Beispiel #1
0
/*
 * Step right from current page.
 *
 * The next page is locked first, before releasing the current page. This is
 * crucial to protect from concurrent page deletion (see comment in
 * ginDeletePage).
 */
Buffer
ginStepRight(Buffer buffer, Relation index, int lockmode)
{
	Buffer		nextbuffer;
	Page		page = BufferGetPage(buffer);
	bool		isLeaf = GinPageIsLeaf(page);
	bool		isData = GinPageIsData(page);
	BlockNumber blkno = GinPageGetOpaque(page)->rightlink;

	nextbuffer = ReadBuffer(index, blkno);
	LockBuffer(nextbuffer, lockmode);
	UnlockReleaseBuffer(buffer);

	/* Sanity check that the page we stepped to is of similar kind. */
	page = BufferGetPage(nextbuffer);
	if (isLeaf != GinPageIsLeaf(page) || isData != GinPageIsData(page))
		elog(ERROR, "right sibling of GIN page is of different type");

	/*
	 * Given the proper lock sequence above, we should never land on a deleted
	 * page.
	 */
	if (GinPageIsDeleted(page))
		elog(ERROR, "right sibling of GIN page was deleted");

	return nextbuffer;
}
Beispiel #2
0
static void
ginRedoInsert(XLogReaderState *record)
{
	XLogRecPtr	lsn = record->EndRecPtr;
	ginxlogInsert *data = (ginxlogInsert *) XLogRecGetData(record);
	Buffer		buffer;
#ifdef NOT_USED
	BlockNumber leftChildBlkno = InvalidBlockNumber;
#endif
	BlockNumber rightChildBlkno = InvalidBlockNumber;
	bool		isLeaf = (data->flags & GIN_INSERT_ISLEAF) != 0;

	/*
	 * First clear incomplete-split flag on child page if this finishes a
	 * split.
	 */
	if (!isLeaf)
	{
		char	   *payload = XLogRecGetData(record) + sizeof(ginxlogInsert);

#ifdef NOT_USED
		leftChildBlkno = BlockIdGetBlockNumber((BlockId) payload);
#endif
		payload += sizeof(BlockIdData);
		rightChildBlkno = BlockIdGetBlockNumber((BlockId) payload);
		payload += sizeof(BlockIdData);

		ginRedoClearIncompleteSplit(record, 1);
	}

	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
	{
		Page		page = BufferGetPage(buffer);
		Size		len;
		char	   *payload = XLogRecGetBlockData(record, 0, &len);

		/* How to insert the payload is tree-type specific */
		if (data->flags & GIN_INSERT_ISDATA)
		{
			Assert(GinPageIsData(page));
			ginRedoInsertData(buffer, isLeaf, rightChildBlkno, payload);
		}
		else
		{
			Assert(!GinPageIsData(page));
			ginRedoInsertEntry(buffer, isLeaf, rightChildBlkno, payload);
		}

		PageSetLSN(page, lsn);
		MarkBufferDirty(buffer);
	}
	if (BufferIsValid(buffer))
		UnlockReleaseBuffer(buffer);
}
Beispiel #3
0
static void
ginRedoDeletePage(XLogReaderState *record)
{
	XLogRecPtr	lsn = record->EndRecPtr;
	ginxlogDeletePage *data = (ginxlogDeletePage *) XLogRecGetData(record);
	Buffer		dbuffer;
	Buffer		pbuffer;
	Buffer		lbuffer;
	Page		page;

	/*
	 * Lock left page first in order to prevent possible deadlock with
	 * ginStepRight().
	 */
	if (XLogReadBufferForRedo(record, 2, &lbuffer) == BLK_NEEDS_REDO)
	{
		page = BufferGetPage(lbuffer);
		Assert(GinPageIsData(page));
		GinPageGetOpaque(page)->rightlink = data->rightLink;
		PageSetLSN(page, lsn);
		MarkBufferDirty(lbuffer);
	}

	if (XLogReadBufferForRedo(record, 0, &dbuffer) == BLK_NEEDS_REDO)
	{
		page = BufferGetPage(dbuffer);
		Assert(GinPageIsData(page));
		GinPageGetOpaque(page)->flags = GIN_DELETED;
		GinPageSetDeleteXid(page, data->deleteXid);
		PageSetLSN(page, lsn);
		MarkBufferDirty(dbuffer);
	}

	if (XLogReadBufferForRedo(record, 1, &pbuffer) == BLK_NEEDS_REDO)
	{
		page = BufferGetPage(pbuffer);
		Assert(GinPageIsData(page));
		Assert(!GinPageIsLeaf(page));
		GinPageDeletePostingItem(page, data->parentOffset);
		PageSetLSN(page, lsn);
		MarkBufferDirty(pbuffer);
	}

	if (BufferIsValid(lbuffer))
		UnlockReleaseBuffer(lbuffer);
	if (BufferIsValid(pbuffer))
		UnlockReleaseBuffer(pbuffer);
	if (BufferIsValid(dbuffer))
		UnlockReleaseBuffer(dbuffer);
}
Beispiel #4
0
static void
ginRedoVacuumDataLeafPage(XLogRecPtr lsn, XLogRecord *record)
{
    ginxlogVacuumDataLeafPage *xlrec = (ginxlogVacuumDataLeafPage *) XLogRecGetData(record);
    Buffer		buffer;
    Page		page;

