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>

26 files changed, 1554 insertions, 0 deletions

diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/MappingContext.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/MappingContext.java
new file mode 100644
index 000000000..cff766e2a
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/MappingContext.java
@@ -0,0 +1,66 @@
+/*
+ * 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;
+
+import com.google.common.base.Optional;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Mapping context is persisted storage where mapping matadata are stored.
+ * A snapshot is created for each transaction to provide consistent view over context data.
+ * After a transaction is successfully finished, objects added to this context are propagated to backing storage.
+ */
+public interface MappingContext extends AutoCloseable {
+
+    /**
+     * Read any mapping context data
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Relevant mapping context data
+     */
+    <T extends DataObject> Optional<T> read(@Nonnull final InstanceIdentifier<T> currentId);
+
+    /**
+     * Delete the node at specified path.
+     *
+     * @param path Node path
+     */
+    void delete(InstanceIdentifier<?> path);
+
+    /**
+     * Merge the specified data with the currently-present data
+     * at specified path.
+     *
+     * @param path Node path
+     * @param data Data to be merged
+     */
+    <T extends DataObject> void merge(InstanceIdentifier<T> path, T data);
+
+    /**
+     * Replace the data at specified path with supplied data.
+     *
+     * @param path Node path
+     * @param data New node data
+     */
+    <T extends DataObject> void put(InstanceIdentifier<T> path, T data);
+
+    @Override
+    void close();
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModifiableSubtreeManagerRegistryBuilder.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModifiableSubtreeManagerRegistryBuilder.java
new file mode 100644
index 000000000..591a9e9bb
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModifiableSubtreeManagerRegistryBuilder.java
@@ -0,0 +1,77 @@
+/*
+ * 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;
+
+import java.util.Collection;
+import java.util.Set;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Registry builder where {@link SubtreeManager}s can be added with or without relationships between them.
+ * The relationships express what the order of execution should be.
+ */
+public interface ModifiableSubtreeManagerRegistryBuilder<S extends SubtreeManager<? extends DataObject>> {
+
+    /**
+     * Add a handler responsible for writing only a single complex node.
+     */
+    ModifiableSubtreeManagerRegistryBuilder<S> add(@Nonnull S handler);
+
+    /**
+     * Add a handler responsible for writing multiple complex nodes within a subtree its responsible for. Identifiers for
+     * subtree nodes handled by a single handler have to be relative from {@link DataObject} that represents subtree
+     * root.
+     */
+    ModifiableSubtreeManagerRegistryBuilder<S> subtreeAdd(@Nonnull Set<InstanceIdentifier<?>> handledChildren,
+                                                          @Nonnull S handler);
+
+    /**
+     * Add a handler and make sure it will be executed before handler identifier by relatedType is executed.
+     */
+    ModifiableSubtreeManagerRegistryBuilder<S> addBefore(@Nonnull S handler,
+                                                         @Nonnull InstanceIdentifier<?> relatedType);
+
+    ModifiableSubtreeManagerRegistryBuilder<S> addBefore(@Nonnull S handler,
+                                                         @Nonnull Collection<InstanceIdentifier<?>> relatedTypes);
+
+    ModifiableSubtreeManagerRegistryBuilder<S> subtreeAddBefore(@Nonnull Set<InstanceIdentifier<?>> handledChildren,
+                                                                @Nonnull S handler,
+                                                                @Nonnull InstanceIdentifier<?> relatedType);
+
+    ModifiableSubtreeManagerRegistryBuilder<S> subtreeAddBefore(@Nonnull Set<InstanceIdentifier<?>> handledChildren,
+                                                                @Nonnull S handler,
+                                                                @Nonnull Collection<InstanceIdentifier<?>> relatedTypes);
+
+    /**
+     * Add a handler and make sure it will be executed after handler identifier by relatedType is executed.
