database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-03 20:02:46 +03:00
Code Activity

Revert no-op changes to BufferGetPage()

Browse Source 
The reverted changes were intended to force a choice of whether any
newly-added BufferGetPage() calls needed to be accompanied by a
test of the snapshot age, to support the "snapshot too old"
feature.  Such an accompanying test is needed in about 7% of the
cases, where the page is being used as part of a scan rather than
positioning for other purposes (such as DML or vacuuming).  The
additional effort required for back-patching, and the doubt whether
the intended benefit would really be there, have indicated it is
best just to rely on developers to do the right thing based on
comments and existing usage, as we do with many other conventions.

This change should have little or no effect on generated executable
code.

Motivated by the back-patching pain of Tom Lane and Robert Haas
This commit is contained in:
Kevin Grittner
2016-04-20 08:31:19 -05:00
parent 4db0d2d2fe
commit a343e223a5
65 changed files with 550 additions and 736 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/backend/access/spgist/spgutils.c
View File

@ -126,8 +126,7 @@ spgGetCache(Relation index)
metabuffer = ReadBuffer(index, SPGIST_METAPAGE_BLKNO);
LockBuffer(metabuffer, BUFFER_LOCK_SHARE);
metadata = SpGistPageGetMeta
(BufferGetPage(metabuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST));
metadata = SpGistPageGetMeta(BufferGetPage(metabuffer));
if (metadata->magicNumber != SPGIST_MAGIC_NUMBER)
elog(ERROR, "index \"%s\" is not an SP-GiST index",
@ -207,8 +206,7 @@ SpGistNewBuffer(Relation index)
*/
if (ConditionalLockBuffer(buffer))
{
Page page = BufferGetPage(buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(buffer);
if (PageIsNew(page))
return buffer; /* OK to use, if never initialized */
@ -258,8 +256,7 @@ SpGistUpdateMetaPage(Relation index)
if (ConditionalLockBuffer(metabuffer))
{
metadata = SpGistPageGetMeta
(BufferGetPage(metabuffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST));
metadata = SpGistPageGetMeta(BufferGetPage(metabuffer));
metadata->lastUsedPages = cache->lastUsedPages;
MarkBufferDirty(metabuffer);
@ -336,9 +333,7 @@ allocNewBuffer(Relation index, int flags)
blkFlags |= GBUF_NULLS;
cache->lastUsedPages.cachedPage[blkFlags].blkno = blkno;
cache->lastUsedPages.cachedPage[blkFlags].freeSpace =
PageGetExactFreeSpace
(BufferGetPage(buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST));
PageGetExactFreeSpace(BufferGetPage(buffer));
UnlockReleaseBuffer(buffer);
}
}
@ -406,7 +401,7 @@ SpGistGetBuffer(Relation index, int flags, int needSpace, bool *isNew)
return allocNewBuffer(index, flags);
}
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(buffer);
if (PageIsNew(page) || SpGistPageIsDeleted(page) || PageIsEmpty(page))
{
@ -465,7 +460,7 @@ SpGistSetLastUsedPage(Relation index, Buffer buffer)
SpGistCache *cache = spgGetCache(index);
SpGistLastUsedPage *lup;
int freeSpace;
Page page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(buffer);
BlockNumber blkno = BufferGetBlockNumber(buffer);
int flags;
@ -513,7 +508,7 @@ void
SpGistInitBuffer(Buffer b, uint16 f)
{
Assert(BufferGetPageSize(b) == BLCKSZ);
SpGistInitPage(BufferGetPage(b, NULL, NULL, BGP_NO_SNAPSHOT_TEST), f);
SpGistInitPage(BufferGetPage(b), f);
}
/*