Added xxh3 64bit hash streaming implementation of WritableSequentialD…

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/MapField.java

@@ -21,9 +21,9 @@
  */
 public record MapField(
         /* A synthetic "key" field in a map entry. */
-        Field keyField,
+        SingleField keyField,
         /* A synthetic "value" field in a map entry. */
-        Field valueField,
+        SingleField valueField,
         // The rest of the fields below simply implement the Field interface:
         boolean repeated,
         int fieldNumber,
@@ -94,7 +94,7 @@ public MapField(Protobuf3Parser.MapFieldContext mapContext, final ContextualLook
      */
     public String javaGenericType() {
         final String fieldTypeName = valueField().type() == FieldType.MESSAGE
-                ? ((SingleField) valueField()).messageType()
+                ? valueField().messageType()
                 : valueField().type().boxedType;
         return "<%s, %s>".formatted(keyField.type().boxedType, fieldTypeName);
     }

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/SingleField.java

@@ -137,6 +137,17 @@ public String javaFieldTypeBase() {
         return javaFieldType(false);
     }
 
+    public String javaFieldTypeBoxed() {
+        return switch (type) {
+            case BOOL -> "Boolean";
+            case INT32, UINT32, SINT32, FIXED32, SFIXED32 -> "Integer";
+            case INT64, SINT64, UINT64, FIXED64, SFIXED64 -> "Long";
+            case FLOAT -> "Float";
+            case DOUBLE -> "Double";
+            default -> javaFieldType();
+        };
+    }
+
     @NonNull
     private String javaFieldType(boolean considerRepeated) {
         String fieldType =

pbj-core/pbj-compiler/src/main/java/com/hedera/pbj/compiler/impl/generators/ModelGenerator.java

@@ -6,7 +6,6 @@
 import static com.hedera.pbj.compiler.impl.Common.camelToUpperSnake;
 import static com.hedera.pbj.compiler.impl.Common.cleanDocStr;
 import static com.hedera.pbj.compiler.impl.Common.cleanJavaDocComment;
-import static com.hedera.pbj.compiler.impl.Common.getFieldsHashCode;
 import static com.hedera.pbj.compiler.impl.Common.javaPrimitiveToObjectType;
 import static com.hedera.pbj.compiler.impl.generators.EnumGenerator.EnumValue;
 import static com.hedera.pbj.compiler.impl.generators.EnumGenerator.createEnum;
@@ -42,21 +41,6 @@ public final class ModelGenerator implements Generator {
 
     private static final String NON_NULL_ANNOTATION = "@NonNull";
 
-    private static final String HASH_CODE_MANIPULATION =
-            """
-            // Shifts: 30, 27, 16, 20, 5, 18, 10, 24, 30
-            hashCode += hashCode << 30;
-            hashCode ^= hashCode >>> 27;
-            hashCode += hashCode << 16;
-            hashCode ^= hashCode >>> 20;
-            hashCode += hashCode << 5;
-            hashCode ^= hashCode >>> 18;
-            hashCode += hashCode << 10;
-            hashCode ^= hashCode >>> 24;
-            hashCode += hashCode << 30;
-        """
-                    .indent(DEFAULT_INDENT * 2);
-
     /**
      * {@inheritDoc}
      *
@@ -94,6 +78,10 @@ public void generate(
         writer.addImport("static " + lookupHelper.getFullyQualifiedMessageClassname(FileType.SCHEMA, msgDef) + ".*");
         writer.addImport("java.util.Collections");
         writer.addImport("java.util.List");
+        writer.addImport("com.hedera.pbj.runtime.hashing.XXH3_64");
+        writer.addImport("com.hedera.pbj.runtime.hashing.XXH3FieldHash");
+        writer.addImport("com.hedera.pbj.runtime.hashing.SixtyFourBitHashable");
+        writer.addImport("static com.hedera.pbj.runtime.hashing.XXH3FieldHash.*");
 