+     */
+    ModifiableSubtreeManagerRegistryBuilder<S> addAfter(@Nonnull S handler,
+                                                        @Nonnull InstanceIdentifier<?> relatedType);
+
+    ModifiableSubtreeManagerRegistryBuilder<S> addAfter(@Nonnull S handler,
+                                                        @Nonnull Collection<InstanceIdentifier<?>> relatedTypes);
+
+    ModifiableSubtreeManagerRegistryBuilder<S> subtreeAddAfter(@Nonnull Set<InstanceIdentifier<?>> handledChildren,
+                                                               @Nonnull S handler,
+                                                               @Nonnull InstanceIdentifier<?> relatedType);
+
+    ModifiableSubtreeManagerRegistryBuilder<S> subtreeAddAfter(@Nonnull Set<InstanceIdentifier<?>> handledChildren,
+                                                               @Nonnull S handler,
+                                                               @Nonnull Collection<InstanceIdentifier<?>> relatedTypes);
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModificationCache.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModificationCache.java
new file mode 100644
index 000000000..cb2d4fde0
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModificationCache.java
@@ -0,0 +1,49 @@
+/*
+ * 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;
+
+import com.google.common.collect.Maps;
+import java.util.HashMap;
+
+/**
+ * Simple context class that provides transient storage during one or more read/write operations
+ */
+public class ModificationCache implements AutoCloseable {
+
+    protected final HashMap<Object, Object> map;
+
+    public ModificationCache() {
+        map = Maps.newHashMap();
+    }
+
+    public Object get(final Object o) {
+        return map.get(o);
+    }
+
+    public boolean containsKey(final Object o) {
+        return map.containsKey(o);
+    }
+
+    public Object put(final Object o, final Object o2) {
+        return map.put(o, o2);
+    }
+
+    @Override
+    public void close() {
+        map.clear();
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModificationContext.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModificationContext.java
new file mode 100644
index 000000000..2c039aba0
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/ModificationContext.java
@@ -0,0 +1,44 @@
+/*
+ * 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;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Common context for both writes and reads
+ */
+public interface ModificationContext extends AutoCloseable {
+
+    /**
+     * Get key value transient storage for customizers. Is cleared for each new transaction.
+     *
+     * @return Context for customizers
+     */
+    @Nonnull
+    ModificationCache getModificationCache();
+
+    /**
+     * Get persistent storage for mapping context. This context survives a modification.
+     *
+     * @return Mapping context accessor
+     */
+    @Nonnull
+    MappingContext getMappingContext();
+
+    @Override
+    void close();
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManager.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManager.java
new file mode 100644
index 000000000..40842763d
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManager.java
@@ -0,0 +1,39 @@
+/*
+ * 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;
+
+import com.google.common.annotations.Beta;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Base identifiable subtree manager(reader, writer etc.)
+ *
+ * @param <D> Specific DataObject derived type, that is managed by this manager
+ */
+@Beta
+public interface SubtreeManager<D extends DataObject> {
+
+    /**
+     * Gets the type of node managed by this reader.
+     *
+     * @return Absolute instance identifier for managed type
+     */
+    @Nonnull
+    InstanceIdentifier<D> getManagedDataObjectType();
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManagerRegistryBuilder.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManagerRegistryBuilder.java
new file mode 100644
index 000000000..2434deddb
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManagerRegistryBuilder.java
@@ -0,0 +1,22 @@
+/*
+ * 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;
+
+public interface SubtreeManagerRegistryBuilder<R> {
+
+    R build();
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/TranslationException.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/TranslationException.java
new file mode 100644
index 000000000..ee0049977
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/TranslationException.java
@@ -0,0 +1,38 @@
+/*
+ * 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;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * Base exception for the translation layer
+ */
+@Beta
+public class TranslationException extends Exception {
+
+    public TranslationException(final String s) {
+        super(s);
+    }
+
+    public TranslationException(final String s, final Throwable cause) {
+        super(s, cause);
+    }
+
+    public TranslationException(final Throwable cause) {
+        super(cause);
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ListReader.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ListReader.java
new file mode 100644
index 000000000..13a7a55da
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ListReader.java
@@ -0,0 +1,66 @@
+/*
+ * 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.read;
+
+import com.google.common.annotations.Beta;
+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;
+
+/**
+ * List reader, allowing read of all the elements.
+ *
+ * @param <D> Specific DataObject derived type, that is handled by this reader
+ */
+@Beta
+public interface ListReader
+        <D extends DataObject & Identifiable<K>, K extends Identifier<D>, B extends Builder<D>> extends Reader<D, B> {
+
+    /**
+     * Read all elements in this list.
+     *
+     * @param id Wildcarded identifier of list managed by this reader
+     * @param ctx Read context
+     *
+     * @return List of all entries in this list
+     * @throws ReadFailedException if read was unsuccessful
+     */
+    @Nonnull
+    List<D> readList(@Nonnull final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx)
+            throws ReadFailedException;
+
+    /**
+     * Get IDs for all entries in the list.
+     */
+    List<K> getAllIds(@Nonnull InstanceIdentifier<D> id, @Nonnull ReadContext ctx)
+            throws ReadFailedException;
+
+    /**
+     * Merge read data into provided parent builder.
