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>

9 files changed, 1624 insertions, 0 deletions

diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/DataBroker.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/DataBroker.java
new file mode 100644
index 000000000..c418ed332
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/DataBroker.java
@@ -0,0 +1,198 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import io.fd.honeycomb.v3po.data.DataModification;
+import io.fd.honeycomb.v3po.data.ModifiableDataManager;
+import io.fd.honeycomb.v3po.data.ReadableDataManager;
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.Collections;
+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.TransactionChainListener;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataBroker;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataBrokerExtension;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataChangeListener;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadOnlyTransaction;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadWriteTransaction;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
+import org.opendaylight.controller.md.sal.dom.api.DOMTransactionChain;
+import org.opendaylight.yangtools.concepts.ListenerRegistration;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Data Broker which provides data transaction functionality for YANG capable data provider using {@link NormalizedNode}
+ * data format.
+ */
+public class DataBroker implements DOMDataBroker, Closeable {
+
+    private static final Logger LOG = LoggerFactory.getLogger(DataBroker.class);
+    private final TransactionFactory transactionFactory;
+
+    /**
+     * Creates DataBroker instance.
+     *
+     * @param transactionFactory transaction producing factory
+     */
+    public DataBroker(final TransactionFactory transactionFactory) {
+        this.transactionFactory = transactionFactory;
+    }
+
+    @Override
+    public DOMDataReadOnlyTransaction newReadOnlyTransaction() {
+        LOG.trace("DataBroker({}).newReadOnlyTransaction()", this);
+        return transactionFactory.newReadOnlyTransaction();
+    }
+
+    @Override
+    public DOMDataReadWriteTransaction newReadWriteTransaction() {
+        LOG.trace("DataBroker({}).newReadWriteTransaction()", this);
+        return transactionFactory.newReadWriteTransaction();
+    }
+
+    @Override
+    public DOMDataWriteTransaction newWriteOnlyTransaction() {
+        LOG.trace("DataBroker({}).newWriteOnlyTransaction()", this);
+        return transactionFactory.newWriteOnlyTransaction();
+    }
+
+    @Override
+    public ListenerRegistration<DOMDataChangeListener> registerDataChangeListener(final LogicalDatastoreType store,
+                                                                                  final YangInstanceIdentifier path,
+                                                                                  final DOMDataChangeListener listener,
+                                                                                  final DataChangeScope triggeringScope) {
+        throw new UnsupportedOperationException("Not supported");
+    }
+
+    @Override
+    public DOMTransactionChain createTransactionChain(final TransactionChainListener listener) {
+        throw new UnsupportedOperationException("Not supported");
+    }
+
+    @Nonnull
+    @Override
+    public Map<Class<? extends DOMDataBrokerExtension>, DOMDataBrokerExtension> getSupportedExtensions() {
+        return Collections.emptyMap();
+    }
+
+    /**
+     * Create DataBroker for a modifiable config DT, but only readable Operational
+     */
+    @Nonnull
+    public static DataBroker create(@Nonnull final ModifiableDataManager configDataTree,
+                             @Nonnull final ReadableDataManager operationalDataTree) {
+        checkNotNull(operationalDataTree, "operationalDataTree should not be null");
+        checkNotNull(configDataTree, "configDataTree should not be null");
+        return new DataBroker(new MainPipelineTxFactory(configDataTree, operationalDataTree));
+    }
+
+    /**
+     * Create DataBroker for modifiable operational DT, but no support for config
+     */
+    @Nonnull
+    public static DataBroker create(@Nonnull final ModifiableDataManager operationalDataTree) {
+        checkNotNull(operationalDataTree, "operationalDataTree should not be null");
+        return new DataBroker(new ContextPipelineTxFactory(operationalDataTree));
+    }
+
+    @Override
+    public void close() throws IOException {
+        // NOOP
+    }
+
+    /**
+     * Transaction provider factory to be used by {@link DataBroker}
+     */
+    public interface TransactionFactory {
+
+        DOMDataReadOnlyTransaction newReadOnlyTransaction();
+
+        DOMDataReadWriteTransaction newReadWriteTransaction();
+
+        DOMDataWriteTransaction newWriteOnlyTransaction();
+    }
+
+    /**
+     * Transaction factory specific for Honeycomb's main pipeline (config: read+write, operational: read-only)
+     */
+    private static class MainPipelineTxFactory implements TransactionFactory {
+        private final ReadableDataManager operationalDataTree;
+        private final ModifiableDataManager configDataTree;
+
+        MainPipelineTxFactory(@Nonnull final ModifiableDataManager configDataTree,
+                              @Nonnull final ReadableDataManager operationalDataTree) {
+            this.operationalDataTree = operationalDataTree;
+            this.configDataTree = configDataTree;
+        }
+
+        @Override
+        public DOMDataReadOnlyTransaction newReadOnlyTransaction() {
+            return ReadOnlyTransaction.create(configDataTree.newModification(), operationalDataTree);
+        }
+
+        @Override
+        public DOMDataReadWriteTransaction newReadWriteTransaction() {
+            final DataModification configModification = configDataTree.newModification();
+            return new ReadWriteTransaction(
+                ReadOnlyTransaction.create(configModification, operationalDataTree),
+                WriteTransaction.createConfigOnly(configModification));
+        }
+
+        @Override
+        public DOMDataWriteTransaction newWriteOnlyTransaction() {
+            return WriteTransaction.createConfigOnly(configDataTree.newModification());
+        }
+    }
+
+    /**
+     * Transaction factory specific for Honeycomb's context pipeline (config: none, operational: read+write)
+     */
+    private static class ContextPipelineTxFactory implements TransactionFactory {
+        private final ModifiableDataManager operationalDataTree;
+
+        ContextPipelineTxFactory(@Nonnull final ModifiableDataManager operationalDataTree) {
+            this.operationalDataTree = operationalDataTree;
+        }
+
+        @Override
+        public DOMDataReadOnlyTransaction newReadOnlyTransaction() {
+            return ReadOnlyTransaction.createOperationalOnly(operationalDataTree);
+        }
+
+        @Override
+        public DOMDataReadWriteTransaction newReadWriteTransaction() {
+            final DataModification dataModification = operationalDataTree.newModification();
+            return new ReadWriteTransaction(
+                ReadOnlyTransaction.createOperationalOnly(dataModification),
+                WriteTransaction.createOperationalOnly(dataModification));
+        }
+
+        @Override
+        public DOMDataWriteTransaction newWriteOnlyTransaction() {
+            return WriteTransaction.createOperationalOnly(operationalDataTree.newModification());
+        }
+    }
+}
+
+
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModifiableDataTreeDelegator.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModifiableDataTreeDelegator.java
new file mode 100644
index 000000000..2c2581ec0
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModifiableDataTreeDelegator.java
@@ -0,0 +1,236 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.util.concurrent.Futures.immediateCheckedFuture;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimap;
+import com.google.common.util.concurrent.CheckedFuture;
+import io.fd.honeycomb.v3po.data.DataModification;
+import io.fd.honeycomb.v3po.data.ReadableDataManager;
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.util.TransactionMappingContext;
+import io.fd.honeycomb.v3po.translate.util.write.TransactionWriteContext;
+import io.fd.honeycomb.v3po.translate.write.DataObjectUpdate;
+import io.fd.honeycomb.v3po.translate.write.WriteContext;
+import io.fd.honeycomb.v3po.translate.write.registry.WriterRegistry;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+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;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Extension of {@link ModifiableDataTreeManager} that propagates data changes to underlying writer layer before they
+ * are fully committed in the backing data tree. Data changes are propagated in BA format.
