HONEYCOMB-9: Remove references to VPP from translation layer

Change-Id: I281db366a112edc08203e8cb392a212708d4552a
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

14 files changed, 801 insertions, 0 deletions

diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/Context.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/Context.java
new file mode 100644
index 000000000..b60963678
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/Context.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 Context implements AutoCloseable {
+
+    protected final HashMap<Object, Object> map;
+
+    public Context() {
+        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/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManager.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/SubtreeManager.java
new file mode 100644
index 000000000..39e403642
--- /dev/null
+++ b/v3po/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 Class object for node managed by this reader
+     */
+    @Nonnull
+    InstanceIdentifier<D> getManagedDataObjectType();
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/TranslationException.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/TranslationException.java
new file mode 100644
index 000000000..ee0049977
--- /dev/null
+++ b/v3po/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/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/VppApiInvocationException.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/VppApiInvocationException.java
new file mode 100644
index 000000000..298c698f7
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/VppApiInvocationException.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;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Preconditions;
+import javax.annotation.Nonnull;
+
+/**
+ * Thrown when Vpp jAPI method invocation failed.
+ */
+@Beta
+public class VppApiInvocationException extends TranslationException {
+    private final String methodName;
+    private final int ctxId;
+    private final int errorCode;
+
+    /**
+     * Constructs an VppApiInvocationFailedException with the specified api method name and error code.
+     *
+     * @param methodName method name that failed to invoke
+     * @param ctxId      api request context identifier
+     * @param errorCode  negative error code value associated with this failure
+     * @throws NullPointerException     if apiMethodName is null
+     * @throws IllegalArgumentException if errorCode is nonnegative
+     */
+    public VppApiInvocationException(@Nonnull final String methodName, final int ctxId, final int errorCode) {
+        super(String.format("vppApi.%s failed with error code: %d (ctxId=%d) ", methodName, errorCode, ctxId));
+        this.methodName = Preconditions.checkNotNull(methodName, "apiMethodName is null!");
+        this.ctxId = ctxId;
+        Preconditions.checkArgument(errorCode < 0);
+        this.errorCode = errorCode;
+    }
+
+    /**
+     * Returns method name that failed to invoke.
+     *
+     * @return method name
+     */
+    public String getMethodName() {
+        return methodName;
+    }
+
+    /**
+     * Returns api request context identifier.
+     *
+     * @return value of context identifier
+     */
+    public int getCtxId() {
+        return ctxId;
+    }
+
+    /**
+     * Returns the error code associated with this failure.
+     *
+     * @return a negative integer error code
+     */
+    public int getErrorCode() {
+        return errorCode;
+    }
+}
+
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ChildReader.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ChildReader.java
new file mode 100644
index 000000000..02b6b8d26
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ChildReader.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.read;
+
+import com.google.common.annotations.Beta;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Child reader allowing its parent to pass the builder object
+ *
+ * @param <C> Specific DataObject derived type, that is handled by this reader
+ */
+@Beta
+public interface ChildReader<C extends DataObject> extends Reader<C> {
+
+    /**
+     * Reads subtree starting from node managed by this reader and place the subtree within parent builder object if the
+     * data exists.
+     *
+     * @param id            Unique identifier pointing to the node managed by this reader. Useful when necessary to
+     *                      determine the exact position within more complex subtrees.
+     * @param parentBuilder Builder of parent DataObject. Objects read on this level (if any) must be placed into the
+     *                      parent builder.
+     * @param ctx Read context
+     *
+     * @throws ReadFailedException if read was unsuccessful
+     */
+    void read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+              @Nonnull final Builder<? extends DataObject> parentBuilder,
+              @Nonnull final ReadContext ctx) throws ReadFailedException;
+
+}
+
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ListReader.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ListReader.java
new file mode 100644
index 000000000..faf6f0a19
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ListReader.java
@@ -0,0 +1,47 @@
+/*
+ * 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.List;
+import javax.annotation.Nonnull;
+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>> extends Reader<D> {
+
+    /**
+     * 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;
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadContext.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadContext.java
new file mode 100644
index 000000000..6b1473548
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadContext.java
@@ -0,0 +1,37 @@
+/*
+ * 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.Context;
+import javax.annotation.Nonnull;
+
+/**
+ * Read Context
+ */
+public interface ReadContext extends AutoCloseable {
+
+    /**
+     * Get key value storage for customizers
+     *
+     * @return Context for customizers
+     */
+    @Nonnull
+    Context getContext();
+
+    @Override
+    void close();
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadFailedException.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReadFailedException.java
new file mode 100644
index 000000000..51d4fcb5a
--- /dev/null
+++ b/v3po/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/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/Reader.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/Reader.java
new file mode 100644
index 000000000..122263cb3
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/Reader.java
@@ -0,0 +1,51 @@
+/*
+ * 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.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> 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 final InstanceIdentifier<? extends DataObject> id,
+                                        @Nonnull ReadContext ctx) throws ReadFailedException;
+
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReaderRegistry.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReaderRegistry.java
new file mode 100644
index 000000000..f34455a27
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/read/ReaderRegistry.java
@@ -0,0 +1,43 @@
+/*
+ * 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.collect.Multimap;
+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 extends Reader<DataObject> {
+
+    /**
+     * 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;