+     */
+    void merge(@Nonnull final Builder<? extends DataObject> builder, @Nonnull final List<D> readData);
+
+    @Override
+    default void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue) {
+        merge(parentBuilder, Collections.singletonList(readValue));
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadContext.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadContext.java
new file mode 100644
index 000000000..e3ddd420c
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadContext.java
@@ -0,0 +1,26 @@
+/*
+ * 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.read;
+
+import io.fd.honeycomb.v3po.translate.ModificationContext;
+
+/**
+ * Context providing information about current state of DataTree to readers
+ */
+public interface ReadContext extends ModificationContext {
+
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadFailedException.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadFailedException.java
new file mode 100644
index 000000000..51d4fcb5a
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadFailedException.java
@@ -0,0 +1,61 @@
+/*
+ * 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.read;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Thrown when a reader or customizer is not able to read data for the given id.
+ */
+public class ReadFailedException extends TranslationException {
+
+    private final InstanceIdentifier<?> failedId;
+
+    /**
+     * Constructs an ReadFailedException given data id and exception cause.
+     *
+     * @param failedId instance identifier of the data object that could not be read
+     * @param cause              the cause of read failure
+     */
+    public ReadFailedException(@Nonnull final InstanceIdentifier<?> failedId, final Throwable cause) {
+        super("Failed to read " + failedId, cause);
+        this.failedId = checkNotNull(failedId, "failedId should not be null");
+    }
+
+    /**
+     * Constructs an ReadFailedException given data id.
+     *
+     * @param failedId instance identifier of the data object that could not be read
+     */
+    public ReadFailedException(@Nonnull final InstanceIdentifier<?> failedId) {
+        this(failedId, null);
+    }
+
+    /**
+     * Returns id of the data object that could not be read.
+     *
+     * @return data object instance identifier
+     */
+    @Nonnull
+    public InstanceIdentifier<?> getFailedId() {
+        return failedId;
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/Reader.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/Reader.java
new file mode 100644
index 000000000..d0bf0dea1
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/Reader.java
@@ -0,0 +1,76 @@
+/*
+ * 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.read;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
+import io.fd.honeycomb.v3po.translate.SubtreeManager;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Base reader, responsible for translation between DataObjects and any other side.
+ *
+ * @param <D> Specific DataObject derived type, that is handled by this reader
+ */
+@Beta
+public interface Reader<D extends DataObject, B extends Builder<D>> extends SubtreeManager<D> {
+
+    // TODO make async
+
+    /**
+     * Reads data identified by id
+     *
+     * @param id unique identifier of subtree to be read. The subtree must contain managed data object type. For
+     *           identifiers pointing below node managed by this reader, it's reader's responsibility to filter out the
+     *           right node or to delegate the read to a child reader.
+     * @param ctx Read context
+     *
+     * @return List of DataObjects identified by id. If the ID points to a single node, it will be wrapped in a list
+     * @throws ReadFailedException if read was unsuccessful
+     */
+    @Nonnull
+    Optional<? extends DataObject> read(@Nonnull InstanceIdentifier<? extends DataObject> id,
+                                        @Nonnull ReadContext ctx) throws ReadFailedException;
+
+    /**
+     * Fill in current node's attributes
+     *
+     * @param id {@link InstanceIdentifier} pointing to current node. In case of keyed list, key must be present.
+     * @param builder Builder object for current node where the read attributes must be placed
+     * @param ctx Current read context
+     */
+    void readCurrentAttributes(@Nonnull InstanceIdentifier<D> id,
+                               @Nonnull B builder,
+                               @Nonnull ReadContext ctx) throws ReadFailedException;
+
+    /**
+     * Return new instance of a builder object for current node
+     *
+     * @param id {@link InstanceIdentifier} pointing to current node. In case of keyed list, key must be present.
+     * @return Builder object for current node type
+     */
+    @Nonnull
+    B getBuilder(InstanceIdentifier<D> id);
+
+    /**
+     * Merge read data into provided parent builder.
+     */
+    void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue);
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReaderFactory.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReaderFactory.java
new file mode 100644
index 000000000..61472f8d2
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReaderFactory.java
@@ -0,0 +1,38 @@
+/*
+ * 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.read;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.read.registry.ModifiableReaderRegistryBuilder;
+import javax.annotation.Nonnull;
+
+/**
+ * Factory producing readers for {@link ModifiableReaderRegistryBuilder}.
+ */
+@Beta
+public interface ReaderFactory extends AutoCloseable {
+
+    /**
+     * Initialize 1 or more readers and add them to provided registry.
+     */
+    void init(@Nonnull ModifiableReaderRegistryBuilder registry);
+
+    @Override
+    default void close() {
+        // NOOP TODO allow unregister
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ModifiableReaderRegistryBuilder.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ModifiableReaderRegistryBuilder.java
new file mode 100644
index 000000000..c2eba4f72
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ModifiableReaderRegistryBuilder.java
@@ -0,0 +1,41 @@
+/*
+ * 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.read.registry;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.ModifiableSubtreeManagerRegistryBuilder;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Mutable registry that allows adding new readers.
