Helper for ConstructingObjectParser for record classes

libs/x-content/src/main/java/org/elasticsearch/xcontent/ConstructingObjectParser.java

@@ -10,11 +10,17 @@
 package org.elasticsearch.xcontent;
 
 import org.elasticsearch.core.RestApiVersion;
+import org.elasticsearch.core.SuppressForbidden;
 import org.elasticsearch.xcontent.ObjectParser.NamedObjectParser;
 import org.elasticsearch.xcontent.ObjectParser.ValueType;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.reflect.RecordComponent;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.EnumMap;
 import java.util.List;
@@ -130,6 +136,50 @@ public ConstructingObjectParser(String name, boolean ignoreUnknownFields, Functi
         this(name, ignoreUnknownFields, (args, context) -> builder.apply(args));
     }
 
+    /**
+     * Build a parser for the given {@code recordClass}.
+     *
+     * @param name The name given to the delegate ObjectParser for error identification. Use what you'd use if the object worked with
+     *        ObjectParser.
+     * @param ignoreUnknownFields Should this parser ignore unknown fields? This should generally be set to true only when parsing responses
+     *        from external systems, never when parsing requests from users.
+     * @param recordClass the {@link Class} of the {@link Record} type to build
+     * @param lookup a {@link java.lang.invoke.MethodHandles.Lookup Lookup} object that can access the record's canonical constructor;
+     *               typically just {@code MethodHandles.lookup()} called by some code that can access the constructor.
+     * @return a function suitable to use as the {@code builder} argument for one of the constructors of this class.
+     */
+    public static <R extends Record, Context> ConstructingObjectParser<R, Context> forRecord(
+        String name,
+        boolean ignoreUnknownFields,
+        Class<R> recordClass,
+        MethodHandles.Lookup lookup
+    ) {
+        Function<Object[], R> builder = recordBuilder(recordClass, lookup);
+        return new ConstructingObjectParser<>(name, ignoreUnknownFields, (args, context) -> builder.apply(args));
+    }
+
+    private static <R extends Record> Function<Object[], R> recordBuilder(Class<R> recordClass, MethodHandles.Lookup lookup) {
+        Class<?>[] ctorArgs = Arrays.stream(recordClass.getRecordComponents()).map(RecordComponent::getType).toArray(Class<?>[]::new);
+        MethodHandle ctor;
+        try {
+            ctor = lookup.findConstructor(recordClass, MethodType.methodType(void.class, ctorArgs));
+        } catch (NoSuchMethodException | IllegalAccessException e) {
+            throw new IllegalStateException("Cannot access record constructor", e);
+        }
+        return (args) -> recordClass.cast(constructRecord(args, ctor));
+    }
+
+    @SuppressForbidden(reason = "We can't use invokeExact because we don't know the argument types statically")
+    private static Object constructRecord(Object[] args, MethodHandle ctor) {
+        Object result;
+        try {
+            result = ctor.invokeWithArguments(args);
+        } catch (Throwable e) {
+            throw new IllegalStateException("Unable to call record constructor", e);
+        }
+        return result;
+    }
+
     /**
      * Build the parser.
      *

libs/x-content/src/test/java/org/elasticsearch/xcontent/ConstructingObjectParserTests.java

@@ -20,6 +20,7 @@
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 import java.util.List;
 import java.util.function.BiConsumer;
 
@@ -850,4 +851,19 @@ class DoubleFieldDeclaration {
         assertThat(exception, instanceOf(IllegalArgumentException.class));
         assertThat(exception.getMessage(), startsWith("Parser already registered for name=[name]"));
     }
+
+    public void testForRecord() throws IOException {
+        record TestRecord(int field1, String field2) {}
+        var PARSER = ConstructingObjectParser.forRecord("record", false, TestRecord.class, MethodHandles.lookup());
+        PARSER.declareInt(constructorArg(), new ParseField("field1"));
+        PARSER.declareString(constructorArg(), new ParseField("field2"));
+
+        TestRecord actual = PARSER.parse(createParser(JsonXContent.jsonXContent, """
+            {
+                "field1": 123,
+                "field2": "value2"
+            }
+            """), null);
+        assertEquals(new TestRecord(123, "value2"), actual);
+    }
 }

modules/ingest-geoip/src/main/java/org/elasticsearch/ingest/geoip/direct/DatabaseConfiguration.java

@@ -25,6 +25,7 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Objects;
@@ -259,10 +260,12 @@ public String getWriteableName() {
 
         private static final ParseField ACCOUNT_ID = new ParseField("account_id");
 
-        private static final ConstructingObjectParser<Maxmind, Void> PARSER = new ConstructingObjectParser<>("maxmind", false, (a, id) -> {
-            String accountId = (String) a[0];
-            return new Maxmind(accountId);
-        });
+        private static final ConstructingObjectParser<Maxmind, Void> PARSER = ConstructingObjectParser.forRecord(
+            "maxmind",
+            false,
+            Maxmind.class,
+            MethodHandles.lookup()
+        );
 
         static {
             PARSER.declareString(ConstructingObjectParser.constructorArg(), ACCOUNT_ID);

server/src/main/java/org/elasticsearch/cluster/metadata/DataStreamAutoShardingEvent.java

@@ -21,6 +21,7 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 import java.util.function.LongSupplier;
 
 /**
@@ -36,10 +37,11 @@ public record DataStreamAutoShardingEvent(String triggerIndexName, int targetNum
     public static final ParseField EVENT_TIME = new ParseField("event_time");
     public static final ParseField EVENT_TIME_MILLIS = new ParseField("event_time_millis");
 
