1 files changed, 225 insertions, 0 deletions
diff --git a/v3po/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilder.java b/v3po/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilder.java
new file mode 100644
index 000000000..f5d218f55
--- /dev/null
+++ b/v3po/translate-utils/src/main/java/io/fd/honeycomb/v3po/translate/util/write/registry/FlatWriterRegistryBuilder.java
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.v3po.translate.util.write.registry;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.write.ModifiableWriterRegistry;
+import io.fd.honeycomb.v3po.translate.write.Writer;
+import io.fd.honeycomb.v3po.translate.write.WriterRegistryBuilder;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.concurrent.NotThreadSafe;
+import org.jgrapht.experimental.dag.DirectedAcyclicGraph;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Builder for {@link FlatWriterRegistry} allowing users to specify inter-writer relationships.
+ */
+@NotThreadSafe
+public final class FlatWriterRegistryBuilder implements ModifiableWriterRegistry, WriterRegistryBuilder, AutoCloseable {
+
+    private static final Logger LOG = LoggerFactory.getLogger(FlatWriterRegistryBuilder.class);
+
+    // Using directed acyclic graph to represent the ordering relationships between writers
+    private final DirectedAcyclicGraph<InstanceIdentifier<?>, WriterRelation>
+            writersRelations = new DirectedAcyclicGraph<>((sourceVertex, targetVertex) -> new WriterRelation());
+    private final Map<InstanceIdentifier<?>, Writer<?>> writersMap = new HashMap<>();
+
+    /**
+     * AddWriter without any special relationship to any other type.
+     */
+    @Override
+    public FlatWriterRegistryBuilder addWriter(@Nonnull final Writer<? extends DataObject> writer) {
+        // Make IID wildcarded just in case
+        // + the way InstanceIdentifier.create + equals work for Identifiable items is unexpected, meaning updates would
+        // not be matched to writers in registry
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(writer.getManagedDataObjectType());
+        checkWriterNotPresentYet(targetType);
+        writersRelations.addVertex(targetType);
+        writersMap.put(targetType, writer);
+        return this;
+    }
+
+    /**
+     * AddWriter without any special relationship to any other type.
+     */
+    @Override
+    public FlatWriterRegistryBuilder addSubtreeWriter(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                      @Nonnull final Writer<? extends DataObject> writer) {
+        addWriter(SubtreeWriter.createForWriter(handledChildren, writer));
+        return this;
+    }
+
+    private void checkWriterNotPresentYet(final InstanceIdentifier<?> targetType) {
+        Preconditions.checkArgument(!writersMap.containsKey(targetType),
+                "Writer for type: %s already present: %s", targetType, writersMap.get(targetType));
+    }
+
+    /**
+     * Add writer with relationship: to be executed before writer handling relatedType.
+     */
+    @Override
+    public FlatWriterRegistryBuilder addWriterBefore(@Nonnull final Writer<? extends DataObject> writer,
+                                                     @Nonnull final InstanceIdentifier<?> relatedType) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(writer.getManagedDataObjectType());
+        final InstanceIdentifier<?> wildcardedRelatedType = RWUtils.makeIidWildcarded(relatedType);
+        checkWriterNotPresentYet(targetType);
+        writersRelations.addVertex(targetType);
+        writersRelations.addVertex(wildcardedRelatedType);
+        addEdge(targetType, wildcardedRelatedType);
+        writersMap.put(targetType, writer);
+        return this;
+    }
+
+    @Override
+    public FlatWriterRegistryBuilder addSubtreeWriterBefore(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                            @Nonnull final Writer<? extends DataObject> writer,
+                                                            @Nonnull final InstanceIdentifier<?> relatedType) {
+        return addWriterBefore(SubtreeWriter.createForWriter(handledChildren, writer), relatedType);
+    }
+
+    @Override
+    public FlatWriterRegistryBuilder addWriterBefore(@Nonnull final Writer<? extends DataObject> writer,
+                                                     @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(writer.getManagedDataObjectType());
+        checkWriterNotPresentYet(targetType);
+        writersRelations.addVertex(targetType);
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(writersRelations::addVertex);
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(type -> addEdge(targetType, type));
+        writersMap.put(targetType, writer);
+        return this;
+    }
+
+    @Override
+    public FlatWriterRegistryBuilder addSubtreeWriterBefore(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                            @Nonnull final Writer<? extends DataObject> writer,
+                                                            @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        return addWriterBefore(SubtreeWriter.createForWriter(handledChildren, writer), relatedTypes);
+    }
+
+    /**
+     * Add writer with relationship: to be executed after writer handling relatedType.
