Function RM_Replicate

src/module.cpp:1872–1910

Replicate the specified command and arguments to slaves and AOF, as effect * of execution of the calling command implementation. * * The replicated commands are always wrapped into the MULTI/EXEC that * contains all the commands replicated in a given module command * execution. However the commands replicated with RedisModule_Call() * are the first items, the ones replicated with RedisModule

 * The command returns REDISMODULE_ERR if the format specifiers are invalid
 * or the command name does not belong to a known command. */
int RM_Replicate(RedisModuleCtx *ctx, const char *cmdname, const char *fmt, ...) {
    struct redisCommand *cmd;
    robj **argv = NULL;
    int argc = 0, flags = 0, j;
    va_list ap;

    cmd = lookupCommandByCString((char*)cmdname);
    if (!cmd) return REDISMODULE_ERR;

    /* Create the client and dispatch the command. */
    va_start(ap, fmt);
    argv = moduleCreateArgvFromUserFormat(cmdname,fmt,&argc,&flags,ap);
    va_end(ap);
    if (argv == NULL) return REDISMODULE_ERR;

    /* Select the propagation target. Usually is AOF + replicas, however
     * the caller can exclude one or the other using the "A" or "R"
     * modifiers. */
    int target = 0;
    if (!(flags & REDISMODULE_ARGV_NO_AOF)) target |= PROPAGATE_AOF;
    if (!(flags & REDISMODULE_ARGV_NO_REPLICAS)) target |= PROPAGATE_REPL;

    /* Replicate! When we are in a threaded context, we want to just insert
     * the replicated command ASAP, since it is not clear when the context
     * will stop being used, so accumulating stuff does not make much sense,
     * nor we could easily use the alsoPropagate() API from threads. */
    if (ctx->flags & REDISMODULE_CTX_THREAD_SAFE) {
        propagate(cmd,ctx->client->db->id,argv,argc,target);
    } else {
        moduleReplicateMultiIfNeeded(ctx);
        alsoPropagate(cmd,ctx->client->db->id,argv,argc,target);
    }

    /* Release the argv. */
    for (j = 0; j < argc; j++) decrRefCount(argv[j]);
    zfree(argv);
    g_pserver->dirty++;
    return REDISMODULE_OK;
}

/* This function will replicate the command exactly as it was invoked
 * by the client. Note that this function will not wrap the command into