    /* If we have a full-page image, restore it and we're done */
    if (record->xl_info & XLR_BKP_BLOCK(0))
    {
        (void) RestoreBackupBlock(lsn, record, 0, false, false);
        return;
    }

    buffer = XLogReadBuffer(xlrec->node, xlrec->blkno, false);
    if (!BufferIsValid(buffer))
        return;
    page = (Page) BufferGetPage(buffer);

    Assert(GinPageIsLeaf(page));
    Assert(GinPageIsData(page));

    if (lsn > PageGetLSN(page))
    {
        ginRedoRecompress(page, &xlrec->data);
        PageSetLSN(page, lsn);
        MarkBufferDirty(buffer);
    }

    UnlockReleaseBuffer(buffer);
}
Beispiel #5
0
static bool
entryIsEnoughSpace(GinBtree btree, Buffer buf, OffsetNumber off,
				   GinBtreeEntryInsertData *insertData)
{
	Size		releasedsz = 0;
	Size		addedsz;
	Page		page = BufferGetPage(buf);

	Assert(insertData->entry);
	Assert(!GinPageIsData(page));

	if (insertData->isDelete)
	{
		IndexTuple	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, off));

		releasedsz = MAXALIGN(IndexTupleSize(itup)) + sizeof(ItemIdData);
	}

	addedsz = MAXALIGN(IndexTupleSize(insertData->entry)) + sizeof(ItemIdData);

	if (PageGetFreeSpace(page) + releasedsz >= addedsz)
		return true;

	return false;
}
Beispiel #6
0
/*
 * Delete tuple on leaf page if tuples was existed and we
 * should update it, update old child blkno to new right page
 * if child split is occured
 */
static BlockNumber
entryPreparePage(GinBtree btree, Page page, OffsetNumber off)
{
	BlockNumber ret = InvalidBlockNumber;

	Assert(btree->entry);
	Assert(!GinPageIsData(page));

	if (btree->isDelete)
	{
		Assert(GinPageIsLeaf(page));
		PageIndexTupleDelete(page, off);
	}

	if (!GinPageIsLeaf(page) && btree->rightblkno != InvalidBlockNumber)
	{
		IndexTuple	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, off));

		ItemPointerSet(&itup->t_tid, btree->rightblkno, InvalidOffsetNumber);
		ret = btree->rightblkno;
	}

	btree->rightblkno = InvalidBlockNumber;

	return ret;
}
Beispiel #7
0
/*
 * Searches correct position for value on leaf page.
 * Page should be correctly chosen.
 * Returns true if value found on page.
 */
static bool
entryLocateLeafEntry(GinBtree btree, GinBtreeStack *stack)
{
	Page		page = BufferGetPage(stack->buffer, NULL, NULL,
									 BGP_NO_SNAPSHOT_TEST);
	OffsetNumber low,
				high;

	Assert(GinPageIsLeaf(page));
	Assert(!GinPageIsData(page));

	if (btree->fullScan)
	{
		stack->off = FirstOffsetNumber;
		return TRUE;
	}

	low = FirstOffsetNumber;
	high = PageGetMaxOffsetNumber(page);

	if (high < low)
	{
		stack->off = FirstOffsetNumber;
		return false;
	}

	high++;

	while (high > low)
	{
		OffsetNumber mid = low + ((high - low) / 2);
		IndexTuple	itup;
		OffsetNumber attnum;
		Datum		key;
		GinNullCategory category;
		int			result;

		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
		attnum = gintuple_get_attrnum(btree->ginstate, itup);
		key = gintuple_get_key(btree->ginstate, itup, &category);
		result = ginCompareAttEntries(btree->ginstate,
									  btree->entryAttnum,
									  btree->entryKey,
									  btree->entryCategory,
									  attnum, key, category);
		if (result == 0)
		{
			stack->off = mid;
			return true;
		}
		else if (result > 0)
			low = mid + 1;
		else
			high = mid;
	}

	stack->off = high;
	return false;
}
/*
 * 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);
}
Beispiel #9
0
/*
 * Searches correct position for value on leaf page.
 * Page should be corrrectly choosen.
 * Returns true if value found on page.
 */
static bool
entryLocateLeafEntry(GinBtree btree, GinBtreeStack *stack)
{
	Page		page = BufferGetPage(stack->buffer);
	OffsetNumber low,
				high;
	IndexTuple	itup;

	Assert(GinPageIsLeaf(page));
	Assert(!GinPageIsData(page));

	if (btree->fullScan)
	{
		stack->off = FirstOffsetNumber;
		return TRUE;
	}

	low = FirstOffsetNumber;
	high = PageGetMaxOffsetNumber(page);

	if (high < low)
	{
		stack->off = FirstOffsetNumber;
		return false;
	}

	high++;

	while (high > low)
	{
		OffsetNumber mid = low + ((high - low) / 2);
		int			result;

		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
		result = ginCompareAttEntries(btree->ginstate,
									  btree->entryAttnum,
									  btree->entryValue,
								 gintuple_get_attrnum(btree->ginstate, itup),
								   gin_index_getattr(btree->ginstate, itup));
		if (result == 0)
		{
			stack->off = mid;
			return true;
		}
		else if (result > 0)
			low = mid + 1;
		else
			high = mid;
	}

	stack->off = high;
	return false;
}
Beispiel #10
0
static BlockNumber
entryGetLeftMostPage(GinBtree btree, Page page)
{
	IndexTuple	itup;

