/*
* Insert value (stored in GinBtree) to tree described by stack
*
* During an index build, buildStats is non-null and the counters
* it contains should be incremented as needed.
*
* NB: the passed-in stack is freed, as though by freeGinBtreeStack.
*/
void
ginInsertValue(GinBtree btree, GinBtreeStack *stack, GinStatsData *buildStats)
{
GinBtreeStack *parent = stack;
BlockNumber rootBlkno = InvalidBuffer;
Page page,
rpage,
lpage;
/* remember root BlockNumber */
while (parent)
{
rootBlkno = parent->blkno;
parent = parent->parent;
}
while (stack)
{
XLogRecData *rdata;
BlockNumber savedRightLink;
page = BufferGetPage(stack->buffer);
savedRightLink = GinPageGetOpaque(page)->rightlink;
if (btree->isEnoughSpace(btree, stack->buffer, stack->off))
{
START_CRIT_SECTION();
btree->placeToPage(btree, stack->buffer, stack->off, &rdata);
MarkBufferDirty(stack->buffer);
if (RelationNeedsWAL(btree->index))
{
XLogRecPtr recptr;
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_INSERT, rdata);
PageSetLSN(page, recptr);
PageSetTLI(page, ThisTimeLineID);
}
LockBuffer(stack->buffer, GIN_UNLOCK);
END_CRIT_SECTION();
freeGinBtreeStack(stack);
return;
}
else
{
Buffer rbuffer = GinNewBuffer(btree->index);
Page newlpage;
/*
* newlpage is a pointer to memory page, it doesn't associate with
* buffer, stack->buffer should be untouched
*/
newlpage = btree->splitPage(btree, stack->buffer, rbuffer, stack->off, &rdata);
((ginxlogSplit *) (rdata->data))->rootBlkno = rootBlkno;
/* During index build, count the newly-split page */
if (buildStats)
{
if (btree->isData)
buildStats->nDataPages++;
else
buildStats->nEntryPages++;
}
parent = stack->parent;
if (parent == NULL)
{
/*
* split root, so we need to allocate new left page and place
* pointer on root to left and right page
*/
Buffer lbuffer = GinNewBuffer(btree->index);
((ginxlogSplit *) (rdata->data))->isRootSplit = TRUE;
((ginxlogSplit *) (rdata->data))->rrlink = InvalidBlockNumber;
page = BufferGetPage(stack->buffer);
lpage = BufferGetPage(lbuffer);
rpage = BufferGetPage(rbuffer);
GinPageGetOpaque(rpage)->rightlink = InvalidBlockNumber;
GinPageGetOpaque(newlpage)->rightlink = BufferGetBlockNumber(rbuffer);
((ginxlogSplit *) (rdata->data))->lblkno = BufferGetBlockNumber(lbuffer);
START_CRIT_SECTION();
GinInitBuffer(stack->buffer, GinPageGetOpaque(newlpage)->flags & ~GIN_LEAF);
PageRestoreTempPage(newlpage, lpage);
btree->fillRoot(btree, stack->buffer, lbuffer, rbuffer);
MarkBufferDirty(rbuffer);
MarkBufferDirty(lbuffer);
MarkBufferDirty(stack->buffer);
if (RelationNeedsWAL(btree->index))
{
XLogRecPtr recptr;
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_SPLIT, rdata);
PageSetLSN(page, recptr);
PageSetTLI(page, ThisTimeLineID);
PageSetLSN(lpage, recptr);
PageSetTLI(lpage, ThisTimeLineID);
PageSetLSN(rpage, recptr);
PageSetTLI(rpage, ThisTimeLineID);
}
UnlockReleaseBuffer(rbuffer);
UnlockReleaseBuffer(lbuffer);
LockBuffer(stack->buffer, GIN_UNLOCK);
END_CRIT_SECTION();
freeGinBtreeStack(stack);
/* During index build, count the newly-added root page */
if (buildStats)
{
if (btree->isData)
buildStats->nDataPages++;
else
buildStats->nEntryPages++;
}
return;
}
else
{
/* split non-root page */
((ginxlogSplit *) (rdata->data))->isRootSplit = FALSE;
((ginxlogSplit *) (rdata->data))->rrlink = savedRightLink;
lpage = BufferGetPage(stack->buffer);
rpage = BufferGetPage(rbuffer);
GinPageGetOpaque(rpage)->rightlink = savedRightLink;
GinPageGetOpaque(newlpage)->rightlink = BufferGetBlockNumber(rbuffer);
START_CRIT_SECTION();
PageRestoreTempPage(newlpage, lpage);
MarkBufferDirty(rbuffer);
MarkBufferDirty(stack->buffer);
if (RelationNeedsWAL(btree->index))
{
XLogRecPtr recptr;
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_SPLIT, rdata);
PageSetLSN(lpage, recptr);
PageSetTLI(lpage, ThisTimeLineID);
PageSetLSN(rpage, recptr);
PageSetTLI(rpage, ThisTimeLineID);
}
UnlockReleaseBuffer(rbuffer);
END_CRIT_SECTION();
}
}
btree->isDelete = FALSE;
/* search parent to lock */
LockBuffer(parent->buffer, GIN_EXCLUSIVE);
/* move right if it's needed */
page = BufferGetPage(parent->buffer);
while ((parent->off = btree->findChildPtr(btree, page, stack->blkno, parent->off)) == InvalidOffsetNumber)
{
BlockNumber rightlink = GinPageGetOpaque(page)->rightlink;
LockBuffer(parent->buffer, GIN_UNLOCK);
if (rightlink == InvalidBlockNumber)
{
/*
* rightmost page, but we don't find parent, we should use
* plain search...
