mariadb/innobase/include/read0read.ic
unknown 98dc4142b2 InnoDB: Some low-level optimizations made based on OProfile results.
innobase/dict/dict0mem.c:
  dict_mem_table_create(): Add a debug assertion.
innobase/include/btr0btr.ic:
  btr_node_ptr_get_child_page_no(): Add a UNIV_UNLIKELY hint.
  Remove a buf_frame_align() call.
innobase/include/btr0cur.ic:
  btr_cur_get_page(): Add a debug assertion.
innobase/include/buf0buf.ic:
  buf_block_peek_if_too_old(): Replace if() with return().
  buf_block_align(), buf_frame_align(): Add UNIV_UNLIKELY hints.
innobase/include/data0type.ic:
  dtype_get_fixed_size(): Add UNIV_UNLIKELY hints.
innobase/include/mem0mem.ic:
  Remove signedness warning in debug assertion.
innobase/include/read0read.ic:
  read_view_sees_trx_id(): Eliminate a comparison inside loop.
innobase/include/row0sel.ic:
  open_step(): Add UNIV_EXPECT hint.
innobase/include/row0upd.ic:
  upd_field_set_field_no(): Add a UNIV_UNLIKELY hint.
innobase/include/sync0rw.ic:
  Add UNIV_LIKELY and UNIV_UNLIKELY hints.
  rw_lock_x_lock_func_nowait(): Eliminate a function call.
  Replace ut_a() assertions with ut_ad().
innobase/include/trx0rseg.ic:
  Add UNIV_UNLIKELY hints.
innobase/include/ut0rnd.ic:
  ut_fold_binary(): Eliminate a loop variable
  to avoid register spilling on x86.
2005-04-22 14:04:18 +03:00

80 lines
1.8 KiB
Text

/******************************************************
Cursor read
(c) 1997 Innobase Oy
Created 2/16/1997 Heikki Tuuri
*******************************************************/
/*************************************************************************
Gets the nth trx id in a read view. */
UNIV_INLINE
dulint
read_view_get_nth_trx_id(
/*=====================*/
/* out: trx id */
read_view_t* view, /* in: read view */
ulint n) /* in: position */
{
ut_ad(n < view->n_trx_ids);
return(*(view->trx_ids + n));
}
/*************************************************************************
Sets the nth trx id in a read view. */
UNIV_INLINE
void
read_view_set_nth_trx_id(
/*=====================*/
read_view_t* view, /* in: read view */
ulint n, /* in: position */
dulint trx_id) /* in: trx id to set */
{
ut_ad(n < view->n_trx_ids);
*(view->trx_ids + n) = trx_id;
}
/*************************************************************************
Checks if a read view sees the specified transaction. */
UNIV_INLINE
ibool
read_view_sees_trx_id(
/*==================*/
/* out: TRUE if sees */
read_view_t* view, /* in: read view */
dulint trx_id) /* in: trx id */
{
ulint n_ids;
int cmp;
ulint i;
if (ut_dulint_cmp(trx_id, view->up_limit_id) < 0) {
return(TRUE);
}
if (ut_dulint_cmp(trx_id, view->low_limit_id) >= 0) {
return(FALSE);
}
/* We go through the trx ids in the array smallest first: this order
may save CPU time, because if there was a very long running
transaction in the trx id array, its trx id is looked at first, and
the first two comparisons may well decide the visibility of trx_id. */
n_ids = view->n_trx_ids;
for (i = 0; i < n_ids; i++) {
cmp = ut_dulint_cmp(trx_id,
read_view_get_nth_trx_id(view, n_ids - i - 1));
if (cmp <= 0) {
return(cmp < 0);
}
}
return(TRUE);
}