-    public static final ConstructingObjectParser<DataStreamAutoShardingEvent, Void> PARSER = new ConstructingObjectParser<>(
+    public static final ConstructingObjectParser<DataStreamAutoShardingEvent, Void> PARSER = ConstructingObjectParser.forRecord(
         "auto_sharding",
         false,
-        (args, unused) -> new DataStreamAutoShardingEvent((String) args[0], (int) args[1], (long) args[2])
+        DataStreamAutoShardingEvent.class,
+        MethodHandles.lookup()
     );
 
     static {

server/src/main/java/org/elasticsearch/cluster/metadata/DataStreamFailureStore.java

@@ -25,6 +25,7 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 
 /**
  * Holds the data stream failure store metadata that enable or disable the failure store of a data stream. Currently, it
@@ -44,10 +45,11 @@ public record DataStreamFailureStore(@Nullable Boolean enabled, @Nullable DataSt
     public static final ParseField ENABLED_FIELD = new ParseField(ENABLED);
     public static final ParseField LIFECYCLE_FIELD = new ParseField(LIFECYCLE);
 
-    public static final ConstructingObjectParser<DataStreamFailureStore, Void> PARSER = new ConstructingObjectParser<>(
+    public static final ConstructingObjectParser<DataStreamFailureStore, Void> PARSER = ConstructingObjectParser.forRecord(
         FAILURE_STORE,
         false,
-        (args, unused) -> new DataStreamFailureStore((Boolean) args[0], (DataStreamLifecycle) args[1])
+        DataStreamFailureStore.class,
+        MethodHandles.lookup()
     );
 
     static {

server/src/main/java/org/elasticsearch/cluster/metadata/DataStreamOptions.java

@@ -24,6 +24,7 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 
 import static org.elasticsearch.cluster.metadata.DataStreamFailureStore.FAILURE_STORE;
 
@@ -42,10 +43,11 @@ public record DataStreamOptions(@Nullable DataStreamFailureStore failureStore)
     public static final DataStreamOptions FAILURE_STORE_DISABLED = new DataStreamOptions(new DataStreamFailureStore(false, null));
     public static final DataStreamOptions EMPTY = new DataStreamOptions(null);
 
-    public static final ConstructingObjectParser<DataStreamOptions, Void> PARSER = new ConstructingObjectParser<>(
+    public static final ConstructingObjectParser<DataStreamOptions, Void> PARSER = ConstructingObjectParser.forRecord(
         "options",
         false,
-        (args, unused) -> new DataStreamOptions((DataStreamFailureStore) args[0])
+        DataStreamOptions.class,
+        MethodHandles.lookup()
     );
 
     static {

server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetadataStats.java

@@ -23,6 +23,7 @@
 import org.elasticsearch.xcontent.XContentParser;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 import java.util.Arrays;
 import java.util.Objects;
 
@@ -131,11 +132,11 @@ public record AverageShardSize(long totalSizeInBytes, int numberOfShards) implem
         public static final ParseField TOTAL_SIZE_IN_BYTES_FIELD = new ParseField("total_size_in_bytes");
         public static final ParseField SHARD_COUNT_FIELD = new ParseField("shard_count");
 
-        @SuppressWarnings("unchecked")
-        private static final ConstructingObjectParser<AverageShardSize, Void> PARSER = new ConstructingObjectParser<>(
+        private static final ConstructingObjectParser<AverageShardSize, Void> PARSER = ConstructingObjectParser.forRecord(
             "average_shard_size",
             false,
-            (args, unused) -> new AverageShardSize((long) args[0], (int) args[1])
+            AverageShardSize.class,
+            MethodHandles.lookup()
         );
 
         static {

x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/profile/ProfileDocument.java

@@ -23,6 +23,7 @@
 import org.elasticsearch.xpack.core.security.user.User;
 
 import java.io.IOException;
+import java.lang.invoke.MethodHandles;
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.time.Instant;
@@ -125,31 +126,18 @@ public static ProfileDocument fromXContent(XContentParser parser) {
         return PARSER.apply(parser, null);
     }
 
-    @SuppressWarnings("unchecked")
-    static final ConstructingObjectParser<ProfileDocumentUser, Void> PROFILE_DOC_USER_PARSER = new ConstructingObjectParser<>(
+    static final ConstructingObjectParser<ProfileDocumentUser, Void> PROFILE_DOC_USER_PARSER = ConstructingObjectParser.forRecord(
         "user_profile_document_user",
         false,
-        (args, v) -> new ProfileDocumentUser(
-            (String) args[0],
-            (List<String>) args[1],
-            (Authentication.RealmRef) args[2],
-            (String) args[3],
-            (String) args[4]
-        )
+        ProfileDocumentUser.class,
+        MethodHandles.lookup()
     );
 
-    @SuppressWarnings("unchecked")
-    static final ConstructingObjectParser<ProfileDocument, Void> PROFILE_DOC_PARSER = new ConstructingObjectParser<>(
+    static final ConstructingObjectParser<ProfileDocument, Void> PROFILE_DOC_PARSER = ConstructingObjectParser.forRecord(
         "user_profile_document",
         false,
-        (args, v) -> new ProfileDocument(
-            (String) args[0],
-            (boolean) args[1],
-            (long) args[2],
-            (ProfileDocumentUser) args[3],
-            (Map<String, Object>) args[4],
-            (BytesReference) args[5]
-        )
+        ProfileDocument.class,
+        MethodHandles.lookup()
     );
 
     static final ConstructingObjectParser<ProfileDocument, Void> PARSER = new ConstructingObjectParser<>(