+ */
+public final class ModifiableDataTreeDelegator extends ModifiableDataTreeManager {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ModifiableDataTreeDelegator.class);
+    private static final ReadableDataManager EMPTY_OPERATIONAL = p -> immediateCheckedFuture(Optional.absent());
+
+    private final WriterRegistry writerRegistry;
+    private final org.opendaylight.controller.md.sal.binding.api.DataBroker contextBroker;
+    // TODO what to use instead of deprecated BindingNormalizedNodeSerializer ?
+    private final BindingNormalizedNodeSerializer serializer;
+
+    /**
+     * Creates configuration data tree instance.
+     *  @param serializer     service for serialization between Java Binding Data representation and NormalizedNode
+     *                       representation.
+     * @param dataTree       data tree for configuration data representation
+     * @param writerRegistry service for translation between Java Binding Data and data provider, capable of performing
+     * @param contextBroker BA broker providing full access to mapping context data
+     */
+    public ModifiableDataTreeDelegator(@Nonnull final BindingNormalizedNodeSerializer serializer,
+                                       @Nonnull final DataTree dataTree,
+                                       @Nonnull final WriterRegistry writerRegistry,
+                                       @Nonnull final org.opendaylight.controller.md.sal.binding.api.DataBroker contextBroker) {
+        super(dataTree);
+        this.contextBroker = checkNotNull(contextBroker, "contextBroker should not be null");
+        this.serializer = checkNotNull(serializer, "serializer should not be null");
+        this.writerRegistry = checkNotNull(writerRegistry, "writerRegistry should not be null");
+    }
+
+    @Override
+    public DataModification newModification() {
+        return new ConfigSnapshot(super.newModification());
+    }
+
+    private final class ConfigSnapshot extends ModifiableDataTreeManager.ConfigSnapshot {
+
+        private final DataModification untouchedModification;
+
+        /**
+         * @param untouchedModification DataModification captured while this modification/snapshot was created.
+         *                              To be used later while invoking writers to provide them with before state
+         *                              (state without current modifications).
+         *                              It must be captured as close as possible to when current modification started.
+         */
+        ConfigSnapshot(final DataModification untouchedModification) {
+            this.untouchedModification = untouchedModification;
+        }
+
+        /**
+         * Pass the changes to underlying writer layer.
+         * Transform from BI to BA.
+         * Revert(Write data before to subtrees that have been successfully modified before failure) in case of failure.
+         */
+        @Override
+        protected void processCandidate(final DataTreeCandidate candidate)
+            throws TranslationException {
+
+            final DataTreeCandidateNode rootNode = candidate.getRootNode();
+            final YangInstanceIdentifier rootPath = candidate.getRootPath();
+            LOG.trace("ConfigDataTree.modify() rootPath={}, rootNode={}, dataBefore={}, dataAfter={}",
+                rootPath, rootNode, rootNode.getDataBefore(), rootNode.getDataAfter());
+
+            final ModificationDiff modificationDiff =
+                    ModificationDiff.recursivelyFromCandidate(YangInstanceIdentifier.EMPTY, rootNode);
+            LOG.debug("ConfigDataTree.modify() diff: {}", modificationDiff);
+
+            // Distinguish between updates (create + update) and deletes
+            final WriterRegistry.DataObjectUpdates baUpdates = toBindingAware(modificationDiff.getUpdates());
+            LOG.debug("ConfigDataTree.modify() extracted updates={}", baUpdates);
+
+            try (final WriteContext ctx = getTransactionWriteContext()) {
+                writerRegistry.update(baUpdates, ctx);
+
+                final CheckedFuture<Void, TransactionCommitFailedException> contextUpdateResult =
+                    ((TransactionMappingContext) ctx.getMappingContext()).submit();
+                // Blocking on context data update
+                contextUpdateResult.checkedGet();
+
+            } catch (WriterRegistry.BulkUpdateException e) {
+                LOG.warn("Failed to apply all changes", e);
+                LOG.info("Trying to revert successful changes for current transaction");
+
+                try {
+                    e.revertChanges();
+                    LOG.info("Changes successfully reverted");
+                } catch (WriterRegistry.Reverter.RevertFailedException revertFailedException) {
+                    // fail with failed revert
+                    LOG.error("Failed to revert successful changes", revertFailedException);
+                    throw revertFailedException;
+                }
+
+                throw e; // fail with success revert
+            } catch (TransactionCommitFailedException e) {
+                // FIXME revert should probably occur when context is not written successfully
+                final String msg = "Error while updating mapping context data";
+                LOG.error(msg, e);
+                throw new TranslationException(msg, e);
+            } catch (TranslationException e) {
+                LOG.error("Error while processing data change (updates={})", baUpdates, e);
+                throw e;
+            }
+        }
+
+        private TransactionWriteContext getTransactionWriteContext() {
+            // Before Tx must use modification
+            final DOMDataReadOnlyTransaction beforeTx = ReadOnlyTransaction.create(untouchedModification, EMPTY_OPERATIONAL);
+            // After Tx must use current modification
+            final DOMDataReadOnlyTransaction afterTx = ReadOnlyTransaction.create(this, EMPTY_OPERATIONAL);
+            final TransactionMappingContext mappingContext = new TransactionMappingContext(
+                contextBroker.newReadWriteTransaction());
+            return new TransactionWriteContext(serializer, beforeTx, afterTx, mappingContext);
+        }
+
+        private WriterRegistry.DataObjectUpdates toBindingAware(
+                final Map<YangInstanceIdentifier, ModificationDiff.NormalizedNodeUpdate> biNodes) {
+            return ModifiableDataTreeDelegator.toBindingAware(biNodes, serializer);
+        }
+    }
+
+    @VisibleForTesting
+    static WriterRegistry.DataObjectUpdates toBindingAware(
+            final Map<YangInstanceIdentifier, ModificationDiff.NormalizedNodeUpdate> biNodes,
+            final BindingNormalizedNodeSerializer serializer) {
+
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate> dataObjectUpdates = HashMultimap.create();
+        final Multimap<InstanceIdentifier<?>, DataObjectUpdate.DataObjectDelete> dataObjectDeletes =
+                HashMultimap.create();
+
+        for (Map.Entry<YangInstanceIdentifier, ModificationDiff.NormalizedNodeUpdate> biEntry : biNodes.entrySet()) {
+            final InstanceIdentifier<?> unkeyedIid =