         // Iterate over all the items in the protobuf schema
         for (final var item : msgDef.messageBody().messageElement()) {
@@ -125,7 +113,7 @@ public void generate(
         // add precomputed fields to fields
         fields.add(new SingleField(
                 false,
-                FieldType.FIXED32,
+                FieldType.FIXED64,
                 -1,
                 "$hashCode",
                 null,
@@ -242,7 +230,7 @@ public void generate(
         bodyContent += "\n";
 
         // hashCode method
-        bodyContent += generateHashCode(fieldsNoPrecomputed);
+        bodyContent += ModelHashCodeGenerator.generateHashCode(fieldsNoPrecomputed);
         bodyContent += "\n";
 
         // equals method
@@ -310,11 +298,11 @@ private void generateClass(
             final boolean isComparable,
             final ContextualLookupHelper lookupHelper)
             throws IOException {
-        final String implementsComparable;
+        final String implementsCode;
         if (isComparable) {
-            implementsComparable = "implements Comparable<$javaRecordName> ";
+            implementsCode = "implements SixtyFourBitHashable, Comparable<$javaRecordName> ";
         } else {
-            implementsComparable = "";
+            implementsCode = "implements SixtyFourBitHashable ";
         }
 
         final String staticModifier = Generator.isInner(msgDef) ? " static" : "";
@@ -330,14 +318,15 @@ private void generateClass(
         // spotless:off
         writer.append("""
                 $javaDocComment$deprecated
+                @java.lang.SuppressWarnings("ForLoopReplaceableByForEach")
                 public final$staticModifier class $javaRecordName $implementsComparable{
                 $bodyContent
 
                 """
                 .replace("$javaDocComment", javaDocComment)
                 .replace("$deprecated", deprecated)
                 .replace("$staticModifier", staticModifier)
-                .replace("$implementsComparable", implementsComparable)
+                .replace("$implementsComparable", implementsCode)
                 .replace("$javaRecordName", javaRecordName)
                 .replace("$bodyContent", bodyContent));
         // spotless:on
@@ -531,63 +520,6 @@ public boolean equals(Object that) {
         return bodyContent;
     }
 
-    /**
-     * Generates the hashCode method
-     *
-     * @param fields the fields to use for the code generation
-     *
-     * @return the generated code
-     */
-    @NonNull
-    private static String generateHashCode(final List<Field> fields) {
-        // Generate a call to private method that iterates through fields and calculates the hashcode
-        final String statements = getFieldsHashCode(fields, "");
-        // spotless:off
-        String bodyContent =
-            """
-            /**
-            * Override the default hashCode method for to make hashCode better distributed and follows protobuf rules
-            * for default values. This is important for backward compatibility. This also lazy computes and caches the
-            * hashCode for future calls. It is designed to be thread safe.
-            */
-            @Override
-            public int hashCode() {
-                // The $hashCode field is subject to a benign data race, making it crucial to ensure that any
-                // observable result of the calculation in this method stays correct under any possible read of this
-                // field. Necessary restrictions to allow this to be correct without explicit memory fences or similar
-                // concurrency primitives is that we can ever only write to this field for a given Model object
-                // instance, and that the computation is idempotent and derived from immutable state.
-                // This is the same trick used in java.lang.String.hashCode() to avoid synchronization.
-
-                if($hashCode == -1) {
-                    int result = 1;
-            """.indent(DEFAULT_INDENT);
-
-        bodyContent += statements;
-
-        bodyContent +=
-            """
-                    if ($unknownFields != null) {
-                        for (int i = 0; i < $unknownFields.size(); i++) {
-                            result = 31 * result + $unknownFields.get(i).hashCode();
-                        }
-                    }
-            """.indent(DEFAULT_INDENT);
-
-        bodyContent +=
-            """
-                    long hashCode = result;
-            $hashCodeManipulation
-                    $hashCode = (int)hashCode;
-                }
-                return $hashCode;
-            }
-            """.replace("$hashCodeManipulation", HASH_CODE_MANIPULATION)
-                .indent(DEFAULT_INDENT);
-        // spotless:on
-        return bodyContent;
-    }
-
     /**
      * Generates the toString method, based on how Java records generate toStrings
      *