.DataObject2.IID);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testAddWriterTwice() throws Exception {
+        final FlatWriterRegistryBuilder flatWriterRegistryBuilder = new FlatWriterRegistryBuilder();
+        flatWriterRegistryBuilder.add(mockWriter(DataObjects.DataObject1.class));
+        flatWriterRegistryBuilder.add(mockWriter(DataObjects.DataObject1.class));
+    }
+
+    @Test
+    public void testAddSubtreeWriter() throws Exception {
+        final FlatWriterRegistryBuilder flatWriterRegistryBuilder = new FlatWriterRegistryBuilder();
+        flatWriterRegistryBuilder.subtreeAdd(
+                Sets.newHashSet(DataObjects.DataObject4.DataObject41.IID,
+                                DataObjects.DataObject4.DataObject41.IID),
+                mockWriter(DataObjects.DataObject4.class));
+        final ImmutableMap<InstanceIdentifier<?>, Writer<?>> mappedWriters =
+                flatWriterRegistryBuilder.getMappedHandlers();
+        final ArrayList<InstanceIdentifier<?>> typesInList = Lists.newArrayList(mappedWriters.keySet());
+
+        assertEquals(DataObjects.DataObject4.IID, typesInList.get(0));
+        assertEquals(1, typesInList.size());
+    }
+
+    @Test
+    public void testCreateSubtreeWriter() throws Exception {
+        final Writer<?> forWriter = SubtreeWriter.createForWriter(Sets.newHashSet(
+                DataObjects.DataObject4.DataObject41.IID,
+                DataObjects.DataObject4.DataObject41.DataObject411.IID,
+                DataObjects.DataObject4.DataObject42.IID),
+                mockWriter(DataObjects.DataObject4.class));
+        assertThat(forWriter, instanceOf(SubtreeWriter.class));
+        assertThat(((SubtreeWriter<?>) forWriter).getHandledChildTypes().size(), is(3));
+        assertThat(((SubtreeWriter<?>) forWriter).getHandledChildTypes(), hasItems(DataObjects.DataObject4.DataObject41.IID,
+                DataObjects.DataObject4.DataObject42.IID, DataObjects.DataObject4.DataObject41.DataObject411.IID));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testCreateInvalidSubtreeWriter() throws Exception {
+        SubtreeWriter.createForWriter(Sets.newHashSet(
+                InstanceIdentifier.create(DataObjects.DataObject3.class).child(DataObjects.DataObject3.DataObject31.class)),
+                mockWriter(DataObjects.DataObject4.class));
+    }
+
+    @SuppressWarnings("unchecked")
+    private Writer<? extends DataObject> mockWriter(final Class<? extends DataObject> doClass)
+            throws NoSuchFieldException, IllegalAccessException {
+        final Writer mock = mock(Writer.class);
+        when(mock.getManagedDataObjectType()).thenReturn((InstanceIdentifier<?>) doClass.getDeclaredField("IID").get(null));
+        return mock;
+    }
+
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryTest.java
new file mode 100644
index 000000000..a72cb4fa7
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryTest.java
@@ -0,0 +1,264 @@
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import static org.hamcrest.CoreMatchers.hasItem;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.verifyZeroInteractions;
+import static org.mockito.Mockito.when;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableMultimap;
+import com.google.common.collect.Multimap;
+import io.fd.honeycomb.v3po.translate.util.DataObjects.DataObject1;
+import io.fd.honeycomb.v3po.translate.util.DataObjects.DataObject2;
+import io.fd.honeycomb.v3po.translate.util.DataObjects.DataObject3;
+import io.fd.honeycomb.v3po.translate.write.DataObjectUpdate;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistry;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InOrder;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class FlatWriterRegistryTest {
+
+    @Mock
+    private Writer<DataObject1> writer1;
+    @Mock
+    private Writer<DataObject2> writer2;
+    @Mock
+    private Writer<DataObject3> writer3;
+    @Mock
+    private WriteContext ctx;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        when(writer1.getManagedDataObjectType()).thenReturn(DataObject1.IID);
+        when(writer2.getManagedDataObjectType()).thenReturn(DataObject2.IID);
+        when(writer3.getManagedDataObjectType()).thenReturn(DataObject3.IID);
+    }
+
+    @Test
+    public void testMultipleUpdatesForSingleWriter() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        final InstanceIdentifier<DataObject1> iid = InstanceIdentifier.create(DataObject1.class);
+        final InstanceIdentifier<DataObject1> iid2 = InstanceIdentifier.create(DataObject1.class);
+        final DataObject1 dataObject = mock(DataObject1.class);