+                    RWUtils.makeIidWildcarded(serializer.fromYangInstanceIdentifier(biEntry.getKey()));
+
+            ModificationDiff.NormalizedNodeUpdate normalizedNodeUpdate = biEntry.getValue();
+            final DataObjectUpdate dataObjectUpdate = toDataObjectUpdate(normalizedNodeUpdate, serializer);
+            if (dataObjectUpdate != null) {
+                if (dataObjectUpdate instanceof DataObjectUpdate.DataObjectDelete) {
+                    dataObjectDeletes.put(unkeyedIid, ((DataObjectUpdate.DataObjectDelete) dataObjectUpdate));
+                } else {
+                    dataObjectUpdates.put(unkeyedIid, dataObjectUpdate);
+                }
+            }
+        }
+        return new WriterRegistry.DataObjectUpdates(dataObjectUpdates, dataObjectDeletes);
+    }
+
+    @Nullable
+    private static DataObjectUpdate toDataObjectUpdate(
+            final ModificationDiff.NormalizedNodeUpdate normalizedNodeUpdate,
+            final BindingNormalizedNodeSerializer serializer) {
+
+        InstanceIdentifier<?> baId = serializer.fromYangInstanceIdentifier(normalizedNodeUpdate.getId());
+        checkNotNull(baId, "Unable to transform instance identifier: %s into BA", normalizedNodeUpdate.getId());
+
+        DataObject dataObjectBefore = getDataObject(serializer,
+                normalizedNodeUpdate.getDataBefore(), normalizedNodeUpdate.getId());
+        DataObject dataObjectAfter =
+                getDataObject(serializer, normalizedNodeUpdate.getDataAfter(), normalizedNodeUpdate.getId());
+
+        return dataObjectBefore == null && dataObjectAfter == null
+                ? null
+                : DataObjectUpdate.create(baId, dataObjectBefore, dataObjectAfter);
+    }
+
+    @Nullable
+    private static DataObject getDataObject(@Nonnull final BindingNormalizedNodeSerializer serializer,
+                                            @Nullable final NormalizedNode<?, ?> data,
+                                            @Nonnull final YangInstanceIdentifier id) {
+        DataObject dataObject = null;
+        if (data != null) {
+            final Map.Entry<InstanceIdentifier<?>, DataObject> dataObjectEntry =
+                    serializer.fromNormalizedNode(id, data);
+            if (dataObjectEntry != null) {
+                dataObject = dataObjectEntry.getValue();
+            }
+        }
+        return dataObject;
+    }
+
+}
+
+
+
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModifiableDataTreeManager.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModifiableDataTreeManager.java
new file mode 100644
index 000000000..1082c479b
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModifiableDataTreeManager.java
@@ -0,0 +1,122 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.util.concurrent.Futures.immediateCheckedFuture;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.CheckedFuture;
+import io.fd.honeycomb.v3po.data.DataModification;
+import io.fd.honeycomb.v3po.data.ModifiableDataManager;
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * DataTree backed implementation for modifiable data manager.
+ */
+public class ModifiableDataTreeManager implements ModifiableDataManager {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ModifiableDataTreeManager.class);
+
+    private final DataTree dataTree;
+
+    public ModifiableDataTreeManager(@Nonnull final DataTree dataTree) {
+        this.dataTree = checkNotNull(dataTree, "dataTree should not be null");
+    }
+
+    @Override
+    public DataModification newModification() {
+        return new ConfigSnapshot();
+    }
+
+    @Override
+    public final CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(@Nonnull final YangInstanceIdentifier path) {
+        return newModification().read(path);
+    }
+
+    protected class ConfigSnapshot implements DataModification {
+        private final DataTreeModification modification;
+        private boolean validated = false;
+
+        ConfigSnapshot() {
+            this(dataTree.takeSnapshot().newModification());
+        }
+
+        protected ConfigSnapshot(final DataTreeModification modification) {
+            this.modification = modification;
+        }
+
+        @Override
+        public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(
+                @Nonnull final YangInstanceIdentifier path) {
+            final Optional<NormalizedNode<?, ?>> node = modification.readNode(path);
+            if (LOG.isTraceEnabled() && node.isPresent()) {
+                LOG.trace("ConfigSnapshot.read: {}", node.get());
+            }
+            return immediateCheckedFuture(node);
+        }
+
+        @Override
+        public final void delete(final YangInstanceIdentifier path) {
+            modification.delete(path);
+        }
+
+        @Override
+        public final void merge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
+            modification.merge(path, data);
+        }
+
+        @Override
+        public final void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
+            modification.write(path, data);
+        }
+
+        @Override
+        public final void commit() throws DataValidationFailedException, TranslationException {
+            if(!validated) {
+                validate();
+            }
+            final DataTreeCandidate candidate = dataTree.prepare(modification);
+            processCandidate(candidate);
+            dataTree.commit(candidate);
+        }
+
+        protected void processCandidate(final DataTreeCandidate candidate) throws TranslationException {
+            // NOOP
+        }
+
+        @Override
+        public final void validate() throws DataValidationFailedException {
+            modification.ready();
+            dataTree.validate(modification);
+            validated = true;
+        }
+    }
+}
+
+
+
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModificationDiff.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModificationDiff.java
new file mode 100644
index 000000000..abc0062de
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ModificationDiff.java
@@ -0,0 +1,278 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.collect.ImmutableMap;
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.AugmentationNode;
+import org.opendaylight.yangtools.yang.data.api.schema.ChoiceNode;
+import org.opendaylight.yangtools.yang.data.api.schema.LeafNode;
+import org.opendaylight.yangtools.yang.data.api.schema.MixinNode;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
+
+/**
+ * Recursively collects and provides all unique and non-null modifications (modified normalized nodes).
+ */
+final class ModificationDiff {
+
+    private static final ModificationDiff EMPTY_DIFF = new ModificationDiff(Collections.emptyMap());
+    private static final EnumSet LEAF_MODIFICATIONS = EnumSet.of(ModificationType.WRITE, ModificationType.DELETE);
+
+    private final Map<YangInstanceIdentifier, NormalizedNodeUpdate> updates;
+
+    private ModificationDiff(@Nonnull Map<YangInstanceIdentifier, NormalizedNodeUpdate> updates) {
+        this.updates = updates;
+    }
+
+    /**
+     * Get processed modifications.
+     *
+     * @return mapped modifications, where key is keyed {@link YangInstanceIdentifier}.
