HONEYCOMB-270 Add isPresent() to Readers/Customizers

So that they can influence whether empty data is to be considered as present

+ Move registries implementations from util to impl
+ Introduce DelegatingReader trait
+ Extend GenericReader where possible to reduce duplication

Change-Id: I5a416acd0c4eab1fbc30fcbe585719991dbe9215
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

1 files changed, 103 insertions, 0 deletions

diff --git a/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/DelegatingReader.java b/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/DelegatingReader.java
new file mode 100644
index 000000000..513639610
--- /dev/null
+++ b/infra/translate-utils/src/main/java/io/fd/honeycomb/translate/util/read/DelegatingReader.java
@@ -0,0 +1,103 @@
+/*
+ * 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.read;
+
+import com.google.common.base.Optional;
+import io.fd.honeycomb.translate.read.ListReader;
+import io.fd.honeycomb.translate.read.ReadContext;
+import io.fd.honeycomb.translate.read.ReadFailedException;
+import io.fd.honeycomb.translate.read.Reader;
+import java.util.List;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.concepts.Builder;
+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;
+
+/**
+ * A trait of a delegating reader. Delegates all the calls to its delegate.
+ */
+public interface DelegatingReader<D extends DataObject, B extends Builder<D>> extends Reader<D, B> {
+
+    Reader<D, B> getDelegate();
+
+    @Nonnull
+    default Optional<? extends DataObject> read(@Nonnull final InstanceIdentifier<? extends DataObject> id,
+                                                @Nonnull final ReadContext ctx) throws ReadFailedException {
+        return getDelegate().read(id, ctx);
+    }
+
+    default void readCurrentAttributes(@Nonnull final InstanceIdentifier<D> id,
+                                      @Nonnull final B builder,
+                                      @Nonnull final ReadContext ctx) throws ReadFailedException {
+        getDelegate().readCurrentAttributes(id, builder, ctx);
+    }
+
+    @Nonnull
+    default B getBuilder(final InstanceIdentifier<D> id) {
+        return getDelegate().getBuilder(id);
+    }
+
+    default void merge(@Nonnull final Builder<? extends DataObject> parentBuilder,
+                       @Nonnull final D readValue) {
+        getDelegate().merge(parentBuilder, readValue);
+    }
+
+    @Override
+    default boolean isPresent(InstanceIdentifier<D> id, D built, final ReadContext ctx) throws ReadFailedException {
+        return getDelegate().isPresent(id, built, ctx);
+    }
+
+    @Nonnull
+    default InstanceIdentifier<D> getManagedDataObjectType() {
+        return getDelegate().getManagedDataObjectType();
+    }
+
+    /**
+     * ListReader specific delegating trait.
+     */
+    interface DelegatingListReader<D extends DataObject & Identifiable<K>, K extends Identifier<D>, B extends Builder<D>>
+            extends DelegatingReader<D, B>, ListReader<D, K, B> {
+
+        ListReader<D, K, B> getDelegate();
+
+        @Override
+        default List<K> getAllIds(@Nonnull InstanceIdentifier<D> id, @Nonnull ReadContext ctx)
+                throws ReadFailedException {
+            return getDelegate().getAllIds(id, ctx);
+        }
+
+        @Nonnull
+        @Override
+        default List<D> readList(@Nonnull final InstanceIdentifier<D> id, @Nonnull final ReadContext ctx)
+                throws ReadFailedException {
+            return getDelegate().readList(id, ctx);
+        }
+
+        @Override
+        default void merge(@Nonnull final Builder<? extends DataObject> builder,
+                           @Nonnull final List<D> readData) {
+            getDelegate().merge(builder, readData);
+        }
+
+        @Override
+        default void merge(@Nonnull final Builder<? extends DataObject> parentBuilder, @Nonnull final D readValue) {
+            getDelegate().merge(parentBuilder, readValue);
+        }
+    }
+}