*/
ginFindParents(btree, stack, rootBlkno);
parent = stack->parent;
page = BufferGetPage(parent->buffer);
break;
}
parent->blkno = rightlink;
parent->buffer = ReleaseAndReadBuffer(parent->buffer, btree->index, parent->blkno);
LockBuffer(parent->buffer, GIN_EXCLUSIVE);
page = BufferGetPage(parent->buffer);
}
UnlockReleaseBuffer(stack->buffer);
pfree(stack);
stack = parent;
}
}
/*
* 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);
}
/*
* Finish a split by inserting the downlink for the new page to parent.
*
* On entry, stack->buffer is exclusively locked.
*
* If freestack is true, all the buffers are released and unlocked as we
* crawl up the tree, and 'stack' is freed. Otherwise stack->buffer is kept
* locked, and stack is unmodified, except for possibly moving right to find
* the correct parent of page.
*/
static void
ginFinishSplit(GinBtree btree, GinBtreeStack *stack, bool freestack,
GinStatsData *buildStats)
{
Page page;
bool done;
bool first = true;
/*
* freestack == false when we encounter an incompletely split page during a
* scan, while freestack == true is used in the normal scenario that a
* split is finished right after the initial insert.
*/
if (!freestack)
elog(DEBUG1, "finishing incomplete split of block %u in gin index \"%s\"",
stack->blkno, RelationGetRelationName(btree->index));
/* this loop crawls up the stack until the insertion is complete */
do
{
GinBtreeStack *parent = stack->parent;
void *insertdata;
BlockNumber updateblkno;
/* search parent to lock */
LockBuffer(parent->buffer, GIN_EXCLUSIVE);
/*
* If the parent page was incompletely split, finish that split first,
* then continue with the current one.
*
* Note: we have to finish *all* incomplete splits we encounter, even
* if we have to move right. Otherwise we might choose as the target
* a page that has no downlink in the parent, and splitting it further
* would fail.
*/
if (GinPageIsIncompleteSplit(BufferGetPage(parent->buffer)))
ginFinishSplit(btree, parent, false, buildStats);
/* move right if it's needed */
page = BufferGetPage(parent->buffer);
while ((parent->off = btree->findChildPtr(btree, page, stack->blkno, parent->off)) == InvalidOffsetNumber)
{
if (GinPageRightMost(page))
{
/*
* rightmost page, but we don't find parent, we should use
* plain search...
*/
LockBuffer(parent->buffer, GIN_UNLOCK);
ginFindParents(btree, stack);
parent = stack->parent;
Assert(parent != NULL);
break;
}
parent->buffer = ginStepRight(parent->buffer, btree->index, GIN_EXCLUSIVE);
parent->blkno = BufferGetBlockNumber(parent->buffer);
page = BufferGetPage(parent->buffer);
if (GinPageIsIncompleteSplit(BufferGetPage(parent->buffer)))
ginFinishSplit(btree, parent, false, buildStats);
}
/* insert the downlink */
insertdata = btree->prepareDownlink(btree, stack->buffer);
updateblkno = GinPageGetOpaque(BufferGetPage(stack->buffer))->rightlink;
done = ginPlaceToPage(btree, parent,
insertdata, updateblkno,
stack->buffer, buildStats);
pfree(insertdata);
/*
* If the caller requested to free the stack, unlock and release the
* child buffer now. Otherwise keep it pinned and locked, but if we
* have to recurse up the tree, we can unlock the upper pages, only
* keeping the page at the bottom of the stack locked.
