/*
* 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;
}
/*
* split page and fills WAL record. original buffer(lbuf) leaves untouched,
* returns shadow page of lbuf filled new data. In leaf page and build mode puts all
* ItemPointers to pages. Also, in build mode splits data by way to full fulled
* left page
*/
static Page
dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRecData **prdata)
{
char *ptr;
OffsetNumber separator;
ItemPointer bound;
Page lpage = PageGetTempPageCopy(BufferGetPage(lbuf));
ItemPointerData oldbound = *GinDataPageGetRightBound(lpage);
int sizeofitem = GinSizeOfDataPageItem(lpage);
OffsetNumber maxoff = GinPageGetOpaque(lpage)->maxoff;
Page rpage = BufferGetPage(rbuf);
Size pageSize = PageGetPageSize(lpage);
Size freeSpace;
uint32 nCopied = 1;
/* these must be static so they can be returned to caller */
static ginxlogSplit data;
static XLogRecData rdata[4];
static char vector[2 * BLCKSZ];
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
freeSpace = GinDataPageGetFreeSpace(rpage);
*prdata = rdata;
data.leftChildBlkno = (GinPageIsLeaf(lpage)) ?
InvalidOffsetNumber : PostingItemGetBlockNumber(&(btree->pitem));
data.updateBlkno = dataPrepareData(btree, lpage, off);
memcpy(vector, GinDataPageGetItem(lpage, FirstOffsetNumber),
maxoff * sizeofitem);
if (GinPageIsLeaf(lpage) && GinPageRightMost(lpage) && off > GinPageGetOpaque(lpage)->maxoff)
{
nCopied = 0;
while (btree->curitem < btree->nitem &&
maxoff * sizeof(ItemPointerData) < 2 * (freeSpace - sizeof(ItemPointerData)))
{
memcpy(vector + maxoff * sizeof(ItemPointerData),
btree->items + btree->curitem,
sizeof(ItemPointerData));
maxoff++;
nCopied++;
btree->curitem++;
}
}
else
{
ptr = vector + (off - 1) * sizeofitem;
if (maxoff + 1 - off != 0)
memmove(ptr + sizeofitem, ptr, (maxoff - off + 1) * sizeofitem);
if (GinPageIsLeaf(lpage))
{
memcpy(ptr, btree->items + btree->curitem, sizeofitem);
btree->curitem++;
}
else
memcpy(ptr, &(btree->pitem), sizeofitem);
maxoff++;
}
/*
* we suppose that during index creation table scaned from begin to end,
* so ItemPointers are monotonically increased..
*/
if (btree->isBuild && GinPageRightMost(lpage))
separator = freeSpace / sizeofitem;
else
separator = maxoff / 2;
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
GinInitPage(lpage, GinPageGetOpaque(rpage)->flags, pageSize);
memcpy(GinDataPageGetItem(lpage, FirstOffsetNumber), vector, separator * sizeofitem);
GinPageGetOpaque(lpage)->maxoff = separator;
memcpy(GinDataPageGetItem(rpage, FirstOffsetNumber),
vector + separator * sizeofitem, (maxoff - separator) * sizeofitem);
GinPageGetOpaque(rpage)->maxoff = maxoff - separator;
PostingItemSetBlockNumber(&(btree->pitem), BufferGetBlockNumber(lbuf));
if (GinPageIsLeaf(lpage))
btree->pitem.key = *(ItemPointerData *) GinDataPageGetItem(lpage,
GinPageGetOpaque(lpage)->maxoff);
else
btree->pitem.key = ((PostingItem *) GinDataPageGetItem(lpage,
GinPageGetOpaque(lpage)->maxoff))->key;
btree->rightblkno = BufferGetBlockNumber(rbuf);
/* set up right bound for left page */
bound = GinDataPageGetRightBound(lpage);
*bound = btree->pitem.key;
/* set up right bound for right page */
bound = GinDataPageGetRightBound(rpage);
*bound = oldbound;
data.node = btree->index->rd_node;
data.rootBlkno = InvalidBlockNumber;
data.lblkno = BufferGetBlockNumber(lbuf);
data.rblkno = BufferGetBlockNumber(rbuf);
data.separator = separator;
data.nitem = maxoff;
data.isData = TRUE;
data.isLeaf = GinPageIsLeaf(lpage) ? TRUE : FALSE;
data.isRootSplit = FALSE;
data.rightbound = oldbound;
rdata[0].buffer = InvalidBuffer;
rdata[0].data = (char *) &data;
rdata[0].len = sizeof(ginxlogSplit);
rdata[0].next = &rdata[1];
rdata[1].buffer = InvalidBuffer;
rdata[1].data = vector;
rdata[1].len = MAXALIGN(maxoff * sizeofitem);
rdata[1].next = NULL;
return lpage;
}
/*
* split page and fills WAL record. original buffer(lbuf) leaves untouched,
