Renamed ignore source function for clarity

Author: Kubik42

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

@@ -153,11 +153,11 @@ private MatchOnlyTextFieldType buildFieldType(MapperBuilderContext context, Mult
         }
 
         /**
-         * This is more of a helper function that's useful in TextFieldMapper.SyntheticSourceHelper.syntheticSourceDelegate()
+         * This is a helper function that's useful in TextFieldMapper.SyntheticSourceHelper.syntheticSourceDelegate()
          */
         private FieldType getFieldType() {
             FieldType fieldType = new FieldType();
-            // by definition, match_only_text are not stored
+            // by definition, match_only_text fields are not stored
             fieldType.setStored(false);
             return fieldType;
         }

modules/mapper-extras/src/test/java/org/elasticsearch/index/mapper/extras/MatchOnlyTextFieldMapperTests.java

@@ -327,8 +327,6 @@ public void testStoreParameterDefaultsSyntheticSourceWithKeywordMultiField() thr
         }
     }
 
-    // TODO: add tests when string length is exceeding, same for TextFieldMapper
-
     public void testStoreParameterDefaultsSyntheticSourceTextFieldIsMultiField() throws IOException {
         var indexSettingsBuilder = getIndexSettingsBuilder();
         indexSettingsBuilder.put(IndexSettings.INDEX_MAPPER_SOURCE_MODE_SETTING.getKey(), "synthetic");

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

@@ -335,6 +335,20 @@ public final void addIgnoredField(IgnoredSourceFieldMapper.NameValue values) {
         }
     }
 
+    /**
+     * This function acts as a more "readable" wrapper around adding ignored fields.
+     *
+     * This is useful when we want to reuse the existing logic that {@link IgnoredSourceFieldMapper} provides for synthetic source, without
+     * explicitly calling addIgnoredField(). Without this, it's a bit confusing why fields that are not meant to be ignored, are being
+     * added to ignored source.
+     */
+    public final void storeFieldForSyntheticSource(String fullPath, String leafName, BytesRef valueBytes, LuceneDocument doc) {
+        if (canAddIgnoredField()) {
+            var fieldData = new IgnoredSourceFieldMapper.NameValue(fullPath, fullPath.lastIndexOf(leafName), valueBytes, doc);
+            ignoredFieldValues.add(fieldData);
+        }
+    }
+
     /**
      * Return the collection of values for fields that have been ignored so far.
      */

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

@@ -214,8 +214,6 @@ public static final class Builder extends FieldMapper.DimensionBuilder {
         private final SourceKeepMode indexSourceKeepMode;
         private final boolean isWithinMultiField;
 
-        private boolean isSyntheticSourceEnabled;
-
         public Builder(final String name, final MappingParserContext mappingParserContext) {
             this(
                 name,
@@ -461,8 +459,6 @@ private KeywordFieldType buildFieldType(MapperBuilderContext context, FieldType
 
         @Override
         public KeywordFieldMapper build(MapperBuilderContext context) {
-            this.isSyntheticSourceEnabled = context.isSourceSynthetic();
-
             FieldType fieldtype = resolveFieldType(
                 enableDocValuesSkipper,
                 forceDocValuesSkipper,

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

@@ -41,8 +41,7 @@ protected TextFamilyFieldMapper(
      */
     protected boolean needsToSupportSyntheticSource() {
         if (multiFieldsNotStoredByDefaultIndexVersionCheck()) {
-            // if we're within a multi field, then supporting synthetic source isn't necessary as that's the
-            // responsibility of the parent field
+            // if we're within a multi field, then supporting synthetic source isn't necessary as that's the responsibility of the parent
             return isSyntheticSourceEnabled && isWithinMultiField == false;
         }
         return isSyntheticSourceEnabled;

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

@@ -1449,21 +1449,19 @@ protected void parseCreateField(DocumentParserContext context) throws IOExceptio
             if (phraseFieldInfo != null) {
                 context.doc().add(new Field(phraseFieldInfo.field, value, phraseFieldInfo.fieldType));
             }
-        } else if (needsToSupportSyntheticSource() && fieldType.stored() == false) {
-            // if synthetic source needs to be supported, yet the field isn't stored, then we need to rely on something
-            // else to support synthetic source
+        }
 
-            // if we can rely on the synthetic source delegate for synthetic source, then return
+        // if synthetic source needs to be supported, yet the field isn't stored, then we need to rely on something else
+        if (needsToSupportSyntheticSource() && fieldType.stored() == false) {
+            // if we can rely on the synthetic source delegate for synthetic source, then exit as there is nothing to do
             if (fieldType().canUseSyntheticSourceDelegateForSyntheticSource(value)) {
                 return;
             }
 
-            // record this field's value in _ignored_source - synthetic source will fallback to it automatically
+            // otherwise, store this field in Lucene so that synthetic source can load it
             var utfBytes = context.parser().optimizedTextOrNull().bytes();
             var valuesBytesRef = new BytesRef(utfBytes.bytes(), utfBytes.offset(), utfBytes.length());
-            context.addIgnoredField(
-                new IgnoredSourceFieldMapper.NameValue(fullPath(), fullPath().lastIndexOf(leafName()), valuesBytesRef, context.doc())
-            );
+            context.storeFieldForSyntheticSource(fullPath(), leafName(), valuesBytesRef, context.doc());
             // final String fieldName = fieldType().syntheticSourceFallbackFieldName();
             // context.doc().add(new StoredField(fieldName, value));
         }