+        updates.put(DataObject1.IID, DataObjectUpdate.create(iid, dataObject, dataObject));
+        updates.put(DataObject1.IID, DataObjectUpdate.create(iid2, dataObject, dataObject));
+        flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, ImmutableMultimap.of()), ctx);
+
+        verify(writer1).update(iid, dataObject, dataObject, ctx);
+        verify(writer1).update(iid2, dataObject, dataObject, ctx);
+        // Invoked when registry is being created
+        verifyNoMoreInteractions(writer1);
+        verifyZeroInteractions(writer2);
+    }
+
+    @Test
+    public void testMultipleUpdatesForMultipleWriters() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        final InstanceIdentifier<DataObject1> iid = InstanceIdentifier.create(DataObject1.class);
+        final DataObject1 dataObject = mock(DataObject1.class);
+        updates.put(DataObject1.IID, DataObjectUpdate.create(iid, dataObject, dataObject));
+        final InstanceIdentifier<DataObject2> iid2 = InstanceIdentifier.create(DataObject2.class);
+        final DataObject2 dataObject2 = mock(DataObject2.class);
+        updates.put(DataObject2.IID, DataObjectUpdate.create(iid2, dataObject2, dataObject2));
+        flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, ImmutableMultimap.of()), ctx);
+
+        final InOrder inOrder = inOrder(writer1, writer2);
+        inOrder.verify(writer1).update(iid, dataObject, dataObject, ctx);
+        inOrder.verify(writer2).update(iid2, dataObject2, dataObject2, ctx);
+
+        verifyNoMoreInteractions(writer1);
+        verifyNoMoreInteractions(writer2);
+    }
+
+    @Test
+    public void testMultipleDeletesForMultipleWriters() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate.DataObjectDelete> deletes = HashMultimap.create();
+        final InstanceIdentifier<DataObject1> iid = InstanceIdentifier.create(DataObject1.class);
+        final DataObject1 dataObject = mock(DataObject1.class);
+        deletes.put(DataObject1.IID, ((DataObjectUpdate.DataObjectDelete) DataObjectUpdate.create(iid, dataObject, null)));
+        final InstanceIdentifier<DataObject2> iid2 = InstanceIdentifier.create(DataObject2.class);
+        final DataObject2 dataObject2 = mock(DataObject2.class);
+        deletes.put(DataObject2.IID, ((DataObjectUpdate.DataObjectDelete) DataObjectUpdate.create(iid2, dataObject2, null)));
+        flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(ImmutableMultimap.of(), deletes), ctx);
+
+        final InOrder inOrder = inOrder(writer1, writer2);
+        // Reversed order of invocation, first writer2 and then writer1
+        inOrder.verify(writer2).update(iid2, dataObject2, null, ctx);
+        inOrder.verify(writer1).update(iid, dataObject, null, ctx);
+
+        verifyNoMoreInteractions(writer1);
+        verifyNoMoreInteractions(writer2);
+    }
+
+    @Test
+    public void testMultipleUpdatesAndDeletesForMultipleWriters() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate.DataObjectDelete> deletes = HashMultimap.create();
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        final InstanceIdentifier<DataObject1> iid = InstanceIdentifier.create(DataObject1.class);
+        final DataObject1 dataObject = mock(DataObject1.class);
+        // Writer 1 delete
+        deletes.put(DataObject1.IID, ((DataObjectUpdate.DataObjectDelete) DataObjectUpdate.create(iid, dataObject, null)));
+        // Writer 1 update
+        updates.put(DataObject1.IID, DataObjectUpdate.create(iid, dataObject, dataObject));
+        final InstanceIdentifier<DataObject2> iid2 = InstanceIdentifier.create(DataObject2.class);
+        final DataObject2 dataObject2 = mock(DataObject2.class);
+        // Writer 2 delete
+        deletes.put(DataObject2.IID, ((DataObjectUpdate.DataObjectDelete) DataObjectUpdate.create(iid2, dataObject2, null)));
+        // Writer 2 update
+        updates.put(DataObject2.IID, DataObjectUpdate.create(iid2, dataObject2, dataObject2));
+        flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, deletes), ctx);
+
+        final InOrder inOrder = inOrder(writer1, writer2);
+        // Reversed order of invocation, first writer2 and then writer1 for deletes
+        inOrder.verify(writer2).update(iid2, dataObject2, null, ctx);
+        inOrder.verify(writer1).update(iid, dataObject, null, ctx);
+        // Then also updates are processed
+        inOrder.verify(writer1).update(iid, dataObject, dataObject, ctx);
+        inOrder.verify(writer2).update(iid2, dataObject2, dataObject2, ctx);
+
+        verifyNoMoreInteractions(writer1);