	Assert(!GinPageIsLeaf(page));
	Assert(!GinPageIsData(page));
	Assert(PageGetMaxOffsetNumber(page) >= FirstOffsetNumber);

	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, FirstOffsetNumber));
	return GinGetDownlink(itup);
}
Beispiel #11
0
/*
 * 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->itemptr,
										GinDataPageGetItemPointer(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;
}
Beispiel #13
0
/*
 * Delete tuple on leaf page if tuples existed and we
 * should update it, update old child blkno to new right page
 * if child split occurred
 */
static void
entryPreparePage(GinBtree btree, Page page, OffsetNumber off,
				 GinBtreeEntryInsertData *insertData, BlockNumber updateblkno)
{
	Assert(insertData->entry);
	Assert(!GinPageIsData(page));

	if (insertData->isDelete)
	{
		Assert(GinPageIsLeaf(page));
		PageIndexTupleDelete(page, off);
	}

	if (!GinPageIsLeaf(page) && updateblkno != InvalidBlockNumber)
	{
		IndexTuple	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, off));

		GinSetDownlink(itup, updateblkno);
	}
}
/*
 * 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;
}
Beispiel #15
0
static bool
entryIsEnoughSpace(GinBtree btree, Buffer buf, OffsetNumber off)
{
	Size		itupsz = 0;
	Page		page = BufferGetPage(buf);

	Assert(btree->entry);
	Assert(!GinPageIsData(page));

	if (btree->isDelete)
	{
		IndexTuple	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, off));

		itupsz = MAXALIGN(IndexTupleSize(itup)) + sizeof(ItemIdData);
	}

	if (PageGetFreeSpace(page) + itupsz >= MAXALIGN(IndexTupleSize(btree->entry)) + sizeof(ItemIdData))
		return true;

	return false;
}
Beispiel #16
0
static OffsetNumber
entryFindChildPtr(GinBtree btree, Page page, BlockNumber blkno, OffsetNumber storedOff)
{
	OffsetNumber i,
				maxoff = PageGetMaxOffsetNumber(page);
	IndexTuple	itup;

	Assert(!GinPageIsLeaf(page));
	Assert(!GinPageIsData(page));

	/* if page isn't changed, we returns storedOff */
	if (storedOff >= FirstOffsetNumber && storedOff <= maxoff)
	{
		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, storedOff));
		if (GinGetDownlink(itup) == 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++)
		{
			itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, i));
			if (GinGetDownlink(itup) == blkno)
				return i;
		}
		maxoff = storedOff - 1;
	}

	/* last chance */
	for (i = FirstOffsetNumber; i <= maxoff; i++)
	{
		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, i));
		if (GinGetDownlink(itup) == blkno)
			return i;
	}

	return InvalidOffsetNumber;
}
/*
 * checks space to install new value,
 * item pointer never deletes!
 */
static bool
dataIsEnoughSpace(GinBtree btree, Buffer buf, OffsetNumber off)
{
    Page		page = BufferGetPage(buf);

    Assert(GinPageIsData(page));
    Assert(!btree->isDelete);

    if (GinPageIsLeaf(page))
    {
        if (GinPageRightMost(page) && off > GinPageGetOpaque(page)->maxoff)
        {
            if ((btree->nitem - btree->curitem) * sizeof(ItemPointerData) <= GinDataPageGetFreeSpace(page))
                return true;
        }
        else if (sizeof(ItemPointerData) <= GinDataPageGetFreeSpace(page))
            return true;
    }
    else if (sizeof(PostingItem) <= GinDataPageGetFreeSpace(page))
        return true;

    return false;
}
/*
 * Create a WAL record for vacuuming entry tree leaf page.
 */
static void
xlogVacuumPage(Relation index, Buffer buffer)
{
	Page		page = BufferGetPage(buffer);
	XLogRecPtr	recptr;

	/* This is only used for entry tree leaf pages. */
	Assert(!GinPageIsData(page));
	Assert(GinPageIsLeaf(page));

	if (!RelationNeedsWAL(index))
		return;

	/*
	 * Always create a full image, we don't track the changes on the page at
	 * any more fine-grained level. This could obviously be improved...
	 */
	XLogBeginInsert();
	XLogRegisterBuffer(0, buffer, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);

	recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_VACUUM_PAGE);
	PageSetLSN(page, recptr);
}
Beispiel #19
0
static void
ginRedoVacuumDataLeafPage(XLogReaderState *record)
{
	XLogRecPtr	lsn = record->EndRecPtr;
	Buffer		buffer;

	if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO)
	{
		Page		page = BufferGetPage(buffer);
		Size		len;
		ginxlogVacuumDataLeafPage *xlrec;

		xlrec = (ginxlogVacuumDataLeafPage *) XLogRecGetBlockData(record, 0, &len);

		Assert(GinPageIsLeaf(page));
		Assert(GinPageIsData(page));

		ginRedoRecompress(page, &xlrec->data);
		PageSetLSN(page, lsn);
		MarkBufferDirty(buffer);
	}
	if (BufferIsValid(buffer))
		UnlockReleaseBuffer(buffer);
}
static bool
ginVacuumPostingTreeLeaves(GinVacuumState *gvs, BlockNumber blkno, bool isRoot, Buffer *rootBuffer)
{
	Buffer		buffer;
	Page		page;
	bool		hasVoidPage = FALSE;
	MemoryContext oldCxt;

