1 files changed, 121 insertions, 0 deletions
diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/write/TransactionWriteContext.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/write/TransactionWriteContext.java
new file mode 100644
index 000000000..51f999294
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/write/TransactionWriteContext.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.fd.honeycomb.translate.util.write;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.CheckedFuture;
+import io.fd.honeycomb.translate.MappingContext;
+import io.fd.honeycomb.translate.ModificationCache;
+import io.fd.honeycomb.translate.write.WriteContext;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
+import org.opendaylight.controller.md.sal.dom.api.DOMDataReadOnlyTransaction;
+import org.opendaylight.yangtools.binding.data.codec.api.BindingNormalizedNodeSerializer;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+
+/**
+ * Transaction based WriteContext
+ */
+public final class TransactionWriteContext implements WriteContext {
+
+    private final DOMDataReadOnlyTransaction beforeTx;
+    private final DOMDataReadOnlyTransaction afterTx;
+    private final ModificationCache ctx;
+    private final BindingNormalizedNodeSerializer serializer;
+    private final MappingContext mappingContext;
+
+    public TransactionWriteContext(final BindingNormalizedNodeSerializer serializer,
+                                   final DOMDataReadOnlyTransaction beforeTx,
+                                   final DOMDataReadOnlyTransaction afterTx,
+                                   final MappingContext mappingContext) {
+        this.serializer = serializer;
+        // TODO do we have a BA transaction adapter ? If so, use it here and don't pass serializer
+        this.beforeTx = beforeTx;
+        this.afterTx = afterTx;
+        this.mappingContext = mappingContext;
+        this.ctx = new ModificationCache();
+    }
+
+    // TODO make this asynchronous
+
+    @Override
+    public <T extends DataObject> Optional<T> readBefore(@Nonnull final InstanceIdentifier<T> currentId) {
+        return read(currentId, beforeTx);
+    }
+
+    @Override
+    public <T extends DataObject> Optional<T> readAfter(@Nonnull final InstanceIdentifier<T> currentId) {
+        return read(currentId, afterTx);
+    }
+
+
+    private <T extends DataObject> Optional<T> read(final InstanceIdentifier<T> currentId,
+                                                    final DOMDataReadOnlyTransaction tx) {
+        final YangInstanceIdentifier path = serializer.toYangInstanceIdentifier(currentId);
+
+        final CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read =
+                tx.read(LogicalDatastoreType.CONFIGURATION, path);
+
+        try {
+            // TODO once the APIs are asynchronous use just Futures.transform
+            final Optional<NormalizedNode<?, ?>> optional = read.checkedGet();
+
+            if (!optional.isPresent()) {
+                return Optional.absent();
+            }
+
+            final NormalizedNode<?, ?> data = optional.get();
+            final Map.Entry<InstanceIdentifier<?>, DataObject> entry = serializer.fromNormalizedNode(path, data);
+
+            final Class<T> targetType = currentId.getTargetType();
+            checkState(targetType.isAssignableFrom(entry.getValue().getClass()),
+                "Unexpected data object type, should be: %s, but was: %s", targetType, entry.getValue().getClass());
+            return Optional.of(targetType.cast(entry.getValue()));
+        } catch (ReadFailedException e) {
+            throw new IllegalStateException("Unable to perform read", e);
+        }
+    }
+
+    @Nonnull
+    @Override
+    public ModificationCache getModificationCache() {
+        return ctx;
+    }
+
+    @Nonnull
+    @Override
+    public MappingContext getMappingContext() {
+        return mappingContext;
+    }
+
+    /**
+     * Does not close the transactions
+     */
+    @Override
+    public void close() {
+        ctx.close();
+        beforeTx.close();
+        afterTx.close();
+    }
+}