+     */
+    Map<YangInstanceIdentifier, NormalizedNodeUpdate> getUpdates() {
+        return updates;
+    }
+
+    private ModificationDiff merge(final ModificationDiff other) {
+        if (this == EMPTY_DIFF) {
+            return other;
+        }
+
+        if (other == EMPTY_DIFF) {
+            return this;
+        }
+
+        return new ModificationDiff(join(updates, other.updates));
+    }
+
+    private static Map<YangInstanceIdentifier, NormalizedNodeUpdate> join(Map<YangInstanceIdentifier, NormalizedNodeUpdate> first,
+                                                                          Map<YangInstanceIdentifier, NormalizedNodeUpdate> second) {
+        final Map<YangInstanceIdentifier, NormalizedNodeUpdate> merged = new HashMap<>();
+        merged.putAll(first);
+        merged.putAll(second);
+        return merged;
+    }
+
+    private static ModificationDiff create(YangInstanceIdentifier id, DataTreeCandidateNode candidate) {
+        return new ModificationDiff(ImmutableMap.of(id, NormalizedNodeUpdate.create(id, candidate)));
+    }
+
+    /**
+     * Produce an aggregated diff from a candidate node recursively. MixinNodes are ignored as modifications and so
+     * are complex nodes which direct leaves were not modified.
+     */
+    @Nonnull
+    static ModificationDiff recursivelyFromCandidate(@Nonnull final YangInstanceIdentifier yangIid,
+                                                     @Nonnull final DataTreeCandidateNode currentCandidate) {
+        // recursively process child nodes for exact modifications
+        return recursivelyChildrenFromCandidate(yangIid, currentCandidate)
+                // also add modification on current level, if elligible
+                .merge(isModification(currentCandidate)
+                        ? ModificationDiff.create(yangIid, currentCandidate)
+                        : EMPTY_DIFF);
+    }
+
+    /**
+     * Check whether current node was modified. {@link MixinNode}s are ignored
+     * and only nodes which direct leaves(or choices) are modified are considered a modification.
+     */
+    private static Boolean isModification(@Nonnull final DataTreeCandidateNode currentCandidate) {
+        // Mixin nodes are not considered modifications
+        if (isMixin(currentCandidate) && !isAugment(currentCandidate)) {
+            return false;
+        } else {
+            return isCurrentModified(currentCandidate);
+        }
+    }
+
+    private static Boolean isCurrentModified(final @Nonnull DataTreeCandidateNode currentCandidate) {
+        // Check if there are any modified leaves and if so, consider current node as modified
+        final Boolean directLeavesModified = currentCandidate.getChildNodes().stream()
+                .filter(ModificationDiff::isLeaf)
+                // For some reason, we get modifications on unmodified list keys TODO debug and report ODL bug
+                // and that messes up our modifications collection here, so we need to skip
+                .filter(ModificationDiff::isBeforeAndAfterDifferent)
+                .filter(child -> LEAF_MODIFICATIONS.contains(child.getModificationType()))
+                .findFirst()
+                .isPresent();
+
+        return directLeavesModified
+                // Also check choices (choices do not exist in BA world and if anything within a choice was modified,
+                // consider its parent as being modified)
+                || currentCandidate.getChildNodes().stream()
+                        .filter(ModificationDiff::isChoice)
+                        // Recursively check each choice if there was any change to it
+                        .filter(ModificationDiff::isCurrentModified)
+                        .findFirst()
+                        .isPresent();
+    }
+
+    /**
+     * Process all non-leaf child nodes recursively, creating aggregated {@link ModificationDiff}.
+     */
+    private static ModificationDiff recursivelyChildrenFromCandidate(final @Nonnull YangInstanceIdentifier yangIid,
+                                                                     final @Nonnull DataTreeCandidateNode currentCandidate) {
+        // recursively process child nodes for specific modifications
+        return currentCandidate.getChildNodes().stream()
+                // not interested in modifications to leaves
+                .filter(child -> !isLeaf(child))
+                .map(candidate -> recursivelyFromCandidate(yangIid.node(candidate.getIdentifier()), candidate))
+                .reduce(ModificationDiff::merge)
+                .orElse(EMPTY_DIFF);
+    }
+
+    /**
+     * Check whether candidate.before and candidate.after is different. If not return false.
+     */
+    private static boolean isBeforeAndAfterDifferent(@Nonnull final DataTreeCandidateNode candidateNode) {
+        if (candidateNode.getDataBefore().isPresent()) {
+            return !candidateNode.getDataBefore().get().equals(candidateNode.getDataAfter().orNull());
+        }
+
+        // considering not a modification if data after is also null
+        return candidateNode.getDataAfter().isPresent();
+    }
+
+    /**
+     * Check whether candidate node is for a leaf type node.
+     */
+    private static boolean isLeaf(final DataTreeCandidateNode candidateNode) {
+        // orNull intentional, some candidate nodes have both data after and data before null
+        return candidateNode.getDataAfter().orNull() instanceof LeafNode<?>
+                || candidateNode.getDataBefore().orNull() instanceof LeafNode<?>;
+    }
+
+    /**
+     * Check whether candidate node is for a Mixin type node.
+     */
+    private static boolean isMixin(final DataTreeCandidateNode candidateNode) {
+        // orNull intentional, some candidate nodes have both data after and data before null
+        return candidateNode.getDataAfter().orNull() instanceof MixinNode
+                || candidateNode.getDataBefore().orNull() instanceof MixinNode;
+    }
+
+    /**
+     * Check whether candidate node is for an Augmentation type node.
+     */
+    private static boolean isAugment(final DataTreeCandidateNode candidateNode) {
+        // orNull intentional, some candidate nodes have both data after and data before null
+        return candidateNode.getDataAfter().orNull() instanceof AugmentationNode
+                || candidateNode.getDataBefore().orNull() instanceof AugmentationNode;
+    }
+
+    /**
+     * Check whether candidate node is for a Choice type node.
+     */
+    private static boolean isChoice(final DataTreeCandidateNode candidateNode) {
+        // orNull intentional, some candidate nodes have both data after and data before null
+        return candidateNode.getDataAfter().orNull() instanceof ChoiceNode
+                || candidateNode.getDataBefore().orNull() instanceof ChoiceNode;
+    }
+
+    @Override
+    public String toString() {
+        return "ModificationDiff{updates=" + updates + '}';
+    }
+
+    /**
+     * Update to a normalized node identifiable by its {@link YangInstanceIdentifier}.