	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))
	{
		oldCxt = MemoryContextSwitchTo(gvs->tmpCxt);
		ginVacuumPostingTreeLeaf(gvs->index, buffer, gvs);
		MemoryContextSwitchTo(oldCxt);
		MemoryContextReset(gvs->tmpCxt);

		/* if root is a leaf page, we don't desire further processing */
		if (!isRoot && !hasVoidPage && GinDataLeafPageIsEmpty(page))
			hasVoidPage = TRUE;
	}
	else
	{
		OffsetNumber i;
		bool		isChildHasVoid = FALSE;

		for (i = FirstOffsetNumber; i <= GinPageGetOpaque(page)->maxoff; i++)
		{
			PostingItem *pitem = GinDataPageGetPostingItem(page, i);

			if (ginVacuumPostingTreeLeaves(gvs, PostingItemGetBlockNumber(pitem), FALSE, NULL))
				isChildHasVoid = TRUE;
		}

		if (isChildHasVoid)
			hasVoidPage = TRUE;
	}

	/*
	 * if we have root and there are empty 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;
}
Beispiel #21
0
static void
ginRedoInsert(XLogRecPtr lsn, XLogRecord *record)
{
    ginxlogInsert *data = (ginxlogInsert *) XLogRecGetData(record);
    Buffer		buffer;
    Page		page;
    char	   *payload;
    BlockNumber leftChildBlkno = InvalidBlockNumber;
    BlockNumber rightChildBlkno = InvalidBlockNumber;
    bool		isLeaf = (data->flags & GIN_INSERT_ISLEAF) != 0;

    payload = XLogRecGetData(record) + sizeof(ginxlogInsert);

    /*
     * First clear incomplete-split flag on child page if this finishes a
     * split.
     */
    if (!isLeaf)
    {
        leftChildBlkno = BlockIdGetBlockNumber((BlockId) payload);
        payload += sizeof(BlockIdData);
        rightChildBlkno = BlockIdGetBlockNumber((BlockId) payload);
        payload += sizeof(BlockIdData);

        if (record->xl_info & XLR_BKP_BLOCK(0))
            (void) RestoreBackupBlock(lsn, record, 0, false, false);
        else
            ginRedoClearIncompleteSplit(lsn, data->node, leftChildBlkno);
    }

    /* If we have a full-page image, restore it and we're done */
    if (record->xl_info & XLR_BKP_BLOCK(isLeaf ? 0 : 1))
    {
        (void) RestoreBackupBlock(lsn, record, isLeaf ? 0 : 1, false, false);
        return;
    }

    buffer = XLogReadBuffer(data->node, data->blkno, false);
    if (!BufferIsValid(buffer))
        return;					/* page was deleted, nothing to do */
    page = (Page) BufferGetPage(buffer);

    if (lsn > PageGetLSN(page))
    {
        /* How to insert the payload is tree-type specific */
        if (data->flags & GIN_INSERT_ISDATA)
        {
            Assert(GinPageIsData(page));
            ginRedoInsertData(buffer, isLeaf, rightChildBlkno, payload);
        }
        else
        {
            Assert(!GinPageIsData(page));
            ginRedoInsertEntry(buffer, isLeaf, rightChildBlkno, payload);
        }

        PageSetLSN(page, lsn);
        MarkBufferDirty(buffer);
    }

    UnlockReleaseBuffer(buffer);
}
Beispiel #22
0
/*
 * 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;
}
Beispiel #23
0
Datum
ginvacuumcleanup(PG_FUNCTION_ARGS)
{
	IndexVacuumInfo *info = (IndexVacuumInfo *) PG_GETARG_POINTER(0);
	IndexBulkDeleteResult *stats = (IndexBulkDeleteResult *) PG_GETARG_POINTER(1);
	Relation	index = info->index;
	bool		needLock;
	BlockNumber npages,
				blkno;
	BlockNumber totFreePages;
	GinState	ginstate;
	GinStatsData idxStat;

	/*
	 * In an autovacuum analyze, we want to clean up pending insertions.
	 * Otherwise, an ANALYZE-only call is a no-op.
	 */
	if (info->analyze_only)
	{
		if (IsAutoVacuumWorkerProcess())
		{
			initGinState(&ginstate, index);
			ginInsertCleanup(&ginstate, true, stats);
		}
		PG_RETURN_POINTER(stats);
	}

	/*
	 * Set up all-zero stats and cleanup pending inserts if ginbulkdelete
	 * wasn't called
	 */
	if (stats == NULL)
	{
		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
		initGinState(&ginstate, index);
		ginInsertCleanup(&ginstate, true, stats);
	}

	memset(&idxStat, 0, sizeof(idxStat));

	/*
	 * XXX we always report the heap tuple count as the number of index
	 * entries.  This is bogus if the index is partial, but it's real hard to
	 * tell how many distinct heap entries are referenced by a GIN index.
	 */
	stats->num_index_tuples = info->num_heap_tuples;
	stats->estimated_count = info->estimated_count;

