Modules Cluster API: add a simple example module.

src/modules/Makefile

@@ -13,7 +13,7 @@ endif
 
 .SUFFIXES: .c .so .xo .o
 
-all: helloworld.so hellotype.so helloblock.so testmodule.so
+all: helloworld.so hellotype.so helloblock.so testmodule.so hellocluster.so
 
 .c.xo:
 	$(CC) -I. $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
@@ -33,6 +33,11 @@ helloblock.xo: ../redismodule.h
 helloblock.so: helloblock.xo
 	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lpthread -lc
 
+hellocluster.xo: ../redismodule.h
+
+hellocluster.so: hellocluster.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
+
 testmodule.xo: ../redismodule.h
 
 testmodule.so: testmodule.xo

src/modules/hellocluster.c

@@ -0,0 +1,79 @@
+/* Helloworld cluster -- A ping/pong cluster API example.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2018, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+#define MSGTYPE_PING 1
+#define MSGTYPE_PONG 2
+
+int PingallCommand_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
+    RedisModule_SendClusterMessage(ctx,NULL,MSGTYPE_PING,(unsigned char*)"Hey",3);
+    return RedisModule_ReplyWithSimpleString(ctx, "OK");
+}
+
+/* Callback for message MSGTYPE_PING */
+void PingReceiver(RedisModuleCtx *ctx, char *sender_id, uint8_t type, const unsigned char *payload, uint32_t len) {
+    RedisModule_Log(ctx,"notice","PING (type %d) RECEIVED from %.*s: '%.*s'",
+        type,REDISMODULE_NODE_ID_LEN,sender_id,(int)len, payload);
+    RedisModule_SendClusterMessage(ctx,NULL,MSGTYPE_PONG,(unsigned char*)"Ohi!",4);
+}
+
+/* Callback for message MSGTYPE_PONG. */
+void PongReceiver(RedisModuleCtx *ctx, char *sender_id, uint8_t type, const unsigned char *payload, uint32_t len) {
+    RedisModule_Log(ctx,"notice","PONG (type %d) RECEIVED from %.*s: '%.*s'",
+        type,REDISMODULE_NODE_ID_LEN,sender_id,(int)len, payload);
+}
+
+/* This function must be present on each Redis module. It is used in order to
+ * register the commands into the Redis server. */
+int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
+    if (RedisModule_Init(ctx,"hellocluster",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellocluster.pingall",
+        PingallCommand_RedisCommand,"readonly",0,0,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    RedisModule_RegisterClusterMessageReceiver(ctx,MSGTYPE_PING,PingReceiver);
+    RedisModule_RegisterClusterMessageReceiver(ctx,MSGTYPE_PONG,PongReceiver);
+    return REDISMODULE_OK;
+}