rename converter to utils

Signed-off-by: xil <fridalu66@gmail.com>

Author: lucy66hw

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/ExpDecayFunctionProtoConverter.java renamed to modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/ExpDecayFunctionProtoUtils.java

@@ -20,30 +20,28 @@
 import java.util.Map;
 
 /**
- * Protocol Buffer converter for ExpDecayFunction.
- * This converter handles the transformation of Protocol Buffer ExpDecayFunction objects
- * into OpenSearch ExpDecayFunctionBuilder instances.
+ * Utility class for converting Protocol Buffer DecayFunction to OpenSearch ExponentialDecayFunctionBuilder.
+ * This utility handles the transformation of Protocol Buffer DecayFunction objects
+ * into OpenSearch ExponentialDecayFunctionBuilder instances.
  */
-public class ExpDecayFunctionProtoConverter {
+class ExpDecayFunctionProtoUtils {
 
-    /**
-     * Default constructor for ExpDecayFunctionProtoConverter.
-     */
-    public ExpDecayFunctionProtoConverter() {
-        // Default constructor
+    private ExpDecayFunctionProtoUtils() {
+        // Utility class, no instances
     }
 
     /**
      * Converts a Protocol Buffer DecayFunction to an OpenSearch ScoreFunctionBuilder.
-     * Similar to {@link org.opensearch.index.query.functionscore.ExponentialDecayFunctionBuilder},
+     * Similar to {@link org.opensearch.index.query.functionscore.DecayFunctionParser#fromXContent(org.opensearch.core.xcontent.XContentParser)},
      * this method parses the Protocol Buffer representation and creates a properly configured
      * ExponentialDecayFunctionBuilder with decay placement parameters (numeric, geo, or date).
+     * Equivalent to {@code #fromProto(DecayFunction)} for gRPC Protocol Buffer conversion.
      *
      * @param decayFunction the Protocol Buffer DecayFunction
      * @return the corresponding OpenSearch ScoreFunctionBuilder
      * @throws IllegalArgumentException if the decayFunction is null or doesn't contain placements
      */
-    public ScoreFunctionBuilder<?> fromProto(DecayFunction decayFunction) {
+    static ScoreFunctionBuilder<?> fromProto(DecayFunction decayFunction) {
         if (decayFunction == null || decayFunction.getPlacementCount() == 0) {
             throw new IllegalArgumentException("DecayFunction must have at least one placement");
         }
@@ -141,5 +139,4 @@ private static ScoreFunctionBuilder<?> parseDateExpDecay(String fieldName, DateD
 
         return builder;
     }
-
 }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/FieldValueFactorFunctionProtoConverter.java renamed to modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/FieldValueFactorFunctionProtoUtils.java

@@ -13,29 +13,27 @@
 import org.opensearch.protobufs.FieldValueFactorScoreFunction;
 
 /**
- * Protocol Buffer converter for FieldValueFactorScoreFunction.
- * This converter handles the transformation of Protocol Buffer FieldValueFactorScoreFunction objects
+ * Utility class for converting Protocol Buffer FieldValueFactorScoreFunction to OpenSearch objects.
+ * This utility handles the transformation of Protocol Buffer FieldValueFactorScoreFunction objects
  * into OpenSearch FieldValueFactorFunctionBuilder instances.
  */
-public class FieldValueFactorFunctionProtoConverter {
+class FieldValueFactorFunctionProtoUtils {
 
-    /**
-     * Default constructor for FieldValueFactorFunctionProtoConverter.
-     */
-    public FieldValueFactorFunctionProtoConverter() {
-        // Default constructor
+    private FieldValueFactorFunctionProtoUtils() {
+        // Utility class, no instances
     }
 
     /**
      * Converts a Protocol Buffer FieldValueFactorScoreFunction to an OpenSearch ScoreFunctionBuilder.
-     * Similar to {@link org.opensearch.index.query.functionscore.FieldValueFactorFunctionBuilder#fromXContent},
-     * this method parses the field, factor, missing value, and modifier parameters.
+     * Similar to {@link FieldValueFactorFunctionBuilder#fromXContent(XContentParser)}, this method
+     * parses the field, factor, missing value, and modifier parameters.
+     * Equivalent to {@code #fromProto(FieldValueFactorScoreFunction)} for gRPC Protocol Buffer conversion.
      *
      * @param fieldValueFactor the Protocol Buffer FieldValueFactorScoreFunction
      * @return the corresponding OpenSearch ScoreFunctionBuilder
      * @throws IllegalArgumentException if the fieldValueFactor is null
      */
-    public ScoreFunctionBuilder<?> fromProto(FieldValueFactorScoreFunction fieldValueFactor) {
+    static ScoreFunctionBuilder<?> fromProto(FieldValueFactorScoreFunction fieldValueFactor) {
         if (fieldValueFactor == null) {
             throw new IllegalArgumentException("FieldValueFactorScoreFunction cannot be null");
         }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/FunctionScoreQueryBuilderProtoUtils.java