*/
if (!first || freestack)
LockBuffer(stack->buffer, GIN_UNLOCK);
if (freestack)
{
ReleaseBuffer(stack->buffer);
pfree(stack);
}
stack = parent;
first = false;
} while (!done);
/* unlock the parent */
LockBuffer(stack->buffer, GIN_UNLOCK);
if (freestack)
freeGinBtreeStack(stack);
}
/*
* Try to find parent for current stack position, returns correct
* parent and child's offset in stack->parent.
* Function should never release root page to prevent conflicts
* with vacuum process
*/
void
ginFindParents(GinBtree btree, GinBtreeStack *stack,
BlockNumber rootBlkno)
{
Page page;
Buffer buffer;
BlockNumber blkno,
leftmostBlkno;
OffsetNumber offset;
GinBtreeStack *root = stack->parent;
GinBtreeStack *ptr;
if (!root)
{
/* XLog mode... */
root = (GinBtreeStack *) palloc(sizeof(GinBtreeStack));
root->blkno = rootBlkno;
root->buffer = ReadBuffer(btree->index, rootBlkno);
LockBuffer(root->buffer, GIN_EXCLUSIVE);
root->parent = NULL;
}
else
{
/*
* find root, we should not release root page until update is
* finished!!
*/
while (root->parent)
{
ReleaseBuffer(root->buffer);
root = root->parent;
}
Assert(root->blkno == rootBlkno);
Assert(BufferGetBlockNumber(root->buffer) == rootBlkno);
LockBuffer(root->buffer, GIN_EXCLUSIVE);
}
root->off = InvalidOffsetNumber;
page = BufferGetPage(root->buffer);
Assert(!GinPageIsLeaf(page));
/* check trivial case */
if ((root->off = btree->findChildPtr(btree, page, stack->blkno, InvalidOffsetNumber)) != InvalidOffsetNumber)
{
stack->parent = root;
return;
}
leftmostBlkno = blkno = btree->getLeftMostPage(btree, page);
LockBuffer(root->buffer, GIN_UNLOCK);
Assert(blkno != InvalidBlockNumber);
for (;;)
{
buffer = ReadBuffer(btree->index, blkno);
LockBuffer(buffer, GIN_EXCLUSIVE);
page = BufferGetPage(buffer);
if (GinPageIsLeaf(page))
elog(ERROR, "Lost path");
leftmostBlkno = btree->getLeftMostPage(btree, page);
while ((offset = btree->findChildPtr(btree, page, stack->blkno, InvalidOffsetNumber)) == InvalidOffsetNumber)
{
blkno = GinPageGetOpaque(page)->rightlink;
LockBuffer(buffer, GIN_UNLOCK);
ReleaseBuffer(buffer);
if (blkno == InvalidBlockNumber)
break;
buffer = ReadBuffer(btree->index, blkno);
LockBuffer(buffer, GIN_EXCLUSIVE);
page = BufferGetPage(buffer);
}
if (blkno != InvalidBlockNumber)
{
ptr = (GinBtreeStack *) palloc(sizeof(GinBtreeStack));
ptr->blkno = blkno;
ptr->buffer = buffer;
ptr->parent = root; /* it's may be wrong, but in next call we will
* correct */
ptr->off = offset;
stack->parent = ptr;
return;
}
blkno = leftmostBlkno;
}
}
/*
* 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;
}
}
/*
* Try to find parent for current stack position. Returns correct parent and
* child's offset in stack->parent. The root page is never released, to
* to prevent conflict with vacuum process.
*/
static void
ginFindParents(GinBtree btree, GinBtreeStack *stack)
{
Page page;
Buffer buffer;
BlockNumber blkno,
leftmostBlkno;
OffsetNumber offset;
GinBtreeStack *root;
GinBtreeStack *ptr;
/*
* Unwind the stack all the way up to the root, leaving only the root
* item.
*
* Be careful not to release the pin on the root page! The pin on root
* page is required to lock out concurrent vacuums on the tree.
