Share data between DocValuesField and ScriptDocValues (#79587)

This change makes it so there is only one path to retrieve values for scripting through the newly 
introduced fields API. To support backwards compatibility of ScriptDocValues, DocValuesField will 
return ScriptDocValues for continued doc access where the values are shared, so there is no 
double loading of field data. For now, for unsupported DocValuesFields we have a 
DelegateDocValuesField that returns the ScriptDocValues for long, double, String, etc.

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

@@ -16,5 +16,10 @@ class org.elasticsearch.script.field.Field @dynamic_type {
 }
 
 class org.elasticsearch.script.DocBasedScript {
-    org.elasticsearch.script.field.Field field(String)
+  org.elasticsearch.script.field.Field field(String)
+}
+
+class org.elasticsearch.script.field.DelegateDocValuesField @dynamic_type {
+  def getValue(def)
+  List getValues()
 }

modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/20_scriptfield.yml

@@ -154,3 +154,32 @@ setup:
     - match: { error.failed_shards.0.reason.caused_by.reason: "no paths escape from while loop" }
     - match: { error.failed_shards.0.reason.type: "script_exception" }
     - match: { error.failed_shards.0.reason.reason: "compile error" }
+
+---
+"Scripted Field with error accessing an unsupported field via the script fields api":
+  - do:
+      catch: bad_request
+      search:
+        rest_total_hits_as_int: true
+        body:
+          script_fields:
+            bar:
+              script:
+                source: "field('foo').getValue('')"
+
+  - match: { error.failed_shards.0.reason.caused_by.type: "unsupported_operation_exception" }
+  - match: { error.failed_shards.0.reason.caused_by.reason: "field [foo] is not supported through the fields api, use [doc] instead"}
+
+  - do:
+      catch: bad_request
+      search:
+        rest_total_hits_as_int: true
+        body:
+          script_fields:
+            bar:
+              script:
+                source: "field('foo').getValues()"
+
+  - match: { error.failed_shards.0.reason.caused_by.type: "unsupported_operation_exception" }
+  - match: { error.failed_shards.0.reason.caused_by.reason: "field [foo] is not supported through the fields api, use [doc] instead" }
+

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/extras/ScaledFloatFieldMapper.java

@@ -18,6 +18,8 @@
 import org.elasticsearch.common.Explicit;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 import org.elasticsearch.xcontent.XContentParser;
 import org.elasticsearch.xcontent.XContentParser.Token;
 import org.elasticsearch.common.xcontent.support.XContentMapValues;
@@ -505,8 +507,8 @@ private static class ScaledFloatLeafFieldData implements LeafNumericFieldData {
         }
 
         @Override
-        public ScriptDocValues.Doubles getScriptValues() {
-            return new ScriptDocValues.Doubles(getDoubleValues());
+        public DocValuesField getScriptField(String name) {
+            return new DelegateDocValuesField(new ScriptDocValues.Doubles(getDoubleValues()), name);
         }
 
         @Override

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

@@ -17,6 +17,8 @@
 import org.elasticsearch.index.mapper.IpFieldMapper;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.script.IpFieldScript;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 import org.elasticsearch.search.aggregations.support.CoreValuesSourceType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -50,8 +52,8 @@ public BinaryScriptLeafFieldData loadDirect(LeafReaderContext context) throws Ex
         IpFieldScript script = leafFactory.newInstance(context);
         return new BinaryScriptLeafFieldData() {
             @Override
-            public ScriptDocValues<String> getScriptValues() {
-                return new IpScriptDocValues(getBytesValues());
+            public DocValuesField getScriptField(String name) {
+                return new DelegateDocValuesField(new IpScriptDocValues(getBytesValues()), name);
             }
 
             @Override

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

@@ -20,17 +20,10 @@
  */
 public interface LeafFieldData extends Accountable, Releasable {
 
-    /**
-     * Returns field values for use in scripting.
-     */
-    ScriptDocValues<?> getScriptValues();
-
     /**
      * Returns an {@code Field} for use in accessing field values in scripting.
      */
-    default DocValuesField getScriptField(String name) {
-        throw new UnsupportedOperationException();
-    }
+    DocValuesField getScriptField(String name);
 
     /**
      * Return a String representation of the values.