@@ -89,7 +89,8 @@ static FunctionScoreQueryBuilder fromProto(FunctionScoreQuery functionScoreQuery
             combineFunction = parseBoostMode(functionScoreQueryProto.getBoostMode());
         }
 
-        if (functionScoreQueryProto.hasScoreMode()) {
+        if (functionScoreQueryProto.hasScoreMode()
+            && functionScoreQueryProto.getScoreMode() != FunctionScoreMode.FUNCTION_SCORE_MODE_UNSPECIFIED) {
             scoreMode = parseScoreMode(functionScoreQueryProto.getScoreMode());
         }
 
@@ -144,13 +145,10 @@ private static FunctionScoreQueryBuilder.FilterFunctionBuilder parseFunctionScor
             filter = registry.fromProto(filterContainer);
         }
 
-        // Check for weight (only set if present, otherwise use default)
         if (container.hasWeight()) {
             functionWeight = container.getWeight();
         }
 
-        // Parse the function score container directly
-        // If there's no function type but there's a weight, create a WeightBuilder
         if (container.getFunctionScoreContainerCase() == FunctionScoreContainer.FunctionScoreContainerCase.FUNCTIONSCORECONTAINER_NOT_SET) {
             scoreFunction = null;
         } else {
@@ -183,58 +181,51 @@ private static ScoreFunctionBuilder<?> parseScoreFunction(FunctionScoreContainer
         FunctionScoreContainer.FunctionScoreContainerCase functionCase = container.getFunctionScoreContainerCase();
 
         return switch (functionCase) {
-            case FIELD_VALUE_FACTOR -> new FieldValueFactorFunctionProtoConverter().fromProto(container.getFieldValueFactor());
-            case RANDOM_SCORE -> new RandomScoreFunctionProtoConverter().fromProto(container.getRandomScore());
-            case SCRIPT_SCORE -> new ScriptScoreFunctionProtoConverter().fromProto(container.getScriptScore());
-            case EXP -> new ExpDecayFunctionProtoConverter().fromProto(container.getExp());
-            case GAUSS -> new GaussDecayFunctionProtoConverter().fromProto(container.getGauss());
-            case LINEAR -> new LinearDecayFunctionProtoConverter().fromProto(container.getLinear());
+            case FIELD_VALUE_FACTOR -> FieldValueFactorFunctionProtoUtils.fromProto(container.getFieldValueFactor());
+            case RANDOM_SCORE -> RandomScoreFunctionProtoUtils.fromProto(container.getRandomScore());
+            case SCRIPT_SCORE -> ScriptScoreFunctionProtoUtils.fromProto(container.getScriptScore());
+            case EXP -> ExpDecayFunctionProtoUtils.fromProto(container.getExp());
+            case GAUSS -> GaussDecayFunctionProtoUtils.fromProto(container.getGauss());
+            case LINEAR -> LinearDecayFunctionProtoUtils.fromProto(container.getLinear());
             default -> throw new IllegalArgumentException("Unsupported function score type: " + functionCase);
         };
     }
 
