C++ GinPageGetOpaque函数代码示例

/*
 * 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++;
}

/*
 * 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++;
}

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);
}

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);
}

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--;
}

/*
 * 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;
}

/*
 * 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);
}

/*
 * 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;
}

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);
}

/*
 * 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;
}