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/ChildWriter.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/ChildWriter.java
new file mode 100644
index 000000000..f933cfd4a
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/ChildWriter.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.write;
+
+import com.google.common.annotations.Beta;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Child writer allowing its parent to pass the builder object
+ *
+ * @param <D> Specific DataObject derived type, that is handled by this writer
+ */
+@Beta
+public interface ChildWriter<D extends DataObject> extends Writer<D> {
+
+    /**
+     * Extract data object managed by this writer from parent data and perform write.
+     *
+     * @param parentId Id of parent node
+     * @param parentDataAfter Parent data from modification to extract data object from
+     * @param ctx Write context for current modification
+     */
+    void writeChild(@Nonnull final InstanceIdentifier<? extends DataObject> parentId,
+                    @Nonnull final DataObject parentDataAfter,
+                    @Nonnull final WriteContext ctx);
+
+    /**
+     * Extract data object managed by this writer(if necessary) from parent data and perform delete.
+     *
+     * @param parentId Id of parent node
+     * @param parentDataBefore Parent data before modification to extract data object from
+     * @param ctx Write context for current modification
+     */
+    void deleteChild(@Nonnull final InstanceIdentifier<? extends DataObject> parentId,
+                     @Nonnull final DataObject parentDataBefore,
+                     @Nonnull final WriteContext ctx);
+
+    /**
+     * Extract data object managed by this writer(if necessary) from parent data and perform delete.
+     *
+     * @param parentId Id of parent node
+     * @param parentDataBefore Parent data before modification to extract data object from
+     * @param parentDataAfter Parent data from modification to extract data object from
+     * @param ctx Write context for current modification
+     */
+    void updateChild(@Nonnull final InstanceIdentifier<? extends DataObject> parentId,
+                     @Nonnull final DataObject parentDataBefore,
+                     @Nonnull final DataObject parentDataAfter,
+                     @Nonnull final WriteContext ctx);
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteContext.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteContext.java
new file mode 100644
index 000000000..bb0b33145
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriteContext.java
@@ -0,0 +1,60 @@
+/*
+ * 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.Context;
+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 AutoCloseable {
+
+    /**
+     * Read any data object before current modification was applied
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data before the modification was applied
+     */
+    Optional<DataObject> readBefore(@Nonnull final InstanceIdentifier<? extends DataObject> currentId);
+
+    /**
+     * Read any data object from current modification
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data from the modification
+     */
+    Optional<DataObject> readAfter(@Nonnull final InstanceIdentifier<? extends DataObject> currentId);
+
+    /**
+     * Get key value storage for customizers
+     *
+     * @return Context for customizers
+     */
+    @Nonnull
+    Context getContext();
+
+    @Override
+    void close();
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/Writer.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/Writer.java
new file mode 100644
index 000000000..08465fdd7
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/Writer.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.write;
+
+import com.google.common.annotations.Beta;
+import io.fd.honeycomb.v3po.translate.TranslationException;
+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(from root) 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 TranslationException if update failed
+     */
+    void update(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                @Nullable final DataObject dataBefore,
+                @Nullable final DataObject dataAfter,
+                @Nonnull final WriteContext ctx) throws TranslationException;
+}
diff --git a/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriterRegistry.java b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriterRegistry.java
new file mode 100644
index 000000000..c5a8116c8
--- /dev/null
+++ b/v3po/translate-api/src/main/java/io/fd/honeycomb/v3po/translate/write/WriterRegistry.java
@@ -0,0 +1,135 @@
+/*
+ * 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 com.google.common.annotations.Beta;
+import com.google.common.collect.ImmutableList;
+import io.fd.honeycomb.v3po.translate.TranslationException;
+import java.util.List;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Special {@link Writer} capable of performing bulk updates
+ */
+@Beta
+public interface WriterRegistry extends Writer<DataObject> {
+
+    /**
+     * 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 final Map<InstanceIdentifier<?>, DataObject> dataBefore,
+                @Nonnull final Map<InstanceIdentifier<?>, DataObject> dataAfter,
+                @Nonnull final WriteContext ctx) throws TranslationException;
+
+    /**
+     * Thrown when bulk update failed.
+     */
+    @Beta
+    class BulkUpdateException extends TranslationException {
+
+        private final Reverter reverter;
+        private final InstanceIdentifier<?> failedId; // TODO change to VppDataModification
+
+        /**
+         * Constructs an BulkUpdateException.
+         *
+         * @param failedId instance identifier of the data object that caused bulk update to fail.
+         * @param cause    the cause of bulk update failure
+         */
+        public BulkUpdateException(@Nonnull final InstanceIdentifier<?> failedId, @Nonnull final Reverter reverter,
+                                   final Throwable cause) {
+            super("Bulk update failed at " + failedId, cause);
+            this.failedId = checkNotNull(failedId, "failedId should not be null");
+            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();
+        }
+
+        /**
+         * Returns instance identifier of the data object that caused bulk update to fail.
+         *
+         * @return data object's instance identifier
+         */
+        @Nonnull
+        public InstanceIdentifier<?> getFailedId() {
+            return failedId;
+        }
+    }
+
+    /**
+     * Abstraction over revert mechanism in cast 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 List<InstanceIdentifier<?>> notRevertedChanges;
+
+            /**
+             * Constructs an 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 List<InstanceIdentifier<?>> notRevertedChanges,
+                                         final Throwable cause) {
+                super(cause);
+                checkNotNull(notRevertedChanges, "notRevertedChanges should not be null");
+                this.notRevertedChanges = ImmutableList.copyOf(notRevertedChanges);
+            }
+
+            /**
+             * Returns the list of changes that were not reverted.
+             *
+             * @return list of changes that were not reverted
+             */
+            @Nonnull
+            public List<InstanceIdentifier<?>> getNotRevertedChanges() {
+                return notRevertedChanges;
+            }
+        }
+    }
+}
\ No newline at end of file