/*
* Deletes posting item from non-leaf page
*/
void
GinPageDeletePostingItem(Page page, OffsetNumber offset)
{
OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
Assert(!GinPageIsLeaf(page));
Assert(offset >= FirstOffsetNumber && offset <= maxoff);
if (offset != maxoff)
memmove(GinDataPageGetItem(page, offset), GinDataPageGetItem(page, offset + 1),
sizeof(PostingItem) * (maxoff - offset));
GinPageGetOpaque(page)->maxoff--;
}
/*
* add ItemPointer or PostingItem to page. data should point to
* correct value! depending on leaf or non-leaf page
*/
void
GinDataPageAddItem(Page page, void *data, OffsetNumber offset)
{
OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
char *ptr;
if (offset == InvalidOffsetNumber)
{
ptr = GinDataPageGetItem(page, maxoff + 1);
}
else
{
ptr = GinDataPageGetItem(page, offset);
if (maxoff + 1 - offset != 0)
memmove(ptr + GinSizeOfItem(page), ptr, (maxoff - offset + 1) * GinSizeOfItem(page));
}
memcpy(ptr, data, GinSizeOfItem(page));
GinPageGetOpaque(page)->maxoff++;
}
/*
* Finds links to blkno on non-leaf page, returns
* offset of PostingItem
*/
static OffsetNumber
dataFindChildPtr(GinBtree btree, Page page, BlockNumber blkno, OffsetNumber storedOff)
{
OffsetNumber i,
maxoff = GinPageGetOpaque(page)->maxoff;
PostingItem *pitem;
Assert(!GinPageIsLeaf(page));
Assert(GinPageIsData(page));
/* if page isn't changed, we return storedOff */
if (storedOff >= FirstOffsetNumber && storedOff <= maxoff)
{
pitem = (PostingItem *) GinDataPageGetItem(page, storedOff);
if (PostingItemGetBlockNumber(pitem) == blkno)
return storedOff;
/*
* we hope, that needed pointer goes to right. It's true if there
* wasn't a deletion
*/
for (i = storedOff + 1; i <= maxoff; i++)
{
pitem = (PostingItem *) GinDataPageGetItem(page, i);
if (PostingItemGetBlockNumber(pitem) == blkno)
return i;
}
maxoff = storedOff - 1;
}
/* last chance */
for (i = FirstOffsetNumber; i <= maxoff; i++)
{
pitem = (PostingItem *) GinDataPageGetItem(page, i);
if (PostingItemGetBlockNumber(pitem) == blkno)
return i;
}
return InvalidOffsetNumber;
}
/*
* returns blkno of leftmost child
*/
static BlockNumber
dataGetLeftMostPage(GinBtree btree, Page page)
{
PostingItem *pitem;
Assert(!GinPageIsLeaf(page));
Assert(GinPageIsData(page));
Assert(GinPageGetOpaque(page)->maxoff >= FirstOffsetNumber);
pitem = (PostingItem *) GinDataPageGetItem(page, FirstOffsetNumber);
return PostingItemGetBlockNumber(pitem);
}
/*
* Searches correct position for value on leaf page.
* Page should be correctly chosen.
* Returns true if value found on page.
*/
static bool
dataLocateLeafItem(GinBtree btree, GinBtreeStack *stack)
{
Page page = BufferGetPage(stack->buffer);
OffsetNumber low,
high;
int result;
Assert(GinPageIsLeaf(page));
Assert(GinPageIsData(page));
if (btree->fullScan)
{
stack->off = FirstOffsetNumber;
return TRUE;
}
low = FirstOffsetNumber;
high = GinPageGetOpaque(page)->maxoff;
if (high < low)
{
stack->off = FirstOffsetNumber;
return false;
}
high++;
while (high > low)
{
OffsetNumber mid = low + ((high - low) / 2);
result = ginCompareItemPointers(btree->items + btree->curitem, (ItemPointer) GinDataPageGetItem(page, mid));
if (result == 0)
{
stack->off = mid;
return true;
}
else if (result > 0)
low = mid + 1;
else
high = mid;
}
stack->off = high;
return false;
}
/*
* In case of previous split update old child blkno to
* new right page
* item pointer never deletes!
