Add BinaryDocValuesField to replace BytesRef (ScriptDocValues)

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

@@ -20,6 +20,13 @@ class org.elasticsearch.script.DocBasedScript {
 }
 
 class org.elasticsearch.script.field.DelegateDocValuesField @dynamic_type {
-  def getValue(def)
   List getValues()
+  def getValue(def)
+  def getValue(int, def)
 }
+
+class org.elasticsearch.script.field.BinaryDocValuesField @dynamic_type {
+  List getValues()
+  BytesRef getValue(BytesRef)
+  BytesRef getValue(int, BytesRef)
+}

modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/60_script_doc_values_binary.yml

@@ -37,3 +37,20 @@
                             source: "doc['binary'].value.utf8ToString()"
     - match: { hits.hits.0.fields.field1.0: "Some binary blob" }
     - match: { hits.hits.0.fields.field2.0: "Some binary blob" }
+
+    - do:
+        search:
+          body:
+            script_fields:
+              field1:
+                script:
+                  source: "field('binary').getValue(null).utf8ToString()"
+              field2:
+                script:
+                  source: "field('binary').getValue(0, null).utf8ToString()"
+              field3:
+                script:
+                  source: "field('binary').getValues()[0].utf8ToString()"
+    - match: { hits.hits.0.fields.field1.0: "Some binary blob" }
+    - match: { hits.hits.0.fields.field2.0: "Some binary blob" }
+    - match: { hits.hits.0.fields.field3.0: "Some binary blob" }

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

@@ -17,6 +17,7 @@
 import org.elasticsearch.common.geo.GeoUtils;
 import org.elasticsearch.common.time.DateUtils;
 import org.elasticsearch.geometry.utils.Geohash;
+import org.elasticsearch.script.field.BinaryDocValuesField;
 
 import java.io.IOException;
 import java.time.Instant;
@@ -573,28 +574,33 @@ public final String getValue() {
         }
     }
 
-    public static final class BytesRefs extends BinaryScriptDocValues<BytesRef> {
+    public static final class BytesRefs extends ScriptDocValues<BytesRef> {
 
-        public BytesRefs(SortedBinaryDocValues in) {
-            super(in);
+        private final BinaryDocValuesField binaryDocValuesField;
+
+        public BytesRefs(BinaryDocValuesField binaryDocValuesField) {
+            this.binaryDocValuesField = binaryDocValuesField;
         }
 
         @Override
-        public BytesRef get(int index) {
-            if (count == 0) {
-                throw new IllegalStateException("A document doesn't have a value for a field! " +
-                    "Use doc[<field>].size()==0 to check if a document is missing a field!");
-            }
-            /**
-             * We need to make a copy here because {@link BinaryScriptDocValues} might reuse the
-             * returned value and the same instance might be used to
-             * return values from multiple documents.
-             **/
-            return values[index].toBytesRef();
+        public void setNextDocId(int docId) throws IOException {
+            throw new UnsupportedOperationException();
         }
 
         public BytesRef getValue() {
-            return get(0);
+            throwIfEmpty();
+            return binaryDocValuesField.getValue(null); // default is ignored
+        }
+
+        @Override
+        public BytesRef get(int index) {
+            throwIfEmpty();
+            return binaryDocValuesField.getValue(null); // default is ignored
+        }
+
+        @Override
+        public int size() {
+            return binaryDocValuesField.size();
         }
     }
 }

server/src/main/java/org/elasticsearch/index/fielddata/plain/BytesBinaryDVLeafFieldData.java

@@ -9,8 +9,7 @@
 package org.elasticsearch.index.fielddata.plain;
 
 import org.apache.lucene.index.BinaryDocValues;
-import org.elasticsearch.index.fielddata.ScriptDocValues;
-import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.BinaryDocValuesField;
 import org.elasticsearch.script.field.DocValuesField;
 
 
@@ -21,7 +20,7 @@ final class BytesBinaryDVLeafFieldData extends AbstractBinaryDVLeafFieldData {
 
     @Override
     public DocValuesField getScriptField(String name) {
-        return new DelegateDocValuesField(new ScriptDocValues.BytesRefs(getBytesValues()), name);
+        return new BinaryDocValuesField(getBytesValues(), name);
     }
 }
 