+ */
+@Beta
+public interface ModifiableReaderRegistryBuilder
+        extends ModifiableSubtreeManagerRegistryBuilder<Reader<? extends DataObject, ? extends Builder<?>>> {
+
+    // TODO we should be able to add structural/reflexive readers automatically in the registry builder, we just need builder class
+    // We would need generated class loading strategy instance and then load builder classes relying on naming + package conventions of Binding spec
+    /**
+     * Add a structural reader that performs no read operation on its own, just fills in the hierarchy.
+     */
+    <D extends DataObject> void addStructuralReader(@Nonnull InstanceIdentifier<D> id,
+                                                    @Nonnull Class<? extends Builder<D>> builderType);
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ReaderRegistry.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ReaderRegistry.java
new file mode 100644
index 000000000..308ec238d
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ReaderRegistry.java
@@ -0,0 +1,62 @@
+/*
+ * 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.read.registry;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
+import com.google.common.collect.Multimap;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Simple delegating reader suitable as a holder for all other root readers, providing readAll feature.
+ */
+@Beta
+public interface ReaderRegistry {
+
+    /**
+     * Performs read on all registered root readers and merges the results into a Multimap. Keys represent identifiers
+     * for root DataObjects from the data tree modeled by YANG.
+     *
+     * @param ctx Read context
+     *
+     * @return multimap that preserves deterministic iteration order across non-distinct key values
+     * @throws ReadFailedException if read was unsuccessful
+     */
+    @Nonnull
+    Multimap<InstanceIdentifier<? extends DataObject>, ? extends DataObject> readAll(@Nonnull final ReadContext ctx)
+            throws ReadFailedException;
+
+    /**
+     * Reads data identified by id.
+     *
+     * @param id unique identifier of subtree to be read. The subtree must contain managed data object type. For
+     *           identifiers pointing below node managed by this reader, it's reader's responsibility to filter out the
+     *           right node or to delegate the read to a child reader.
+     * @param ctx Read context
+     *
+     * @return List of DataObjects identified by id. If the ID points to a single node, it will be wrapped in a list
+     * @throws ReadFailedException if read was unsuccessful
+     */
+    @Nonnull
+    Optional<? extends DataObject> read(@Nonnull InstanceIdentifier<? extends DataObject> id,
+                                        @Nonnull ReadContext ctx)
+            throws ReadFailedException;
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ReaderRegistryBuilder.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ReaderRegistryBuilder.java
new file mode 100644
index 000000000..ff95d6248
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/registry/ReaderRegistryBuilder.java
@@ -0,0 +1,27 @@
+/*
+ * 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.read.registry;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.SubtreeManagerRegistryBuilder;
+
+/**
+ * Builder for reader registries.
+ */
+@Beta
+public interface ReaderRegistryBuilder extends SubtreeManagerRegistryBuilder<ReaderRegistry> {
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/DataObjectUpdate.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/DataObjectUpdate.java
new file mode 100644
index 000000000..0d891ecba
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/DataObjectUpdate.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.write;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Simple wrapper for BA id + data before and after state. Does not allow both before and after to be null.
+ */
+public class DataObjectUpdate {
+
+    @Nonnull
+    private final InstanceIdentifier<?> id;
+    @Nullable
+    private final DataObject dataBefore;
+    @Nullable
+    private final DataObject dataAfter;
+
+    private DataObjectUpdate(@Nonnull final InstanceIdentifier<?> id,
+                             @Nullable final DataObject dataBefore,
+                             @Nullable final DataObject dataAfter) {
+        this.id = checkNotNull(id);
+        this.dataAfter = dataAfter;
+        this.dataBefore = dataBefore;
+    }
+
+    public DataObject getDataBefore() {
+        return dataBefore;
+    }
+
+    public DataObject getDataAfter() {
+        return dataAfter;
+    }
+
+    public InstanceIdentifier<?> getId() {
+        return id;
+    }
+
+    public static DataObjectUpdate create(@Nonnull final InstanceIdentifier<?> id,
+                                    @Nullable final DataObject dataBefore,
+                                    @Nullable final DataObject dataAfter) {
+        checkArgument(!(dataBefore == null && dataAfter == null), "Both before and after data are null");
+        if (dataBefore != null) {
+            checkArgument(id.getTargetType().isAssignableFrom(dataBefore.getClass()));
+        }
+        if (dataAfter != null) {
+            checkArgument(id.getTargetType().isAssignableFrom(dataAfter.getClass()));
+        }
+
+        return dataAfter == null
+                ? new DataObjectDelete(id, dataBefore)
+                : new DataObjectUpdate(id, dataBefore, dataAfter);
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        final DataObjectUpdate that = (DataObjectUpdate) o;
+
+        return id.equals(that.id);
+
+    }
+
+    @Override
+    public int hashCode() {
+        return id.hashCode();
+    }
+
+    @Override
+    public String toString() {
+        return "DataObjectUpdate{" + "id=" + id
+                + ", dataBefore=" + dataBefore
+                + ", dataAfter=" + dataAfter
+                + '}';
+    }
+
+    public DataObjectUpdate reverse() {
+        return DataObjectUpdate.create(id, dataAfter, dataBefore);
+    }
+
+    public static class DataObjectDelete extends DataObjectUpdate {
+
+        private DataObjectDelete(@Nonnull final InstanceIdentifier<?> id,
+                                 @Nullable final DataObject dataBefore) {
+            super(id, dataBefore, null);
+        }
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/ListWriter.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/ListWriter.java
new file mode 100644
index 000000000..f29289d2d
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/ListWriter.java
@@ -0,0 +1,33 @@
+/*
+ * 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.write;
+
+import com.google.common.annotations.Beta;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.Identifiable;
+import org.opendaylight.yangtools.yang.binding.Identifier;
+
+/**
+ * List writer, responsible for translation between a list of DataObjects and any other side.
