database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-13 20:03:16 +03:00
Code Activity

branches/zip: Clarify why certain calls of

Browse Source 
btr_rec_copy_externally_stored_field() are safe.

row_merge_copy_blobs(): Note that the table is locked during index creation.
Therefore, none of its BLOBs can be freed.

row_sel_fetch_columns(): Note that rec must be protected by a page latch.
Add const qualifier to rec.

row_sel_get_clust_rec(): Note that the clustered index record is protected
by a page latch that was acquired when the persistent cursor was positioned
and that the latch will be freed by mini-transaction commit.

row_sel_try_search_shortcut(): Check the delete-mark flag before fetching
the columns.  Note that the clustered index record is protected
by a page latch that was acquired when the persistent cursor was positioned
and that the latch will be freed by mini-transaction commit.

row_sel(), row_search_for_mysql(): Note that the clustered index record
is protected by a page latch that was acquired when the persistent cursor
was positioned and that the latch will be freed by mini-transaction commit.

row_sel_field_store_in_mysql_format(): Add const qualifier to data.

row_sel_store_mysql_rec(), row_sel_push_cache_row_for_mysql():
Add const qualifier to rec.  Note that rec must be protected by a page latch.
This commit is contained in:
marko
2008-01-11 19:59:47 +00:00
parent d837c2040f
commit aaccf9264f
2 changed files with 67 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
row/row0merge.c
View File

@@ -1511,6 +1511,11 @@ row_merge_copy_blobs(
ut_ad(!dfield_is_null(field));
/* The table is locked during index creation.
Therefore, externally stored columns cannot possibly
be freed between the time the BLOB pointers are read
(row_merge_read_clustered_index()) and dereferenced
(below). */
data = btr_rec_copy_externally_stored_field(
mrec, offsets, zip_size, i, &len, heap);

