[Backport 2.x] Adding support for handling multiple transport protocols (#12967)

CHANGELOG.md

@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Detect breaking changes on pull requests ([#9044](https://github.com/opensearch-project/OpenSearch/pull/9044))
 - Add cluster primary balance contraint for rebalancing with buffer ([#12656](https://github.com/opensearch-project/OpenSearch/pull/12656))
 - Derived fields support to derive field values at query time without indexing ([#12569](https://github.com/opensearch-project/OpenSearch/pull/12569))
+- Add support for more than one protocol for transport ([#12967](https://github.com/opensearch-project/OpenSearch/pull/12967))
 
 ### Dependencies
 - Bump `org.apache.commons:commons-configuration2` from 2.10.0 to 2.10.1 ([#12896](https://github.com/opensearch-project/OpenSearch/pull/12896))

server/build.gradle

@@ -423,7 +423,7 @@ tasks.register("japicmp", me.champeau.gradle.japicmp.JapicmpTask) {
     onlyModified = true
     failOnModification = true
     ignoreMissingClasses = true
-    annotationIncludes = ['@org.opensearch.common.annotation.PublicApi']
+    annotationIncludes = ['@org.opensearch.common.annotation.PublicApi', '@org.opensearch.common.annotation.DeprecatedApi']
     txtOutputFile = layout.buildDirectory.file("reports/java-compatibility/report.txt")
     htmlOutputFile = layout.buildDirectory.file("reports/java-compatibility/report.html")
     dependsOn downloadSnapshot

server/src/main/java/org/opensearch/transport/Header.java

@@ -75,19 +75,19 @@ public int getNetworkMessageSize() {
         return networkMessageSize;
     }
 
-    Version getVersion() {
+    public Version getVersion() {
         return version;
     }
 
-    long getRequestId() {
+    public long getRequestId() {
         return requestId;
     }
 
     byte getStatus() {
         return status;
     }
 
-    boolean isRequest() {
+    public boolean isRequest() {
         return TransportStatus.isRequest(status);
     }
 
@@ -99,7 +99,7 @@ boolean isError() {
         return TransportStatus.isError(status);
     }
 
-    boolean isHandshake() {
+    public boolean isHandshake() {
         return TransportStatus.isHandshake(status);
     }
 

server/src/main/java/org/opensearch/transport/InboundBytesHandler.java

@@ -0,0 +1,32 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.transport;
+
+import org.opensearch.common.bytes.ReleasableBytesReference;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.function.BiConsumer;
+
+/**
+ * Interface for handling inbound bytes. Can be implemented by different transport protocols.
+ */
+public interface InboundBytesHandler extends Closeable {
+
+    public void doHandleBytes(
+        TcpChannel channel,
+        ReleasableBytesReference reference,
+        BiConsumer<TcpChannel, ProtocolInboundMessage> messageHandler
+    ) throws IOException;
+
+    public boolean canHandleBytes(ReleasableBytesReference reference);
+
+    @Override
+    void close();
+}

server/src/main/java/org/opensearch/transport/InboundDecoder.java

@@ -50,8 +50,8 @@
  */
 public class InboundDecoder implements Releasable {
 
-    static final Object PING = new Object();
-    static final Object END_CONTENT = new Object();
+    public static final Object PING = new Object();
+    public static final Object END_CONTENT = new Object();
 
     private final Version version;
     private final PageCacheRecycler recycler;