+ * Handling all update operations(create, update, delete)
+ *
+ * @param <D> Specific DataObject derived type, that is handled by this writer
+ * @param <K> Identifier/key for D
+ */
+@Beta
+public interface ListWriter<D extends DataObject & Identifiable<K>, K extends Identifier<D>> extends Writer<D> {
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteContext.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteContext.java
new file mode 100644
index 000000000..3433b3f34
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteContext.java
@@ -0,0 +1,50 @@
+/*
+ * 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.write;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
+import io.fd.honeycomb.v3po.translate.ModificationContext;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Context providing information about current state of DataTree to writers
+ */
+@Beta
+public interface WriteContext extends ModificationContext {
+
+    /**
+     * Read any config data object before current modification was applied
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data before the modification was applied
+     */
+    <T extends DataObject> Optional<T> readBefore(@Nonnull final InstanceIdentifier<T> currentId);
+
+    /**
+     * Read any config data object from current modification
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data from the modification
+     */
+    <T extends DataObject> Optional<T> readAfter(@Nonnull final InstanceIdentifier<T> currentId);
+
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteFailedException.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteFailedException.java
new file mode 100644
index 000000000..10a664fcf
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteFailedException.java
@@ -0,0 +1,166 @@
+/*
+ * 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.write;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Thrown when a writer or customizer is not able to write/update/delete data .
+ */
+public class WriteFailedException extends TranslationException {
+
+    private final InstanceIdentifier<?> failedId;
+
+    /**
+     * Constructs an WriteFailedException given data id, exception detail message and exception cause.
+     *
+     * @param failedId instance identifier of the data object that could not be read
+     * @param cause    the cause of read failure
+     * @param message  the exception detail message
+     */
+    public WriteFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                @Nonnull final String message,
+                                @Nonnull final Throwable cause) {
+        super(message, cause);
+        this.failedId = checkNotNull(failedId, "failedId should not be null");
+    }
+
+    /**
+     * Constructs an WriteFailedException given data id.
+     *
+     * @param failedId instance identifier of the data object that could not be written
+     */
+    public WriteFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                @Nonnull final String message) {
+        super(message);
+        this.failedId = checkNotNull(failedId, "failedId should not be null");
+    }
+
+    /**
+     * Constructs an WriteFailedException given data id and exception cause.
+     *
+     * @param failedId instance identifier of the data object that could not be read
+     * @param cause    the cause of read failure
+     */
+    public WriteFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                @Nonnull final Throwable cause) {
+        super(cause);
+        this.failedId = checkNotNull(failedId, "failedId should not be null");
+    }
+
+    /**
+     * Returns id of the data object that could not be written.