     /**
-     * Parses a FunctionBoostMode enum to CombineFunction.
+     * Parses a FunctionBoostMode enum to CombineFunction.     *
+     * @param boostMode the FunctionBoostMode to parse
+     * @return the corresponding CombineFunction
+     * @throws IllegalArgumentException if the boostMode is unknown or unsupported
      */
     private static CombineFunction parseBoostMode(FunctionBoostMode boostMode) {
-        switch (boostMode) {
-            case FUNCTION_BOOST_MODE_AVG:
-                return CombineFunction.AVG;
-            case FUNCTION_BOOST_MODE_MAX:
-                return CombineFunction.MAX;
-            case FUNCTION_BOOST_MODE_MIN:
-                return CombineFunction.MIN;
-            case FUNCTION_BOOST_MODE_MULTIPLY:
-                return CombineFunction.MULTIPLY;
-            case FUNCTION_BOOST_MODE_REPLACE:
-                return CombineFunction.REPLACE;
-            case FUNCTION_BOOST_MODE_SUM:
-                return CombineFunction.SUM;
-            default:
-                throw new IllegalArgumentException("Unsupported boost mode: " + boostMode);
-        }
+        return switch (boostMode) {
+            case FUNCTION_BOOST_MODE_AVG -> CombineFunction.AVG;
+            case FUNCTION_BOOST_MODE_MAX -> CombineFunction.MAX;
+            case FUNCTION_BOOST_MODE_MIN -> CombineFunction.MIN;
+            case FUNCTION_BOOST_MODE_MULTIPLY -> CombineFunction.MULTIPLY;
+            case FUNCTION_BOOST_MODE_REPLACE -> CombineFunction.REPLACE;
+            case FUNCTION_BOOST_MODE_SUM -> CombineFunction.SUM;
+            default -> throw new IllegalArgumentException("Unsupported boost mode: " + boostMode);
+        };
     }
 
     /**
-     * Parses a FunctionScoreMode enum to FunctionScoreQuery.ScoreMode.
+     * Parses a FunctionScoreMode enum to ScoreMode.
+     *
+     * @param scoreMode the FunctionScoreMode to parse
+     * @return the corresponding FunctionScoreQuery.ScoreMode
+     * @throws IllegalArgumentException if the scoreMode is unknown or unsupported
      */
     private static org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode parseScoreMode(FunctionScoreMode scoreMode) {
-        switch (scoreMode) {
-            case FUNCTION_SCORE_MODE_AVG:
-                return org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.AVG;
-            case FUNCTION_SCORE_MODE_FIRST:
-                return org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.FIRST;
-            case FUNCTION_SCORE_MODE_MAX:
-                return org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.MAX;
-            case FUNCTION_SCORE_MODE_MIN:
-                return org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.MIN;
-            case FUNCTION_SCORE_MODE_MULTIPLY:
-                return org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.MULTIPLY;
-            case FUNCTION_SCORE_MODE_SUM:
-                return org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.SUM;
-            default:
-                return FunctionScoreQueryBuilder.DEFAULT_SCORE_MODE;
-        }
+        return switch (scoreMode) {
+            case FUNCTION_SCORE_MODE_AVG -> org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.AVG;
+            case FUNCTION_SCORE_MODE_FIRST -> org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.FIRST;
+            case FUNCTION_SCORE_MODE_MAX -> org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.MAX;
+            case FUNCTION_SCORE_MODE_MIN -> org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.MIN;
+            case FUNCTION_SCORE_MODE_MULTIPLY -> org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.MULTIPLY;
+            case FUNCTION_SCORE_MODE_SUM -> org.opensearch.common.lucene.search.function.FunctionScoreQuery.ScoreMode.SUM;
+            default -> throw new IllegalArgumentException("Unsupported score mode: " + scoreMode);
+        };
     }
 
 }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/GaussDecayFunctionProtoConverter.java renamed to modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/GaussDecayFunctionProtoUtils.java

@@ -20,30 +20,28 @@
 import java.util.Map;
 
 /**
- * Protocol Buffer converter for GaussDecayFunction.
- * This converter handles the transformation of Protocol Buffer GaussDecayFunction objects
+ * Utility class for converting Protocol Buffer DecayFunction to OpenSearch GaussDecayFunctionBuilder.
+ * This utility handles the transformation of Protocol Buffer DecayFunction objects
  * into OpenSearch GaussDecayFunctionBuilder instances.
  */
-public class GaussDecayFunctionProtoConverter {
+class GaussDecayFunctionProtoUtils {
 
-    /**
-     * Default constructor for GaussDecayFunctionProtoConverter.
-     */
-    public GaussDecayFunctionProtoConverter() {
-        // Default constructor
+    private GaussDecayFunctionProtoUtils() {
+        // Utility class, no instances
     }
 