*/
static BlockNumber
dataPrepareData(GinBtree btree, Page page, OffsetNumber off)
{
BlockNumber ret = InvalidBlockNumber;
Assert(GinPageIsData(page));
if (!GinPageIsLeaf(page) && btree->rightblkno != InvalidBlockNumber)
{
PostingItem *pitem = (PostingItem *) GinDataPageGetItem(page, off);
PostingItemSetBlockNumber(pitem, btree->rightblkno);
ret = btree->rightblkno;
}
btree->rightblkno = InvalidBlockNumber;
return ret;
}
static bool
findItemInPage(Page page, ItemPointer item, OffsetNumber *off)
{
OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
int res;
if ( GinPageGetOpaque(page)->flags & GIN_DELETED )
/* page was deleted by concurrent vacuum */
return false;
/*
* scan page to find equal or first greater value
*/
for (*off = FirstOffsetNumber; *off <= maxoff; (*off)++)
{
res = compareItemPointers(item, (ItemPointer) GinDataPageGetItem(page, *off));
if (res <= 0)
return true;
}
return false;
}
/*
* scans posting tree and deletes empty pages
*/
static bool
ginScanToDelete(GinVacuumState *gvs, BlockNumber blkno, bool isRoot, DataPageDeleteStack *parent, OffsetNumber myoff)
{
DataPageDeleteStack *me;
Buffer buffer;
Page page;
bool meDelete = FALSE;
if (isRoot)
{
me = parent;
}
else
{
if (!parent->child)
{
me = (DataPageDeleteStack *) palloc0(sizeof(DataPageDeleteStack));
me->parent = parent;
parent->child = me;
me->leftBlkno = InvalidBlockNumber;
}
else
me = parent->child;
}
buffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, blkno,
RBM_NORMAL, gvs->strategy);
page = BufferGetPage(buffer);
Assert(GinPageIsData(page));
if (!GinPageIsLeaf(page))
{
OffsetNumber i;
me->blkno = blkno;
for (i = FirstOffsetNumber; i <= GinPageGetOpaque(page)->maxoff; i++)
{
PostingItem *pitem = (PostingItem *) GinDataPageGetItem(page, i);
if (ginScanToDelete(gvs, PostingItemGetBlockNumber(pitem), FALSE, me, i))
i--;
}
}
if (GinPageGetOpaque(page)->maxoff < FirstOffsetNumber)
{
if (!(me->leftBlkno == InvalidBlockNumber && GinPageRightMost(page)))
{
/* we never delete right most branch */
Assert(!isRoot);
if (GinPageGetOpaque(page)->maxoff < FirstOffsetNumber)
{
ginDeletePage(gvs, blkno, me->leftBlkno, me->parent->blkno, myoff, me->parent->isRoot);
meDelete = TRUE;
}
}
}
ReleaseBuffer(buffer);
if (!meDelete)
me->leftBlkno = blkno;
return meDelete;
}
static void
ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkno,
BlockNumber parentBlkno, OffsetNumber myoff, bool isParentRoot)
{
Buffer dBuffer;
Buffer lBuffer;
Buffer pBuffer;
Page page,
parentPage;
dBuffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, deleteBlkno,
RBM_NORMAL, gvs->strategy);
if (leftBlkno != InvalidBlockNumber)
lBuffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, leftBlkno,
RBM_NORMAL, gvs->strategy);
else
lBuffer = InvalidBuffer;
pBuffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, parentBlkno,
RBM_NORMAL, gvs->strategy);
LockBuffer(dBuffer, GIN_EXCLUSIVE);
if (!isParentRoot) /* parent is already locked by