+     *
+     * @return data object instance identifier
+     */
+    @Nonnull
+    public InstanceIdentifier<?> getFailedId() {
+        return failedId;
+    }
+
+
+    /**
+     * Delete specific write failed exception
+     */
+    public static class DeleteFailedException extends WriteFailedException {
+
+        public DeleteFailedException(@Nonnull final InstanceIdentifier<?> failedId, @Nonnull final Throwable cause) {
+            super(failedId, getMsg(failedId), cause);
+        }
+
+        private static String getMsg(@Nonnull final InstanceIdentifier<?> failedId) {
+            return String.format("Failed to delete data at: %s", failedId);
+        }
+
+        public DeleteFailedException(@Nonnull final InstanceIdentifier<?> failedId) {
+            super(failedId, getMsg(failedId));
+        }
+    }
+
+    /**
+     * Create specific write failed exception
+     */
+    public static class CreateFailedException extends WriteFailedException {
+
+        private final DataObject data;
+
+        public CreateFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                     @Nonnull final DataObject data,
+                                     @Nonnull final Throwable cause) {
+            super(failedId, getMsg(failedId, data), cause);
+            this.data = checkNotNull(data, "data");
+        }
+
+        private static String getMsg(final @Nonnull InstanceIdentifier<?> failedId, final DataObject data) {
+            return String.format("Failed to create data: %s at: %s", data, failedId);
+        }
+
+        public CreateFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                     @Nonnull final DataObject data) {
+            super(failedId, getMsg(failedId, data));
+            this.data = checkNotNull(data, "data");
+        }
+
+        public DataObject getData() {
+            return data;
+        }
+    }
+
+    /**
+     * Update specific write failed exception
+     */
+    public static class UpdateFailedException extends WriteFailedException {
+
+        private final DataObject dataBefore;
+        private final DataObject dataAfter;
+
+        public UpdateFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                     @Nonnull final DataObject dataBefore,
+                                     @Nonnull final DataObject dataAfter,
+                                     @Nonnull final Throwable cause) {
+            super(failedId, getMsg(failedId, dataBefore, dataAfter), cause);
+            this.dataBefore = checkNotNull(dataBefore, "dataBefore");
+            this.dataAfter = checkNotNull(dataAfter, "dataAfter");
+        }
+
+        private static String getMsg(final @Nonnull InstanceIdentifier<?> failedId, final DataObject dataBefore,
+                                     final DataObject dataAfter) {
+            return String.format("Failed to update data from: %s to: %s, at: %s", dataBefore, dataAfter, failedId);
+        }
+
+        public UpdateFailedException(@Nonnull final InstanceIdentifier<?> failedId,
+                                     @Nonnull final DataObject dataBefore,
+                                     @Nonnull final DataObject dataAfter) {
+            super(failedId, getMsg(failedId, dataBefore, dataAfter));
+            this.dataBefore = checkNotNull(dataBefore, "dataBefore");
+            this.dataAfter = checkNotNull(dataAfter, "dataAfter");
+        }
+
+        public DataObject getDataBefore() {
+            return dataBefore;
+        }
+
+        public DataObject getDataAfter() {
+            return dataAfter;
+        }
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/Writer.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/Writer.java
new file mode 100644
index 000000000..77abe341c
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/Writer.java
@@ -0,0 +1,48 @@
+/*
+ * 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.write;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.SubtreeManager;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Base writer, responsible for translation between DataObjects and any other side. Handling all update operations(create,
+ * update, delete)
+ *
+ * @param <D> Specific DataObject derived type, that is handled by this writer
+ */
+@Beta
+public interface Writer<D extends DataObject> extends SubtreeManager<D> {
+
+    /**
+     * Handle update operation. U from CRUD.
+     *
+     * @param id         Identifier of data being written
+     * @param dataBefore Old data
+     * @param dataAfter  New, updated data
+     * @param ctx        Write context enabling writer to get information about candidate data as well as current data
+     * @throws WriteFailedException if update failed
+     */
+    void update(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                @Nullable final DataObject dataBefore,
+                @Nullable final DataObject dataAfter,
+                @Nonnull final WriteContext ctx) throws WriteFailedException;
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriterFactory.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriterFactory.java
new file mode 100644
index 000000000..ffc76a0e4
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriterFactory.java
@@ -0,0 +1,38 @@
+/*
+ * 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.write;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.write.registry.ModifiableWriterRegistryBuilder;
+import javax.annotation.Nonnull;
+
+/**
+ * Factory producing writers for {@link ModifiableWriterRegistryBuilder}.
+ */
+@Beta
+public interface WriterFactory extends AutoCloseable {
+
+    /**
+     * Initialize 1 or more writers and add them to provided registry.
+     */
+    void init(@Nonnull ModifiableWriterRegistryBuilder registry);
+
+    @Override
+    default void close() {
+        // NOOP TODO allow unregister
+    }
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/ModifiableWriterRegistryBuilder.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/ModifiableWriterRegistryBuilder.java
new file mode 100644
index 000000000..8670a5059
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/ModifiableWriterRegistryBuilder.java
@@ -0,0 +1,31 @@
+/*
+ * 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.write.registry;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.ModifiableSubtreeManagerRegistryBuilder;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+
+/**
+ * Mutable registry that allows adding new writers.
+ */
+@Beta
+public interface ModifiableWriterRegistryBuilder
+        extends ModifiableSubtreeManagerRegistryBuilder<Writer<? extends DataObject>> {
+
+}
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/WriterRegistry.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/WriterRegistry.java
new file mode 100644
index 000000000..439a85410
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/WriterRegistry.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.write.registry;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.annotations.Beta;
+import com.google.common.collect.ImmutableSet;
+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.write.DataObjectUpdate;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import java.util.Set;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Special {@link Writer} capable of performing bulk updates.