83
row/row0sel.c
View File

@@ -344,8 +344,8 @@ void
row_sel_fetch_columns(
/*==================*/
dict_index_t* index, /* in: record index */
rec_t* rec, /* in: record in a clustered or non-clustered
index */
const rec_t* rec, /* in: record in a clustered or non-clustered
index; must be protected by a page latch */
const ulint* offsets,/* in: rec_get_offsets(rec, index) */
sym_node_t* column) /* in: first column in a column list, or
NULL */
@@ -353,7 +353,7 @@ row_sel_fetch_columns(
dfield_t* val;
ulint index_type;
ulint field_no;
byte* data;
const byte* data;
ulint len;
ut_ad(rec_offs_validate(rec, index, offsets));
@@ -879,7 +879,10 @@ row_sel_get_clust_rec(
}
}
/* Fetch the columns needed in test conditions */
/* Fetch the columns needed in test conditions. The clustered
index record is protected by a page latch that was acquired
when plan->clust_pcur was positioned. The latch will not be
released until mtr_commit(mtr). */
row_sel_fetch_columns(index, clust_rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
@@ -1186,10 +1189,7 @@ row_sel_try_search_shortcut(
goto func_exit;
}
/* Test deleted flag. Fetch the columns needed in test conditions. */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the deleted flag. */
if (rec_get_deleted_flag(rec, dict_table_is_comp(plan->table))) {
@@ -1197,6 +1197,14 @@ row_sel_try_search_shortcut(
goto func_exit;
}
/* Fetch the columns needed in test conditions. The index
record is protected by a page latch that was acquired when
plan->pcur was positioned. The latch will not be released
until mtr_commit(mtr). */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
/* Test the rest of search conditions */
if (!row_sel_test_other_conds(plan)) {
@@ -1584,6 +1592,16 @@ skip_lock:
offsets = rec_get_offsets(
rec, index, offsets,
ULINT_UNDEFINED, &heap);
/* Fetch the columns needed in
test conditions. The clustered
index record is protected by a
page latch that was acquired
by row_sel_open_pcur() or
row_sel_restore_pcur_pos().
The latch will not be released
until mtr_commit(mtr). */
row_sel_fetch_columns(
index, rec, offsets,
UT_LIST_GET_FIRST(
@@ -1607,7 +1625,10 @@ skip_lock:
/* PHASE 4: Test search end conditions and deleted flag */
/* Fetch the columns needed in test conditions */
/* Fetch the columns needed in test conditions. The record is
protected by a page latch that was acquired by
row_sel_open_pcur() or row_sel_restore_pcur_pos(). The latch
will not be released until mtr_commit(mtr). */
row_sel_fetch_columns(index, rec, offsets,
UT_LIST_GET_FIRST(plan->columns));
@@ -2502,14 +2523,18 @@ static
void
row_sel_field_store_in_mysql_format(
/*================================*/
byte* dest, /* in/out: buffer where to store; NOTE that BLOBs
are not in themselves stored here: the caller must
allocate and copy the BLOB into buffer before, and pass
the pointer to the BLOB in 'data' */
const mysql_row_templ_t* templ, /* in: MySQL column template.
byte* dest, /* in/out: buffer where to store; NOTE
that BLOBs are not in themselves
stored here: the caller must allocate
and copy the BLOB into buffer before,
and pass the pointer to the BLOB in
'data' */
const mysql_row_templ_t* templ,
/* in: MySQL column template.
Its following fields are referenced:
type, is_unsigned, mysql_col_len, mbminlen, mbmaxlen */
byte* data, /* in: data to store */
type, is_unsigned, mysql_col_len,
mbminlen, mbmaxlen */
const byte* data, /* in: data to store */
ulint len) /* in: length of the data */
{
byte* ptr;
@@ -2661,16 +2686,17 @@ row_sel_store_mysql_rec(
case) */
byte* mysql_rec, /* out: row in the MySQL format */
row_prebuilt_t* prebuilt, /* in: prebuilt struct */
rec_t* rec, /* in: Innobase record in the index
const rec_t* rec, /* in: Innobase record in the index
which was described in prebuilt's
template */
template; must be protected by
a page latch */
const ulint* offsets) /* in: array returned by
rec_get_offsets() */
{
mysql_row_templ_t* templ;
mem_heap_t* extern_field_heap = NULL;
mem_heap_t* heap;
byte* data;
const byte* data;
ulint len;
ulint i;
@@ -2771,7 +2797,7 @@ row_sel_store_mysql_rec(
BLOB, TEXT and true VARCHAR) with space. */
if (UNIV_UNLIKELY(templ->mbminlen == 2)) {
/* Treat UCS2 as a special case. */
data = mysql_rec
byte* d = mysql_rec
+ templ->mysql_col_offset;
len = templ->mysql_col_len;
/* There are two UCS2 bytes per char,
@@ -2779,8 +2805,8 @@ row_sel_store_mysql_rec(
ut_a(!(len & 1));
/* Pad with 0x0020. */
while (len) {
*data++ = 0x00;
*data++ = 0x20;
*d++ = 0x00;
*d++ = 0x20;
len -= 2;
}
continue;
@@ -3146,7 +3172,8 @@ void
row_sel_push_cache_row_for_mysql(
/*=============================*/
row_prebuilt_t* prebuilt, /* in: prebuilt struct */
rec_t* rec, /* in: record to push */
const rec_t* rec, /* in: record to push; must
be protected by a page latch */
const ulint* offsets) /* in: rec_get_offsets() */
{
byte* buf;
@@ -3573,6 +3600,12 @@ row_search_for_mysql(
ut_a(0 == cmp_dtuple_rec(search_tuple,
rec, offsets));
#endif
/* At this point, rec is protected by
a page latch that was acquired by
row_sel_try_search_shortcut_for_mysql().
The latch will not be released until
mtr_commit(&mtr). */
if (!row_sel_store_mysql_rec(buf, prebuilt,
rec, offsets)) {
err = DB_TOO_BIG_RECORD;
@@ -4294,6 +4327,10 @@ requires_clust_rec:
result_rec != rec ? clust_index : index,
offsets));
/* At this point, the clustered index record is protected
by a page latch that was acquired when pcur was positioned.
The latch will not be released until mtr_commit(&mtr). */
if ((match_mode == ROW_SEL_EXACT
|| prebuilt->n_rows_fetched >= MYSQL_FETCH_CACHE_THRESHOLD)
&& prebuilt->select_lock_type == LOCK_NONE