+     */
+    static final class NormalizedNodeUpdate {
+
+        @Nonnull
+        private final YangInstanceIdentifier id;
+        @Nullable
+        private final NormalizedNode<?, ?> dataBefore;
+        @Nullable
+        private final NormalizedNode<?, ?> dataAfter;
+
+        private NormalizedNodeUpdate(@Nonnull final YangInstanceIdentifier id,
+                                     @Nullable final NormalizedNode<?, ?> dataBefore,
+                                     @Nullable final NormalizedNode<?, ?> dataAfter) {
+            this.id = checkNotNull(id);
+            this.dataAfter = dataAfter;
+            this.dataBefore = dataBefore;
+        }
+
+        @Nullable
+        public NormalizedNode<?, ?> getDataBefore() {
+            return dataBefore;
+        }
+
+        @Nullable
+        public NormalizedNode<?, ?> getDataAfter() {
+            return dataAfter;
+        }
+
+        @Nonnull
+        public YangInstanceIdentifier getId() {
+            return id;
+        }
+
+        static NormalizedNodeUpdate create(@Nonnull final YangInstanceIdentifier id,
+                                           @Nonnull final DataTreeCandidateNode candidate) {
+            return create(id, candidate.getDataBefore().orNull(), candidate.getDataAfter().orNull());
+        }
+
+        static NormalizedNodeUpdate create(@Nonnull final YangInstanceIdentifier id,
+                                           @Nullable final NormalizedNode<?, ?> dataBefore,
+                                           @Nullable final NormalizedNode<?, ?> dataAfter) {
+            checkArgument(!(dataBefore == null && dataAfter == null), "Both before and after data are null");
+            return new NormalizedNodeUpdate(id, dataBefore, dataAfter);
+        }
+
+        @Override
+        public boolean equals(final Object other) {
+            if (this == other) {
+                return true;
+            }
+            if (other == null || getClass() != other.getClass()) {
+                return false;
+            }
+
+            final NormalizedNodeUpdate that = (NormalizedNodeUpdate) other;
+
+            return id.equals(that.id);
+
+        }
+
+        @Override
+        public int hashCode() {
+            return id.hashCode();
+        }
+
+        @Override
+        public String toString() {
+            return "NormalizedNodeUpdate{" + "id=" + id
+                    + ", dataBefore=" + dataBefore
+                    + ", dataAfter=" + dataAfter
+                    + '}';
+        }
+    }
+
+}
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/PersistingDataTreeAdapter.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/PersistingDataTreeAdapter.java
new file mode 100644
index 000000000..9b71dfd62
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/PersistingDataTreeAdapter.java
@@ -0,0 +1,151 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.base.Optional;
+import io.fd.honeycomb.v3po.translate.util.JsonUtils;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.sal.core.api.model.SchemaService;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Adapter for a DataTree that stores current state of data in backing DataTree on each successful commit.
+ * Uses JSON format.
+ */
+public class PersistingDataTreeAdapter implements DataTree, AutoCloseable {
+
+    private static final Logger LOG = LoggerFactory.getLogger(PersistingDataTreeAdapter.class);
+
+    private final DataTree delegateDependency;
+    private final SchemaService schemaServiceDependency;
+    private final Path path;
+
+    /**
+     * Create new Persisting DataTree adapter
+     *
+     * @param delegate backing data tree that actually handles all the operations
+     * @param persistPath path to a file (existing or not) to be used as storage for persistence. Full control over
+     *                    a file at peristPath is expected
+     * @param schemaService schemaContext provier
+     */
+    public PersistingDataTreeAdapter(@Nonnull final DataTree delegate,
+                                     @Nonnull final SchemaService schemaService,
+                                     @Nonnull final Path persistPath) {
+        this.path = testPersistPath(checkNotNull(persistPath, "persistPath is null"));
+        this.delegateDependency = checkNotNull(delegate, "delegate is null");
+        this.schemaServiceDependency = checkNotNull(schemaService, "schemaService is null");
+    }
+
+    /**
+     * Test whether file at persistPath exists and is readable or create it along with its parent structure
+     */
+    private Path testPersistPath(final Path persistPath) {
+        try {
+            checkArgument(!Files.isDirectory(persistPath), "Path %s points to a directory", persistPath);
+            if(Files.exists(persistPath)) {
+                checkArgument(Files.isReadable(persistPath),
+                    "Provided path %s points to existing, but non-readable file", persistPath);
+                return persistPath;
+            }
+            Files.createDirectories(persistPath.getParent());
+            Files.write(persistPath, new byte[]{}, StandardOpenOption.CREATE);
+        } catch (IOException | UnsupportedOperationException e) {
+            LOG.warn("Provided path for persistence: {} is not usable", persistPath, e);
+            throw new IllegalArgumentException("Path " + persistPath + " cannot be used as ");
+        }
+
+        return persistPath;
+    }
+
+    @Override
+    public DataTreeSnapshot takeSnapshot() {
+        return delegateDependency.takeSnapshot();
+    }
+
+    @Override
+    public void setSchemaContext(final SchemaContext schemaContext) {
+        delegateDependency.setSchemaContext(schemaContext);
+    }
+
+    @Override
+    public void commit(final DataTreeCandidate dataTreeCandidate) {
+        LOG.trace("Commit detected");
+        delegateDependency.commit(dataTreeCandidate);
+        LOG.debug("Delegate commit successful. Persisting data");
+
+        // FIXME doing full read and full write might not be the fastest way of persisting data here
+        final DataTreeSnapshot dataTreeSnapshot = delegateDependency.takeSnapshot();
+
+        // TODO this can be handled in background by a dedicated thread + a limited blocking queue
+        // TODO enable configurable granularity for persists. Maybe doing write on every modification is too much
+        // and we could do bulk persist
+        persistCurrentData(dataTreeSnapshot.readNode(YangInstanceIdentifier.EMPTY));
+    }
+
+    private void persistCurrentData(final Optional<NormalizedNode<?, ?>> currentRoot) {
+        if(currentRoot.isPresent()) {
+            try {
+                LOG.trace("Persisting current data: {} into: {}", currentRoot.get(), path);
+                JsonUtils.writeJsonRoot(currentRoot.get(), schemaServiceDependency.getGlobalContext(),
+                    Files.newOutputStream(path, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING));
+                LOG.trace("Data persisted successfully in {}", path);
+            } catch (IOException e) {
+                throw new IllegalStateException("Unable to persist current data", e);
+            }
+        } else {
+            LOG.debug("Skipping persistence, since there's no data to persist");
+        }
+    }
+
+    @Override
+    public YangInstanceIdentifier getRootPath() {
+        return delegateDependency.getRootPath();
+    }
+
+    @Override
+    public void validate(final DataTreeModification dataTreeModification) throws DataValidationFailedException {
+        delegateDependency.validate(dataTreeModification);
+    }
+
+    @Override
+    public DataTreeCandidate prepare(
+        final DataTreeModification dataTreeModification) {
+        return delegateDependency.prepare(dataTreeModification);
+    }
+
+    @Override
+    public void close() throws Exception {
+        LOG.trace("Closing {} for {}", getClass().getSimpleName(), path);
+        // NOOP
+    }
+}
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadOnlyTransaction.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadOnlyTransaction.java
new file mode 100644
index 000000000..2850a0d9a
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadOnlyTransaction.java
@@ -0,0 +1,119 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+import static java.util.Objects.requireNonNull;
+
+import com.google.common.base.Function;
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import io.fd.honeycomb.v3po.data.ReadableDataManager;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+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.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+final class ReadOnlyTransaction implements DOMDataReadOnlyTransaction {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ReadOnlyTransaction.class);