+ */
+@Beta
+public interface WriterRegistry {
+
+    /**
+     * Performs bulk update.
+     *
+     * @throws BulkUpdateException in case bulk update fails
+     * @throws TranslationException in case some other error occurs while processing update request
+     */
+    void update(@Nonnull DataObjectUpdates updates,
+                @Nonnull WriteContext ctx) throws TranslationException;
+
+    /**
+     * Simple DTO containing updates for {@link WriterRegistry}. Currently only deletes and updates (create + update)
+     * are distinguished.
+     */
+    @Beta
+    final class DataObjectUpdates {
+
+        private final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates;
+        private final Multimap<InstanceIdentifier<?>, DataObjectUpdate.DataObjectDelete> deletes;
+
+        /**
+         * Create new instance.
+         *
+         * @param updates All updates indexed by their unkeyed {@link InstanceIdentifier}
+         * @param deletes All deletes indexed by their unkeyed {@link InstanceIdentifier}
+         */
+        public DataObjectUpdates(@Nonnull final Multimap<InstanceIdentifier<?>, DataObjectUpdate> updates,
+                                 @Nonnull final Multimap<InstanceIdentifier<?>, DataObjectUpdate.DataObjectDelete> deletes) {
+            this.deletes = deletes;
+            this.updates = updates;
+        }
+
+        public Multimap<InstanceIdentifier<?>, DataObjectUpdate> getUpdates() {
+            return updates;
+        }
+
+        public Multimap<InstanceIdentifier<?>, DataObjectUpdate.DataObjectDelete> getDeletes() {
+            return deletes;
+        }
+
+        public boolean isEmpty() {
+            return updates.isEmpty() && deletes.isEmpty();
+        }
+
+        @Override
+        public String toString() {
+            return "DataObjectUpdates{" + "updates=" + updates + ", deletes=" + deletes + '}';
+        }
+
+        /**
+         * Get a {@link Set} containing all update types from both updates as well as deletes.
+         */
+        public Set<InstanceIdentifier<?>> getTypeIntersection() {
+            return Sets.union(deletes.keySet(), updates.keySet());
+        }
+
+        /**
+         * Check whether there is only a single type of data object to be updated.
+         *
+         * @return true if there is only a single type of updates (update + delete)
+         */
+        public boolean containsOnlySingleType() {
+            return getTypeIntersection().size() == 1;
+        }
+
+        @Override
+        public boolean equals(final Object other) {
+            if (this == other) {
+                return true;
+            }
+            if (other == null || getClass() != other.getClass()) {
+                return false;
+            }
+
+            final DataObjectUpdates that = (DataObjectUpdates) other;
+
+            if (!updates.equals(that.updates)) {
+                return false;
+            }
+            return deletes.equals(that.deletes);
+
+        }
+
+        @Override
+        public int hashCode() {
+            int result = updates.hashCode();
+            result = 31 * result + deletes.hashCode();
+            return result;
+        }
+
+    }
+
+    /**
+     * Thrown when bulk update failed.
+     */
+    @Beta
+    class BulkUpdateException extends TranslationException {
+
+        private final Reverter reverter;
+        private final Set<InstanceIdentifier<?>> failedIds;
+
+        /**
+         * Constructs an BulkUpdateException.
+         * @param failedIds instance identifiers of the data objects that were not processed during bulk update.
+         * @param cause the cause of bulk update failure
+         */
+        public BulkUpdateException(@Nonnull final Set<InstanceIdentifier<?>> failedIds,
+                                   @Nonnull final Reverter reverter,
+                                   @Nonnull final Throwable cause) {
+            super("Bulk update failed at: " + failedIds, cause);
+            this.failedIds = failedIds;
+            this.reverter = checkNotNull(reverter, "reverter should not be null");
+        }
+
+        /**
+         * Reverts changes that were successfully applied during bulk update before failure occurred.
+         *
+         * @throws Reverter.RevertFailedException if revert fails
+         */
+        public void revertChanges() throws Reverter.RevertFailedException {
+            reverter.revert();
+        }
+
+        public Set<InstanceIdentifier<?>> getFailedIds() {
+            return failedIds;
+        }
+    }
+
+    /**
+     * Abstraction over revert mechanism in case of a bulk update failure.
+     */
+    @Beta
+    interface Reverter {
+
+        /**
+         * Reverts changes that were successfully applied during bulk update before failure occurred. Changes are
+         * reverted in reverse order they were applied.
+         *
+         * @throws RevertFailedException if not all of applied changes were successfully reverted
+         */
+        void revert() throws RevertFailedException;
+
+        /**
+         * Thrown when some of the changes applied during bulk update were not reverted.