	/*
	 * Need lock unless it's local to this backend.
	 */
	needLock = !RELATION_IS_LOCAL(index);

	if (needLock)
		LockRelationForExtension(index, ExclusiveLock);
	npages = RelationGetNumberOfBlocks(index);
	if (needLock)
		UnlockRelationForExtension(index, ExclusiveLock);

	totFreePages = 0;

	for (blkno = GIN_ROOT_BLKNO; blkno < npages; blkno++)
	{
		Buffer		buffer;
		Page		page;

		vacuum_delay_point();

		buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
									RBM_NORMAL, info->strategy);
		LockBuffer(buffer, GIN_SHARE);
		page = (Page) BufferGetPage(buffer);

		if (GinPageIsDeleted(page))
		{
			Assert(blkno != GIN_ROOT_BLKNO);
			RecordFreeIndexPage(index, blkno);
			totFreePages++;
		}
		else if (GinPageIsData(page))
		{
			idxStat.nDataPages++;
		}
		else if (!GinPageIsList(page))
		{
			idxStat.nEntryPages++;

			if (GinPageIsLeaf(page))
				idxStat.nEntries += PageGetMaxOffsetNumber(page);
		}

		UnlockReleaseBuffer(buffer);
	}

	/* Update the metapage with accurate page and entry counts */
	idxStat.nTotalPages = npages;
	ginUpdateStats(info->index, &idxStat);

	/* Finally, vacuum the FSM */
	IndexFreeSpaceMapVacuum(info->index);

	stats->pages_free = totFreePages;

	if (needLock)
		LockRelationForExtension(index, ExclusiveLock);
	stats->num_pages = RelationGetNumberOfBlocks(index);
	if (needLock)
		UnlockRelationForExtension(index, ExclusiveLock);

	PG_RETURN_POINTER(stats);
}
Beispiel #24
0
static void
ginRedoDeletePage(XLogRecPtr lsn, XLogRecord *record)
{
    ginxlogDeletePage *data = (ginxlogDeletePage *) XLogRecGetData(record);
    Buffer		dbuffer;
    Buffer		pbuffer;
    Buffer		lbuffer;
    Page		page;

    if (record->xl_info & XLR_BKP_BLOCK(0))
        dbuffer = RestoreBackupBlock(lsn, record, 0, false, true);
    else
    {
        dbuffer = XLogReadBuffer(data->node, data->blkno, false);
        if (BufferIsValid(dbuffer))
        {
            page = BufferGetPage(dbuffer);
            if (lsn > PageGetLSN(page))
            {
                Assert(GinPageIsData(page));
                GinPageGetOpaque(page)->flags = GIN_DELETED;
                PageSetLSN(page, lsn);
                MarkBufferDirty(dbuffer);
            }
        }
    }

    if (record->xl_info & XLR_BKP_BLOCK(1))
        pbuffer = RestoreBackupBlock(lsn, record, 1, false, true);
    else
    {
        pbuffer = XLogReadBuffer(data->node, data->parentBlkno, false);
        if (BufferIsValid(pbuffer))
        {
            page = BufferGetPage(pbuffer);
            if (lsn > PageGetLSN(page))
            {
                Assert(GinPageIsData(page));
                Assert(!GinPageIsLeaf(page));
                GinPageDeletePostingItem(page, data->parentOffset);
                PageSetLSN(page, lsn);
                MarkBufferDirty(pbuffer);
            }
        }
    }

    if (record->xl_info & XLR_BKP_BLOCK(2))
        (void) RestoreBackupBlock(lsn, record, 2, false, false);
    else if (data->leftBlkno != InvalidBlockNumber)
    {
        lbuffer = XLogReadBuffer(data->node, data->leftBlkno, false);
        if (BufferIsValid(lbuffer))
        {
            page = BufferGetPage(lbuffer);
            if (lsn > PageGetLSN(page))
            {
                Assert(GinPageIsData(page));
                GinPageGetOpaque(page)->rightlink = data->rightLink;
                PageSetLSN(page, lsn);
                MarkBufferDirty(lbuffer);
            }
            UnlockReleaseBuffer(lbuffer);
        }
    }

    if (BufferIsValid(pbuffer))
        UnlockReleaseBuffer(pbuffer);
    if (BufferIsValid(dbuffer))
        UnlockReleaseBuffer(dbuffer);
}
Beispiel #25
0
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;
}
Beispiel #26
0
/*
 * Find correct tuple in non-leaf page. It supposed that
 * page correctly chosen and searching value SHOULD be on page
 */
static BlockNumber
entryLocateEntry(GinBtree btree, GinBtreeStack *stack)
{
	OffsetNumber low,
				high,
				maxoff;
	IndexTuple	itup = NULL;
	int			result;
	Page		page = BufferGetPage(stack->buffer);

	Assert(!GinPageIsLeaf(page));
	Assert(!GinPageIsData(page));

	if (btree->fullScan)
	{
		stack->off = FirstOffsetNumber;
		stack->predictNumber *= PageGetMaxOffsetNumber(page);
		return btree->getLeftMostChild(btree, page);
	}

	low = FirstOffsetNumber;
	maxoff = high = PageGetMaxOffsetNumber(page);
	Assert(high >= low);

	high++;

	while (high > low)
	{
		OffsetNumber mid = low + ((high - low) / 2);

		if (mid == maxoff && GinPageRightMost(page))
		{
			/* Right infinity */
			result = -1;
		}
		else
		{
			OffsetNumber attnum;
			Datum		key;
			GinNullCategory category;

			itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
			attnum = gintuple_get_attrnum(btree->ginstate, itup);
			key = gintuple_get_key(btree->ginstate, itup, &category);
			result = ginCompareAttEntries(btree->ginstate,
										  btree->entryAttnum,
										  btree->entryKey,
										  btree->entryCategory,
										  attnum, key, category);
		}

		if (result == 0)
		{
			stack->off = mid;
			Assert(GinGetDownlink(itup) != GIN_ROOT_BLKNO);
			return GinGetDownlink(itup);
		}
		else if (result > 0)
			low = mid + 1;
		else
			high = mid;
	}