* LockBufferForCleanup() */
LockBuffer(pBuffer, GIN_EXCLUSIVE);
if (leftBlkno != InvalidBlockNumber)
LockBuffer(lBuffer, GIN_EXCLUSIVE);
START_CRIT_SECTION();
if (leftBlkno != InvalidBlockNumber)
{
BlockNumber rightlink;
page = BufferGetPage(dBuffer);
rightlink = GinPageGetOpaque(page)->rightlink;
page = BufferGetPage(lBuffer);
GinPageGetOpaque(page)->rightlink = rightlink;
}
parentPage = BufferGetPage(pBuffer);
#ifdef USE_ASSERT_CHECKING
do
{
PostingItem *tod = (PostingItem *) GinDataPageGetItem(parentPage, myoff);
Assert(PostingItemGetBlockNumber(tod) == deleteBlkno);
} while (0);
#endif
GinPageDeletePostingItem(parentPage, myoff);
page = BufferGetPage(dBuffer);
/*
* we shouldn't change rightlink field to save workability of running
* search scan
*/
GinPageGetOpaque(page)->flags = GIN_DELETED;
MarkBufferDirty(pBuffer);
if (leftBlkno != InvalidBlockNumber)
MarkBufferDirty(lBuffer);
MarkBufferDirty(dBuffer);
if (RelationNeedsWAL(gvs->index))
{
XLogRecPtr recptr;
XLogRecData rdata[4];
ginxlogDeletePage data;
int n;
data.node = gvs->index->rd_node;
data.blkno = deleteBlkno;
data.parentBlkno = parentBlkno;
data.parentOffset = myoff;
data.leftBlkno = leftBlkno;
data.rightLink = GinPageGetOpaque(page)->rightlink;
rdata[0].buffer = dBuffer;
rdata[0].buffer_std = FALSE;
rdata[0].data = NULL;
rdata[0].len = 0;
rdata[0].next = rdata + 1;
rdata[1].buffer = pBuffer;
rdata[1].buffer_std = FALSE;
rdata[1].data = NULL;
rdata[1].len = 0;
rdata[1].next = rdata + 2;
if (leftBlkno != InvalidBlockNumber)
{
rdata[2].buffer = lBuffer;
rdata[2].buffer_std = FALSE;
rdata[2].data = NULL;
rdata[2].len = 0;
rdata[2].next = rdata + 3;
n = 3;
}
else
n = 2;
rdata[n].buffer = InvalidBuffer;
rdata[n].buffer_std = FALSE;
rdata[n].len = sizeof(ginxlogDeletePage);
rdata[n].data = (char *) &data;
rdata[n].next = NULL;
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_DELETE_PAGE, rdata);
PageSetLSN(page, recptr);
PageSetTLI(page, ThisTimeLineID);
PageSetLSN(parentPage, recptr);
PageSetTLI(parentPage, ThisTimeLineID);
if (leftBlkno != InvalidBlockNumber)
{
page = BufferGetPage(lBuffer);
PageSetLSN(page, recptr);
PageSetTLI(page, ThisTimeLineID);
}
}
if (!isParentRoot)
LockBuffer(pBuffer, GIN_UNLOCK);
ReleaseBuffer(pBuffer);
if (leftBlkno != InvalidBlockNumber)
UnlockReleaseBuffer(lBuffer);
UnlockReleaseBuffer(dBuffer);
END_CRIT_SECTION();
gvs->result->pages_deleted++;
}
static bool
ginVacuumPostingTreeLeaves(GinVacuumState *gvs, BlockNumber blkno, bool isRoot, Buffer *rootBuffer)
{
Buffer buffer;
Page page;
bool hasVoidPage = FALSE;
buffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, blkno,
RBM_NORMAL, gvs->strategy);
page = BufferGetPage(buffer);
/*
* We should be sure that we don't concurrent with inserts, insert process
* never release root page until end (but it can unlock it and lock
* again). New scan can't start but previously started ones work
* concurrently.
