Function queue_write_head

src/cls/queue/cls_queue_src.cc:20–45

const uint64_t large_chunk_size = 1ul << 22;

int queue_write_head(cls_method_context_t hctx, cls_queue_head& head)
{
  bufferlist bl;
  uint16_t entry_start = QUEUE_HEAD_START;
  encode(entry_start, bl);

  bufferlist bl_head;
  encode(head, bl_head);

  uint64_t encoded_len = bl_head.length();
  encode(encoded_len, bl);

  bl.claim_append(bl_head);

  if (bl.length() > head.max_head_size) {
    CLS_LOG(0, "ERROR: queue_write_head: invalid head size = %u and urgent data size = %u \n", bl.length(), head.bl_urgent_data.length());
    return -EINVAL;
  }

  int ret = cls_cxx_write2(hctx, 0, bl.length(), &bl, CEPH_OSD_OP_FLAG_FADVISE_WILLNEED);
  if (ret < 0) {
    CLS_LOG(5, "ERROR: queue_write_head: failed to write head");
    return ret;
  }
  return 0;
}

int queue_read_head(cls_method_context_t hctx, cls_queue_head& head)
{