Example #1
0
/*
 * add PostingItem to a non-leaf page.
 */
void
GinDataPageAddPostingItem(Page page, PostingItem *data, OffsetNumber offset)
{
	OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
	char	   *ptr;

	Assert(PostingItemGetBlockNumber(data) != InvalidBlockNumber);
	Assert(!GinPageIsLeaf(page));

	if (offset == InvalidOffsetNumber)
	{
		ptr = (char *) GinDataPageGetPostingItem(page, maxoff + 1);
	}
	else
	{
		ptr = (char *) GinDataPageGetPostingItem(page, offset);
		if (maxoff + 1 - offset != 0)
			memmove(ptr + sizeof(PostingItem),
					ptr,
					(maxoff - offset + 1) * sizeof(PostingItem));
	}
	memcpy(ptr, data, sizeof(PostingItem));

	GinPageGetOpaque(page)->maxoff++;
}
Example #2
0
/*
 * add ItemPointer to a leaf page.
 */
void
GinDataPageAddItemPointer(Page page, ItemPointer data, OffsetNumber offset)
{
	OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
	char	   *ptr;

	Assert(ItemPointerIsValid(data));
	Assert(GinPageIsLeaf(page));

	if (offset == InvalidOffsetNumber)
	{
		ptr = (char *) GinDataPageGetItemPointer(page, maxoff + 1);
	}
	else
	{
		ptr = (char *) GinDataPageGetItemPointer(page, offset);
		if (maxoff + 1 - offset != 0)
			memmove(ptr + sizeof(ItemPointerData),
					ptr,
					(maxoff - offset + 1) * sizeof(ItemPointerData));
	}
	memcpy(ptr, data, sizeof(ItemPointerData));

	GinPageGetOpaque(page)->maxoff++;
}
Example #3
0
static void
ginRedoInsertListPage(XLogReaderState *record)
{
	XLogRecPtr	lsn = record->EndRecPtr;
	ginxlogInsertListPage *data = (ginxlogInsertListPage *) XLogRecGetData(record);
	Buffer		buffer;
	Page		page;
	OffsetNumber l,
				off = FirstOffsetNumber;
	int			i,
				tupsize;
	char	   *payload;
	IndexTuple	tuples;
	Size		totaltupsize;

	/* We always re-initialize the page. */
	buffer = XLogInitBufferForRedo(record, 0);
	page = BufferGetPage(buffer);

	GinInitBuffer(buffer, GIN_LIST);
	GinPageGetOpaque(page)->rightlink = data->rightlink;
	if (data->rightlink == InvalidBlockNumber)
	{
		/* tail of sublist */
		GinPageSetFullRow(page);
		GinPageGetOpaque(page)->maxoff = 1;
	}
	else
	{
		GinPageGetOpaque(page)->maxoff = 0;
	}

	payload = XLogRecGetBlockData(record, 0, &totaltupsize);

	tuples = (IndexTuple) payload;
	for (i = 0; i < data->ntuples; i++)
	{
		tupsize = IndexTupleSize(tuples);

		l = PageAddItem(page, (Item) tuples, tupsize, off, false, false);

		if (l == InvalidOffsetNumber)
			elog(ERROR, "failed to add item to index page");

		tuples = (IndexTuple) (((char *) tuples) + tupsize);
		off++;
	}
	Assert((char *) tuples == payload + totaltupsize);

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

	UnlockReleaseBuffer(buffer);
}
static void
ginRedoInsertListPage(XLogRecPtr lsn, XLogRecord *record)
{
	ginxlogInsertListPage *data = (ginxlogInsertListPage *) XLogRecGetData(record);
	Buffer		buffer;
	Page		page;
	OffsetNumber l,
				off = FirstOffsetNumber;
	int			i,
				tupsize;
	IndexTuple	tuples = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogInsertListPage));

	/* 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(data->node, data->blkno, true);
	Assert(BufferIsValid(buffer));
	page = BufferGetPage(buffer);