*/
if (isRoot)
LockBufferForCleanup(buffer);
else
LockBuffer(buffer, GIN_EXCLUSIVE);
Assert(GinPageIsData(page));
if (GinPageIsLeaf(page))
{
OffsetNumber newMaxOff,
oldMaxOff = GinPageGetOpaque(page)->maxoff;
ItemPointerData *cleaned = NULL;
newMaxOff = ginVacuumPostingList(gvs,
(ItemPointer) GinDataPageGetData(page), oldMaxOff, &cleaned);
/* saves changes about deleted tuple ... */
if (oldMaxOff != newMaxOff)
{
START_CRIT_SECTION();
if (newMaxOff > 0)
memcpy(GinDataPageGetData(page), cleaned, sizeof(ItemPointerData) * newMaxOff);
pfree(cleaned);
GinPageGetOpaque(page)->maxoff = newMaxOff;
MarkBufferDirty(buffer);
xlogVacuumPage(gvs->index, buffer);
END_CRIT_SECTION();
/* if root is a leaf page, we don't desire further processing */
if (!isRoot && GinPageGetOpaque(page)->maxoff < FirstOffsetNumber)
hasVoidPage = TRUE;
}
}
else
{
OffsetNumber i;
bool isChildHasVoid = FALSE;
for (i = FirstOffsetNumber; i <= GinPageGetOpaque(page)->maxoff; i++)
{
PostingItem *pitem = (PostingItem *) GinDataPageGetItem(page, i);
if (ginVacuumPostingTreeLeaves(gvs, PostingItemGetBlockNumber(pitem), FALSE, NULL))
isChildHasVoid = TRUE;
}
if (isChildHasVoid)
hasVoidPage = TRUE;
}
/*
* if we have root and theres void pages in tree, then we don't release
* lock to go further processing and guarantee that tree is unused
*/
if (!(isRoot && hasVoidPage))
{
UnlockReleaseBuffer(buffer);
}
else
{
Assert(rootBuffer);
*rootBuffer = buffer;
}
return hasVoidPage;
}
/*
* Find correct PostingItem in non-leaf page. It supposed that page
* correctly chosen and searching value SHOULD be on page
*/
static BlockNumber
dataLocateItem(GinBtree btree, GinBtreeStack *stack)
{
OffsetNumber low,
high,
maxoff;
PostingItem *pitem = NULL;
int result;
Page page = BufferGetPage(stack->buffer);
Assert(!GinPageIsLeaf(page));
Assert(GinPageIsData(page));
if (btree->fullScan)
{
stack->off = FirstOffsetNumber;
stack->predictNumber *= GinPageGetOpaque(page)->maxoff;
return btree->getLeftMostPage(btree, page);
}
low = FirstOffsetNumber;
maxoff = high = GinPageGetOpaque(page)->maxoff;
Assert(high >= low);
high++;
while (high > low)
{
OffsetNumber mid = low + ((high - low) / 2);
pitem = (PostingItem *) GinDataPageGetItem(page, mid);
if (mid == maxoff)
{
/*
* Right infinity, page already correctly chosen with a help of
* dataIsMoveRight
*/
result = -1;
}
else
{
pitem = (PostingItem *) GinDataPageGetItem(page, mid);
result = ginCompareItemPointers(btree->items + btree->curitem, &(pitem->key));
}
if (result == 0)
{
stack->off = mid;
return PostingItemGetBlockNumber(pitem);
}
else if (result > 0)
low = mid + 1;
else
high = mid;
}
Assert(high >= FirstOffsetNumber && high <= maxoff);
stack->off = high;
pitem = (PostingItem *) GinDataPageGetItem(page, high);
return PostingItemGetBlockNumber(pitem);
}
/*
* split page and fills WAL record. original buffer(lbuf) leaves untouched,
* returns shadow page of lbuf filled new data. In leaf page and build mode puts all
* ItemPointers to pages. Also, in build mode splits data by way to full fulled
* left page
*/
static Page
dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRecData **prdata)
{
char *ptr;
OffsetNumber separator;
ItemPointer bound;
Page lpage = PageGetTempPageCopy(BufferGetPage(lbuf));
ItemPointerData oldbound = *GinDataPageGetRightBound(lpage);
int sizeofitem = GinSizeOfDataPageItem(lpage);
OffsetNumber maxoff = GinPageGetOpaque(lpage)->maxoff;
Page rpage = BufferGetPage(rbuf);
Size pageSize = PageGetPageSize(lpage);
Size freeSpace;
uint32 nCopied = 1;
/* these must be static so they can be returned to caller */
static ginxlogSplit data;
static XLogRecData rdata[4];
static char vector[2 * BLCKSZ];
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
freeSpace = GinDataPageGetFreeSpace(rpage);
*prdata = rdata;
data.leftChildBlkno = (GinPageIsLeaf(lpage)) ?