	Assert(high >= FirstOffsetNumber && high <= maxoff);

	stack->off = high;
	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, high));
	Assert(GinGetDownlink(itup) != GIN_ROOT_BLKNO);
	return GinGetDownlink(itup);
}
Beispiel #27
0
Datum
ginbulkdelete(PG_FUNCTION_ARGS)
{
	IndexVacuumInfo *info = (IndexVacuumInfo *) PG_GETARG_POINTER(0);
	IndexBulkDeleteResult *stats = (IndexBulkDeleteResult *) PG_GETARG_POINTER(1);
	IndexBulkDeleteCallback callback = (IndexBulkDeleteCallback) PG_GETARG_POINTER(2);
	void	   *callback_state = (void *) PG_GETARG_POINTER(3);
	Relation	index = info->index;
	BlockNumber blkno = GIN_ROOT_BLKNO;
	GinVacuumState gvs;
	Buffer		buffer;
	BlockNumber rootOfPostingTree[BLCKSZ / (sizeof(IndexTupleData) + sizeof(ItemId))];
	uint32		nRoot;

	gvs.index = index;
	gvs.callback = callback;
	gvs.callback_state = callback_state;
	gvs.strategy = info->strategy;
	initGinState(&gvs.ginstate, index);

	/* first time through? */
	if (stats == NULL)
	{
		/* Yes, so initialize stats to zeroes */
		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
		/* and cleanup any pending inserts */
		ginInsertCleanup(&gvs.ginstate, true, stats);
	}

	/* we'll re-count the tuples each time */
	stats->num_index_tuples = 0;
	gvs.result = stats;

	buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
								RBM_NORMAL, info->strategy);

	/* find leaf page */
	for (;;)
	{
		Page		page = BufferGetPage(buffer);
		IndexTuple	itup;

		LockBuffer(buffer, GIN_SHARE);

		Assert(!GinPageIsData(page));

		if (GinPageIsLeaf(page))
		{
			LockBuffer(buffer, GIN_UNLOCK);
			LockBuffer(buffer, GIN_EXCLUSIVE);

			if (blkno == GIN_ROOT_BLKNO && !GinPageIsLeaf(page))
			{
				LockBuffer(buffer, GIN_UNLOCK);
				continue;		/* check it one more */
			}
			break;
		}

		Assert(PageGetMaxOffsetNumber(page) >= FirstOffsetNumber);

		itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, FirstOffsetNumber));
		blkno = GinGetDownlink(itup);
		Assert(blkno != InvalidBlockNumber);

		UnlockReleaseBuffer(buffer);
		buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
									RBM_NORMAL, info->strategy);
	}

	/* right now we found leftmost page in entry's BTree */

	for (;;)
	{
		Page		page = BufferGetPage(buffer);
		Page		resPage;
		uint32		i;

		Assert(!GinPageIsData(page));

		resPage = ginVacuumEntryPage(&gvs, buffer, rootOfPostingTree, &nRoot);

		blkno = GinPageGetOpaque(page)->rightlink;

		if (resPage)
		{
			START_CRIT_SECTION();
			PageRestoreTempPage(resPage, page);
			MarkBufferDirty(buffer);
			xlogVacuumPage(gvs.index, buffer);
			UnlockReleaseBuffer(buffer);
			END_CRIT_SECTION();
		}
		else
		{
			UnlockReleaseBuffer(buffer);
		}

		vacuum_delay_point();

		for (i = 0; i < nRoot; i++)
		{
			ginVacuumPostingTree(&gvs, rootOfPostingTree[i]);
			vacuum_delay_point();
		}

		if (blkno == InvalidBlockNumber)		/* rightmost page */
			break;

		buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
									RBM_NORMAL, info->strategy);
		LockBuffer(buffer, GIN_EXCLUSIVE);
	}

	PG_RETURN_POINTER(gvs.result);
}
/*
 * 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);
}
Beispiel #29
0
/*
 * fills WAL record for vacuum leaf page
 */
static void
xlogVacuumPage(Relation index, Buffer buffer)
{
	Page		page = BufferGetPage(buffer);
	XLogRecPtr	recptr;
	XLogRecData rdata[3];
	ginxlogVacuumPage data;
	char	   *backup;
	char		itups[BLCKSZ];
	uint32		len = 0;