+     */
+    @Override
+    public FlatWriterRegistryBuilder addWriterAfter(@Nonnull final Writer<? extends DataObject> writer,
+                                                    @Nonnull final InstanceIdentifier<?> relatedType) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(writer.getManagedDataObjectType());
+        final InstanceIdentifier<?> wildcardedRelatedType = RWUtils.makeIidWildcarded(relatedType);
+        checkWriterNotPresentYet(targetType);
+        writersRelations.addVertex(targetType);
+        writersRelations.addVertex(wildcardedRelatedType);
+        // set edge to indicate before relationship, just reversed
+        addEdge(wildcardedRelatedType, targetType);
+        writersMap.put(targetType, writer);
+        return this;
+    }
+
+    @Override
+    public FlatWriterRegistryBuilder addSubtreeWriterAfter(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                           @Nonnull final Writer<? extends DataObject> writer,
+                                                           @Nonnull final InstanceIdentifier<?> relatedType) {
+        return addWriterAfter(SubtreeWriter.createForWriter(handledChildren, writer), relatedType);
+    }
+
+    @Override
+    public FlatWriterRegistryBuilder addWriterAfter(@Nonnull final Writer<? extends DataObject> writer,
+                                                    @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        final InstanceIdentifier<?> targetType = RWUtils.makeIidWildcarded(writer.getManagedDataObjectType());
+        checkWriterNotPresentYet(targetType);
+        writersRelations.addVertex(targetType);
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(writersRelations::addVertex);
+        // set edge to indicate before relationship, just reversed
+        relatedTypes.stream()
+                .map(RWUtils::makeIidWildcarded)
+                .forEach(type -> addEdge(type, targetType));
+        writersMap.put(targetType, writer);
+        return this;
+    }
+
+    @Override
+    public FlatWriterRegistryBuilder addSubtreeWriterAfter(@Nonnull final Set<InstanceIdentifier<?>> handledChildren,
+                                                           @Nonnull final Writer<? extends DataObject> writer,
+                                                           @Nonnull final Collection<InstanceIdentifier<?>> relatedTypes) {
+        return addWriterAfter(SubtreeWriter.createForWriter(handledChildren, writer), relatedTypes);
+    }
+
+
+    private void addEdge(final InstanceIdentifier<?> targetType,
+                         final InstanceIdentifier<?> relatedType) {
+        try {
+            writersRelations.addDagEdge(targetType, relatedType);
+        } catch (DirectedAcyclicGraph.CycleFoundException e) {
+            throw new IllegalArgumentException(String.format(
+                    "Unable to add writer with relation: %s -> %s. Loop detected", targetType, relatedType), e);
+        }
+    }
+
+    /**
+     * Create FlatWriterRegistry with writers ordered according to submitted relationships.
+     */
+    @Override
+    public FlatWriterRegistry build() {
+        final ImmutableMap<InstanceIdentifier<?>, Writer<?>> mappedWriters = getMappedWriters();
+        LOG.debug("Building writer registry with writers: {}",
+                mappedWriters.keySet().stream()
+                        .map(InstanceIdentifier::getTargetType)
+                        .map(Class::getSimpleName)
+                        .collect(Collectors.joining(", ")));
+        LOG.trace("Building writer registry with writers: {}", mappedWriters);
+        return new FlatWriterRegistry(mappedWriters);
+    }
+
+    @VisibleForTesting
+    ImmutableMap<InstanceIdentifier<?>, Writer<?>> getMappedWriters() {
+        final ImmutableMap.Builder<InstanceIdentifier<?>, Writer<?>> builder = ImmutableMap.builder();
+        // Iterate writer types according to their relationships from graph
+        writersRelations.iterator()
+                .forEachRemaining(writerType -> {
+                    // There might be types stored just for relationship sake, no real writer, ignoring those
+                    if (writersMap.containsKey(writerType)) {
+                        builder.put(writerType, writersMap.get(writerType));
+                    }
+                });
+        return builder.build();
+    }
+
+    @Override
+    public void close() throws Exception {
+        writersMap.clear();
+        writersRelations.removeAllEdges(writersRelations.edgeSet());
+        writersRelations.removeAllVertices(writersRelations.vertexSet());
+    }
+
+    // Represents edges in graph
+    private static final class WriterRelation {}
+}