InvalidOffsetNumber : PostingItemGetBlockNumber(&(btree->pitem));
data.updateBlkno = dataPrepareData(btree, lpage, off);
memcpy(vector, GinDataPageGetItem(lpage, FirstOffsetNumber),
maxoff * sizeofitem);
if (GinPageIsLeaf(lpage) && GinPageRightMost(lpage) && off > GinPageGetOpaque(lpage)->maxoff)
{
nCopied = 0;
while (btree->curitem < btree->nitem &&
maxoff * sizeof(ItemPointerData) < 2 * (freeSpace - sizeof(ItemPointerData)))
{
memcpy(vector + maxoff * sizeof(ItemPointerData),
btree->items + btree->curitem,
sizeof(ItemPointerData));
maxoff++;
nCopied++;
btree->curitem++;
}
}
else
{
ptr = vector + (off - 1) * sizeofitem;
if (maxoff + 1 - off != 0)
memmove(ptr + sizeofitem, ptr, (maxoff - off + 1) * sizeofitem);
if (GinPageIsLeaf(lpage))
{
memcpy(ptr, btree->items + btree->curitem, sizeofitem);
btree->curitem++;
}
else
memcpy(ptr, &(btree->pitem), sizeofitem);
maxoff++;
}
/*
* we suppose that during index creation table scaned from begin to end,
* so ItemPointers are monotonically increased..
*/
if (btree->isBuild && GinPageRightMost(lpage))
separator = freeSpace / sizeofitem;
else
separator = maxoff / 2;
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
GinInitPage(lpage, GinPageGetOpaque(rpage)->flags, pageSize);
memcpy(GinDataPageGetItem(lpage, FirstOffsetNumber), vector, separator * sizeofitem);
GinPageGetOpaque(lpage)->maxoff = separator;
memcpy(GinDataPageGetItem(rpage, FirstOffsetNumber),
vector + separator * sizeofitem, (maxoff - separator) * sizeofitem);
GinPageGetOpaque(rpage)->maxoff = maxoff - separator;
PostingItemSetBlockNumber(&(btree->pitem), BufferGetBlockNumber(lbuf));
if (GinPageIsLeaf(lpage))
btree->pitem.key = *(ItemPointerData *) GinDataPageGetItem(lpage,
GinPageGetOpaque(lpage)->maxoff);
else
btree->pitem.key = ((PostingItem *) GinDataPageGetItem(lpage,
GinPageGetOpaque(lpage)->maxoff))->key;
btree->rightblkno = BufferGetBlockNumber(rbuf);
/* set up right bound for left page */
bound = GinDataPageGetRightBound(lpage);
*bound = btree->pitem.key;
/* set up right bound for right page */
bound = GinDataPageGetRightBound(rpage);
*bound = oldbound;
data.node = btree->index->rd_node;
data.rootBlkno = InvalidBlockNumber;
data.lblkno = BufferGetBlockNumber(lbuf);
data.rblkno = BufferGetBlockNumber(rbuf);
data.separator = separator;
data.nitem = maxoff;
data.isData = TRUE;
data.isLeaf = GinPageIsLeaf(lpage) ? TRUE : FALSE;
data.isRootSplit = FALSE;
data.rightbound = oldbound;
rdata[0].buffer = InvalidBuffer;
rdata[0].data = (char *) &data;
rdata[0].len = sizeof(ginxlogSplit);
rdata[0].next = &rdata[1];
rdata[1].buffer = InvalidBuffer;
rdata[1].data = vector;
rdata[1].len = MAXALIGN(maxoff * sizeofitem);
rdata[1].next = NULL;
return lpage;
}
/*
* Start* functions setup state of searches: find correct buffer and locks it,
* Stop* functions unlock buffer (but don't release!)
*/
static void
startScanEntry(Relation index, GinState *ginstate, GinScanEntry entry)
{
GinBtreeData btreeEntry;
GinBtreeStack *stackEntry;
Page page;
bool needUnlock = TRUE;
if (entry->master != NULL)
{
entry->isFinished = entry->master->isFinished;
return;
}
/*
* We should find entry, and begin scan of posting tree
* or just store posting list in memory
*/
prepareEntryScan(&btreeEntry, index, entry->entry, ginstate);
btreeEntry.searchMode = TRUE;
stackEntry = ginFindLeafPage(&btreeEntry, NULL);
page = BufferGetPage(stackEntry->buffer);
entry->isFinished = TRUE;
entry->buffer = InvalidBuffer;
entry->offset = InvalidOffsetNumber;
entry->list = NULL;
entry->nlist = 0;
entry->reduceResult = FALSE;
entry->predictNumberResult = 0;
if (btreeEntry.findItem(&btreeEntry, stackEntry))
{
IndexTuple itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stackEntry->off));
if (GinIsPostingTree(itup))
{
BlockNumber rootPostingTree = GinGetPostingTree(itup);
GinPostingTreeScan *gdi;
Page page;
LockBuffer(stackEntry->buffer, GIN_UNLOCK);
needUnlock = FALSE;
gdi = prepareScanPostingTree(index, rootPostingTree, TRUE);
entry->buffer = scanBeginPostingTree(gdi);
/*
* We keep buffer pinned because we need to prevent deletition
* page during scan. See GIN's vacuum implementation. RefCount
* is increased to keep buffer pinned after freeGinBtreeStack() call.