     /**
      * Converts a Protocol Buffer DecayFunction to an OpenSearch ScoreFunctionBuilder.
-     * Similar to {@link org.opensearch.index.query.functionscore.GaussDecayFunctionBuilder},
+     * Similar to {@link org.opensearch.index.query.functionscore.DecayFunctionParser#fromXContent(org.opensearch.core.xcontent.XContentParser)},
      * this method parses the Protocol Buffer representation and creates a properly configured
      * GaussDecayFunctionBuilder with decay placement parameters (numeric, geo, or date).
+     * Equivalent to {@code #fromProto(DecayFunction)} for gRPC Protocol Buffer conversion.
      *
      * @param decayFunction the Protocol Buffer DecayFunction
      * @return the corresponding OpenSearch ScoreFunctionBuilder
      * @throws IllegalArgumentException if the decayFunction is null or doesn't contain placements
      */
-    public ScoreFunctionBuilder<?> fromProto(DecayFunction decayFunction) {
+    static ScoreFunctionBuilder<?> fromProto(DecayFunction decayFunction) {
         if (decayFunction == null || decayFunction.getPlacementCount() == 0) {
             throw new IllegalArgumentException("DecayFunction must have at least one placement");
         }
@@ -141,5 +139,4 @@ private static ScoreFunctionBuilder<?> parseDateGaussDecay(String fieldName, Dat
 
         return builder;
     }
-
 }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/LinearDecayFunctionProtoConverter.java renamed to modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/LinearDecayFunctionProtoUtils.java

@@ -20,30 +20,28 @@
 import java.util.Map;
 
 /**
- * Protocol Buffer converter for LinearDecayFunction.
- * This converter handles the transformation of Protocol Buffer LinearDecayFunction objects
+ * Utility class for converting Protocol Buffer DecayFunction to OpenSearch LinearDecayFunctionBuilder.
+ * This utility handles the transformation of Protocol Buffer DecayFunction objects
  * into OpenSearch LinearDecayFunctionBuilder instances.
  */
-public class LinearDecayFunctionProtoConverter {
+class LinearDecayFunctionProtoUtils {
 
-    /**
-     * Default constructor for LinearDecayFunctionProtoConverter.
-     */
-    public LinearDecayFunctionProtoConverter() {
-        // Default constructor
+    private LinearDecayFunctionProtoUtils() {
+        // Utility class, no instances
     }
 
     /**
      * Converts a Protocol Buffer DecayFunction to an OpenSearch ScoreFunctionBuilder.
-     * Similar to {@link org.opensearch.index.query.functionscore.LinearDecayFunctionBuilder},
+     * Similar to {@link org.opensearch.index.query.functionscore.DecayFunctionParser#fromXContent(org.opensearch.core.xcontent.XContentParser)},
      * this method parses the Protocol Buffer representation and creates a properly configured
      * LinearDecayFunctionBuilder with decay placement parameters (numeric, geo, or date).
+     * Equivalent to {@code #fromProto(DecayFunction)} for gRPC Protocol Buffer conversion.
      *
      * @param decayFunction the Protocol Buffer DecayFunction
      * @return the corresponding OpenSearch ScoreFunctionBuilder
      * @throws IllegalArgumentException if the decayFunction is null or doesn't contain placements
      */
-    public ScoreFunctionBuilder<?> fromProto(DecayFunction decayFunction) {
+    static ScoreFunctionBuilder<?> fromProto(DecayFunction decayFunction) {
         if (decayFunction == null || decayFunction.getPlacementCount() == 0) {
             throw new IllegalArgumentException("DecayFunction must have at least one placement");
         }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/RandomScoreFunctionProtoConverter.java renamed to modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/RandomScoreFunctionProtoUtils.java

@@ -12,29 +12,27 @@
 import org.opensearch.protobufs.RandomScoreFunction;
 
 /**
- * Protocol Buffer converter for RandomScoreFunction.
- * This converter handles the transformation of Protocol Buffer RandomScoreFunction objects
+ * Utility class for converting Protocol Buffer RandomScoreFunction to OpenSearch objects.
+ * This utility handles the transformation of Protocol Buffer RandomScoreFunction objects
  * into OpenSearch RandomScoreFunctionBuilder instances.
  */
-public class RandomScoreFunctionProtoConverter {
+class RandomScoreFunctionProtoUtils {
 
-    /**
-     * Default constructor for RandomScoreFunctionProtoConverter.
-     */
-    public RandomScoreFunctionProtoConverter() {
-        // Default constructor
+    private RandomScoreFunctionProtoUtils() {
+        // Utility class, no instances
     }
 
