HONEYCOMB-9: Remove references to VPP from translation layer

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

1 files changed, 232 insertions, 0 deletions

diff --git a/v3po/translate-impl/src/main/java/io/fd/honeycomb/v3po/translate/impl/read/AbstractCompositeReader.java b/v3po/translate-impl/src/main/java/io/fd/honeycomb/v3po/translate/impl/read/AbstractCompositeReader.java
new file mode 100644
index 000000000..f9fa0eeaa
--- /dev/null
+++ b/v3po/translate-impl/src/main/java/io/fd/honeycomb/v3po/translate/impl/read/AbstractCompositeReader.java
@@ -0,0 +1,232 @@
+/*
+ * 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.impl.read;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+import io.fd.honeycomb.v3po.translate.util.ReflectionUtils;
+import io.fd.honeycomb.v3po.translate.util.RWUtils;
+import io.fd.honeycomb.v3po.translate.read.ChildReader;
+import io.fd.honeycomb.v3po.translate.read.ReadContext;
+import io.fd.honeycomb.v3po.translate.read.ReadFailedException;
+import io.fd.honeycomb.v3po.translate.read.Reader;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.yangtools.concepts.Builder;
+import org.opendaylight.yangtools.yang.binding.Augmentation;
+import org.opendaylight.yangtools.yang.binding.ChildOf;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.Identifier;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Beta
+abstract class AbstractCompositeReader<D extends DataObject, B extends Builder<D>> implements Reader<D> {
+
+    private static final Logger LOG = LoggerFactory.getLogger(AbstractCompositeReader.class);
+
+    private final Map<Class<? extends DataObject>, ChildReader<? extends ChildOf<D>>> childReaders;
+    private final Map<Class<? extends DataObject>, ChildReader<? extends Augmentation<D>>> augReaders;
+    private final InstanceIdentifier<D> instanceIdentifier;
+
+    AbstractCompositeReader(final Class<D> managedDataObjectType,
+                            final List<ChildReader<? extends ChildOf<D>>> childReaders,
+                            final List<ChildReader<? extends Augmentation<D>>> augReaders) {
+        this.childReaders = RWUtils.uniqueLinkedIndex(childReaders, RWUtils.MANAGER_CLASS_FUNCTION);
+        this.augReaders = RWUtils.uniqueLinkedIndex(augReaders, RWUtils.MANAGER_CLASS_AUG_FUNCTION);
+        this.instanceIdentifier = InstanceIdentifier.create(managedDataObjectType);
+    }
+
+    @Nonnull
+    @Override
+    public final InstanceIdentifier<D> getManagedDataObjectType() {
+        return instanceIdentifier;
+    }
+
+    /**
+     * @param id {@link InstanceIdentifier} pointing to current node. In case of keyed list, key must be present.
+     *
+     */
+    protected Optional<D> readCurrent(final InstanceIdentifier<D> id,
+                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
+        LOG.debug("{}: Reading current: {}", this, id);
+        final B builder = getBuilder(id);
+        // Cache empty value to determine if anything has changed later TODO cache in a field
+        final D emptyValue = builder.build();
+
+        LOG.trace("{}: Reading current attributes", this);
+        readCurrentAttributes(id, builder, ctx);
+
+        // TODO expect exceptions from reader
+        for (ChildReader<? extends ChildOf<D>> child : childReaders.values()) {
+            LOG.debug("{}: Reading child from: {}", this, child);
+            child.read(id, builder, ctx);
+        }
+
+        for (ChildReader<? extends Augmentation<D>> child : augReaders.values()) {
+            LOG.debug("{}: Reading augment from: {}", this, child);
+            child.read(id, builder, ctx);
+        }
+
+        // Need to check whether anything was filled in to determine if data is present or not.
+        final D built = builder.build();
+        final Optional<D> read = built.equals(emptyValue)
+            ? Optional.<D>absent()
+            : Optional.of(built);
+
+        LOG.debug("{}: Current node read successfully. Result: {}", this, read);
+        return read;
+    }
+
+    @Nonnull
+    @Override
+    @SuppressWarnings("unchecked")
+    public Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                               @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        LOG.trace("{}: Reading : {}", this, id);
+        if (id.getTargetType().equals(getManagedDataObjectType().getTargetType())) {
+            return readCurrent((InstanceIdentifier<D>) id, ctx);
+        } else {
+            return readSubtree(id, ctx);
+        }
+    }
+
+    private Optional<? extends DataObject> readSubtree(final InstanceIdentifier<? extends DataObject> id,
+                                                       @Nonnull final ReadContext ctx)
+            throws ReadFailedException {
+        LOG.debug("{}: Reading subtree: {}", this, id);
+        final Class<? extends DataObject> next = RWUtils.getNextId(id, getManagedDataObjectType()).getType();
+        final ChildReader<? extends ChildOf<D>> reader = childReaders.get(next);
+
+        if (reader != null) {
+            LOG.debug("{}: Reading subtree: {} from: {}", this, id, reader);
+            return reader.read(id, ctx);
+        } else {
