Function SDL_ReserveSpaceInDataQueue

deps/SDL2/src/SDL_dataqueue.c:299–336

}

void *
SDL_ReserveSpaceInDataQueue(SDL_DataQueue *queue, const size_t len)
{
    SDL_DataQueuePacket *packet;

    if (!queue) {
        SDL_InvalidParamError("queue");
        return NULL;
    } else if (len == 0) {
        SDL_InvalidParamError("len");
        return NULL;
    } else if (len > queue->packet_size) {
        SDL_SetError("len is larger than packet size");
        return NULL;
    }

    packet = queue->head;
    if (packet) {
        const size_t avail = queue->packet_size - packet->datalen;
        if (len <= avail) {  /* we can use the space at end of this packet. */
            void *retval = packet->data + packet->datalen;
            packet->datalen += len;
            queue->queued_bytes += len;
            return retval;
        }
    }

    /* Need a fresh packet. */
    packet = AllocateDataQueuePacket(queue);
    if (!packet) {
        SDL_OutOfMemory();
        return NULL;
    }

    packet->datalen = len;
    queue->queued_bytes += len;
    return packet->data;
}

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