Histogram Facet: Allow to define a key field and value script, closes #517.

modules/elasticsearch/src/main/java/org/elasticsearch/search/facet/histogram/HistogramFacetCollectorParser.java

@@ -93,11 +93,9 @@ public class HistogramFacetCollectorParser implements FacetCollectorParser {
             throw new FacetPhaseExecutionException(facetName, "[interval] is required to be set for histogram facet");
         }
 
-        if (interval < 0) {
+        if (valueScript != null) {
-            throw new FacetPhaseExecutionException(facetName, "[interval] is required to be positive for histogram facet");
+            return new KeyValueScriptHistogramFacetCollector(facetName, keyField, scriptLang, valueScript, params, interval, comparatorType, context);
-        }
+        } else if (valueField == null || keyField.equals(valueField)) {
-
-        if (valueField == null || keyField.equals(valueField)) {
             return new HistogramFacetCollector(facetName, keyField, interval, comparatorType, context);
         } else {
             // we have a value field, and its different than the key

modules/elasticsearch/src/main/java/org/elasticsearch/search/facet/histogram/HistogramScriptFacetBuilder.java

@@ -33,6 +33,7 @@ import java.util.Map;
  */
 public class HistogramScriptFacetBuilder extends AbstractFacetBuilder {
     private String lang;
+    private String keyFieldName;
     private String keyScript;
     private String valueScript;
     private Map<String, Object> params;
@@ -51,6 +52,11 @@ public class HistogramScriptFacetBuilder extends AbstractFacetBuilder {
         return this;
     }
 
+    public HistogramScriptFacetBuilder keyField(String keyFieldName) {
+        this.keyFieldName = keyFieldName;
+        return this;
+    }
+
     public HistogramScriptFacetBuilder keyScript(String keyScript) {
         this.keyScript = keyScript;
         return this;
@@ -90,8 +96,8 @@ public class HistogramScriptFacetBuilder extends AbstractFacetBuilder {
     }
 
     @Override public void toXContent(XContentBuilder builder, Params params) throws IOException {
-        if (keyScript == null) {
+        if (keyScript == null && keyFieldName == null) {
-            throw new SearchSourceBuilderException("key_script must be set on histogram script facet for facet [" + name + "]");
+            throw new SearchSourceBuilderException("key_script or key_field must be set on histogram script facet for facet [" + name + "]");
         }
         if (valueScript == null) {
             throw new SearchSourceBuilderException("value_script must be set on histogram script facet for facet [" + name + "]");
@@ -99,7 +105,11 @@ public class HistogramScriptFacetBuilder extends AbstractFacetBuilder {
         builder.startObject(name);
 
         builder.startObject(HistogramFacetCollectorParser.NAME);
-        builder.field("key_script", keyScript);
+        if (keyFieldName != null) {
+            builder.field("key_field", keyFieldName);
+        } else if (keyScript != null) {
+            builder.field("key_script", keyScript);
+        }
         builder.field("value_script", valueScript);
         if (lang != null) {
             builder.field("lang", lang);

modules/elasticsearch/src/main/java/org/elasticsearch/search/facet/histogram/KeyValueScriptHistogramFacetCollector.java