	Assert(GinPageIsLeaf(page));

	if (!RelationNeedsWAL(index))
		return;

	data.node = index->rd_node;
	data.blkno = BufferGetBlockNumber(buffer);

	if (GinPageIsData(page))
	{
		backup = GinDataPageGetData(page);
		data.nitem = GinPageGetOpaque(page)->maxoff;
		if (data.nitem)
			len = MAXALIGN(sizeof(ItemPointerData) * data.nitem);
	}
	else
	{
		char	   *ptr;
		OffsetNumber i;

		ptr = backup = itups;
		for (i = FirstOffsetNumber; i <= PageGetMaxOffsetNumber(page); i++)
		{
			IndexTuple	itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, i));

			memcpy(ptr, itup, IndexTupleSize(itup));
			ptr += MAXALIGN(IndexTupleSize(itup));
		}

		data.nitem = PageGetMaxOffsetNumber(page);
		len = ptr - backup;
	}

	rdata[0].buffer = buffer;
	rdata[0].buffer_std = (GinPageIsData(page)) ? FALSE : TRUE;
	rdata[0].len = 0;
	rdata[0].data = NULL;
	rdata[0].next = rdata + 1;

	rdata[1].buffer = InvalidBuffer;
	rdata[1].len = sizeof(ginxlogVacuumPage);
	rdata[1].data = (char *) &data;

	if (len == 0)
	{
		rdata[1].next = NULL;
	}
	else
	{
		rdata[1].next = rdata + 2;

		rdata[2].buffer = InvalidBuffer;
		rdata[2].len = len;
		rdata[2].data = backup;
		rdata[2].next = NULL;
	}

	recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_VACUUM_PAGE, rdata);
	PageSetLSN(page, recptr);
	PageSetTLI(page, ThisTimeLineID);
}
Beispiel #30
0
/*
 * Insert a new item to a page.
 *
 * Returns true if the insertion was finished. On false, the page was split and
 * the parent needs to be updated. (a root split returns true as it doesn't
 * need any further action by the caller to complete)
 *
 * When inserting a downlink to a internal page, 'childbuf' contains the
 * child page that was split. Its GIN_INCOMPLETE_SPLIT flag will be cleared
 * atomically with the insert. Also, the existing item at the given location
 * is updated to point to 'updateblkno'.
 *
 * stack->buffer is locked on entry, and is kept locked.
 */
static bool
ginPlaceToPage(GinBtree btree, GinBtreeStack *stack,
			   void *insertdata, BlockNumber updateblkno,
			   Buffer childbuf, GinStatsData *buildStats)
{
	Page		page = BufferGetPage(stack->buffer);
	XLogRecData *payloadrdata;
	bool		fit;
	uint16		xlflags = 0;
	Page		childpage = NULL;

	if (GinPageIsData(page))
		xlflags |= GIN_INSERT_ISDATA;
	if (GinPageIsLeaf(page))
	{
		xlflags |= GIN_INSERT_ISLEAF;
		Assert(!BufferIsValid(childbuf));
		Assert(updateblkno == InvalidBlockNumber);
	}
	else
	{
		Assert(BufferIsValid(childbuf));
		Assert(updateblkno != InvalidBlockNumber);
		childpage = BufferGetPage(childbuf);
	}

	/*
	 * Try to put the incoming tuple on the page. If it doesn't fit,
	 * placeToPage method will return false and leave the page unmodified, and
	 * we'll have to split the page.
	 */
	START_CRIT_SECTION();
	fit = btree->placeToPage(btree, stack->buffer, stack->off,
							 insertdata, updateblkno,
							 &payloadrdata);
	if (fit)
	{
		MarkBufferDirty(stack->buffer);

		/* An insert to an internal page finishes the split of the child. */
		if (childbuf != InvalidBuffer)
		{
			GinPageGetOpaque(childpage)->flags &= ~GIN_INCOMPLETE_SPLIT;
			MarkBufferDirty(childbuf);
		}

		if (RelationNeedsWAL(btree->index))
		{
			XLogRecPtr	recptr;
			XLogRecData rdata[3];
			ginxlogInsert xlrec;
			BlockIdData	childblknos[2];

			xlrec.node = btree->index->rd_node;
			xlrec.blkno = BufferGetBlockNumber(stack->buffer);
			xlrec.offset = stack->off;
			xlrec.flags = xlflags;

			rdata[0].buffer = InvalidBuffer;
			rdata[0].data = (char *) &xlrec;
			rdata[0].len = sizeof(ginxlogInsert);

			/*
			 * Log information about child if this was an insertion of a
			 * downlink.
			 */
			if (childbuf != InvalidBuffer)
			{
				rdata[0].next = &rdata[1];

				BlockIdSet(&childblknos[0], BufferGetBlockNumber(childbuf));
				BlockIdSet(&childblknos[1], GinPageGetOpaque(childpage)->rightlink);

				rdata[1].buffer = InvalidBuffer;
				rdata[1].data = (char *) childblknos;
				rdata[1].len = sizeof(BlockIdData) * 2;
				rdata[1].next = &rdata[2];

				rdata[2].buffer = childbuf;
				rdata[2].buffer_std = false;
				rdata[2].data = NULL;
				rdata[2].len = 0;
				rdata[2].next = payloadrdata;
			}
			else
				rdata[0].next = payloadrdata;

			recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_INSERT, rdata);
			PageSetLSN(page, recptr);
			if (childbuf != InvalidBuffer)
				PageSetLSN(childpage, recptr);
		}

		END_CRIT_SECTION();

		return true;
	}
	else
	{
		/* Didn't fit, have to split */
		Buffer		rbuffer;
		Page		newlpage;
		BlockNumber savedRightLink;
		Page		rpage;
		XLogRecData rdata[2];
		ginxlogSplit data;
		Buffer		lbuffer = InvalidBuffer;
		Page		newrootpg = NULL;

		END_CRIT_SECTION();

		rbuffer = GinNewBuffer(btree->index);

