Dimension injecting sink. (#111)

* Dimension injecting sink.

* Separated the configuration into defaultDimensions and overrideDimensions and inject this into the union map between the data dimensions. Specifically, data overrides defaults and overrides overwrite both.

Author: vjkoskela

src/main/java/com/arpnetworking/tsdcore/sinks/DimensionInjectingSink.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright 2016 Groupon.com
+ *
+ * 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 com.arpnetworking.tsdcore.sinks;
+
+import com.arpnetworking.tsdcore.model.DefaultKey;
+import com.arpnetworking.tsdcore.model.PeriodicData;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+import net.sf.oval.constraint.NotNull;
+
+import java.util.Map;
+
+/**
+ * Sink adds any specified dimensions.
+ *
+ * @author Ville Koskela (ville dot koskela at inscopemetrics dot com)
+ */
+public final class DimensionInjectingSink extends BaseSink {
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void recordAggregateData(final PeriodicData data) {
+        final Map<String, String> mergedDimensions = Maps.newHashMap(_defaultDimensions);
+        mergedDimensions.putAll(data.getDimensions().getParameters());
+        mergedDimensions.putAll(_overrideDimensions);
+        final PeriodicData.Builder dataBuilder = PeriodicData.Builder.clone(data);
+        dataBuilder.setDimensions(new DefaultKey(ImmutableMap.copyOf(mergedDimensions)));
+        _sink.recordAggregateData(dataBuilder.build());
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void close() {
+        // Nothing to do
+    }
+
+    private DimensionInjectingSink(final Builder builder) {
+        super(builder);
+        _sink = builder._sink;
+        _defaultDimensions = builder._defaultDimensions;
+        _overrideDimensions = builder._overrideDimensions;
+    }
+
+    private final Sink _sink;
+    private final ImmutableMap<String, String> _defaultDimensions;
+    private final ImmutableMap<String, String> _overrideDimensions;
+
+    /**
+     * Implementation of builder pattern for {@link DimensionInjectingSink}.
+     *
+     * @author Ville Koskela (ville dot koskela at inscopemetrics dot com)
+     */
+    public static final class Builder extends BaseSink.Builder<Builder, DimensionInjectingSink> {
+
+        /**
+         * Public constructor.
+         */
+        public Builder() {
+            super(DimensionInjectingSink::new);
+        }
+
+        /**
+         * Sets the default dimensions to inject. Matching dimensions in the data
+         * overwrite any default dimensions.
+         *
+         * @param value The default dimensions to inject.
+         * @return This instance of {@link Builder}.
+         */
+        public Builder setDefaultDimensions(final ImmutableMap<String, String> value) {
+            _defaultDimensions = value;
+            return self();
+        }
+
+        /**
+         * Sets the override dimensions to inject. Matching dimensions in the data
+         * are overwritten by override dimensions.
+         *
+         * @param value The overrride dimensions to inject.
+         * @return This instance of {@link Builder}.
+         */
+        public Builder setOverrideDimensions(final ImmutableMap<String, String> value) {
+            _overrideDimensions = value;
+            return self();
+        }
+
+        /**
+         * The sink to wrap. Cannot be null.
+         *
+         * @param value The sink to wrap.
+         * @return This instance of {@link Builder}.
+         */
+        public Builder setSink(final Sink value) {
+            _sink = value;
+            return this;
+        }
+
+        /**
+         * {@inheritDoc}
+         */
+        @Override
+        protected Builder self() {
+            return this;
+        }
+
+        @NotNull
+        private ImmutableMap<String, String> _defaultDimensions = ImmutableMap.of();
+        @NotNull
+        private ImmutableMap<String, String> _overrideDimensions = ImmutableMap.of();
+        @NotNull
+        private Sink _sink;
+    }
+}