	GinInitBuffer(buffer, GIN_LIST);
	GinPageGetOpaque(page)->rightlink = data->rightlink;
	if (data->rightlink == InvalidBlockNumber)
	{
		/* tail of sublist */
		GinPageSetFullRow(page);
		GinPageGetOpaque(page)->maxoff = 1;
	}
	else
	{
		GinPageGetOpaque(page)->maxoff = 0;
	}

	for (i = 0; i < data->ntuples; i++)
	{
		tupsize = IndexTupleSize(tuples);

		l = PageAddItem(page, (Item) tuples, tupsize, off, false, false);

		if (l == InvalidOffsetNumber)
			elog(ERROR, "failed to add item to index page");

		tuples = (IndexTuple) (((char *) tuples) + tupsize);
	}

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

	UnlockReleaseBuffer(buffer);
}
Example #5
0
static void
ginRedoInsertListPage(XLogRecPtr lsn, XLogRecord *record)
{
    ginxlogInsertListPage *data = (ginxlogInsertListPage *) XLogRecGetData(record);
    Buffer		buffer;
    Page		page;
    OffsetNumber l,
                 off = FirstOffsetNumber;
    int			i,
                tupsize;
    IndexTuple	tuples = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogInsertListPage));

    /*
     * Backup blocks are not used, we always re-initialize the page.
     */
    Assert(!(record->xl_info & XLR_BKP_BLOCK_MASK));

    buffer = XLogReadBuffer(data->node, data->blkno, true);
    Assert(BufferIsValid(buffer));
    page = BufferGetPage(buffer);

    GinInitBuffer(buffer, GIN_LIST);
    GinPageGetOpaque(page)->rightlink = data->rightlink;
    if (data->rightlink == InvalidBlockNumber)
    {
        /* tail of sublist */
        GinPageSetFullRow(page);
        GinPageGetOpaque(page)->maxoff = 1;
    }
    else
    {
        GinPageGetOpaque(page)->maxoff = 0;
    }

    for (i = 0; i < data->ntuples; i++)
    {
        tupsize = IndexTupleSize(tuples);

        l = PageAddItem(page, (Item) tuples, tupsize, off, false, false);

        if (l == InvalidOffsetNumber)
            elog(ERROR, "failed to add item to index page");

        tuples = (IndexTuple) (((char *) tuples) + tupsize);
        off++;
    }

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

    UnlockReleaseBuffer(buffer);
}
Example #6
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);
}
/*
 * 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--;
}
Example #8
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;
}
Example #9
0
/*
 * Mask a GIN page before running consistency checks on it.
 */
void
gin_mask(char *pagedata, BlockNumber blkno)
{
	Page		page = (Page) pagedata;
	GinPageOpaque opaque;

	mask_page_lsn_and_checksum(page);
	opaque = GinPageGetOpaque(page);

	mask_page_hint_bits(page);

	/*
	 * GIN metapage doesn't use pd_lower/pd_upper. Other page types do. Hence,
	 * we need to apply masking for those pages.
	 */
	if (opaque->flags != GIN_META)
	{
		/*
		 * For GIN_DELETED page, the page is initialized to empty. Hence, mask
		 * the page content.
		 */
		if (opaque->flags & GIN_DELETED)
			mask_page_content(page);
		else
			mask_unused_space(page);
	}
}
/*
 * 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++;
}
void
GinInitPage(Page page, uint32 f, Size pageSize)
{
	GinPageOpaque opaque;

	PageInit(page, pageSize, sizeof(GinPageOpaqueData));

	opaque = GinPageGetOpaque(page);
	memset(opaque, 0, sizeof(GinPageOpaqueData));
	opaque->flags = f;
	opaque->rightlink = InvalidBlockNumber;
}
/*
 * 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);
}
Example #13
0
/*
 * Creates posting tree with one page. Function
 * suppose that items[] fits to page
 */
static BlockNumber
createPostingTree(Relation index, ItemPointerData *items, uint32 nitems)
{
	BlockNumber blkno;
	Buffer		buffer = GinNewBuffer(index);
	Page		page;

