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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

48
src/backend/access/gist/gist.c
View File

@ -211,8 +211,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
bool markfollowright)
{
BlockNumber blkno = BufferGetBlockNumber(buffer);
Page page = BufferGetPage(buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(buffer);
bool is_leaf = (GistPageIsLeaf(page)) ? true : false;
XLogRecPtr recptr;
int i;
@ -317,9 +316,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
dist->buffer = buffer;
dist->block.blkno = BufferGetBlockNumber(buffer);
dist->page =
PageGetTempPageCopySpecial(BufferGetPage(buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST));
dist->page = PageGetTempPageCopySpecial(BufferGetPage(buffer));
/* clean all flags except F_LEAF */
GistPageGetOpaque(dist->page)->flags = (is_leaf) ? F_LEAF : 0;
@ -331,7 +328,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
/* Allocate new page */
ptr->buffer = gistNewBuffer(rel);
GISTInitBuffer(ptr->buffer, (is_leaf) ? F_LEAF : 0);
ptr->page = BufferGetPage(ptr->buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
ptr->page = BufferGetPage(ptr->buffer);
ptr->block.blkno = BufferGetBlockNumber(ptr->buffer);
}
@ -357,10 +354,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
int i;
rootpg.buffer = buffer;
rootpg.page =
PageGetTempPageCopySpecial(BufferGetPage(rootpg.buffer,
NULL, NULL,
BGP_NO_SNAPSHOT_TEST));
rootpg.page = PageGetTempPageCopySpecial(BufferGetPage(rootpg.buffer));
GistPageGetOpaque(rootpg.page)->flags = 0;
/* Prepare a vector of all the downlinks */
@ -468,11 +462,8 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
* The first page in the chain was a temporary working copy meant to
* replace the old page. Copy it over the old page.
*/
PageRestoreTempPage(dist->page, BufferGetPage(dist->buffer,
NULL, NULL,
BGP_NO_SNAPSHOT_TEST));
dist->page = BufferGetPage(dist->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
PageRestoreTempPage(dist->page, BufferGetPage(dist->buffer));
dist->page = BufferGetPage(dist->buffer);
/* Write the WAL record */
if (RelationNeedsWAL(rel))
@ -563,8 +554,7 @@ gistplacetopage(Relation rel, Size freespace, GISTSTATE *giststate,
*/
if (BufferIsValid(leftchildbuf))
{
Page leftpg = BufferGetPage(leftchildbuf, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
Page leftpg = BufferGetPage(leftchildbuf);
GistPageSetNSN(leftpg, recptr);
GistClearFollowRight(leftpg);
@ -624,8 +614,7 @@ gistdoinsert(Relation r, IndexTuple itup, Size freespace, GISTSTATE *giststate)
gistcheckpage(state.r, stack->buffer);
}
stack->page = BufferGetPage(stack->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
stack->page = (Page) BufferGetPage(stack->buffer);
stack->lsn = PageGetLSN(stack->page);
Assert(!RelationNeedsWAL(state.r) || !XLogRecPtrIsInvalid(stack->lsn));
@ -710,8 +699,7 @@ gistdoinsert(Relation r, IndexTuple itup, Size freespace, GISTSTATE *giststate)
LockBuffer(stack->buffer, GIST_UNLOCK);
LockBuffer(stack->buffer, GIST_EXCLUSIVE);
xlocked = true;
stack->page = BufferGetPage(stack->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
stack->page = (Page) BufferGetPage(stack->buffer);
if (PageGetLSN(stack->page) != stack->lsn)
{
@ -775,8 +763,7 @@ gistdoinsert(Relation r, IndexTuple itup, Size freespace, GISTSTATE *giststate)
LockBuffer(stack->buffer, GIST_UNLOCK);
LockBuffer(stack->buffer, GIST_EXCLUSIVE);
xlocked = true;
stack->page = BufferGetPage(stack->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
stack->page = (Page) BufferGetPage(stack->buffer);
stack->lsn = PageGetLSN(stack->page);
if (stack->blkno == GIST_ROOT_BLKNO)
@ -866,7 +853,7 @@ gistFindPath(Relation r, BlockNumber child, OffsetNumber *downlinkoffnum)
buffer = ReadBuffer(r, top->blkno);
LockBuffer(buffer, GIST_SHARE);
gistcheckpage(r, buffer);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
if (GistPageIsLeaf(page))
{
@ -954,8 +941,7 @@ gistFindCorrectParent(Relation r, GISTInsertStack *child)
GISTInsertStack *parent = child->parent;
gistcheckpage(r, parent->buffer);
parent->page = BufferGetPage(parent->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
parent->page = (Page) BufferGetPage(parent->buffer);
/* here we don't need to distinguish between split and page update */
if (child->downlinkoffnum == InvalidOffsetNumber ||
@ -996,8 +982,7 @@ gistFindCorrectParent(Relation r, GISTInsertStack *child)
parent->buffer = ReadBuffer(r, parent->blkno);
LockBuffer(parent->buffer, GIST_EXCLUSIVE);
gistcheckpage(r, parent->buffer);
parent->page = BufferGetPage(parent->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
parent->page = (Page) BufferGetPage(parent->buffer);
}
/*
@ -1021,8 +1006,7 @@ gistFindCorrectParent(Relation r, GISTInsertStack *child)
while (ptr)
{
ptr->buffer = ReadBuffer(r, ptr->blkno);
ptr->page = BufferGetPage(ptr->buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
ptr->page = (Page) BufferGetPage(ptr->buffer);
ptr = ptr->parent;
}
@ -1044,7 +1028,7 @@ static IndexTuple
gistformdownlink(Relation rel, Buffer buf, GISTSTATE *giststate,
GISTInsertStack *stack)
{
Page page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(buf);
OffsetNumber maxoff;
OffsetNumber offset;
IndexTuple downlink = NULL;
@ -1125,7 +1109,7 @@ gistfixsplit(GISTInsertState *state, GISTSTATE *giststate)
GISTPageSplitInfo *si = palloc(sizeof(GISTPageSplitInfo));
IndexTuple downlink;
page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(buf);
/* Form the new downlink tuples to insert to parent */
downlink = gistformdownlink(state->r, buf, giststate, stack);