+
+    @Nullable
+    private ReadableDataManager operationalData;
+    @Nullable
+    private ReadableDataManager configSnapshot;
+
+    private boolean closed = false;
+
+    /**
+     * @param configData config data tree manager. Null if config reads are not to be supported
+     * @param operationalData operational data tree manager. Null if operational reads are not to be supported
+     */
+    private ReadOnlyTransaction(@Nullable final ReadableDataManager configData,
+                                @Nullable final ReadableDataManager operationalData) {
+        this.configSnapshot = configData;
+        this.operationalData = operationalData;
+    }
+
+    @Override
+    public synchronized void close() {
+        closed = true;
+        configSnapshot = null;
+        operationalData = null;
+    }
+
+    @Override
+    public synchronized CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(
+            final LogicalDatastoreType store,
+            final YangInstanceIdentifier path) {
+        LOG.debug("ReadOnlyTransaction.read(), store={}, path={}", store, path);
+        checkState(!closed, "Transaction has been closed");
+
+        if (store == LogicalDatastoreType.OPERATIONAL) {
+            checkArgument(operationalData != null, "{} reads not supported", store);
+            return operationalData.read(path);
+        } else {
+            checkArgument(configSnapshot != null, "{} reads not supported", store);
+            return configSnapshot.read(path);
+        }
+    }
+
+    @Override
+    public CheckedFuture<Boolean, ReadFailedException> exists(final LogicalDatastoreType store,
+                                                              final YangInstanceIdentifier path) {
+        LOG.debug("ReadOnlyTransaction.exists() store={}, path={}", store, path);
+
+        ListenableFuture<Boolean> listenableFuture = Futures.transform(read(store, path), IS_NODE_PRESENT);
+        return Futures.makeChecked(listenableFuture, ANY_EX_TO_READ_FAILED_EXCEPTION_MAPPER);
+    }
+
+    @Nonnull
+    @Override
+    public Object getIdentifier() {
+        return this;
+    }
+
+    @Nonnull
+    static ReadOnlyTransaction createOperationalOnly(@Nonnull final ReadableDataManager operationalData) {
+        return new ReadOnlyTransaction(null, requireNonNull(operationalData));
+    }
+
+    @Nonnull
+    static ReadOnlyTransaction createConfigOnly(@Nonnull final ReadableDataManager configData) {
+        return new ReadOnlyTransaction(requireNonNull(configData), null);
+    }
+
+    @Nonnull
+    static ReadOnlyTransaction create(@Nonnull final ReadableDataManager configData,
+                                      @Nonnull final ReadableDataManager operationalData) {
+        return new ReadOnlyTransaction(requireNonNull(configData), requireNonNull(operationalData));
+    }
+
+    private static final Function<? super Optional<NormalizedNode<?, ?>>, ? extends Boolean> IS_NODE_PRESENT =
+        (Function<Optional<NormalizedNode<?, ?>>, Boolean>) input -> input == null ? Boolean.FALSE : input.isPresent();
+
+    private static final Function<? super Exception, ReadFailedException> ANY_EX_TO_READ_FAILED_EXCEPTION_MAPPER =
+        (Function<Exception, ReadFailedException>) e -> new ReadFailedException("Exists failed", e);
+}
\ No newline at end of file
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadWriteTransaction.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadWriteTransaction.java
new file mode 100644
index 000000000..88b46437e
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadWriteTransaction.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.data.impl;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.ListenableFuture;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.common.api.TransactionStatus;
+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.controller.md.sal.dom.api.DOMDataReadOnlyTransaction;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadTransaction;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadWriteTransaction;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
+import org.opendaylight.yangtools.yang.common.RpcResult;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+
+/**
+ * Composite DOM transaction that delegates reads to a {@link DOMDataReadTransaction} delegate and writes to a {@link
+ * DOMDataWriteTransaction} delegate.
+ */
+final class ReadWriteTransaction implements DOMDataReadWriteTransaction {
+
+    private final DOMDataReadOnlyTransaction delegateReadTx;
+    private final DOMDataWriteTransaction delegateWriteTx;
+
+    ReadWriteTransaction(@Nonnull final DOMDataReadOnlyTransaction delegateReadTx,
+                         @Nonnull final DOMDataWriteTransaction delegateWriteTx) {
+        this.delegateReadTx = Preconditions.checkNotNull(delegateReadTx, "delegateReadTx should not be null");
+        this.delegateWriteTx = Preconditions.checkNotNull(delegateWriteTx, "delegateWriteTx should not be null");
+    }
+
+    @Override
+    public boolean cancel() {
+        delegateReadTx.close();
+        return delegateWriteTx.cancel();
+    }
+
+    @Override
+    public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
+                    final NormalizedNode<?, ?> data) {
+        delegateWriteTx.put(store, path, data);
+    }
+
+    @Override
+    public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
+                      final NormalizedNode<?, ?> data) {
+        delegateWriteTx.merge(store, path, data);
+    }
+
+    @Override
+    public void delete(final LogicalDatastoreType store, final YangInstanceIdentifier path) {
+        delegateWriteTx.delete(store, path);
+    }
+
+    @Override
+    public CheckedFuture<Void, TransactionCommitFailedException> submit() {
+        return delegateWriteTx.submit();
+    }
+
+    @Override
+    public ListenableFuture<RpcResult<TransactionStatus>> commit() {
+        return delegateWriteTx.commit();
+    }
+
+    @Override
+    public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final LogicalDatastoreType store,
+                                                                                   final YangInstanceIdentifier path) {
+        return delegateReadTx.read(store, path);
+    }
+
+    @Override
+    public CheckedFuture<Boolean, ReadFailedException> exists(final LogicalDatastoreType store,
+                                                              final YangInstanceIdentifier path) {
+        return delegateReadTx.exists(store, path);
+    }
+
+    @Override
+    public Object getIdentifier() {
+        return this;
+    }
+}
+
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadableDataTreeDelegator.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadableDataTreeDelegator.java
new file mode 100644
index 000000000..aff023ebc
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/ReadableDataTreeDelegator.java
@@ -0,0 +1,242 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.collect.Iterables.getOnlyElement;
+
+import com.google.common.base.Function;
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Collections2;
+import com.google.common.collect.Multimap;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.Futures;
+import io.fd.honeycomb.v3po.data.ReadableDataManager;
+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.registry.ReaderRegistry;
+import io.fd.honeycomb.v3po.translate.util.TransactionMappingContext;
+import java.util.Collection;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+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.ContainerNode;
+import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
+import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
+import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListEntryNode;
+import org.opendaylight.yangtools.yang.data.api.schema.UnkeyedListNode;
+import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
+import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.CollectionNodeBuilder;
+import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.DataContainerNodeAttrBuilder;
+import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.ListSchemaNode;
+import org.opendaylight.yangtools.yang.model.api.SchemaContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * ReadableDataTree implementation for operational data.
+ */
+public final class ReadableDataTreeDelegator implements ReadableDataManager {
+    private static final Logger LOG = LoggerFactory.getLogger(ReadableDataTreeDelegator.class);
+
+    private final BindingNormalizedNodeSerializer serializer;
+    private final ReaderRegistry readerRegistry;
+    private final SchemaContext globalContext;
+    private final org.opendaylight.controller.md.sal.binding.api.DataBroker contextBroker;
+
+    /**
+     * Creates operational data tree instance.