	START_CRIT_SECTION();

	GinInitBuffer(buffer, GIN_DATA | GIN_LEAF);
	page = BufferGetPage(buffer);
	blkno = BufferGetBlockNumber(buffer);

	memcpy(GinDataPageGetData(page), items, sizeof(ItemPointerData) * nitems);
	GinPageGetOpaque(page)->maxoff = nitems;

	MarkBufferDirty(buffer);

	if (!index->rd_istemp)
	{
		XLogRecPtr	recptr;
		XLogRecData rdata[2];
		ginxlogCreatePostingTree data;

		data.node = index->rd_node;
		data.blkno = blkno;
		data.nitem = nitems;

		rdata[0].buffer = InvalidBuffer;
		rdata[0].data = (char *) &data;
		rdata[0].len = sizeof(ginxlogCreatePostingTree);
		rdata[0].next = &rdata[1];

		rdata[1].buffer = InvalidBuffer;
		rdata[1].data = (char *) items;
		rdata[1].len = sizeof(ItemPointerData) * nitems;
		rdata[1].next = NULL;



		recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_CREATE_PTREE, rdata);
		PageSetLSN(page, recptr);
		PageSetTLI(page, ThisTimeLineID);

	}

	UnlockReleaseBuffer(buffer);

	END_CRIT_SECTION();

	return blkno;
}
Example #14
0
static void
ginRedoDeleteListPages(XLogRecPtr lsn, XLogRecord *record)
{
    ginxlogDeleteListPages *data = (ginxlogDeleteListPages *) XLogRecGetData(record);
    Buffer		metabuffer;
    Page		metapage;
    int			i;

    /* Backup blocks are not used in delete_listpage records */
    Assert(!(record->xl_info & XLR_BKP_BLOCK_MASK));

    metabuffer = XLogReadBuffer(data->node, GIN_METAPAGE_BLKNO, false);
    if (!BufferIsValid(metabuffer))
        return;					/* assume index was deleted, nothing to do */
    metapage = BufferGetPage(metabuffer);

    memcpy(GinPageGetMeta(metapage), &data->metadata, sizeof(GinMetaPageData));
    PageSetLSN(metapage, lsn);
    MarkBufferDirty(metabuffer);

    /*
     * In normal operation, shiftList() takes exclusive lock on all the
     * pages-to-be-deleted simultaneously.  During replay, however, it should
     * be all right to lock them one at a time.  This is dependent on the fact
     * that we are deleting pages from the head of the list, and that readers
     * share-lock the next page before releasing the one they are on. So we
     * cannot get past a reader that is on, or due to visit, any page we are
     * going to delete.  New incoming readers will block behind our metapage
     * lock and then see a fully updated page list.
     */
    for (i = 0; i < data->ndeleted; i++)
    {
        Buffer		buffer = XLogReadBuffer(data->node, data->toDelete[i], false);

        if (BufferIsValid(buffer))
        {
            Page		page = BufferGetPage(buffer);

            if (lsn > PageGetLSN(page))
            {
                GinPageGetOpaque(page)->flags = GIN_DELETED;

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

            UnlockReleaseBuffer(buffer);
        }
    }
    UnlockReleaseBuffer(metabuffer);
}
Example #15
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;
}
Example #16
0
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;
}
Example #17
0
static void
ginRedoClearIncompleteSplit(XLogReaderState *record, uint8 block_id)
{
	XLogRecPtr	lsn = record->EndRecPtr;
	Buffer		buffer;
	Page		page;

	if (XLogReadBufferForRedo(record, block_id, &buffer) == BLK_NEEDS_REDO)
	{
		page = (Page) BufferGetPage(buffer);
		GinPageGetOpaque(page)->flags &= ~GIN_INCOMPLETE_SPLIT;

		PageSetLSN(page, lsn);
		MarkBufferDirty(buffer);
	}
	if (BufferIsValid(buffer))
		UnlockReleaseBuffer(buffer);
}
/*
 * 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;
}
Example #19
0
static void
ginRedoClearIncompleteSplit(XLogRecPtr lsn, RelFileNode node, BlockNumber blkno)
{
    Buffer		buffer;
    Page		page;