* returns shadow page of lbuf filled new data. In leaf page and build mode puts all
* ItemPointers to pages. Also, in build mode splits data by way to full fulled
* left page
*/
static Page
dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off,
void *insertdata, BlockNumber updateblkno, XLogRecData **prdata)
{
char *ptr;
OffsetNumber separator;
ItemPointer bound;
Page lpage = PageGetTempPageCopy(BufferGetPage(lbuf));
bool isleaf = GinPageIsLeaf(lpage);
ItemPointerData oldbound = *GinDataPageGetRightBound(lpage);
int sizeofitem = GinSizeOfDataPageItem(lpage);
OffsetNumber maxoff = GinPageGetOpaque(lpage)->maxoff;
Page rpage = BufferGetPage(rbuf);
Size pageSize = PageGetPageSize(lpage);
Size freeSpace;
/* these must be static so they can be returned to caller */
static ginxlogSplitData data;
static XLogRecData rdata[2];
static char vector[2 * BLCKSZ];
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
freeSpace = GinDataPageGetFreeSpace(rpage);
*prdata = rdata;
/* Update existing downlink to point to next page (on internal page) */
if (!isleaf)
{
PostingItem *pitem = GinDataPageGetPostingItem(lpage, off);
PostingItemSetBlockNumber(pitem, updateblkno);
}
if (isleaf)
{
memcpy(vector,
GinDataPageGetItemPointer(lpage, FirstOffsetNumber),
maxoff * sizeof(ItemPointerData));
}
else
{
memcpy(vector,
GinDataPageGetPostingItem(lpage, FirstOffsetNumber),
maxoff * sizeof(PostingItem));
}
if (isleaf && GinPageRightMost(lpage) && off > GinPageGetOpaque(lpage)->maxoff)
{
/* append new items to the end */
GinBtreeDataLeafInsertData *items = insertdata;
while (items->curitem < items->nitem &&
maxoff * sizeof(ItemPointerData) < 2 * (freeSpace - sizeof(ItemPointerData)))
{
memcpy(vector + maxoff * sizeof(ItemPointerData),
items->items + items->curitem,
sizeof(ItemPointerData));
maxoff++;
items->curitem++;
}
}
else
{
ptr = vector + (off - 1) * sizeofitem;
if (maxoff + 1 - off != 0)
memmove(ptr + sizeofitem, ptr, (maxoff - off + 1) * sizeofitem);
if (isleaf)
{
GinBtreeDataLeafInsertData *items = insertdata;
memcpy(ptr, items->items + items->curitem, sizeofitem);
items->curitem++;
}
else
{
PostingItem *pitem = insertdata;
memcpy(ptr, pitem, sizeofitem);
}
maxoff++;
}
/*
* we assume that during index creation the table scanned from beginning
* to end, so ItemPointers are in monotonically increasing order.
*/
if (btree->isBuild && GinPageRightMost(lpage))
separator = freeSpace / sizeofitem;
else
separator = maxoff / 2;
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
GinInitPage(lpage, GinPageGetOpaque(rpage)->flags, pageSize);
if (isleaf)
memcpy(GinDataPageGetItemPointer(lpage, FirstOffsetNumber),
vector, separator * sizeof(ItemPointerData));
else
memcpy(GinDataPageGetPostingItem(lpage, FirstOffsetNumber),
vector, separator * sizeof(PostingItem));
GinPageGetOpaque(lpage)->maxoff = separator;
if (isleaf)
memcpy(GinDataPageGetItemPointer(rpage, FirstOffsetNumber),
vector + separator * sizeof(ItemPointerData),
(maxoff - separator) * sizeof(ItemPointerData));
else
memcpy(GinDataPageGetPostingItem(rpage, FirstOffsetNumber),
vector + separator * sizeof(PostingItem),
(maxoff - separator) * sizeof(PostingItem));
GinPageGetOpaque(rpage)->maxoff = maxoff - separator;
/* set up right bound for left page */
bound = GinDataPageGetRightBound(lpage);
if (GinPageIsLeaf(lpage))
*bound = *GinDataPageGetItemPointer(lpage,
GinPageGetOpaque(lpage)->maxoff);
else
*bound = GinDataPageGetPostingItem(lpage,
GinPageGetOpaque(lpage)->maxoff)->key;
/* set up right bound for right page */
bound = GinDataPageGetRightBound(rpage);
*bound = oldbound;
data.separator = separator;
data.nitem = maxoff;
data.rightbound = oldbound;
rdata[0].buffer = InvalidBuffer;
rdata[0].data = (char *) &data;
rdata[0].len = sizeof(ginxlogSplitData);
rdata[0].next = &rdata[1];
rdata[1].buffer = InvalidBuffer;
rdata[1].data = vector;
rdata[1].len = maxoff * sizeofitem;
rdata[1].next = NULL;
return lpage;
}