server/src/main/java/org/elasticsearch/script/field/BinaryDocValuesField.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.script.field;
+
+import org.apache.lucene.util.ArrayUtil;
+import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.BytesRefBuilder;
+import org.elasticsearch.index.fielddata.ScriptDocValues;
+import org.elasticsearch.index.fielddata.ScriptDocValues.BytesRefs;
+import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class BinaryDocValuesField implements DocValuesField {
+
+    private final SortedBinaryDocValues input;
+    private final String name;
+
+    private BytesRefBuilder[] values = new BytesRefBuilder[0];
+    private int count;
+
+    // used for backwards compatibility for old-style "doc" access
+    // as a delegate to this field class
+    private BytesRefs bytesRefs = null;
+
+    public BinaryDocValuesField(SortedBinaryDocValues input, String name) {
+        this.input = input;
+        this.name = name;
+    }
+
+    @Override
+    public void setNextDocId(int docId) throws IOException {
+        if (input.advanceExact(docId)) {
+            resize(input.docValueCount());
+            for (int i = 0; i < count; i++) {
+                // We need to make a copy here, because BytesBinaryDVLeafFieldData's SortedBinaryDocValues
+                // implementation reuses the returned BytesRef. Otherwise, we would end up with the same BytesRef
+                // instance for all slots in the values array.
+                values[i].copyBytes(input.nextValue());
+            }
+        } else {
+            resize(0);
+        }
+    }
+
+    private void resize(int newSize) {
+        count = newSize;
+
+        if (newSize > values.length) {
+            int oldLength = values.length;
+            values = ArrayUtil.grow(values, count);
+
+            for (int i = oldLength; i < values.length; ++i) {
+                values[i] = new BytesRefBuilder();
+            }
+        }
+    }
+
+    @Override
+    public ScriptDocValues<?> getScriptDocValues() {
+        if (bytesRefs == null) {
+            bytesRefs = new BytesRefs(this);
+        }
+
+        return bytesRefs;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return count == 0;
+    }
+
+    @Override
+    public int size() {
+        return count;
+    }
+
+    public List<BytesRef> getValues() {
+        if (isEmpty()) {
+            return Collections.emptyList();
+        }
+
+        List<BytesRef> values = new ArrayList<>(count);
+
+        for (int index = 0; index < count; ++index) {
+            values.add(this.values[index].toBytesRef());
+        }
+
+        return values;
+    }
+
+    public BytesRef getValue(BytesRef defaultValue) {
+        return getValue(0, defaultValue);
+    }
+
+    public BytesRef getValue(int index, BytesRef defaultValue) {
+        if (isEmpty() || index < 0 || index >= count) {
+            return defaultValue;
+        }
+
+        return values[index].toBytesRef();
+    }
+}

server/src/main/java/org/elasticsearch/script/field/DelegateDocValuesField.java

@@ -52,11 +52,15 @@ public int size() {
         throw new UnsupportedOperationException("field [" + name + "] is not supported through the fields api, use [doc] instead");
     }
 
+    public List<?> getValues() {
+        throw new UnsupportedOperationException("field [" + name + "] is not supported through the fields api, use [doc] instead");
+    }
+
     public Object getValue(Object defaultValue) {
         throw new UnsupportedOperationException("field [" + name + "] is not supported through the fields api, use [doc] instead");
     }
 
-    public List<?> getValues() {
+    public Object getValue(int index, Object defaultValue) {
         throw new UnsupportedOperationException("field [" + name + "] is not supported through the fields api, use [doc] instead");
     }
 }

server/src/test/java/org/elasticsearch/index/fielddata/BinaryDVFieldDataTests.java

@@ -13,6 +13,7 @@
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.compress.CompressedXContent;
+import org.elasticsearch.script.field.BinaryDocValuesField;
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xcontent.XContentFactory;
 import org.elasticsearch.xcontent.XContentType;
@@ -109,15 +110,15 @@ public void testDocValue() throws Exception {
         assertEquals(bytesList2.get(0), bytesValues.nextValue());
         assertEquals(bytesList2.get(1), bytesValues.nextValue());
 
-        // Test whether ScriptDocValues.BytesRefs makes a deepcopy
+        // Test whether BinaryDocValuesField makes a deepcopy
         fieldData = indexFieldData.load(reader);
-        ScriptDocValues<?> scriptValues = fieldData.getScriptField("test").getScriptDocValues();
+        BinaryDocValuesField binaryDocValuesField = (BinaryDocValuesField)fieldData.getScriptField("test");
         Object[][] retValues = new BytesRef[4][0];
         for (int i = 0; i < 4; i++) {
-            scriptValues.setNextDocId(i);
-            retValues[i] = new BytesRef[scriptValues.size()];
+            binaryDocValuesField.setNextDocId(i);
+            retValues[i] = new BytesRef[binaryDocValuesField.size()];
             for (int j = 0; j < retValues[i].length; j++) {
-                retValues[i][j] = scriptValues.get(j);
+                retValues[i][j] = binaryDocValuesField.getValue(j, null);
             }
         }
         assertEquals(2, retValues[0].length);

x-pack/plugin/mapper-unsigned-long/src/main/java/org/elasticsearch/xpack/unsignedlong/UnsignedLongDocValuesField.java

@@ -50,6 +50,11 @@ public void setNextDocId(int docId) throws IOException {
         }
     }
 
+    private void resize(int newSize) {
+        count = newSize;
+        values = ArrayUtil.grow(values, count);
+    }
+
     @Override
     public ScriptDocValues<?> getScriptDocValues() {
         if (unsignedLongScriptDocValues == null) {
@@ -59,11 +64,6 @@ public ScriptDocValues<?> getScriptDocValues() {
         return unsignedLongScriptDocValues;
     }
 
-    protected void resize(int newSize) {
-        count = newSize;
-        values = ArrayUtil.grow(values, count);
-    }
-
     @Override
     public String getName() {
         return name;