iter

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

@@ -12,10 +12,16 @@
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.join.BitSetProducer;
+import org.elasticsearch.index.query.SearchExecutionContext;
 
 import java.util.Map;
 import java.util.function.Function;
 
+/**
+ * An abstract {@link MetadataFieldMapper} used as a placeholder for implementation
+ * in the inference module. It is required by {@link SourceFieldMapper} to identify
+ * the field name for removal from _source.
+ */
 public abstract class InferenceMetadataFieldsMapper extends MetadataFieldMapper {
     public static final String NAME = "_inference_fields";
     public static final String CONTENT_TYPE = "_inference_fields";
@@ -39,6 +45,9 @@ public InferenceMetadataFieldType() {
             super(NAME, false, false, false, TextSearchInfo.NONE, Map.of());
         }
 
+        /**
+         * Returns a {@link ValueFetcher} without requiring the construction of a full {@link SearchExecutionContext}.
+         */
         public abstract ValueFetcher valueFetcher(
             MappingLookup mappingLookup,
             Function<Query, BitSetProducer> bitSetCache,

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/highlight/SemanticTextHighlighter.java

@@ -46,6 +46,11 @@
 import java.util.List;
 import java.util.Map;
 
+/**
+ * A {@link Highlighter} designed for the {@link SemanticTextFieldMapper}.
+ * It extracts semantic queries and compares them against each chunk in the document.
+ * The top-scoring chunks are returned as snippets, sorted by their scores.
+ */
 public class SemanticTextHighlighter implements Highlighter {
     public static final String NAME = "semantic";
 
@@ -54,6 +59,7 @@ private record OffsetAndScore(OffsetSourceFieldMapper.OffsetSource offset, float
     @Override
     public boolean canHighlight(MappedFieldType fieldType) {
         if (fieldType instanceof SemanticTextFieldMapper.SemanticTextFieldType semanticTextFieldType) {
+            // TODO: Handle semantic text field prior to the inference metadata fields version.
             return semanticTextFieldType.getIndexVersionCreated().onOrAfter(IndexVersions.INFERENCE_METADATA_FIELDS);
         }
         return false;