PostgreSQL数据库WAL——XLogResetInsertion重置写入日志需要用的各种变量

/*
 * Reset WAL record construction buffers.
 */
void
XLogResetInsertion(void)
{
  int      i;

  for (i = 0; i < max_registered_block_id; i++)
    registered_buffers[i].in_use = false;

  num_rdatas = 0;
  max_registered_block_id = 0;
  mainrdata_len = 0;
  mainrdata_last = (XLogRecData *) &mainrdata_head;
  curinsert_flags = 0;
  begininsert_called = false;
}