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

@@ -11,6 +11,8 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
 import org.elasticsearch.script.StringFieldScript;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 import org.elasticsearch.search.aggregations.support.CoreValuesSourceType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
@@ -42,8 +44,8 @@ public BinaryScriptLeafFieldData loadDirect(LeafReaderContext context) throws Ex
         StringFieldScript script = leafFactory.newInstance(context);
         return new BinaryScriptLeafFieldData() {
             @Override
-            public ScriptDocValues<?> getScriptValues() {
-                return new ScriptDocValues.Strings(getBytesValues());
+            public DocValuesField getScriptField(String name) {
+                return new DelegateDocValuesField(new ScriptDocValues.Strings(getBytesValues()), name);
             }
 
             @Override

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

@@ -13,6 +13,8 @@
 import org.elasticsearch.index.fielddata.MultiGeoPointValues;
 import org.elasticsearch.index.fielddata.ScriptDocValues;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -25,8 +27,8 @@ public final SortedBinaryDocValues getBytesValues() {
     }
 
     @Override
-    public final ScriptDocValues.GeoPoints getScriptValues() {
-        return new ScriptDocValues.GeoPoints(getGeoPointValues());
+    public final DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(new ScriptDocValues.GeoPoints(getGeoPointValues()), name);
     }
 
     public static LeafGeoPointFieldData empty(final int maxDoc) {

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

@@ -15,6 +15,8 @@
 import org.elasticsearch.index.fielddata.FieldData;
 import org.elasticsearch.index.fielddata.ScriptDocValues;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -34,8 +36,8 @@ protected AbstractLeafOrdinalsFieldData(Function<SortedSetDocValues, ScriptDocVa
     }
 
     @Override
-    public final ScriptDocValues<?> getScriptValues() {
-        return scriptFunction.apply(getOrdinalsValues());
+    public final DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(scriptFunction.apply(getOrdinalsValues()), name);
     }
 
     @Override

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

@@ -12,11 +12,12 @@
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.util.Accountable;
-import org.elasticsearch.index.fielddata.LeafFieldData;
 import org.elasticsearch.index.fielddata.FieldData;
+import org.elasticsearch.index.fielddata.LeafFieldData;
 import org.elasticsearch.index.fielddata.ScriptDocValues;
-import org.elasticsearch.index.fielddata.ScriptDocValues.Strings;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 
 import java.io.IOException;
 import java.util.Collection;
@@ -44,8 +45,8 @@ public SortedBinaryDocValues getBytesValues() {
     }
 
     @Override
-    public Strings getScriptValues() {
-        return new ScriptDocValues.Strings(getBytesValues());
+    public DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(new ScriptDocValues.Strings(getBytesValues()), name);
     }
 
     @Override

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

@@ -9,8 +9,9 @@
 package org.elasticsearch.index.fielddata.plain;
 
 import org.apache.lucene.index.BinaryDocValues;
-import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.index.fielddata.ScriptDocValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 
 
 final class BytesBinaryDVLeafFieldData extends AbstractBinaryDVLeafFieldData {
@@ -19,8 +20,8 @@ final class BytesBinaryDVLeafFieldData extends AbstractBinaryDVLeafFieldData {
     }
 
     @Override
-    public ScriptDocValues<BytesRef> getScriptValues() {
-        return new ScriptDocValues.BytesRefs(getBytesValues());
+    public DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(new ScriptDocValues.BytesRefs(getBytesValues()), name);
     }
 }
 

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

@@ -16,6 +16,8 @@
 import org.elasticsearch.index.fielddata.ScriptDocValues;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
 import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 import org.elasticsearch.search.DocValueFormat;
 
 import java.io.IOException;
@@ -40,8 +42,8 @@ public long ramBytesUsed() {
     }
 
     @Override
-    public final ScriptDocValues<Double> getScriptValues() {
-        return new ScriptDocValues.Doubles(getDoubleValues());
+    public final DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(new ScriptDocValues.Doubles(getDoubleValues()), name);
     }
 
     @Override

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

@@ -16,6 +16,8 @@
 import org.elasticsearch.index.fielddata.ScriptDocValues;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
 import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 import org.elasticsearch.search.DocValueFormat;
 
 import java.io.IOException;
@@ -27,7 +29,7 @@ public abstract class LeafLongFieldData implements LeafNumericFieldData {
 
     private final long ramBytesUsed;
     /**
-     * Type of this field. Used to expose appropriate types in {@link #getScriptValues()}.
+     * Type of this field. Used to expose appropriate types in {@link #getScriptField(String)}}.
      */
     private final NumericType numericType;
 