+     * @param serializer     service for serialization between Java Binding Data representation and NormalizedNode
+     *                       representation.
+     * @param globalContext  service for obtaining top level context data from all yang modules.
+     * @param readerRegistry service responsible for translation between DataObjects and data provider.
+     * @param contextBroker BA broker for context data
+     */
+    public ReadableDataTreeDelegator(@Nonnull BindingNormalizedNodeSerializer serializer,
+                                     @Nonnull final SchemaContext globalContext,
+                                     @Nonnull final ReaderRegistry readerRegistry,
+                                     @Nonnull final org.opendaylight.controller.md.sal.binding.api.DataBroker contextBroker) {
+        this.contextBroker = checkNotNull(contextBroker, "contextBroker should not be null");
+        this.globalContext = checkNotNull(globalContext, "globalContext should not be null");
+        this.serializer = checkNotNull(serializer, "serializer should not be null");
+        this.readerRegistry = checkNotNull(readerRegistry, "reader should not be null");
+    }
+
+    @Override
+    public CheckedFuture<Optional<NormalizedNode<?, ?>>,
+            org.opendaylight.controller.md.sal.common.api.data.ReadFailedException> read(
+            @Nonnull final YangInstanceIdentifier yangInstanceIdentifier) {
+
+        try(TransactionMappingContext mappingContext = new TransactionMappingContext(contextBroker.newReadWriteTransaction());
+            ReadContext ctx = new ReadContextImpl(mappingContext)) {
+
+            final Optional<NormalizedNode<?, ?>> value;
+            if (checkNotNull(yangInstanceIdentifier).equals(YangInstanceIdentifier.EMPTY)) {
+                value = readRoot(ctx);
+            } else {
+                value = readNode(yangInstanceIdentifier, ctx);
+            }
+
+            // Submit context mapping updates
+            final CheckedFuture<Void, TransactionCommitFailedException> contextUpdateResult =
+                ((TransactionMappingContext) ctx.getMappingContext()).submit();
+            // Blocking on context data update
+            contextUpdateResult.checkedGet();
+
+            return Futures.immediateCheckedFuture(value);
+
+        } catch (ReadFailedException e) {
+            return Futures.immediateFailedCheckedFuture(
+                new org.opendaylight.controller.md.sal.common.api.data.ReadFailedException(
+                    "Failed to read VPP data", e));
+        } catch (TransactionCommitFailedException e) {
+            // FIXME revert should probably occur when context is not written successfully
+            final String msg = "Error while updating mapping context data";
+            LOG.error(msg, e);
+            return Futures.immediateFailedCheckedFuture(
+                new org.opendaylight.controller.md.sal.common.api.data.ReadFailedException(msg, e)
+            );
+        }
+    }
+
+    private Optional<NormalizedNode<?, ?>> readNode(final YangInstanceIdentifier yangInstanceIdentifier,
+                                                    final ReadContext ctx) throws ReadFailedException {
+        LOG.debug("OperationalDataTree.readNode(), yangInstanceIdentifier={}", yangInstanceIdentifier);
+        final InstanceIdentifier<?> path = serializer.fromYangInstanceIdentifier(yangInstanceIdentifier);
+        checkNotNull(path, "Invalid instance identifier %s. Cannot create BA equivalent.", yangInstanceIdentifier);
+        LOG.debug("OperationalDataTree.readNode(), path={}", path);
+
+        final Optional<? extends DataObject> dataObject;
+
+        dataObject = readerRegistry.read(path, ctx);
+        if (dataObject.isPresent()) {
+            final NormalizedNode<?, ?> value = toNormalizedNodeFunction(path).apply(dataObject.get());
+            return Optional.<NormalizedNode<?, ?>>fromNullable(value);
+        } else {
+            return Optional.absent();
+        }
+    }
+
+    private Optional<NormalizedNode<?, ?>> readRoot(final ReadContext ctx) throws ReadFailedException {
+        LOG.debug("OperationalDataTree.readRoot()");
+
+        final DataContainerNodeAttrBuilder<YangInstanceIdentifier.NodeIdentifier, ContainerNode> dataNodeBuilder =
+                Builders.containerBuilder()
+                        .withNodeIdentifier(new YangInstanceIdentifier.NodeIdentifier(SchemaContext.NAME));
+
+        final Multimap<InstanceIdentifier<? extends DataObject>, ? extends DataObject> dataObjects =
+                readerRegistry.readAll(ctx);
+
+        for (final InstanceIdentifier<? extends DataObject> instanceIdentifier : dataObjects.keySet()) {
+            final YangInstanceIdentifier rootElementId = serializer.toYangInstanceIdentifier(instanceIdentifier);
+            final NormalizedNode<?, ?> node =
+                    wrapDataObjects(rootElementId, instanceIdentifier, dataObjects.get(instanceIdentifier));
+            dataNodeBuilder.withChild((DataContainerChild<?, ?>) node);
+        }
+        return Optional.<NormalizedNode<?, ?>>of(dataNodeBuilder.build());
+    }
+
+    private NormalizedNode<?, ?> wrapDataObjects(final YangInstanceIdentifier yangInstanceIdentifier,
+                                                 final InstanceIdentifier<? extends DataObject> instanceIdentifier,
+                                                 final Collection<? extends DataObject> dataObjects) {
+        final Collection<NormalizedNode<?, ?>> normalizedRootElements = Collections2
+                .transform(dataObjects, toNormalizedNodeFunction(instanceIdentifier));
+
+        final DataSchemaNode schemaNode =
+                globalContext.getDataChildByName(yangInstanceIdentifier.getLastPathArgument().getNodeType());
+        if (schemaNode instanceof ListSchemaNode) {
+            // In case of a list, wrap all the values in a Mixin parent node
+            final ListSchemaNode listSchema = (ListSchemaNode) schemaNode;
+            return wrapListIntoMixinNode(normalizedRootElements, listSchema);
+        } else {
+            Preconditions.checkState(dataObjects.size() == 1, "Singleton list was expected");
+            return getOnlyElement(normalizedRootElements);
+        }
+    }
+
+    private static DataContainerChild<?, ?> wrapListIntoMixinNode(
+            final Collection<NormalizedNode<?, ?>> normalizedRootElements, final ListSchemaNode listSchema) {
+        if (listSchema.getKeyDefinition().isEmpty()) {
+            final CollectionNodeBuilder<UnkeyedListEntryNode, UnkeyedListNode> listBuilder =
+                    Builders.unkeyedListBuilder();
+            for (NormalizedNode<?, ?> normalizedRootElement : normalizedRootElements) {
+                listBuilder.withChild((UnkeyedListEntryNode) normalizedRootElement);
+            }
+            return listBuilder.build();
+        } else {
+            final CollectionNodeBuilder<MapEntryNode, ? extends MapNode> listBuilder =
+                    listSchema.isUserOrdered()
+                            ? Builders.orderedMapBuilder()
+                            : Builders.mapBuilder();
+
+            for (NormalizedNode<?, ?> normalizedRootElement : normalizedRootElements) {
+                listBuilder.withChild((MapEntryNode) normalizedRootElement);
+            }
+            return listBuilder.build();
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private Function<DataObject, NormalizedNode<?, ?>> toNormalizedNodeFunction(final InstanceIdentifier path) {