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

    if (lsn > PageGetLSN(page))
    {
        GinPageGetOpaque(page)->flags &= ~GIN_INCOMPLETE_SPLIT;

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

    UnlockReleaseBuffer(buffer);
}
Example #20
0
static void
ginRedoSplitData(Page lpage, Page rpage, void *rdata)
{
    bool		isleaf = GinPageIsLeaf(lpage);

    if (isleaf)
    {
        ginxlogSplitDataLeaf *data = (ginxlogSplitDataLeaf *) rdata;
        Pointer		lptr = (Pointer) rdata + sizeof(ginxlogSplitDataLeaf);
        Pointer		rptr = lptr + data->lsize;

        Assert(data->lsize > 0 && data->lsize <= GinDataPageMaxDataSize);
        Assert(data->rsize > 0 && data->rsize <= GinDataPageMaxDataSize);

        memcpy(GinDataLeafPageGetPostingList(lpage), lptr, data->lsize);
        memcpy(GinDataLeafPageGetPostingList(rpage), rptr, data->rsize);

        GinDataPageSetDataSize(lpage, data->lsize);
        GinDataPageSetDataSize(rpage, data->rsize);
        *GinDataPageGetRightBound(lpage) = data->lrightbound;
        *GinDataPageGetRightBound(rpage) = data->rrightbound;
    }
    else
    {
        ginxlogSplitDataInternal *data = (ginxlogSplitDataInternal *) rdata;
        PostingItem *items = (PostingItem *) ((char *) rdata + sizeof(ginxlogSplitDataInternal));
        OffsetNumber i;
        OffsetNumber maxoff;

        for (i = 0; i < data->separator; i++)
            GinDataPageAddPostingItem(lpage, &items[i], InvalidOffsetNumber);
        for (i = data->separator; i < data->nitem; i++)
            GinDataPageAddPostingItem(rpage, &items[i], InvalidOffsetNumber);

        /* set up right key */
        maxoff = GinPageGetOpaque(lpage)->maxoff;
        *GinDataPageGetRightBound(lpage) = GinDataPageGetPostingItem(lpage, maxoff)->key;
        *GinDataPageGetRightBound(rpage) = data->rightbound;
    }
}
/*
 * 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;
}
Example #22
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);
}
Example #23
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);
}
Example #24
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;
}
Example #25
0
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++;
}
Example #26
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;
}
Example #27
0
/*
 * Delete a posting tree page.
 */
static void
ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkno,
			  BlockNumber parentBlkno, OffsetNumber myoff, bool isParentRoot)
{
	Buffer		dBuffer;
	Buffer		lBuffer;
	Buffer		pBuffer;
	Page		page,
				parentPage;
	BlockNumber rightlink;

	/*
	 * Lock the pages in the same order as an insertion would, to avoid
	 * deadlocks: left, then right, then parent.
	 */
	lBuffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, leftBlkno,
								 RBM_NORMAL, gvs->strategy);
	dBuffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, deleteBlkno,
								 RBM_NORMAL, gvs->strategy);
	pBuffer = ReadBufferExtended(gvs->index, MAIN_FORKNUM, parentBlkno,
								 RBM_NORMAL, gvs->strategy);

	LockBuffer(lBuffer, GIN_EXCLUSIVE);
	LockBuffer(dBuffer, GIN_EXCLUSIVE);
	if (!isParentRoot)			/* parent is already locked by
								 * LockBufferForCleanup() */
		LockBuffer(pBuffer, GIN_EXCLUSIVE);

	START_CRIT_SECTION();

	/* Unlink the page by changing left sibling's rightlink */
	page = BufferGetPage(dBuffer);
	rightlink = GinPageGetOpaque(page)->rightlink;

	page = BufferGetPage(lBuffer);
	GinPageGetOpaque(page)->rightlink = rightlink;