@@ -42,18 +44,19 @@ public long ramBytesUsed() {
     }
 
     @Override
-    public final ScriptDocValues<?> getScriptValues() {
+    public final DocValuesField getScriptField(String name) {
         switch (numericType) {
         // for now, dates and nanoseconds are treated the same, which also means, that the precision is only on millisecond level
         case DATE:
-            return new ScriptDocValues.Dates(getLongValues(), false);
+            return new DelegateDocValuesField(new ScriptDocValues.Dates(getLongValues(), false), name);
         case DATE_NANOSECONDS:
             assert this instanceof SortedNumericIndexFieldData.NanoSecondFieldData;
-            return new ScriptDocValues.Dates(((SortedNumericIndexFieldData.NanoSecondFieldData) this).getLongValuesAsNanos(), true);
+            return new DelegateDocValuesField(
+                    new ScriptDocValues.Dates(((SortedNumericIndexFieldData.NanoSecondFieldData) this).getLongValuesAsNanos(), true), name);
         case BOOLEAN:
-            return new ScriptDocValues.Booleans(getLongValues());
+            return new DelegateDocValuesField(new ScriptDocValues.Booleans(getLongValues()), name);
         default:
-            return new ScriptDocValues.Longs(getLongValues());
+            return new DelegateDocValuesField(new ScriptDocValues.Longs(getLongValues()), name);
         }
     }
 

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

@@ -10,14 +10,16 @@
 
 import org.apache.lucene.index.BinaryDocValues;
 import org.elasticsearch.index.fielddata.ScriptDocValues;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 
 final class StringBinaryDVLeafFieldData extends AbstractBinaryDVLeafFieldData {
     StringBinaryDVLeafFieldData(BinaryDocValues values) {
         super(values);
     }
 
     @Override
-    public ScriptDocValues<String> getScriptValues() {
-        return new ScriptDocValues.Strings(getBytesValues());
+    public DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(new ScriptDocValues.Strings(getBytesValues()), name);
     }
 }

server/src/main/java/org/elasticsearch/index/mapper/IdFieldMapper.java

@@ -32,6 +32,8 @@
 import org.elasticsearch.index.query.SearchExecutionContext;
 import org.elasticsearch.indices.IndicesService;
 import org.elasticsearch.indices.breaker.CircuitBreakerService;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 import org.elasticsearch.search.DocValueFormat;
 import org.elasticsearch.search.MultiValueMode;
 import org.elasticsearch.search.aggregations.support.CoreValuesSourceType;
@@ -211,8 +213,8 @@ public long ramBytesUsed() {
             }
 
             @Override
-            public ScriptDocValues<?> getScriptValues() {
-                return new ScriptDocValues.Strings(getBytesValues());
+            public DocValuesField getScriptField(String name) {
+                return new DelegateDocValuesField(new ScriptDocValues.Strings(getBytesValues()), name);
             }
 
             @Override

server/src/main/java/org/elasticsearch/index/mapper/flattened/KeyedFlattenedLeafFieldData.java

@@ -13,11 +13,12 @@
 import org.apache.lucene.util.Accountable;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.index.fielddata.AbstractSortedSetDocValues;
-import org.elasticsearch.index.fielddata.LeafOrdinalsFieldData;
 import org.elasticsearch.index.fielddata.FieldData;
-import org.elasticsearch.index.fielddata.ScriptDocValues;
+import org.elasticsearch.index.fielddata.LeafOrdinalsFieldData;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
 import org.elasticsearch.index.fielddata.plain.AbstractLeafOrdinalsFieldData;
+import org.elasticsearch.script.field.DelegateDocValuesField;
+import org.elasticsearch.script.field.DocValuesField;
 
 import java.io.IOException;
 import java.io.UncheckedIOException;
@@ -79,9 +80,9 @@ public void close() {
     }
 
     @Override
-    public ScriptDocValues<?> getScriptValues() {
-        return AbstractLeafOrdinalsFieldData.DEFAULT_SCRIPT_FUNCTION
-            .apply(getOrdinalsValues());
+    public DocValuesField getScriptField(String name) {
+        return new DelegateDocValuesField(
+                AbstractLeafOrdinalsFieldData.DEFAULT_SCRIPT_FUNCTION.apply(getOrdinalsValues()), name);
     }
 
     @Override