@@ -0,0 +1,138 @@
+/*
+ * Licensed to Elastic Search and Shay Banon under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Elastic Search 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.facet.histogram;
+
+import org.apache.lucene.index.IndexReader;
+import org.elasticsearch.common.trove.TLongDoubleHashMap;
+import org.elasticsearch.common.trove.TLongLongHashMap;
+import org.elasticsearch.index.cache.field.data.FieldDataCache;
+import org.elasticsearch.index.field.data.FieldDataType;
+import org.elasticsearch.index.field.data.NumericFieldData;
+import org.elasticsearch.index.mapper.FieldMapper;
+import org.elasticsearch.index.mapper.MapperService;
+import org.elasticsearch.script.search.SearchScript;
+import org.elasticsearch.search.facet.Facet;
+import org.elasticsearch.search.facet.FacetPhaseExecutionException;
+import org.elasticsearch.search.facet.support.AbstractFacetCollector;
+import org.elasticsearch.search.internal.SearchContext;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * A histogram facet collector that uses the same field as the key as well as the
+ * value.
+ *
+ * @author kimchy (shay.banon)
+ */
+public class KeyValueScriptHistogramFacetCollector extends AbstractFacetCollector {
+
+    private final String fieldName;
+
+    private final String indexFieldName;
+
+    private final long interval;
+
+    private final HistogramFacet.ComparatorType comparatorType;
+
+    private final FieldDataCache fieldDataCache;
+
+    private final FieldDataType fieldDataType;
+
+    private NumericFieldData fieldData;
+
+    private final SearchScript valueScript;
+
+    private final HistogramProc histoProc;
+
+    public KeyValueScriptHistogramFacetCollector(String facetName, String fieldName, String scriptLang, String valueScript, Map<String, Object> params, long interval, HistogramFacet.ComparatorType comparatorType, SearchContext context) {
+        super(facetName);
+        this.fieldName = fieldName;
+        this.interval = interval;
+        this.comparatorType = comparatorType;
+        this.fieldDataCache = context.fieldDataCache();
+
+        MapperService.SmartNameFieldMappers smartMappers = context.mapperService().smartName(fieldName);
+        if (smartMappers == null || !smartMappers.hasMapper()) {
+            throw new FacetPhaseExecutionException(facetName, "No mapping found for field [" + fieldName + "]");
+        }
+
+        // add type filter if there is exact doc mapper associated with it
+        if (smartMappers.hasDocMapper()) {
+            setFilter(context.filterCache().cache(smartMappers.docMapper().typeFilter()));
+        }
+
+        this.valueScript = new SearchScript(context.scriptSearchLookup(), scriptLang, valueScript, params, context.scriptService());
+
+        FieldMapper mapper = smartMappers.mapper();
+
+        indexFieldName = mapper.names().indexName();
+        fieldDataType = mapper.fieldDataType();
+
+        histoProc = new HistogramProc(interval, this.valueScript);
+    }
+
+    @Override protected void doCollect(int doc) throws IOException {
+        fieldData.forEachValueInDoc(doc, histoProc);
+    }
+
+    @Override protected void doSetNextReader(IndexReader reader, int docBase) throws IOException {
+        fieldData = (NumericFieldData) fieldDataCache.cache(fieldDataType, reader, indexFieldName);
+    }
+
+    @Override public Facet facet() {
+        return new InternalHistogramFacet(facetName, fieldName, fieldName, interval, comparatorType, histoProc.counts(), histoProc.totals());
+    }
+
+    public static long bucket(double value, long interval) {
+        return (((long) (value / interval)) * interval);
+    }
+
+    public static class HistogramProc implements NumericFieldData.DoubleValueInDocProc {
+
+        private final long interval;
+
+        private final SearchScript valueScript;
+
+        private final TLongLongHashMap counts = new TLongLongHashMap();
+
+        private final TLongDoubleHashMap totals = new TLongDoubleHashMap();
+
+        public HistogramProc(long interval, SearchScript valueScript) {
+            this.interval = interval;
+            this.valueScript = valueScript;
+        }
+
+        @Override public void onValue(int docId, double value) {
+            long bucket = bucket(value, interval);
+            counts.adjustOrPutValue(bucket, 1, 1);
+            double scriptValue = ((Number) valueScript.execute(docId)).doubleValue();
+            totals.adjustOrPutValue(bucket, scriptValue, scriptValue);
+        }
+
+        public TLongLongHashMap counts() {
+            return counts;
+        }
+
+        public TLongDoubleHashMap totals() {
+            return totals;
+        }
+    }
+}

modules/test/integration/src/test/java/org/elasticsearch/test/integration/search/facet/SimpleFacetsTests.java

@@ -631,6 +631,7 @@ public class SimpleFacetsTests extends AbstractNodesTests {
                 .addFacet(histogramFacet("stats3").keyField("num").valueField("multi_num").interval(100))
                 .addFacet(histogramScriptFacet("stats4").keyScript("doc['date'].date.minuteOfHour").valueScript("doc['num'].value"))
                 .addFacet(histogramFacet("stats5").field("date").interval(1, TimeUnit.MINUTES))
+                .addFacet(histogramScriptFacet("stats6").keyField("num").valueScript("doc['num'].value").interval(100))
                 .execute().actionGet();
 
         if (searchResponse.failedShards() > 0) {
@@ -700,6 +701,18 @@ public class SimpleFacetsTests extends AbstractNodesTests {
         assertThat(facet.entries().get(0).count(), equalTo(2l));
         assertThat(facet.entries().get(1).key(), equalTo(TimeValue.timeValueMinutes(2).millis()));
         assertThat(facet.entries().get(1).count(), equalTo(1l));
+
+        facet = searchResponse.facets().facet("stats6");
+        assertThat(facet.name(), equalTo("stats6"));
+        assertThat(facet.entries().size(), equalTo(2));
+        assertThat(facet.entries().get(0).key(), equalTo(1000l));
+        assertThat(facet.entries().get(0).count(), equalTo(2l));
+        assertThat(facet.entries().get(0).total(), equalTo(2120d));
+        assertThat(facet.entries().get(0).mean(), equalTo(1060d));
+        assertThat(facet.entries().get(1).key(), equalTo(1100l));
+        assertThat(facet.entries().get(1).count(), equalTo(1l));
+        assertThat(facet.entries().get(1).total(), equalTo(1175d));
+        assertThat(facet.entries().get(1).mean(), equalTo(1175d));
     }
 
     @Test public void testRangeFacets() throws Exception {