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Refactor per-page logic common to all redo routines to a new function.

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Every redo routine uses the same idiom to determine what to do to a page:
check if there's a backup block for it, and if not read, the buffer if the
block exists, and check its LSN. Refactor that into a common function,
XLogReadBufferForRedo, making all the redo routines shorter and more
readable.

This has no user-visible effect, and makes no changes to the WAL format.

Reviewed by Andres Freund, Alvaro Herrera, Michael Paquier.
This commit is contained in:
Heikki Linnakangas
2014-08-13 15:39:08 +03:00
parent 26f8b99b24
commit f8f4227976
8 changed files with 1430 additions and 1739 deletions
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191
src/backend/access/gist/gistxlog.c
View File

@ -48,31 +48,26 @@ gistRedoClearFollowRight(XLogRecPtr lsn, XLogRecord *record, int block_index,
{
Buffer buffer;
Page page;
if (record->xl_info & XLR_BKP_BLOCK(block_index))
buffer = RestoreBackupBlock(lsn, record, block_index, false, true);
else
{
buffer = XLogReadBuffer(node, childblkno, false);
if (!BufferIsValid(buffer))
return; /* page was deleted, nothing to do */
}
page = (Page) BufferGetPage(buffer);
XLogRedoAction action;
/*
* Note that we still update the page even if page LSN is equal to the LSN
* of this record, because the updated NSN is not included in the full
* page image.
* Note that we still update the page even if it was restored from a full
* page image, because the updated NSN is not included in the image.
*/
if (lsn >= PageGetLSN(page))
action = XLogReadBufferForRedo(lsn, record, block_index, node, childblkno,
&buffer);
if (action == BLK_NEEDS_REDO || action == BLK_RESTORED)
{
page = BufferGetPage(buffer);
GistPageSetNSN(page, lsn);
GistClearFollowRight(page);
PageSetLSN(page, lsn);
MarkBufferDirty(buffer);
}
UnlockReleaseBuffer(buffer);
if (BufferIsValid(buffer))
UnlockReleaseBuffer(buffer);
}
/*
@ -87,104 +82,86 @@ gistRedoPageUpdateRecord(XLogRecPtr lsn, XLogRecord *record)
Page page;
char *data;
/*
* We need to acquire and hold lock on target page while updating the left
* child page. If we have a full-page image of target page, getting the
* lock is a side-effect of restoring that image. Note that even if the
* target page no longer exists, we'll still attempt to replay the change
* on the child page.
*/
if (record->xl_info & XLR_BKP_BLOCK(0))
buffer = RestoreBackupBlock(lsn, record, 0, false, true);
else
buffer = XLogReadBuffer(xldata->node, xldata->blkno, false);
if (XLogReadBufferForRedo(lsn, record, 0, xldata->node, xldata->blkno,
&buffer) == BLK_NEEDS_REDO)
{
page = (Page) BufferGetPage(buffer);
/* Fix follow-right data on left child page */
data = begin + sizeof(gistxlogPageUpdate);
/* Delete old tuples */
if (xldata->ntodelete > 0)
{
int i;
OffsetNumber *todelete = (OffsetNumber *) data;
data += sizeof(OffsetNumber) * xldata->ntodelete;
for (i = 0; i < xldata->ntodelete; i++)
PageIndexTupleDelete(page, todelete[i]);
if (GistPageIsLeaf(page))
GistMarkTuplesDeleted(page);
}
/* add tuples */
if (data - begin < record->xl_len)
{
OffsetNumber off = (PageIsEmpty(page)) ? FirstOffsetNumber :
OffsetNumberNext(PageGetMaxOffsetNumber(page));
while (data - begin < record->xl_len)
{
IndexTuple itup = (IndexTuple) data;
Size sz = IndexTupleSize(itup);
OffsetNumber l;
data += sz;
l = PageAddItem(page, (Item) itup, sz, off, false, false);
if (l == InvalidOffsetNumber)
elog(ERROR, "failed to add item to GiST index page, size %d bytes",
(int) sz);
off++;
}
}
else
{
/*
* special case: leafpage, nothing to insert, nothing to delete,
* then vacuum marks page
*/
if (GistPageIsLeaf(page) && xldata->ntodelete == 0)
GistClearTuplesDeleted(page);
}
if (!GistPageIsLeaf(page) &&
PageGetMaxOffsetNumber(page) == InvalidOffsetNumber &&
xldata->blkno == GIST_ROOT_BLKNO)
{
/*
* all links on non-leaf root page was deleted by vacuum full, so
* root page becomes a leaf
*/
GistPageSetLeaf(page);
}
PageSetLSN(page, lsn);
MarkBufferDirty(buffer);
}
/*
* Fix follow-right data on left child page
*
* This must be done while still holding the lock on the target page. Note
* that even if the target page no longer exists, we still attempt to
* replay the change on the child page.
*/
if (BlockNumberIsValid(xldata->leftchild))
gistRedoClearFollowRight(lsn, record, 1,
xldata->node, xldata->leftchild);
/* Done if target page no longer exists */
if (!BufferIsValid(buffer))
return;
/* nothing more to do if page was backed up (and no info to do it with) */
if (record->xl_info & XLR_BKP_BLOCK(0))
{
if (BufferIsValid(buffer))
UnlockReleaseBuffer(buffer);
return;
}
page = (Page) BufferGetPage(buffer);
/* nothing more to do if change already applied */
if (lsn <= PageGetLSN(page))
{
UnlockReleaseBuffer(buffer);
return;
}
data = begin + sizeof(gistxlogPageUpdate);
/* Delete old tuples */
if (xldata->ntodelete > 0)
{
int i;
OffsetNumber *todelete = (OffsetNumber *) data;
data += sizeof(OffsetNumber) * xldata->ntodelete;
for (i = 0; i < xldata->ntodelete; i++)
PageIndexTupleDelete(page, todelete[i]);
if (GistPageIsLeaf(page))
GistMarkTuplesDeleted(page);
}
/* add tuples */
if (data - begin < record->xl_len)
{
OffsetNumber off = (PageIsEmpty(page)) ? FirstOffsetNumber :
OffsetNumberNext(PageGetMaxOffsetNumber(page));
while (data - begin < record->xl_len)
{
IndexTuple itup = (IndexTuple) data;
Size sz = IndexTupleSize(itup);
OffsetNumber l;
data += sz;
l = PageAddItem(page, (Item) itup, sz, off, false, false);
if (l == InvalidOffsetNumber)
elog(ERROR, "failed to add item to GiST index page, size %d bytes",
(int) sz);
off++;
}
}
else
{
/*
* special case: leafpage, nothing to insert, nothing to delete, then
* vacuum marks page
*/
if (GistPageIsLeaf(page) && xldata->ntodelete == 0)
GistClearTuplesDeleted(page);
}
if (!GistPageIsLeaf(page) &&
PageGetMaxOffsetNumber(page) == InvalidOffsetNumber &&
xldata->blkno == GIST_ROOT_BLKNO)
{
/*
* all links on non-leaf root page was deleted by vacuum full, so root
* page becomes a leaf
*/
GistPageSetLeaf(page);
}
PageSetLSN(page, lsn);
MarkBufferDirty(buffer);
UnlockReleaseBuffer(buffer);
}
static void