1 #include 
    
       2 #include 
     
        3 #include 
      
         4 #include 
       
          5 #include 
        
           6 #include 
         
           7 #include 
          
            8 9 void doTest() 10 { 11 int timeout = 10000; 12 struct timeval tv; 13 tv.tv_sec = timeout / 1000; 14 tv.tv_usec = timeout * 1000; 15 //以带有超时的方式链接Redis服务器，同时获取与Redis连接的上下文对象。 16 //该对象将用于其后所有与Redis操作的函数。 17 redisContext* c = redisConnectWithTimeout("192.168.149.137",6379,tv); 18 if (c->err) { 19 redisFree(c); 20 return; 21 } 22 const char* command1 = "set stest1 value1"; 23 redisReply* r = (redisReply*)redisCommand(c,command1); 24 //需要注意的是，如果返回的对象是NULL，则表示客户端和服务器之间出现严重错误，必须重新链接。 25 //这里只是举例说明，简便起见，后面的命令就不再做这样的判断了。 26 if (NULL == r) { 27 redisFree(c); 28 return; 29 } 30 //不同的Redis命令返回的数据类型不同，在获取之前需要先判断它的实际类型。 31 //至于各种命令的返回值信息，可以参考Redis的官方文档，或者查看该系列博客的前几篇 32 //有关Redis各种数据类型的博客。:) 33 //字符串类型的set命令的返回值的类型是REDIS_REPLY_STATUS，然后只有当返回信息是"OK" 34 //时，才表示该命令执行成功。后面的例子以此类推，就不再过多赘述了。 35 if (!(r->type == REDIS_REPLY_STATUS && strcasecmp(r->str,"OK") == 0)) { 36 printf("Failed to execute command[%s].\n",command1); 37 freeReplyObject(r); 38 redisFree(c); 39 return; 40 } 41 //由于后面重复使用该变量，所以需要提前释放，否则内存泄漏。 42 freeReplyObject(r); 43 printf("Succeed to execute command[%s].\n",command1); 44 45 const char* command2 = "strlen stest1"; 46 r = (redisReply*)redisCommand(c,command2); 47 if (r->type != REDIS_REPLY_INTEGER) { 48 printf("Failed to execute command[%s].\n",command2); 49 freeReplyObject(r); 50 redisFree(c); 51 return; 52 } 53 int length = r->integer; 54 freeReplyObject(r); 55 printf("The length of 'stest1' is %d.\n",length); 56 printf("Succeed to execute command[%s].\n",command2); 57 58 const char* command3 = "get stest1"; 59 r = (redisReply*)redisCommand(c,command3); 60 if (r->type != REDIS_REPLY_STRING) { 61 printf("Failed to execute command[%s].\n",command3); 62 freeReplyObject(r); 63 redisFree(c); 64 return; 65 } 66 printf("The value of 'stest1' is %s.\n",r->str); 67 freeReplyObject(r); 68 printf("Succeed to execute command[%s].\n",command3); 69 70 const char* command4 = "get stest2"; 71 r = (redisReply*)redisCommand(c,command4); 72 //这里需要先说明一下，由于stest2键并不存在，因此Redis会返回空结果，这里只是为了演示。 73 if (r->type != REDIS_REPLY_NIL) { 74 printf("Failed to execute command[%s].\n",command4); 75 freeReplyObject(r); 76 redisFree(c); 77 return; 78 } 79 freeReplyObject(r); 80 printf("Succeed to execute command[%s].\n",command4); 81 82 const char* command5 = "mget stest1 stest2"; 83 r = (redisReply*)redisCommand(c,command5); 84 //不论stest2存在与否，Redis都会给出结果，只是第二个值为nil。 85 //由于有多个值返回，因为返回应答的类型是数组类型。 86 if (r->type != REDIS_REPLY_ARRAY) { 87 printf("Failed to execute command[%s].\n",command5); 88 freeReplyObject(r); 89 redisFree(c); 90 //r->elements表示子元素的数量，不管请求的key是否存在，该值都等于请求是键的数量。 91 assert(2 == r->elements); 92 return; 93 } 94 for (int i = 0; i < r->elements; ++i) { 95 redisReply* childReply = r->element[i]; 96 //之前已经介绍过，get命令返回的数据类型是string。 97 //对于不存在key的返回值，其类型为REDIS_REPLY_NIL。 98 if (childReply->type == REDIS_REPLY_STRING) 99 printf("The value is %s.