Function RM_OpenKey

app/redis-6.2.6/src/module.c:2251–2270

Return an handle representing a Redis key, so that it is possible * to call other APIs with the key handle as argument to perform * operations on the key. * * The return value is the handle representing the key, that must be * closed with RM_CloseKey(). * * If the key does not exist and WRITE mode is requested, the handle * is still returned, since it is possible to perform operations on

 * call RedisModule_CloseKey() and RedisModule_KeyType() on a NULL
 * value. */
void *RM_OpenKey(RedisModuleCtx *ctx, robj *keyname, int mode) {
    RedisModuleKey *kp;
    robj *value;
    int flags = mode & REDISMODULE_OPEN_KEY_NOTOUCH? LOOKUP_NOTOUCH: 0;

    if (mode & REDISMODULE_WRITE) {
        value = lookupKeyWriteWithFlags(ctx->client->db,keyname, flags);
    } else {
        value = lookupKeyReadWithFlags(ctx->client->db,keyname, flags);
        if (value == NULL) {
            return NULL;
        }
    }

    /* Setup the key handle. */
    kp = zmalloc(sizeof(*kp));
    moduleInitKey(kp, ctx, keyname, value, mode);
    autoMemoryAdd(ctx,REDISMODULE_AM_KEY,kp);
    return (void*)kp;
}

/* Destroy a RedisModuleKey struct (freeing is the responsibility of the caller). */
static void moduleCloseKey(RedisModuleKey *key) {