+            LOG.debug("{}: Dedicated subtree reader missing for: {}. Reading current and filtering", this, next);
+            // If there's no dedicated reader, use read current
+            final InstanceIdentifier<D> currentId = RWUtils.cutId(id, getManagedDataObjectType());
+            final Optional<D> current = readCurrent(currentId, ctx);
+            // then perform post-reading filtering (return only requested sub-node)
+            final Optional<? extends DataObject> readSubtree = current.isPresent()
+                ? filterSubtree(current.get(), id, getManagedDataObjectType().getTargetType())
+                : current;
+
+            LOG.debug("{}: Subtree: {} read successfully. Result: {}", this, id, readSubtree);
+            return readSubtree;
+        }
+    }
+
+    /**
+     * Fill in current node's attributes
+     *
+     * @param id {@link InstanceIdentifier} pointing to current node. In case of keyed list, key must be present.
+     * @param builder Builder object for current node where the read attributes must be placed
+     * @param ctx Current read context
+     */
+    protected abstract void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id, @Nonnull final B builder,
+                                                  @Nonnull final ReadContext ctx) throws ReadFailedException;
+
+    /**
+     * Return new instance of a builder object for current node
+     *
+     * @param id {@link InstanceIdentifier} pointing to current node. In case of keyed list, key must be present.
+     * @return Builder object for current node type
+     */
+    protected abstract B getBuilder(InstanceIdentifier<D> id);
+
+    // TODO move filtering out of here into a dedicated Filter ifc
+    @Nonnull
+    private static Optional<? extends DataObject> filterSubtree(@Nonnull final DataObject parent,
+                                                            @Nonnull final InstanceIdentifier<? extends DataObject> absolutPath,
+                                                            @Nonnull final Class<?> managedType) {
+        // TODO is there a better way than reflection ? e.g. convert into NN and filter out with a utility
+        // FIXME this needs to be recursive. right now it expects only 1 additional element in ID + test
+
+        final InstanceIdentifier.PathArgument nextId =
+            RWUtils.getNextId(absolutPath, InstanceIdentifier.create(parent.getClass()));
+
+        Optional<Method> method = ReflectionUtils.findMethodReflex(managedType, "get",
+            Collections.<Class<?>>emptyList(), nextId.getType());
+
+        if (method.isPresent()) {
+            return Optional.fromNullable(filterSingle(parent, nextId, method.get()));
+        } else {
+            // List child nodes
+            method = ReflectionUtils.findMethodReflex(managedType,
+                "get" + nextId.getType().getSimpleName(), Collections.<Class<?>>emptyList(), List.class);
+
+            if (method.isPresent()) {
+                return filterList(parent, nextId, method.get());
+            } else {
+                throw new IllegalStateException(
+                    "Unable to filter " + nextId + " from " + parent + " getters not found using reflexion");
+            }
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private static Optional<? extends DataObject> filterList(final DataObject parent,
+                                                             final InstanceIdentifier.PathArgument nextId,
+                                                             final Method method) {
+        final List<? extends DataObject> invoke = (List<? extends DataObject>) invoke(method, nextId, parent);
+
+        checkArgument(nextId instanceof InstanceIdentifier.IdentifiableItem<?, ?>,
+            "Unable to perform wildcarded read for %s", nextId);
+        final Identifier key = ((InstanceIdentifier.IdentifiableItem) nextId).getKey();
+        return Iterables.tryFind(invoke, new Predicate<DataObject>() {
+            @Override
+            public boolean apply(@Nullable final DataObject input) {
+                final Optional<Method> keyGetter =
+                    ReflectionUtils.findMethodReflex(nextId.getType(), "get",
+                        Collections.<Class<?>>emptyList(), key.getClass());
+                final Object actualKey;
+                actualKey = invoke(keyGetter.get(), nextId, input);
+                return key.equals(actualKey);
+            }
+        });
+    }
+
+    private static DataObject filterSingle(final DataObject parent,
+                                           final InstanceIdentifier.PathArgument nextId, final Method method) {
+        return nextId.getType().cast(invoke(method, nextId, parent));
+    }
+
+    private static Object invoke(final Method method,
+                                 final InstanceIdentifier.PathArgument nextId, final DataObject parent) {
+        try {
+            return method.invoke(parent);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new IllegalArgumentException("Unable to get " + nextId + " from " + parent, e);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Reader[%s]", getManagedDataObjectType().getTargetType().getSimpleName());
+    }
+}