+         */
+        @Beta
+        class RevertFailedException extends TranslationException {
+
+            // TODO change to list of VppDataModifications to make debugging easier
+            private final Set<InstanceIdentifier<?>> notRevertedChanges;
+
+            /**
+             * Constructs a RevertFailedException with the list of changes that were not reverted.
+             *
+             * @param notRevertedChanges list of changes that were not reverted
+             * @param cause              the cause of revert failure
+             */
+            public RevertFailedException(@Nonnull final Set<InstanceIdentifier<?>> notRevertedChanges,
+                                         final Throwable cause) {
+                super(cause);
+                checkNotNull(notRevertedChanges, "notRevertedChanges should not be null");
+                this.notRevertedChanges = ImmutableSet.copyOf(notRevertedChanges);
+            }
+
+            /**
+             * Returns the list of changes that were not reverted.
+             *
+             * @return list of changes that were not reverted
+             */
+            @Nonnull
+            public Set<InstanceIdentifier<?>> getNotRevertedChanges() {
+                return notRevertedChanges;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/WriterRegistryBuilder.java b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/WriterRegistryBuilder.java
new file mode 100644
index 000000000..3f0289ece
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/registry/WriterRegistryBuilder.java
@@ -0,0 +1,27 @@
+/*
+ * 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.write.registry;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.SubtreeManagerRegistryBuilder;
+
+/**
+ * Builder for writer registries.
+ */
+@Beta
+public interface WriterRegistryBuilder extends SubtreeManagerRegistryBuilder<WriterRegistry> {
+}
diff --git a/infra/translate-api/src/main/yang/translate-api.yang b/infra/translate-api/src/main/yang/translate-api.yang
new file mode 100644
index 000000000..796632dd2
--- /dev/null
+++ b/infra/translate-api/src/main/yang/translate-api.yang
@@ -0,0 +1,52 @@
+module translate-api {
+    yang-version 1;
+    namespace "urn:honeycomb:params:xml:ns:yang:translate:api";
+    prefix "tapi";
+
+    import config { prefix config; revision-date 2013-04-05; }
+
+    description
+        "This module contains the base YANG definitions for
+         readers/writers plugged into a honeycomb";
+
+    revision "2016-04-06" {
+        description
+            "Initial revision.";
+    }
+
+    identity honeycomb-reader-factory {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.read.ReaderFactory;
+    }
+
+    identity honeycomb-reader-registry {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.read.registry.ModifiableReaderRegistryBuilder;
+    }
+
+    identity honeycomb-reader-registry-builder {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.read.registry.ReaderRegistryBuilder;
+    }
+
+    identity honeycomb-writer-factory {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.write.WriterFactory;
+    }
+
+    identity honeycomb-writer-registry {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.write.registry.ModifiableWriterRegistryBuilder;
+    }
+
+    identity honeycomb-writer-registry-builder {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.write.registry.WriterRegistryBuilder;
+    }
+
+    identity honeycomb-mapping-context {
+        base "config:service-type";
+        config:java-class io.fd.honeycomb.v3po.translate.MappingContext;
+    }
+
+}
\ No newline at end of file
diff --git a/infra/translate-api/src/test/java/io/fd/honeycomb/v3po/translate/ReadFailedExceptionTest.java b/infra/translate-api/src/test/java/io/fd/honeycomb/v3po/translate/ReadFailedExceptionTest.java
new file mode 100644
index 000000000..71c0afbd3
--- /dev/null
+++ b/infra/translate-api/src/test/java/io/fd/honeycomb/v3po/translate/ReadFailedExceptionTest.java
@@ -0,0 +1,50 @@
+/*
+ * 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;
+
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import org.junit.Assert;
+import org.junit.Test;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+public class ReadFailedExceptionTest {
+
+    @Test
+    public void testInstantiation() {
+        final InstanceIdentifier<DataObject> id = InstanceIdentifier.create(DataObject.class);
+        ReadFailedException e = new ReadFailedException(id);
+        Assert.assertEquals(id, e.getFailedId());
+        Assert.assertNull(e.getCause());
+        Assert.assertTrue(e.getMessage().contains(id.toString()));
+    }
+
+    @Test
+    public void testInstantiationWithCause() {
+        final InstanceIdentifier<DataObject> id = InstanceIdentifier.create(DataObject.class);
+        final RuntimeException cause = new RuntimeException();
+        ReadFailedException e = new ReadFailedException(id, cause);
+        Assert.assertEquals(id, e.getFailedId());
+        Assert.assertEquals(cause, e.getCause());
+        Assert.assertTrue(e.getMessage().contains(id.toString()));
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void testInstantiationFailed() {
+        new ReadFailedException(null);
+    }
+}
\ No newline at end of file