     /**
      * Converts a Protocol Buffer RandomScoreFunction to an OpenSearch ScoreFunctionBuilder.
-     * Similar to {@link RandomScoreFunctionBuilder#fromXContent(XContentParser)},
-     * this method parses the seed and optional field parameters.
+     * Similar to {@link RandomScoreFunctionBuilder#fromXContent(XContentParser)}, this method
+     * parses the seed and optional field parameters.
+     * Equivalent to {@code #fromProto(RandomScoreFunction)} for gRPC Protocol Buffer conversion.
      *
      * @param randomScore the Protocol Buffer RandomScoreFunction
      * @return the corresponding OpenSearch ScoreFunctionBuilder
      * @throws IllegalArgumentException if the randomScore is null
      */
-    public ScoreFunctionBuilder<?> fromProto(RandomScoreFunction randomScore) {
+    static ScoreFunctionBuilder<?> fromProto(RandomScoreFunction randomScore) {
         if (randomScore == null) {
             throw new IllegalArgumentException("RandomScoreFunction cannot be null");
         }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/ScriptScoreFunctionProtoConverter.java renamed to modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/ScriptScoreFunctionProtoUtils.java

@@ -13,28 +13,26 @@
 import org.opensearch.transport.grpc.proto.request.common.ScriptProtoUtils;
 
 /**
- * Converter for ScriptScoreFunction.
- * This class converts Protocol Buffer ScriptScoreFunction objects into OpenSearch ScriptScoreFunctionBuilder instances.
+ * Utility class for converting Protocol Buffer ScriptScoreFunction to OpenSearch objects.
+ * This utility converts Protocol Buffer ScriptScoreFunction objects into OpenSearch ScriptScoreFunctionBuilder instances.
  */
-public class ScriptScoreFunctionProtoConverter {
+class ScriptScoreFunctionProtoUtils {
 
-    /**
-     * Default constructor for ScriptScoreFunctionProtoConverter.
-     */
-    public ScriptScoreFunctionProtoConverter() {
-        // Default constructor
+    private ScriptScoreFunctionProtoUtils() {
+        // Utility class, no instances
     }
 
     /**
      * Converts a Protocol Buffer ScriptScoreFunction to an OpenSearch ScoreFunctionBuilder.
-     * Similar to {@link org.opensearch.index.query.functionscore.ScriptScoreFunctionBuilder#fromXContent(XContentParser)},
-     * this method parses the script parameter and constructs the builder.
+     * Similar to {@link org.opensearch.index.query.functionscore.ScriptScoreFunctionBuilder#fromXContent(org.opensearch.core.xcontent.XContentParser)}, this method
+     * parses the script parameter and constructs the builder.
+     * Equivalent to {@code #fromProto(ScriptScoreFunction)} for gRPC Protocol Buffer conversion.
      *
      * @param scriptScore the Protocol Buffer ScriptScoreFunction
      * @return the corresponding OpenSearch ScoreFunctionBuilder
      * @throws IllegalArgumentException if the scriptScore is null or doesn't contain a script
      */
-    public ScoreFunctionBuilder<?> fromProto(ScriptScoreFunction scriptScore) {
+    static ScoreFunctionBuilder<?> fromProto(ScriptScoreFunction scriptScore) {
         if (scriptScore == null) {
             throw new IllegalArgumentException("ScriptScoreFunction cannot be null");
         }

modules/transport-grpc/src/main/java/org/opensearch/transport/grpc/proto/request/search/query/functionscore/package-info.java

@@ -7,19 +7,9 @@
  */
 
 /**
- * Package for converting protobuf function score containers to OpenSearch ScoreFunctionBuilder instances.
- *
- * This package contains converters for various function score types including:
- * <ul>
- *   <li>Exponential decay functions</li>
- *   <li>Gaussian decay functions</li>
- *   <li>Linear decay functions</li>
- *   <li>Script score functions</li>
- *   <li>Field value factor functions</li>
- *   <li>Random score functions</li>
- * </ul>
- *
- * Each converter is responsible for converting protobuf representations to their corresponding
- * OpenSearch ScoreFunctionBuilder implementations.
+ * This package contains utility classes for converting function score components between OpenSearch
+ * and Protocol Buffers formats. These utilities handle the transformation of score function builders,
+ * function parameters, and function configurations to ensure proper communication between gRPC clients
+ * and the OpenSearch server.
  */
 package org.opensearch.transport.grpc.proto.request.search.query.functionscore;