+        verifyNoMoreInteractions(writer2);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testMultipleUpdatesOneMissing() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(ImmutableMap.of(DataObject1.IID, writer1));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        addUpdate(updates, DataObject1.class);
+        addUpdate(updates, DataObject2.class);
+        flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, ImmutableMultimap.of()), ctx);
+    }
+
+    @Test
+    public void testMultipleUpdatesOneFailing() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2));
+
+        // Writer1 always fails
+        doThrow(new RuntimeException()).when(writer1)
+                .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        addUpdate(updates, DataObject1.class);
+        addUpdate(updates, DataObject2.class);
+
+        try {
+            flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, ImmutableMultimap.of()), ctx);
+            fail("Bulk update should have failed on writer1");
+        } catch (WriterRegistry.BulkUpdateException e) {
+            assertThat(e.getFailedIds().size(), is(2));
+            assertThat(e.getFailedIds(), hasItem(InstanceIdentifier.create(DataObject2.class)));
+            assertThat(e.getFailedIds(), hasItem(InstanceIdentifier.create(DataObject1.class)));
+        }
+    }
+
+    @Test
+    public void testMultipleUpdatesOneFailingThenRevertWithSuccess() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(
+                        ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2, DataObject3.IID, writer3));
+
+        // Writer1 always fails
+        doThrow(new RuntimeException()).when(writer3)
+                .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        addUpdate(updates, DataObject1.class);
+        addUpdate(updates, DataObject3.class);
+        final InstanceIdentifier<DataObject2> iid2 = InstanceIdentifier.create(DataObject2.class);
+        final DataObject2 before2 = mock(DataObject2.class);
+        final DataObject2 after2 = mock(DataObject2.class);
+        updates.put(DataObject2.IID, DataObjectUpdate.create(iid2, before2, after2));
+
+        try {
+            flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, ImmutableMultimap.of()), ctx);
+            fail("Bulk update should have failed on writer1");
+        } catch (WriterRegistry.BulkUpdateException e) {
+            assertThat(e.getFailedIds().size(), is(1));
+
+            final InOrder inOrder = inOrder(writer1, writer2, writer3);
+            inOrder.verify(writer1)
+                .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+            inOrder.verify(writer2)
+                .update(iid2, before2, after2, ctx);
+            inOrder.verify(writer3)
+                .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+
+            e.revertChanges();
+            // Revert changes. Successful updates are iterated in reverse
+            inOrder.verify(writer2)
+                    .update(iid2, after2, before2, ctx);
+            inOrder.verify(writer1)
+                    .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+            verifyNoMoreInteractions(writer3);
+        }
+    }
+
+    @Test
+    public void testMultipleUpdatesOneFailingThenRevertWithFail() throws Exception {
+        final FlatWriterRegistry flatWriterRegistry =
+                new FlatWriterRegistry(
+                        ImmutableMap.of(DataObject1.IID, writer1, DataObject2.IID, writer2, DataObject3.IID, writer3));
+
+        // Writer1 always fails
+        doThrow(new RuntimeException()).when(writer3)
+                .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates = HashMultimap.create();
+        addUpdate(updates, DataObject1.class);
+        addUpdate(updates, DataObject2.class);
+        addUpdate(updates, DataObject3.class);
+
+        try {
+            flatWriterRegistry.update(new WriterRegistry.DataObjectUpdates(updates, ImmutableMultimap.of()), ctx);
+            fail("Bulk update should have failed on writer1");
+        } catch (WriterRegistry.BulkUpdateException e) {
+            // Writer1 always fails from now
+            doThrow(new RuntimeException()).when(writer1)
+                    .update(any(InstanceIdentifier.class), any(DataObject.class), any(DataObject.class), any(WriteContext.class));
+            try {
+                e.revertChanges();
+            } catch (WriterRegistry.Reverter.RevertFailedException e1) {
+                assertThat(e1.getNotRevertedChanges().size(), is(1));
+                assertThat(e1.getNotRevertedChanges(), hasItem(InstanceIdentifier.create(DataObject1.class)));
