merge example-uvtm with example-libuv, add more comments, fix com…

…piler warnings

Makefile

@@ -166,9 +166,6 @@ hiredis-example-macosx: examples/example-macosx.c adapters/macosx.h $(STLIBNAME)
 hiredis-example-ssl: examples/example-ssl.c $(STLIBNAME) $(SSL_STLIBNAME)
 	$(CC) -o examples/$@ $(REAL_CFLAGS) -I. $< $(STLIBNAME) $(SSL_STLIBNAME) $(REAL_LDFLAGS) $(SSL_LDFLAGS)
 
-hiredis-example-uvtm: examples/example-uvtm.c adapters/libuv.h $(STLIBNAME) $(SSL_STLIBNAME)
-	$(CC) -o examples/$@ $(REAL_CFLAGS) -I. $< -luv $(STLIBNAME) $(SSL_STLIBNAME) $(REAL_LDFLAGS) $(SSL_LDFLAGS)
-
 ifndef AE_DIR
 hiredis-example-ae:
 	@echo "Please specify AE_DIR (e.g. <redis repository>/src)"
@@ -179,10 +176,11 @@ hiredis-example-ae: examples/example-ae.c adapters/ae.h $(STLIBNAME)
 endif
 
 ifndef LIBUV_DIR
-hiredis-example-libuv:
-	@echo "Please specify LIBUV_DIR (e.g. ../libuv/)"
-	@false
+# dynamic link libuv.so
+hiredis-example-libuv: examples/example-libuv.c adapters/libuv.h $(STLIBNAME)
+	$(CC) -o examples/$@ $(REAL_CFLAGS) -I. -I$(LIBUV_DIR)/include $< -luv -lpthread -lrt $(STLIBNAME) $(REAL_LDFLAGS)
 else
+# use user provided static lib
 hiredis-example-libuv: examples/example-libuv.c adapters/libuv.h $(STLIBNAME)
 	$(CC) -o examples/$@ $(REAL_CFLAGS) -I. -I$(LIBUV_DIR)/include $< $(LIBUV_DIR)/.libs/libuv.a -lpthread -lrt $(STLIBNAME) $(REAL_LDFLAGS)
 endif

adapters/libuv.h

@@ -108,7 +108,12 @@ static void redisLibuvSetTimeout(void *privdata, struct timeval tv) {
     }
     // updates the timeout if the timer has already started
     // or start the timer
-    uv_timer_start(&p->timer, redisLibuvTimeout, millsec, 0);
+    uv_timer_start(&p->timer, (uv_timer_cb)redisLibuvTimeout, millsec, 0);
+    // In some version of libuv, the `uv_timer_cb` have signature of
+    // `void(*)(uv_timer_t*, int), while in other version the signature is
+    // `void(*)(uv_timer_t*). Now that we don't care the second parameter,
+    // we simply convert the `redisLibuvTimeout` to (uv_timer_cb) to supress
+    // compiler warnings.
 }
 
 static void redisLibuvCleanup(void *privdata) {

examples/example-libuv.c

@@ -7,26 +7,41 @@
 #include <async.h>
 #include <adapters/libuv.h>
 
+void debugCallback(redisAsyncContext *c, void *r, void *privdata) {
+    (void)privdata; //unused
+    redisReply *reply = r;
+    if (reply == NULL) {
+        /* The DEBUG SLEEP command will almost always fail, because we have set a 1 second timeout */
+        printf("`DEBUG SLEEP` error: %s\n", c->errstr ? c->errstr : "unknown error");
+        return;
+    }
+    /* Disconnect after receiving the reply of DEBUG SLEEP (which will not)*/
+    redisAsyncDisconnect(c);
+}
+
 void getCallback(redisAsyncContext *c, void *r, void *privdata) {
     redisReply *reply = r;
-    if (reply == NULL) return;
-    printf("argv[%s]: %s\n", (char*)privdata, reply->str);
+    if (reply == NULL) {
+        printf("`GET key` error: %s\n", c->errstr ? c->errstr : "unknown error");
+        return;
+    }
+    printf("`GET key` result: argv[%s]: %s\n", (char*)privdata, reply->str);
 
-    /* Disconnect after receiving the reply to GET */
-    redisAsyncDisconnect(c);
+    /* start another request that demonstrate timeout */
+    redisAsyncCommand(c, debugCallback, NULL, "DEBUG SLEEP %f", 1.5);
 }
 
 void connectCallback(const redisAsyncContext *c, int status) {
     if (status != REDIS_OK) {
-        printf("Error: %s\n", c->errstr);
+        printf("connect error: %s\n", c->errstr);
         return;
     }
     printf("Connected...\n");
 }
 
 void disconnectCallback(const redisAsyncContext *c, int status) {
     if (status != REDIS_OK) {
-        printf("Error: %s\n", c->errstr);
+        printf("disconnect because of error: %s\n", c->errstr);
         return;
     }
     printf("Disconnected...\n");
@@ -49,8 +64,18 @@ int main (int argc, char **argv) {
     redisLibuvAttach(c,loop);
     redisAsyncSetConnectCallback(c,connectCallback);
     redisAsyncSetDisconnectCallback(c,disconnectCallback);
+    redisAsyncSetTimeout(c, (struct timeval){ .tv_sec = 1, .tv_usec = 0});
+
+    /*
+    In this demo, we first `set key`, then `get key` to demonstrate the basic usage of libuv adapter.
+    Then in `getCallback`, we start a `debug sleep` command to create 1.5 second long request.
+    Because we have set a 1 second timeout to the connection, the command will always fail with a
+    timeout error, which is shown in the `debugCallback`.
+    */
+
     redisAsyncCommand(c, NULL, NULL, "SET key %b", argv[argc-1], strlen(argv[argc-1]));
     redisAsyncCommand(c, getCallback, (char*)"end-1", "GET key");
+
     uv_run(loop, UV_RUN_DEFAULT);
     return 0;
 }