漫话Redis源码之九十九

本文主要是介绍漫话Redis源码之九十九，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

这里是movable keys command的一个sample, 比较简单：

#include "redismodule.h"
#include <strings.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>#define UNUSED(V) ((void) V)/* A sample movable keys command that returns a list of all* arguments that follow a KEY argument, i.e.*/
int getkeys_command(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{int i;int count = 0;/* Handle getkeys-api introspection */if (RedisModule_IsKeysPositionRequest(ctx)) {for (i = 0; i < argc; i++) {size_t len;const char *str = RedisModule_StringPtrLen(argv[i], &len);if (len == 3 && !strncasecmp(str, "key", 3) && i + 1 < argc)RedisModule_KeyAtPos(ctx, i + 1);}return REDISMODULE_OK;}/* Handle real command invocation */RedisModule_ReplyWithArray(ctx, REDISMODULE_POSTPONED_ARRAY_LEN);for (i = 0; i < argc; i++) {size_t len;const char *str = RedisModule_StringPtrLen(argv[i], &len);if (len == 3 && !strncasecmp(str, "key", 3) && i + 1 < argc) {RedisModule_ReplyWithString(ctx, argv[i+1]);count++;}}RedisModule_ReplySetArrayLength(ctx, count);return REDISMODULE_OK;
}int getkeys_fixed(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{int i;RedisModule_ReplyWithArray(ctx, argc - 1);for (i = 1; i < argc; i++) {RedisModule_ReplyWithString(ctx, argv[i]);}return REDISMODULE_OK;
}/* Introspect a command using RM_GetCommandKeys() and returns the list* of keys. Essentially this is COMMAND GETKEYS implemented in a module.*/
int getkeys_introspect(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
{UNUSED(argv);UNUSED(argc);if (argc < 3) {RedisModule_WrongArity(ctx);return REDISMODULE_OK;}int num_keys;int *keyidx = RedisModule_GetCommandKeys(ctx, &argv[1], argc - 1, &num_keys);if (!keyidx) {if (!errno)RedisModule_ReplyWithEmptyArray(ctx);else {char err[100];switch (errno) {case ENOENT:RedisModule_ReplyWithError(ctx, "ERR ENOENT");break;case EINVAL:RedisModule_ReplyWithError(ctx, "ERR EINVAL");break;default:snprintf(err, sizeof(err) - 1, "ERR errno=%d", errno);RedisModule_ReplyWithError(ctx, err);break;}}} else {int i;RedisModule_ReplyWithArray(ctx, num_keys);for (i = 0; i < num_keys; i++)RedisModule_ReplyWithString(ctx, argv[1 + keyidx[i]]);RedisModule_Free(keyidx);}return REDISMODULE_OK;
}int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {UNUSED(argv);UNUSED(argc);if (RedisModule_Init(ctx,"getkeys",1,REDISMODULE_APIVER_1)== REDISMODULE_ERR)return REDISMODULE_ERR;if (RedisModule_CreateCommand(ctx,"getkeys.command", getkeys_command,"getkeys-api",0,0,0) == REDISMODULE_ERR)return REDISMODULE_ERR;if (RedisModule_CreateCommand(ctx,"getkeys.fixed", getkeys_fixed,"",2,4,1) == REDISMODULE_ERR)return REDISMODULE_ERR;if (RedisModule_CreateCommand(ctx,"getkeys.introspect", getkeys_introspect,"",0,0,0) == REDISMODULE_ERR)return REDISMODULE_ERR;return REDISMODULE_OK;
}

这篇关于漫话Redis源码之九十九的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

---