14
src/backend/access/gist/gistbuild.c
View File

@ -169,7 +169,7 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
/* initialize the root page */
buffer = gistNewBuffer(index);
Assert(BufferGetBlockNumber(buffer) == GIST_ROOT_BLKNO);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(buffer);
START_CRIT_SECTION();
@ -589,7 +589,7 @@ gistProcessItup(GISTBuildState *buildstate, IndexTuple itup,
buffer = ReadBuffer(indexrel, blkno);
LockBuffer(buffer, GIST_EXCLUSIVE);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
childoffnum = gistchoose(indexrel, page, itup, giststate);
iid = PageGetItemId(page, childoffnum);
idxtuple = (IndexTuple) PageGetItem(page, iid);
@ -699,8 +699,7 @@ gistbufferinginserttuples(GISTBuildState *buildstate, Buffer buffer, int level,
*/
if (is_split && BufferGetBlockNumber(buffer) == GIST_ROOT_BLKNO)
{
Page page = BufferGetPage(buffer, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(buffer);
OffsetNumber off;
OffsetNumber maxoff;
@ -867,7 +866,7 @@ gistBufferingFindCorrectParent(GISTBuildState *buildstate,
}
buffer = ReadBuffer(buildstate->indexrel, parent);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(buffer);
LockBuffer(buffer, GIST_EXCLUSIVE);
gistcheckpage(buildstate->indexrel, buffer);
maxoff = PageGetMaxOffsetNumber(page);
@ -1068,7 +1067,7 @@ gistGetMaxLevel(Relation index)
* pro forma.
*/
LockBuffer(buffer, GIST_SHARE);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
if (GistPageIsLeaf(page))
{
@ -1168,8 +1167,7 @@ gistMemorizeAllDownlinks(GISTBuildState *buildstate, Buffer parentbuf)
OffsetNumber maxoff;
OffsetNumber off;
BlockNumber parentblkno = BufferGetBlockNumber(parentbuf);
Page page = BufferGetPage(parentbuf, NULL, NULL,
BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(parentbuf);
Assert(!GistPageIsLeaf(page));