*/
IncrBufferRefCount(entry->buffer);
page = BufferGetPage(entry->buffer);
entry->predictNumberResult = gdi->stack->predictNumber * GinPageGetOpaque(page)->maxoff;
/*
* Keep page content in memory to prevent durable page locking
*/
entry->list = (ItemPointerData *) palloc( BLCKSZ );
entry->nlist = GinPageGetOpaque(page)->maxoff;
memcpy( entry->list, GinDataPageGetItem(page, FirstOffsetNumber),
GinPageGetOpaque(page)->maxoff * sizeof(ItemPointerData) );
LockBuffer(entry->buffer, GIN_UNLOCK);
freeGinBtreeStack(gdi->stack);
pfree(gdi);
entry->isFinished = FALSE;
}
else if (GinGetNPosting(itup) > 0)
{
entry->nlist = GinGetNPosting(itup);
entry->list = (ItemPointerData *) palloc(sizeof(ItemPointerData) * entry->nlist);
memcpy(entry->list, GinGetPosting(itup), sizeof(ItemPointerData) * entry->nlist);
entry->isFinished = FALSE;
}
}
if (needUnlock)
LockBuffer(stackEntry->buffer, GIN_UNLOCK);
freeGinBtreeStack(stackEntry);
}
/*
* Gets next ItemPointer from PostingTree. Note, that we copy
* page into GinScanEntry->list array and unlock page, but keep it pinned
* to prevent interference with vacuum
*/
static void
entryGetNextItem(Relation index, GinScanEntry entry)
{
Page page;
BlockNumber blkno;
for(;;)
{
entry->offset++;
if (entry->offset <= entry->nlist)
{
entry->curItem = entry->list[entry->offset - 1];
return;
}
LockBuffer(entry->buffer, GIN_SHARE);
page = BufferGetPage(entry->buffer);
for(;;)
{
/*
* It's needed to go by right link. During that we should refind
* first ItemPointer greater that stored
*/
blkno = GinPageGetOpaque(page)->rightlink;
LockBuffer(entry->buffer, GIN_UNLOCK);
if (blkno == InvalidBlockNumber)
{
ReleaseBuffer(entry->buffer);
ItemPointerSet(&entry->curItem, InvalidBlockNumber, InvalidOffsetNumber);
entry->buffer = InvalidBuffer;
entry->isFinished = TRUE;
return;
}
entry->buffer = ReleaseAndReadBuffer(entry->buffer, index, blkno);
LockBuffer(entry->buffer, GIN_SHARE);
page = BufferGetPage(entry->buffer);
entry->offset = InvalidOffsetNumber;
if (!ItemPointerIsValid(&entry->curItem) || findItemInPage(page, &entry->curItem, &entry->offset))
{
/*
* Found position equal to or greater than stored
*/
entry->nlist = GinPageGetOpaque(page)->maxoff;
memcpy( entry->list, GinDataPageGetItem(page, FirstOffsetNumber),
GinPageGetOpaque(page)->maxoff * sizeof(ItemPointerData) );
LockBuffer(entry->buffer, GIN_UNLOCK);
if ( !ItemPointerIsValid(&entry->curItem) ||
compareItemPointers( &entry->curItem, entry->list + entry->offset - 1 ) == 0 )
{
/*
* First pages are deleted or empty, or we found exact position,
* so break inner loop and continue outer one.
*/
break;
}
/*
* Find greater than entry->curItem position, store it.
*/
entry->curItem = entry->list[entry->offset - 1];
return;
}
}
}
}