		/* During index build, count the new page */
		if (buildStats)
		{
			if (btree->isData)
				buildStats->nDataPages++;
			else
				buildStats->nEntryPages++;
		}

		savedRightLink = GinPageGetOpaque(page)->rightlink;

		/*
		 * newlpage is a pointer to memory page, it is not associated with a
		 * buffer. stack->buffer is not touched yet.
		 */
		newlpage = btree->splitPage(btree, stack->buffer, rbuffer, stack->off,
									insertdata, updateblkno,
									&payloadrdata);

		data.node = btree->index->rd_node;
		data.rblkno = BufferGetBlockNumber(rbuffer);
		data.flags = xlflags;
		if (childbuf != InvalidBuffer)
		{
			Page childpage = BufferGetPage(childbuf);
			GinPageGetOpaque(childpage)->flags &= ~GIN_INCOMPLETE_SPLIT;

			data.leftChildBlkno = BufferGetBlockNumber(childbuf);
			data.rightChildBlkno = GinPageGetOpaque(childpage)->rightlink;
		}
		else
			data.leftChildBlkno = data.rightChildBlkno = InvalidBlockNumber;

		rdata[0].buffer = InvalidBuffer;
		rdata[0].data = (char *) &data;
		rdata[0].len = sizeof(ginxlogSplit);

		if (childbuf != InvalidBuffer)
		{
			rdata[0].next = &rdata[1];

			rdata[1].buffer = childbuf;
			rdata[1].buffer_std = false;
			rdata[1].data = NULL;
			rdata[1].len = 0;
			rdata[1].next = payloadrdata;
		}
		else
			rdata[0].next = payloadrdata;

		rpage = BufferGetPage(rbuffer);

		if (stack->parent == NULL)
		{
			/*
			 * split root, so we need to allocate new left page and place
			 * pointer on root to left and right page
			 */
			lbuffer = GinNewBuffer(btree->index);

			/* During index build, count the newly-added root page */
			if (buildStats)
			{
				if (btree->isData)
					buildStats->nDataPages++;
				else
					buildStats->nEntryPages++;
			}

			/*
			 * root never has a right-link, so we borrow the rrlink field to
			 * store the root block number.
			 */
			data.rrlink = BufferGetBlockNumber(stack->buffer);
			data.lblkno = BufferGetBlockNumber(lbuffer);
			data.flags |= GIN_SPLIT_ROOT;

			GinPageGetOpaque(rpage)->rightlink = InvalidBlockNumber;
			GinPageGetOpaque(newlpage)->rightlink = BufferGetBlockNumber(rbuffer);

			/*
			 * Construct a new root page containing downlinks to the new left
			 * and right pages. (do this in a temporary copy first rather
			 * than overwriting the original page directly, so that we can still
			 * abort gracefully if this fails.)
			 */
			newrootpg = PageGetTempPage(rpage);
			GinInitPage(newrootpg, GinPageGetOpaque(newlpage)->flags & ~GIN_LEAF, BLCKSZ);

			btree->fillRoot(btree, newrootpg,
							BufferGetBlockNumber(lbuffer), newlpage,
							BufferGetBlockNumber(rbuffer), rpage);
		}
		else
		{
			/* split non-root page */
			data.rrlink = savedRightLink;
			data.lblkno = BufferGetBlockNumber(stack->buffer);

			GinPageGetOpaque(rpage)->rightlink = savedRightLink;
			GinPageGetOpaque(newlpage)->flags |= GIN_INCOMPLETE_SPLIT;
			GinPageGetOpaque(newlpage)->rightlink = BufferGetBlockNumber(rbuffer);
		}

		/*
		 * Ok, we have the new contents of the left page in a temporary copy
		 * now (newlpage), and the newly-allocated right block has been filled
		 * in. The original page is still unchanged.
		 *
		 * If this is a root split, we also have a temporary page containing
		 * the new contents of the root. Copy the new left page to a
		 * newly-allocated block, and initialize the (original) root page the
		 * new copy. Otherwise, copy over the temporary copy of the new left
		 * page over the old left page.
		 */

		START_CRIT_SECTION();

		MarkBufferDirty(rbuffer);

		if (stack->parent == NULL)
		{
			PageRestoreTempPage(newlpage, BufferGetPage(lbuffer));
			MarkBufferDirty(lbuffer);
			newlpage = newrootpg;
		}

		PageRestoreTempPage(newlpage, BufferGetPage(stack->buffer));
		MarkBufferDirty(stack->buffer);

		/* write WAL record */
		if (RelationNeedsWAL(btree->index))
		{
			XLogRecPtr	recptr;

			recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_SPLIT, rdata);
			PageSetLSN(BufferGetPage(stack->buffer), recptr);
			PageSetLSN(rpage, recptr);
			if (stack->parent == NULL)
				PageSetLSN(BufferGetPage(lbuffer), recptr);
		}
		END_CRIT_SECTION();

		/*
		 * We can release the lock on the right page now, but keep the
		 * original buffer locked.
		 */
		UnlockReleaseBuffer(rbuffer);
		if (stack->parent == NULL)
			UnlockReleaseBuffer(lbuffer);

		/*
		 * If we split the root, we're done. Otherwise the split is not
		 * complete until the downlink for the new page has been inserted to
		 * the parent.
		 */
		if (stack->parent == NULL)
			return true;
		else
			return false;
	}
}