Add support for booleans in scripts (elastic#20950)

* Scripting: Add support for booleans in scripts

Since 2.0, booleans have been represented as numeric fields (longs).
However, in scripts, this is odd, since you expect doing a comparison
against a boolean to work. While languages like groovy will auto convert
between booleans and longs, painless does not.

This changes the doc values accessor for boolean fields in scripts to
return Boolean objects instead of Long objects.

closes elastic#20949

* Make Booleans final and remove wrapping of `this` for getValues()

Author: rjernst

core/src/main/java/org/elasticsearch/index/fielddata/ScriptDocValues.java

@@ -291,4 +291,38 @@ public double geohashDistanceWithDefault(String geohash, double defaultValue) {
             return geohashDistance(geohash);
         }
     }
+
+    final class Booleans extends AbstractList<Boolean> implements ScriptDocValues<Boolean> {
+
+        private final SortedNumericDocValues values;
+
+        public Booleans(SortedNumericDocValues values) {
+            this.values = values;
+        }
+
+        @Override
+        public void setNextDocId(int docId) {
+            values.setDocument(docId);
+        }
+
+        @Override
+        public List<Boolean> getValues() {
+            return this;
+        }
+
+        public boolean getValue() {
+            return values.count() != 0 && values.valueAt(0) == 1;
+        }
+
+        @Override
+        public Boolean get(int index) {
+            return values.valueAt(index) == 1;
+        }
+
+        @Override
+        public int size() {
+            return values.count();
+        }
+
+    }
 }

core/src/main/java/org/elasticsearch/index/fielddata/plain/AtomicLongFieldData.java

@@ -19,28 +19,24 @@
 
 package org.elasticsearch.index.fielddata.plain;
 
-import org.apache.lucene.index.DocValues;
-import org.apache.lucene.index.SortedNumericDocValues;
-import org.apache.lucene.util.Accountable;
 import org.elasticsearch.index.fielddata.AtomicNumericFieldData;
 import org.elasticsearch.index.fielddata.FieldData;
 import org.elasticsearch.index.fielddata.ScriptDocValues;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
 import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
 
-import java.util.Collection;
-import java.util.Collections;
-
-
 /**
  * Specialization of {@link AtomicNumericFieldData} for integers.
  */
 abstract class AtomicLongFieldData implements AtomicNumericFieldData {
 
     private final long ramBytesUsed;
+    /** True if this numeric data is for a boolean field, and so only has values 0 and 1. */
+    private final boolean isBoolean;
 
-    AtomicLongFieldData(long ramBytesUsed) {
+    AtomicLongFieldData(long ramBytesUsed, boolean isBoolean) {
         this.ramBytesUsed = ramBytesUsed;
+        this.isBoolean = isBoolean;
     }
 
     @Override
@@ -50,7 +46,11 @@ public long ramBytesUsed() {
 
     @Override
     public final ScriptDocValues getScriptValues() {
-        return new ScriptDocValues.Longs(getLongValues());
+        if (isBoolean) {
+            return new ScriptDocValues.Booleans(getLongValues());
+        } else {
+            return new ScriptDocValues.Longs(getLongValues());
+        }
     }
 
     @Override
@@ -63,24 +63,6 @@ public final SortedNumericDoubleValues getDoubleValues() {
         return FieldData.castToDouble(getLongValues());
     }
 
-    public static AtomicNumericFieldData empty(final int maxDoc) {
-        return new AtomicLongFieldData(0) {
-
-            @Override
-            public SortedNumericDocValues getLongValues() {
-                return DocValues.emptySortedNumeric(maxDoc);
-            }
-
-            @Override
-            public Collection<Accountable> getChildResources() {
-                return Collections.emptyList();
-            }
-
-        };
-    }
-
     @Override
-    public void close() {
-    }
-
+    public void close() {}
 }

core/src/main/java/org/elasticsearch/index/fielddata/plain/SortedNumericDVIndexFieldData.java

@@ -96,7 +96,7 @@ public AtomicNumericFieldData load(LeafReaderContext context) {
             case DOUBLE:
                 return new SortedNumericDoubleFieldData(reader, field);
             default:
-                return new SortedNumericLongFieldData(reader, field);
+                return new SortedNumericLongFieldData(reader, field, numericType == NumericType.BOOLEAN);
         }
     }
 
@@ -117,8 +117,8 @@ static final class SortedNumericLongFieldData extends AtomicLongFieldData {
         final LeafReader reader;
         final String field;
 
-        SortedNumericLongFieldData(LeafReader reader, String field) {
-            super(0L);
+        SortedNumericLongFieldData(LeafReader reader, String field, boolean isBoolean) {
+            super(0L, isBoolean);
             this.reader = reader;
             this.field = field;
         }

modules/lang-painless/src/main/resources/org/elasticsearch/painless/org.elasticsearch.txt

@@ -101,6 +101,12 @@ class org.elasticsearch.index.fielddata.ScriptDocValues.GeoPoints -> org.elastic
   double geohashDistanceWithDefault(String,double)
 }
 
+class org.elasticsearch.index.fielddata.ScriptDocValues.Booleans -> org.elasticsearch.index.fielddata.ScriptDocValues$Booleans extends List,Collection,Iterable,Object {
+  Boolean get(int)
+  boolean getValue()
+  List getValues()
+}
+
 # for testing.
 # currently FeatureTest exposes overloaded constructor, field load store, and overloaded static methods
 class org.elasticsearch.painless.FeatureTest -> org.elasticsearch.painless.FeatureTest extends Object {

modules/lang-painless/src/test/resources/rest-api-spec/test/plan_a/30_search.yaml

@@ -6,19 +6,19 @@
             index: test
             type: test
             id: 1
-            body: { "test": "value beck", "num1": 1.0 }
+            body: { "test": "value beck", "num1": 1.0, "bool": true }
     - do:
         index:
             index: test
             type: test
             id: 2
-            body: { "test": "value beck", "num1": 2.0 }
+            body: { "test": "value beck", "num1": 2.0, "bool": false }
     - do:
         index:
             index: test
             type: test
             id: 3
-            body: { "test": "value beck", "num1": 3.0 }
+            body: { "test": "value beck", "num1": 3.0, "bool": true }
     - do:
         indices.refresh: {}
 
@@ -95,6 +95,19 @@
     - match: { hits.hits.1.fields.sNum1.0: 2.0 }
     - match: { hits.hits.2.fields.sNum1.0: 3.0 }
 
+    - do:
+        index: test
+        search:
+            body:
+                query:
+                    script:
+                        script:
+                            inline: "doc['bool'].value == false"
+                            lang: painless
+
+    - match: { hits.total: 1 }
+    - match: { hits.hits.0._id: "2" }
+
 ---
 
 "Custom Script Boost":