5
src/backend/access/gist/gistget.c
View File

@ -54,7 +54,7 @@ gistkillitems(IndexScanDesc scan)
LockBuffer(buffer, GIST_SHARE);
gistcheckpage(scan->indexRelation, buffer);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(buffer);
/*
* If page LSN differs it means that the page was modified since the last read.
@ -336,7 +336,8 @@ gistScanPage(IndexScanDesc scan, GISTSearchItem *pageItem, double *myDistances,
buffer = ReadBuffer(scan->indexRelation, pageItem->blkno);
LockBuffer(buffer, GIST_SHARE);
gistcheckpage(scan->indexRelation, buffer);
page = BufferGetPage(buffer, scan->xs_snapshot, r, BGP_TEST_FOR_OLD_SNAPSHOT);
page = BufferGetPage(buffer);
TestForOldSnapshot(scan->xs_snapshot, r, page);
opaque = GistPageGetOpaque(page);
/*

6
src/backend/access/gist/gistutil.c
View File

@ -701,7 +701,7 @@ GISTInitBuffer(Buffer b, uint32 f)
Size pageSize;
pageSize = BufferGetPageSize(b);
page = BufferGetPage(b, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(b);
PageInit(page, pageSize, sizeof(GISTPageOpaqueData));
opaque = GistPageGetOpaque(page);
@ -718,7 +718,7 @@ GISTInitBuffer(Buffer b, uint32 f)
void
gistcheckpage(Relation rel, Buffer buf)
{
Page page = BufferGetPage(buf, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
Page page = BufferGetPage(buf);
/*
* ReadBuffer verifies that every newly-read page passes
@ -776,7 +776,7 @@ gistNewBuffer(Relation r)
*/
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 */

6
src/backend/access/gist/gistvacuum.c
View File

@ -75,7 +75,7 @@ gistvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
buffer = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL,
info->strategy);
LockBuffer(buffer, GIST_SHARE);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
if (PageIsNew(page) || GistPageIsDeleted(page))
{
@ -166,7 +166,7 @@ gistbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
RBM_NORMAL, info->strategy);
LockBuffer(buffer, GIST_SHARE);
gistcheckpage(rel, buffer);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
if (GistPageIsLeaf(page))
{
@ -176,7 +176,7 @@ gistbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
LockBuffer(buffer, GIST_UNLOCK);
LockBuffer(buffer, GIST_EXCLUSIVE);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
if (stack->blkno == GIST_ROOT_BLKNO && !GistPageIsLeaf(page))
{
/* only the root can become non-leaf during relock */

8
src/backend/access/gist/gistxlog.c
View File

@ -46,7 +46,7 @@ gistRedoClearFollowRight(XLogReaderState *record, uint8 block_id)
action = XLogReadBufferForRedo(record, block_id, &buffer);
if (action == BLK_NEEDS_REDO || action == BLK_RESTORED)
{
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = BufferGetPage(buffer);
GistPageSetNSN(page, lsn);
GistClearFollowRight(page);
@ -78,7 +78,7 @@ gistRedoPageUpdateRecord(XLogReaderState *record)
data = begin = XLogRecGetBlockData(record, 0, &datalen);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
/* Delete old tuples */
if (xldata->ntodelete > 0)
@ -199,7 +199,7 @@ gistRedoPageSplitRecord(XLogReaderState *record)
}
buffer = XLogInitBufferForRedo(record, i + 1);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
data = XLogRecGetBlockData(record, i + 1, &datalen);
tuples = decodePageSplitRecord(data, datalen, &num);
@ -265,7 +265,7 @@ gistRedoCreateIndex(XLogReaderState *record)
buffer = XLogInitBufferForRedo(record, 0);
Assert(BufferGetBlockNumber(buffer) == GIST_ROOT_BLKNO);
page = BufferGetPage(buffer, NULL, NULL, BGP_NO_SNAPSHOT_TEST);
page = (Page) BufferGetPage(buffer);
GISTInitBuffer(buffer, F_LEAF);