+            }
+        }
+    }
+
+    private <D extends DataObject> void addUpdate(final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates,
+                           final Class<D> type) throws Exception {
+        final InstanceIdentifier<D> iid = (InstanceIdentifier<D>) type.getDeclaredField("IID").get(null);
+        updates.put(iid, DataObjectUpdate.create(iid, mock(type), mock(type)));
+    }
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/SubtreeWriterTest.java b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/SubtreeWriterTest.java
new file mode 100644
index 000000000..627c69c92
--- /dev/null
+++ b/infra/translate-utils/src/test/java/io/fd/honeycomb/v3po/translate/util/write/registry/SubtreeWriterTest.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import static org.hamcrest.CoreMatchers.hasItem;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.when;
+
+import com.google.common.collect.Sets;
+import io.fd.honeycomb.v3po.translate.util.DataObjects;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import java.util.Collections;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class SubtreeWriterTest {
+
+    @Mock
+    Writer<DataObjects.DataObject4> writer;
+    @Mock
+    Writer<DataObjects.DataObject4.DataObject41> writer11;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        when(writer.getManagedDataObjectType()).thenReturn(DataObjects.DataObject4.IID);
+        when(writer11.getManagedDataObjectType()).thenReturn(DataObjects.DataObject4.DataObject41.IID);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testSubtreeWriterCreationFail() throws Exception {
+        // The subtree node identified by IID.c(DataObject.class) is not a child of writer.getManagedDataObjectType
+        SubtreeWriter.createForWriter(Collections.singleton(InstanceIdentifier.create(DataObject.class)), writer);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testSubtreeWriterCreationFailInvalidIid() throws Exception {
+        // The subtree node identified by IID.c(DataObject.class) is not a child of writer.getManagedDataObjectType
+        SubtreeWriter.createForWriter(Collections.singleton(DataObjects.DataObject4.IID), writer);
+    }
+
+    @Test
+    public void testSubtreeWriterCreation() throws Exception {
+        final SubtreeWriter<?> forWriter = (SubtreeWriter<?>) SubtreeWriter.createForWriter(Sets.newHashSet(
+                DataObjects.DataObject4.DataObject41.IID,
+                DataObjects.DataObject4.DataObject41.DataObject411.IID,
+                DataObjects.DataObject4.DataObject42.IID),
+                writer);
+
+        assertEquals(writer.getManagedDataObjectType(), forWriter.getManagedDataObjectType());
+        assertEquals(3, forWriter.getHandledChildTypes().size());
+    }
+
+    @Test
+    public void testSubtreeWriterHandledTypes() throws Exception {
+        final SubtreeWriter<?> forWriter = (SubtreeWriter<?>) SubtreeWriter.createForWriter(Sets.newHashSet(
+                DataObjects.DataObject4.DataObject41.DataObject411.IID),
+                writer);
+
+        assertEquals(writer.getManagedDataObjectType(), forWriter.getManagedDataObjectType());
+        assertEquals(1, forWriter.getHandledChildTypes().size());
+        assertThat(forWriter.getHandledChildTypes(), hasItem(DataObjects.DataObject4.DataObject41.DataObject411.IID));
+    }
+
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/resources/expected-persisted-output.txt b/infra/translate-utils/src/test/resources/expected-persisted-output.txt
new file mode 100644
index 000000000..f0f5902e2
--- /dev/null
+++ b/infra/translate-utils/src/test/resources/expected-persisted-output.txt
@@ -0,0 +1,8 @@
+{
+  "test-persistence:top-container": {
+    "string": "testing"
+  },
+  "test-persistence:top-container2": {
+    "string": "testing"
+  }
+}
\ No newline at end of file
diff --git a/infra/translate-utils/src/test/resources/test-persistence.yang b/infra/translate-utils/src/test/resources/test-persistence.yang
new file mode 100644
index 000000000..6dca9f2d5
--- /dev/null
+++ b/infra/translate-utils/src/test/resources/test-persistence.yang
@@ -0,0 +1,22 @@
+module test-persistence {
+    yang-version 1;
+    namespace "urn:opendaylight:params:xml:ns:yang:test:persistence";
+    prefix "tp";
+
+    revision "2015-01-05" {
+        description "Initial revision";
+    }
+
+    container top-container {
+        leaf string {
+            type string;
+        }
+    }
+
+    container top-container2 {
+        leaf string {
+            type string;
+        }
+    }
+
+}