+        return dataObject -> {
+            LOG.trace("OperationalDataTree.toNormalizedNode(), path={}, dataObject={}", path, dataObject);
+            final Map.Entry<YangInstanceIdentifier, NormalizedNode<?, ?>> entry =
+                    serializer.toNormalizedNode(path, dataObject);
+
+            LOG.trace("OperationalDataTree.toNormalizedNode(), normalizedNodeEntry={}", entry);
+            return entry.getValue();
+        };
+    }
+
+    private static final class ReadContextImpl implements ReadContext {
+
+        private final ModificationCache ctx = new ModificationCache();
+        private final MappingContext mappingContext;
+
+        private ReadContextImpl(final MappingContext mappingContext) {
+            this.mappingContext = mappingContext;
+        }
+
+        @Nonnull
+        @Override
+        public ModificationCache getModificationCache() {
+            return ctx;
+        }
+
+        @Nonnull
+        @Override
+        public MappingContext getMappingContext() {
+            return mappingContext;
+        }
+
+        @Override
+        public void close() {
+            // Make sure to clear the storage in case some customizer stored a reference to it to prevent memory leaks
+            ctx.close();
+        }
+    }
+}
diff --git a/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/WriteTransaction.java b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/WriteTransaction.java
new file mode 100644
index 000000000..c8f9bd3db
--- /dev/null
+++ b/infra/data-impl/src/main/java/io/fd/honeycomb/v3po/data/impl/WriteTransaction.java
@@ -0,0 +1,177 @@
+/*
+ * 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.data.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static java.util.Objects.requireNonNull;
+import static org.opendaylight.controller.md.sal.common.api.TransactionStatus.CANCELED;
+import static org.opendaylight.controller.md.sal.common.api.TransactionStatus.COMMITED;
+import static org.opendaylight.controller.md.sal.common.api.TransactionStatus.FAILED;
+import static org.opendaylight.controller.md.sal.common.api.TransactionStatus.NEW;
+import static org.opendaylight.controller.md.sal.common.api.TransactionStatus.SUBMITED;
+
+import com.google.common.base.Preconditions;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import io.fd.honeycomb.v3po.data.DataModification;
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import java.util.function.Consumer;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.NotThreadSafe;
+import org.opendaylight.controller.md.sal.common.api.TransactionStatus;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
+import org.opendaylight.yangtools.yang.common.RpcResult;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@NotThreadSafe
+final class WriteTransaction implements DOMDataWriteTransaction {
+
+    private static final Logger LOG = LoggerFactory.getLogger(WriteTransaction.class);
+
+    @Nullable
+    private DataModification operationalModification;
+    @Nullable
+    private DataModification configModification;
+    private TransactionStatus status = NEW;
+
+    private WriteTransaction(@Nullable final DataModification configModification,
+                             @Nullable final DataModification operationalModification) {
+        this.operationalModification = operationalModification;
+        this.configModification = configModification;
+    }
+
+    private void checkIsNew() {
+        Preconditions.checkState(status == NEW, "Transaction was submitted or canceled");
+    }
+
+    @Override
+    public void put(final LogicalDatastoreType store, final YangInstanceIdentifier path,
+                    final NormalizedNode<?, ?> data) {
+        LOG.debug("WriteTransaction.put() store={}, path={}, data={}", store, path, data);
+        checkIsNew();
+        handleOperation(store, (modification) -> modification.write(path, data));
+    }
+
+    private void handleOperation(final LogicalDatastoreType store,
+                                 final Consumer<DataModification> r) {
+        switch (store) {
+            case CONFIGURATION:
+                checkArgument(configModification != null, "Modification of %s is not supported", store);
+                r.accept(configModification);
+                break;
+            case OPERATIONAL:
+                checkArgument(operationalModification != null, "Modification of %s is not supported", store);
+                r.accept(operationalModification);
+                break;
+        }
+    }
+
+    @Override
+    public void merge(final LogicalDatastoreType store, final YangInstanceIdentifier path,
+                      final NormalizedNode<?, ?> data) {
+        LOG.debug("WriteTransaction.merge() store={}, path={}, data={}", store, path, data);
+        checkIsNew();
+        handleOperation(store, (modification) -> modification.merge(path, data));
+    }
+
+    @Override
+    public boolean cancel() {
+        if (status != NEW) {
+            // only NEW transactions can be cancelled
+            return false;
+        } else {
+            status = CANCELED;
+            return true;
+        }
+    }
+
+    @Override
+    public void delete(LogicalDatastoreType store, final YangInstanceIdentifier path) {
+        LOG.debug("WriteTransaction.delete() store={}, path={}", store, path);
+        checkIsNew();
+        handleOperation(store, (modification) -> modification.delete(path));
+    }
+
+    @Override
+    public CheckedFuture<Void, TransactionCommitFailedException> submit() {
+        LOG.trace("WriteTransaction.submit()");
+        checkIsNew();
+
+        try {
+            status = SUBMITED;
+
+            // Validate first to catch any issues before attempting commit
+            if (configModification != null) {
+                configModification.validate();
+            }
+            if (operationalModification != null) {
+                operationalModification.validate();
+            }
+
+            if(configModification != null) {
+                configModification.commit();
+            }
+            if(operationalModification != null) {
+                operationalModification.commit();
+            }
+
+            status = COMMITED;
+        } catch (DataValidationFailedException | TranslationException e) {
+            status = FAILED;
+            LOG.error("Failed modify data tree", e);
+            return Futures.immediateFailedCheckedFuture(
+                new TransactionCommitFailedException("Failed to validate DataTreeModification", e));
+        }
+        return Futures.immediateCheckedFuture(null);
+    }
+
+    @Override
+    @Deprecated
+    public ListenableFuture<RpcResult<TransactionStatus>> commit() {
+        throw new UnsupportedOperationException("deprecated");
+    }
+
+    @Override
+    public Object getIdentifier() {
+        return this;
+    }
+
+
+    @Nonnull
+    static WriteTransaction createOperationalOnly(@Nonnull final DataModification operationalData) {
+        return new WriteTransaction(null, requireNonNull(operationalData));
+    }
+
+    @Nonnull
+    static WriteTransaction createConfigOnly(@Nonnull final DataModification configData) {
+        return new WriteTransaction(requireNonNull(configData), null);
+    }
+
+    @Nonnull
+    static WriteTransaction create(@Nonnull final DataModification configData,
+                            @Nonnull final DataModification operationalData) {
+        return new WriteTransaction(requireNonNull(configData), requireNonNull(operationalData));
+    }
+}