Function RM_ReplySetArrayLength

src/module.cpp:1651–1673

When RedisModule_ReplyWithArray() is used with the argument * REDISMODULE_POSTPONED_ARRAY_LEN, because we don't know beforehand the number * of items we are going to output as elements of the array, this function * will take care to set the array length. * * Since it is possible to have multiple array replies pending with unknown * length, this function guarantees to always set the latest ar

 * that is not easy to calculate in advance the number of elements.
 */
void RM_ReplySetArrayLength(RedisModuleCtx *ctx, long len) {
    client *c = moduleGetReplyClient(ctx);
    if (c == NULL) return;
    AeLocker locker;
    std::unique_lock<fastlock> lock(c->lock);
    locker.arm(c);
    if (ctx->postponed_arrays_count == 0) {
        serverLog(LL_WARNING,
            "API misuse detected in module %s: "
            "RedisModule_ReplySetArrayLength() called without previous "
            "RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN) "
            "call.", ctx->module->name);
            return;
    }
    ctx->postponed_arrays_count--;
    setDeferredArrayLen(c,
            ctx->postponed_arrays[ctx->postponed_arrays_count],
            len);
    if (ctx->postponed_arrays_count == 0) {
        zfree(ctx->postponed_arrays);
        ctx->postponed_arrays = NULL;
    }
}

/* Reply with a bulk string, taking in input a C buffer pointer and length.
 *