So, let’s put some fun in redis

redis的命令列表是写死在代码里面,编译后就没法修改(跟nginx一个德行)

硬编码一些额外的方法到redis中

最初写的一个hello world级的测试命令

void wendalCommand(redisClient *c) {      struct timeval tv;           // 从timeCommand拷贝的...      addReplyMultiBulkLen(c,3);   // 共返回3个结果      addReplyBulkCString(c, "Hi,Wendal"); // 输出个字符串啦      gettimeofday(&tv,NULL);              // 获取时间, 也是从timeCommand拷贝的      addReplyBulkLongLong(c,tv.tv_sec);   // 不解释了      addReplyBulkLongLong(c,tv.tv_usec);  // 不解释了  }

然后在redisCommandTable中声明一个新的命令,就搞定了

{"wendal", wendalCommand,1,"rR",0,NULL,0,0,0,0,0}

做得更灵活?上动态库,哈哈

so,我声明了2个新的命令, 加载/卸载动态库

   {"loadlib",loadlibCommand,2,"wmaR",0,NULL,0,0,0,0,0},      {"unloadlib",unloadlibCommand,2,"wmaR",0,NULL,0,0,0,0,0}

// 简化版的loadlibCommand  void loadlibCommand(redisClient *c) {      void *handle;      char *error;      int (*redis_lib_init)(redisClient*, dict*);      int re;            handle = dlopen(c->argv[1]->ptr, RTLD_LAZY);      if (!handle) {          addReplyError(c, dlerror());          return;      }      redis_lib_init = dlsym(handle, "redis_lib_init"); // 查找redis_lib_init      if ((error = dlerror()) != NULL)  {          dlclose(handle);          addReplyError(c, error);          return;      }      re = redis_lib_init(c, server.commands); // 执行之, 返回0就成功      if (re) {          dlclose(handle);          addReplyError(c, "lib init error");          return;      }      addReply(c,shared.ok);      server.dirty ++;                        // 使dirty自增,这样就能同步到slave了  }

redis动态库示例

禁用flushdb命令

#include <redis.h>    static void* flushdb;    extern int redis_lib_init(redisClient *c) {      flushdb = dictFetchValue(server.commands, sdsnew("FLUSHDB")); // 命令列表就是server.commands中,一个dict      if (!flushdb) return 1; // 找不到? 被其他库删掉了?      dictDeleteNoFree(server.commands, sdsnew("FLUSHDB")); // 删除但不要执行free      return 0;  }    extern void redis_lib_depose(redisClient *c) {      dictAdd(server.commands, sdsnew("FLUSHDB"), flushdb); // 卸载的时候就赋值回去,呵呵      return;  }

项目地址

https://raw.github.com/wendal/redis_plugins

https://raw.github.com/wendal/redis