Module hooks: fixes and an example module.

4 files changed, 70 insertions, 2 deletions

diff --git a/src/module.c b/src/module.c
index 9bbd150c1..e2fe663b8 100644
--- a/src/module.c
+++ b/src/module.c
@@ -5769,6 +5769,7 @@ void moduleFireServerEvent(uint64_t eid, int subid, void *data) {
             if (eid == REDISMODULE_EVENT_CLIENT_CHANGE) {
                 modulePopulateClientInfoStructure(&civ1,data,
                                                   el->event.dataver);
+                moduledata = &civ1;
             }
             el->callback(&ctx,el->event,subid,moduledata);
             moduleFreeContext(&ctx);
diff --git a/src/modules/Makefile b/src/modules/Makefile
index 4f6b50f2e..9fb84cff8 100644
--- a/src/modules/Makefile
+++ b/src/modules/Makefile
@@ -13,7 +13,7 @@ endif
 
 .SUFFIXES: .c .so .xo .o
 
-all: helloworld.so hellotype.so helloblock.so testmodule.so hellocluster.so hellotimer.so hellodict.so
+all: helloworld.so hellotype.so helloblock.so testmodule.so hellocluster.so hellotimer.so hellodict.so hellohook.so
 
 .c.xo:
 	$(CC) -I. $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
@@ -46,6 +46,12 @@ hellotimer.so: hellotimer.xo
 hellodict.xo: ../redismodule.h
 
 hellodict.so: hellodict.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
+
+hellohook.xo: ../redismodule.h
+
+hellohook.so: hellohook.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
 
 testmodule.xo: ../redismodule.h
 
diff --git a/src/modules/hellohook.c b/src/modules/hellohook.c
new file mode 100644
index 000000000..ec3c9d264
--- /dev/null
+++ b/src/modules/hellohook.c
@@ -0,0 +1,60 @@
+/* Server hooks API example
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2019, 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.
+ */
+
+#define REDISMODULE_EXPERIMENTAL_API
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+/* Client state change callback. */
+void clientChangeCallback(RedisModuleCtx *ctx, RedisModuleEvent e, uint64_t sub, void *data)
+{
+    REDISMODULE_NOT_USED(ctx);
+    RedisModuleClientInfo *ci = data;
+    printf("Client event for client #%llu %s:%d\n",ci->id,ci->addr,ci->port);
+}
+
+/* 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,"hellohook",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    RedisModule_SubscribeToServerEvent(ctx,
+        RedisModuleEvent_ClientChange, clientChangeCallback);
+    return REDISMODULE_OK;
+}
diff --git a/src/redismodule.h b/src/redismodule.h
index 02cfa9586..9f7cc7e72 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -178,7 +178,7 @@ typedef struct RedisModuleEvent {
 } RedisModuleEvent;
 
 struct RedisModuleCtx;
-typedef int (*RedisModuleEventCallback)(struct RedisModuleCtx *ctx, RedisModuleEvent eid, uint64_t subevent, void *data);
+typedef void (*RedisModuleEventCallback)(struct RedisModuleCtx *ctx, RedisModuleEvent eid, uint64_t subevent, void *data);
 
 static RedisModuleEvent
     RedisModuleEvent_ReplicationRoleChanged = {
@@ -299,6 +299,7 @@ typedef struct RedisModuleTypeMethods {
 typedef struct RedisModuleClientInfo {
     uint64_t version;       /* Version of this structure for ABI compat. */
     uint64_t flags;         /* REDISMODULE_CLIENTINFO_FLAG_* */
+    uint64_t id;            /* Client ID. */
     char addr[46];          /* IPv4 or IPv6 address. */
     uint16_t port;          /* TCP port. */
     uint16_t db;            /* Selected DB. */