	/* Delete downlink from parent */
	parentPage = BufferGetPage(pBuffer);
#ifdef USE_ASSERT_CHECKING
	do
	{
		PostingItem *tod = GinDataPageGetPostingItem(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);
	MarkBufferDirty(lBuffer);
	MarkBufferDirty(dBuffer);

	if (RelationNeedsWAL(gvs->index))
	{
		XLogRecPtr	recptr;
		ginxlogDeletePage data;

		/*
		 * We can't pass REGBUF_STANDARD for the deleted page, because we
		 * didn't set pd_lower on pre-9.4 versions. The page might've been
		 * binary-upgraded from an older version, and hence not have pd_lower
		 * set correctly. Ditto for the left page, but removing the item from
		 * the parent updated its pd_lower, so we know that's OK at this
		 * point.
		 */
		XLogBeginInsert();
		XLogRegisterBuffer(0, dBuffer, 0);
		XLogRegisterBuffer(1, pBuffer, REGBUF_STANDARD);
		XLogRegisterBuffer(2, lBuffer, 0);

		data.parentOffset = myoff;
		data.rightLink = GinPageGetOpaque(page)->rightlink;

		XLogRegisterData((char *) &data, sizeof(ginxlogDeletePage));

		recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_DELETE_PAGE);
		PageSetLSN(page, recptr);
		PageSetLSN(parentPage, recptr);
		PageSetLSN(BufferGetPage(lBuffer), recptr);
	}

	if (!isParentRoot)
		LockBuffer(pBuffer, GIN_UNLOCK);
	ReleaseBuffer(pBuffer);
	UnlockReleaseBuffer(lBuffer);
	UnlockReleaseBuffer(dBuffer);

	END_CRIT_SECTION();

	gvs->result->pages_deleted++;
}
Example #28
0
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;
}
Example #29
0
/*
 * Split entry page and insert new data.
 *
 * Returns new temp pages to *newlpage and *newrpage.
 * The original buffer is left untouched.
 */
static void
entrySplitPage(GinBtree btree, Buffer origbuf,
			   GinBtreeStack *stack,
			   GinBtreeEntryInsertData *insertData,
			   BlockNumber updateblkno,
			   Page *newlpage, Page *newrpage)
{
	OffsetNumber off = stack->off;
	OffsetNumber i,
				maxoff,
				separator = InvalidOffsetNumber;
	Size		totalsize = 0;
	Size		lsize = 0,
				size;
	char	   *ptr;
	IndexTuple	itup;
	Page		page;
	Page		lpage = PageGetTempPageCopy(BufferGetPage(origbuf));
	Page		rpage = PageGetTempPageCopy(BufferGetPage(origbuf));
	Size		pageSize = PageGetPageSize(lpage);
	char		tupstore[2 * BLCKSZ];

	entryPreparePage(btree, lpage, off, insertData, updateblkno);

	/*
	 * First, append all the existing tuples and the new tuple we're inserting
	 * one after another in a temporary workspace.
	 */
	maxoff = PageGetMaxOffsetNumber(lpage);
	ptr = tupstore;
	for (i = FirstOffsetNumber; i <= maxoff; i++)
	{
		if (i == off)
		{
			size = MAXALIGN(IndexTupleSize(insertData->entry));
			memcpy(ptr, insertData->entry, size);
			ptr += size;
			totalsize += size + sizeof(ItemIdData);
		}

		itup = (IndexTuple) PageGetItem(lpage, PageGetItemId(lpage, i));
		size = MAXALIGN(IndexTupleSize(itup));
		memcpy(ptr, itup, size);
		ptr += size;
		totalsize += size + sizeof(ItemIdData);
	}

	if (off == maxoff + 1)
	{
		size = MAXALIGN(IndexTupleSize(insertData->entry));
		memcpy(ptr, insertData->entry, size);
		ptr += size;
		totalsize += size + sizeof(ItemIdData);
	}

