Aggregations: Add stats_bucket / extended_stats_bucket pipeline aggregations

These are the complements to the stats/extended_stats metric aggregations, and can be used
to calculate a variety of statistics over buckets

1 files changed, 134 insertions, 0 deletions

diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/pipeline/bucketmetrics/stats/extended/ExtendedStatsBucketPipelineAggregator.java b/core/src/main/java/org/elasticsearch/search/aggregations/pipeline/bucketmetrics/stats/extended/ExtendedStatsBucketPipelineAggregator.java
new file mode 100644
index 0000000000..6a7f2bec3f
--- /dev/null
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/pipeline/bucketmetrics/stats/extended/ExtendedStatsBucketPipelineAggregator.java
@@ -0,0 +1,134 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you 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 org.elasticsearch.search.aggregations.pipeline.bucketmetrics.stats.extended;
+
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.search.aggregations.AggregatorFactory;
+import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.aggregations.InternalAggregation.Type;
+import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorFactory;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorStreams;
+import org.elasticsearch.search.aggregations.pipeline.bucketmetrics.BucketMetricsPipelineAggregator;
+import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+public class ExtendedStatsBucketPipelineAggregator extends BucketMetricsPipelineAggregator {
+
+    public final static Type TYPE = new Type("extended_stats_bucket");
+
+    public final static PipelineAggregatorStreams.Stream STREAM = new PipelineAggregatorStreams.Stream() {
+        @Override
+        public ExtendedStatsBucketPipelineAggregator readResult(StreamInput in) throws IOException {
+            ExtendedStatsBucketPipelineAggregator result = new ExtendedStatsBucketPipelineAggregator();
+            result.readFrom(in);
+            return result;
+        }
+    };
+
+    public static void registerStreams() {
+        PipelineAggregatorStreams.registerStream(STREAM, TYPE.stream());
+        InternalExtendedStatsBucket.registerStreams();
+    }
+
+    private double sum = 0;
+    private long count = 0;
+    private double min = Double.POSITIVE_INFINITY;
+    private double max = Double.NEGATIVE_INFINITY;
+    private double sumOfSqrs = 1;
+    private double sigma;
+
+    protected ExtendedStatsBucketPipelineAggregator(String name, String[] bucketsPaths, double sigma, GapPolicy gapPolicy,
+                                                    ValueFormatter formatter, Map<String, Object> metaData) {
+        super(name, bucketsPaths, gapPolicy, formatter, metaData);
+        this.sigma = sigma;
+    }
+
+    ExtendedStatsBucketPipelineAggregator() {
+        // For Serialization
+    }
+
+    @Override
+    public Type type() {
+        return TYPE;
+    }
+
+    @Override
+    protected void preCollection() {
+        sum = 0;
+        count = 0;
+        min = Double.POSITIVE_INFINITY;
+        max = Double.NEGATIVE_INFINITY;
+        sumOfSqrs = 1;
+    }
+
+    @Override
+    protected void collectBucketValue(String bucketKey, Double bucketValue) {
+        sum += bucketValue;
+        min = Math.min(min, bucketValue);
+        max = Math.max(max, bucketValue);
+        count += 1;
+        sumOfSqrs += bucketValue * bucketValue;
+    }
+
+    @Override
+    protected InternalAggregation buildAggregation(List<PipelineAggregator> pipelineAggregators, Map<String, Object> metadata) {
+        return new InternalExtendedStatsBucket(name(), count, sum, min, max, sumOfSqrs, sigma, formatter, pipelineAggregators, metadata);
+    }
+
+    public static class Factory extends PipelineAggregatorFactory {
+
+        private final ValueFormatter formatter;
+        private final GapPolicy gapPolicy;
+        private final double sigma;
+
+        public Factory(String name, String[] bucketsPaths, double sigma, GapPolicy gapPolicy, ValueFormatter formatter) {
+            super(name, TYPE.name(), bucketsPaths);
+            this.gapPolicy = gapPolicy;
+            this.formatter = formatter;
+            this.sigma = sigma;
+        }
+
+        @Override
+        protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
+            return new ExtendedStatsBucketPipelineAggregator(name, bucketsPaths, sigma, gapPolicy, formatter, metaData);
+        }
+
+        @Override
+        public void doValidate(AggregatorFactory parent, AggregatorFactory[] aggFactories,
+                List<PipelineAggregatorFactory> pipelineAggregatorFactories) {
+            if (bucketsPaths.length != 1) {
+                throw new IllegalStateException(Parser.BUCKETS_PATH.getPreferredName()
+                        + " must contain a single entry for aggregation [" + name + "]");
+            }
+
+            if (sigma < 0.0 ) {
+                throw new IllegalStateException(ExtendedStatsBucketParser.SIGMA.getPreferredName()
+                        + " must be a non-negative double");
+            }
+        }
+
+    }
+
+}