Expose tcp nodelay option on crt sockets (#1007)

Author: DmitriyMusatkin

crt/aws-c-cal

@@ -66,6 +66,34 @@ int getValue() {
         }
     }
 
+    /**
+     * Controls the TCP_NODELAY option (Nagle's algorithm). TCP only; ignored for UDP and LOCAL sockets.
+     */
+    public enum TcpNoDelay {
+        /**
+         * Leaves the OS default in place (Nagle's algorithm typically enabled).
+         */
+        DEFAULT(0),
+        /**
+         * Disables Nagle's algorithm, sending small writes immediately.
+         */
+        ON(1),
+        /**
+         * Explicitly enables Nagle's algorithm.
+         */
+        OFF(2);
+
+        private int tcpNoDelay;
+
+        TcpNoDelay(int val) {
+            tcpNoDelay = val;
+        }
+
+        int getValue() {
+            return tcpNoDelay;
+        }
+    }
+
     /**
      * Sets the socket domain
      */
@@ -100,6 +128,14 @@ int getValue() {
      */
     public boolean keepAlive = false;
 
+    /**
+     * Controls the TCP_NODELAY option (Nagle's algorithm).
+     * Defaults to {@link TcpNoDelay#ON}.
+     * Set to {@link TcpNoDelay#ON} to disable Nagle's algorithm (send small writes immediately),
+     * or {@link TcpNoDelay#OFF} to explicitly enable it. TCP only; ignored for UDP and LOCAL sockets.
+     */
+    public TcpNoDelay tcpNoDelay = TcpNoDelay.ON;
+
     /**
      * Creates a new set of socket options
      */
@@ -152,7 +188,8 @@ public long getNativeHandle() {
                 keepAliveIntervalSecs,
                 keepAliveTimeoutSecs,
                 keepAliveMaxFailedProbes,
-                keepAlive
+                keepAlive,
+                tcpNoDelay.getValue()
             ));
         }
         return super.getNativeHandle();
@@ -179,7 +216,7 @@ protected void releaseNativeHandle() {
      * native methods
      ******************************************************************************/
     private static native long socketOptionsNew(
-            int domain, int type, int connectTimeoutMs, int keepAliveIntervalSecs, int keepAliveTimeoutSecs, int keepAliveMaxFailedProbes, boolean keepAlive);
+            int domain, int type, int connectTimeoutMs, int keepAliveIntervalSecs, int keepAliveTimeoutSecs, int keepAliveMaxFailedProbes, boolean keepAlive, int tcpNoDelay);
 
     private static native void socketOptionsDestroy(long elg);
 };

crt/aws-c-io

@@ -32,7 +32,8 @@ jlong JNICALL Java_software_amazon_awssdk_crt_io_SocketOptions_socketOptionsNew(
     jint keep_alive_interval_secs,
     jint keep_alive_timeout_secs,
     jint keep_alive_max_failed_probes,
-    jboolean keep_alive) {
+    jboolean keep_alive,
+    jint tcp_nodelay) {
     (void)jni_class;
     aws_cache_jni_ids(env);
 
@@ -48,6 +49,7 @@ jlong JNICALL Java_software_amazon_awssdk_crt_io_SocketOptions_socketOptionsNew(
     options->keep_alive_timeout_sec = (uint16_t)keep_alive_timeout_secs;
     options->keep_alive_max_failed_probes = (uint16_t)keep_alive_max_failed_probes;
     options->keepalive = keep_alive;
+    options->tcp_nodelay = (enum aws_socket_tcp_nodelay)tcp_nodelay;
 
     return (jlong)options;
 }

crt/aws-c-s3

@@ -0,0 +1,31 @@
+/**
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0.
+ */
+package software.amazon.awssdk.crt.test;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import software.amazon.awssdk.crt.io.SocketOptions;
+
+public class SocketOptionsTest extends CrtTestFixture {
+
+    @Test
+    public void testSocketOptionsDefaults() {
+        try (SocketOptions options = new SocketOptions()) {
+            Assert.assertEquals(SocketOptions.TcpNoDelay.ON, options.tcpNoDelay);
+            Assert.assertNotEquals(0, options.getNativeHandle());
+        }
+    }
+
+    @Test
+    public void testSocketOptionsTcpNoDelay() {
+        for (SocketOptions.TcpNoDelay tcpNoDelay : SocketOptions.TcpNoDelay.values()) {
+            try (SocketOptions options = new SocketOptions()) {
+                options.tcpNoDelay = tcpNoDelay;
+                Assert.assertNotEquals(0, options.getNativeHandle());
+            }
+        }
+    }
+}