\n",childReply->str);100 }101 //对于每一个子应答，无需使用者单独释放，只需释放最外部的redisReply即可。102 freeReplyObject(r);103 printf("Succeed to execute command[%s].\n",command5);104 105 printf("Begin to test pipeline.\n");106 //该命令只是将待发送的命令写入到上下文对象的输出缓冲区中，直到调用后面的107 //redisGetReply命令才会批量将缓冲区中的命令写出到Redis服务器。这样可以108 //有效的减少客户端与服务器之间的同步等候时间，以及网络IO引起的延迟。109 //至于管线的具体性能优势，可以考虑该系列博客中的管线主题。110 if (REDIS_OK != redisAppendCommand(c,command1)111 || REDIS_OK != redisAppendCommand(c,command2)112 || REDIS_OK != redisAppendCommand(c,command3)113 || REDIS_OK != redisAppendCommand(c,command4)114 || REDIS_OK != redisAppendCommand(c,command5)) {115 redisFree(c);116 return;117 }118 119 redisReply* reply = NULL;120 //对pipeline返回结果的处理方式，和前面代码的处理方式完全一直，这里就不再重复给出了。121 if (REDIS_OK != redisGetReply(c,(void**)&reply)) {122 printf("Failed to execute command[%s] with Pipeline.\n",command1);123 freeReplyObject(reply);124 redisFree(c);125 }126 freeReplyObject(reply);127 printf("Succeed to execute command[%s] with Pipeline.\n",command1);128 129 if (REDIS_OK != redisGetReply(c,(void**)&reply)) {130 printf("Failed to execute command[%s] with Pipeline.\n",command2);131 freeReplyObject(reply);132 redisFree(c);133 }134 freeReplyObject(reply);135 printf("Succeed to execute command[%s] with Pipeline.\n",command2);136 137 if (REDIS_OK != redisGetReply(c,(void**)&reply)) {138 printf("Failed to execute command[%s] with Pipeline.\n",command3);139 freeReplyObject(reply);140 redisFree(c);141 }142 freeReplyObject(reply);143 printf("Succeed to execute command[%s] with Pipeline.\n",command3);144 145 if (REDIS_OK != redisGetReply(c,(void**)&reply)) {146 printf("Failed to execute command[%s] with Pipeline.\n",command4);147 freeReplyObject(reply);148 redisFree(c);149 }150 freeReplyObject(reply);151 printf("Succeed to execute command[%s] with Pipeline.\n",command4);152 153 if (REDIS_OK != redisGetReply(c,(void**)&reply)) {154 printf("Failed to execute command[%s] with Pipeline.\n",command5);155 freeReplyObject(reply);156 redisFree(c);157 }158 freeReplyObject(reply);159 printf("Succeed to execute command[%s] with Pipeline.\n",command5);160 //由于所有通过pipeline提交的命令结果均已为返回，如果此时继续调用redisGetReply，161 //将会导致该函数阻塞并挂起当前线程，直到有新的通过管线提交的命令结果返回。162 //最后不要忘记在退出前释放当前连接的上下文对象。163 redisFree(c);164 return;165 }166 167 int main() 168 {169 doTest();170 return 0;171 }172 173 //输出结果如下：174 //Succeed to execute command[set stest1 value1].175 //The length of 'stest1' is 6.176 //Succeed to execute command[strlen stest1].177 //The value of 'stest1' is value1.178 //Succeed to execute command[get stest1].179 //Succeed to execute command[get stest2].180 //The value is value1.181 //Succeed to execute command[mget stest1 stest2].182 //Begin to test pipeline.183 //Succeed to execute command[set stest1 value1] with Pipeline.184 //Succeed to execute command[strlen stest1] with Pipeline.185 //Succeed to execute command[get stest1] with Pipeline.186 //Succeed to execute command[get stest2] with Pipeline.187 //Succeed to execute command[mget stest1 stest2] with Pipeline.