	/*
	 * Initialize the left and right pages, and copy all the tuples back to
	 * them.
	 */
	GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
	GinInitPage(lpage, GinPageGetOpaque(rpage)->flags, pageSize);

	ptr = tupstore;
	maxoff++;
	lsize = 0;

	page = lpage;
	for (i = FirstOffsetNumber; i <= maxoff; i++)
	{
		itup = (IndexTuple) ptr;

		/*
		 * Decide where to split.  We try to equalize the pages' total data
		 * size, not number of tuples.
		 */
		if (lsize > totalsize / 2)
		{
			if (separator == InvalidOffsetNumber)
				separator = i - 1;
			page = rpage;
		}
		else
		{
			lsize += MAXALIGN(IndexTupleSize(itup)) + sizeof(ItemIdData);
		}

		if (PageAddItem(page, (Item) itup, IndexTupleSize(itup), InvalidOffsetNumber, false, false) == InvalidOffsetNumber)
			elog(ERROR, "failed to add item to index page in \"%s\"",
				 RelationGetRelationName(btree->index));
		ptr += MAXALIGN(IndexTupleSize(itup));
	}

	/* return temp pages to caller */
	*newlpage = lpage;
	*newrpage = rpage;
}
Example #30
0
static void
ginRedoUpdateMetapage(XLogReaderState *record)
{
	XLogRecPtr	lsn = record->EndRecPtr;
	ginxlogUpdateMeta *data = (ginxlogUpdateMeta *) XLogRecGetData(record);
	Buffer		metabuffer;
	Page		metapage;
	Buffer		buffer;

	/*
	 * Restore the metapage. This is essentially the same as a full-page
	 * image, so restore the metapage unconditionally without looking at the
	 * LSN, to avoid torn page hazards.
	 */
	metabuffer = XLogInitBufferForRedo(record, 0);
	Assert(BufferGetBlockNumber(metabuffer) == GIN_METAPAGE_BLKNO);
	metapage = BufferGetPage(metabuffer);

	memcpy(GinPageGetMeta(metapage), &data->metadata, sizeof(GinMetaPageData));
	PageSetLSN(metapage, lsn);
	MarkBufferDirty(metabuffer);

	if (data->ntuples > 0)
	{
		/*
		 * insert into tail page
		 */
		if (XLogReadBufferForRedo(record, 1, &buffer) == BLK_NEEDS_REDO)
		{
			Page		page = BufferGetPage(buffer);
			OffsetNumber off;
			int			i;
			Size		tupsize;
			char	   *payload;
			IndexTuple	tuples;
			Size		totaltupsize;

			payload = XLogRecGetBlockData(record, 1, &totaltupsize);
			tuples = (IndexTuple) payload;

			if (PageIsEmpty(page))
				off = FirstOffsetNumber;
			else
				off = OffsetNumberNext(PageGetMaxOffsetNumber(page));

			for (i = 0; i < data->ntuples; i++)
			{
				tupsize = IndexTupleSize(tuples);

				if (PageAddItem(page, (Item) tuples, tupsize, off,
								false, false) == InvalidOffsetNumber)
					elog(ERROR, "failed to add item to index page");

				tuples = (IndexTuple) (((char *) tuples) + tupsize);

				off++;
			}
			Assert(payload + totaltupsize == (char *) tuples);

			/*
			 * Increase counter of heap tuples
			 */
			GinPageGetOpaque(page)->maxoff++;

			PageSetLSN(page, lsn);
			MarkBufferDirty(buffer);
		}
		if (BufferIsValid(buffer))
			UnlockReleaseBuffer(buffer);
	}
	else if (data->prevTail != InvalidBlockNumber)
	{
		/*
		 * New tail
		 */
		if (XLogReadBufferForRedo(record, 1, &buffer) == BLK_NEEDS_REDO)
		{
			Page		page = BufferGetPage(buffer);

			GinPageGetOpaque(page)->rightlink = data->newRightlink;

			PageSetLSN(page, lsn);
			MarkBufferDirty(buffer);
		}
		if (BufferIsValid(buffer))
			UnlockReleaseBuffer(buffer);
	}

	UnlockReleaseBuffer(metabuffer);
}