*/
root = stack->parent;
while (root->parent)
{
ReleaseBuffer(root->buffer);
root = root->parent;
}
Assert(root->blkno == btree->rootBlkno);
Assert(BufferGetBlockNumber(root->buffer) == btree->rootBlkno);
root->off = InvalidOffsetNumber;
blkno = root->blkno;
buffer = root->buffer;
offset = InvalidOffsetNumber;
ptr = (GinBtreeStack *) palloc(sizeof(GinBtreeStack));
for (;;)
{
LockBuffer(buffer, GIN_EXCLUSIVE);
page = BufferGetPage(buffer);
if (GinPageIsLeaf(page))
elog(ERROR, "Lost path");
if (GinPageIsIncompleteSplit(page))
{
Assert(blkno != btree->rootBlkno);
ptr->blkno = blkno;
ptr->buffer = buffer;
/*
* parent may be wrong, but if so, the ginFinishSplit call will
* recurse to call ginFindParents again to fix it.
*/
ptr->parent = root;
ptr->off = InvalidOffsetNumber;
ginFinishSplit(btree, ptr, false, NULL);
}
leftmostBlkno = btree->getLeftMostChild(btree, page);
while ((offset = btree->findChildPtr(btree, page, stack->blkno, InvalidOffsetNumber)) == InvalidOffsetNumber)
{
blkno = GinPageGetOpaque(page)->rightlink;
if (blkno == InvalidBlockNumber)
{
UnlockReleaseBuffer(buffer);
break;
}
buffer = ginStepRight(buffer, btree->index, GIN_EXCLUSIVE);
page = BufferGetPage(buffer);
/* finish any incomplete splits, as above */
if (GinPageIsIncompleteSplit(page))
{
Assert(blkno != btree->rootBlkno);
ptr->blkno = blkno;
ptr->buffer = buffer;
ptr->parent = root;
ptr->off = InvalidOffsetNumber;
ginFinishSplit(btree, ptr, false, NULL);
}
}
if (blkno != InvalidBlockNumber)
{
ptr->blkno = blkno;
ptr->buffer = buffer;
ptr->parent = root; /* it may be wrong, but in next call we will
* correct */
ptr->off = offset;
stack->parent = ptr;
return;
}
/* Descend down to next level */
blkno = leftmostBlkno;
buffer = ReadBuffer(btree->index, blkno);
}
}
/*
* 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);
}
/*
* 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 an 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 offset stack->off
* in the target page is updated to point to updateblkno.
*
* stack->buffer is locked on entry, and is kept locked.
* Likewise for childbuf, if given.
*/
static bool
ginPlaceToPage(GinBtree btree, GinBtreeStack *stack,
void *insertdata, BlockNumber updateblkno,
Buffer childbuf, GinStatsData *buildStats)
{
Page page = BufferGetPage(stack->buffer);
bool result;
GinPlaceToPageRC rc;
uint16 xlflags = 0;
Page childpage = NULL;
Page newlpage = NULL,
newrpage = NULL;
void *ptp_workspace = NULL;
XLogRecData payloadrdata[10];
MemoryContext tmpCxt;
MemoryContext oldCxt;
/*
* We do all the work of this function and its subfunctions in a temporary
* memory context. This avoids leakages and simplifies APIs, since some
* subfunctions allocate storage that has to survive until we've finished
* the WAL insertion.
*/
tmpCxt = AllocSetContextCreate(CurrentMemoryContext,
"ginPlaceToPage temporary context",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldCxt = MemoryContextSwitchTo(tmpCxt);
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);
}
/*
* See if the incoming tuple will fit on the page. beginPlaceToPage will
* decide if the page needs to be split, and will compute the split
* contents if so. See comments for beginPlaceToPage and execPlaceToPage
* functions for more details of the API here.
*/
rc = btree->beginPlaceToPage(btree, stack->buffer, stack,
insertdata, updateblkno,
&ptp_workspace,
&newlpage, &newrpage,
payloadrdata);
if (rc == GPTP_NO_WORK)
{
/* Nothing to do */
result = true;
}
else if (rc == GPTP_INSERT)
{
/* It will fit, perform the insertion */
START_CRIT_SECTION();
/* Perform the page update, and set up WAL data about it */
btree->execPlaceToPage(btree, stack->buffer, stack,
insertdata, updateblkno,
ptp_workspace, payloadrdata);
MarkBufferDirty(stack->buffer);
/* An insert to an internal page finishes the split of the child. */
if (BufferIsValid(childbuf))
{
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.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 (BufferIsValid(childbuf))
{
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 = true;
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 (BufferIsValid(childbuf))
PageSetLSN(childpage, recptr);
}
END_CRIT_SECTION();
/* Insertion is complete. */
result = true;
}
else if (rc == GPTP_SPLIT)
{
/*
* Didn't fit, need to split. The split has been computed in newlpage
* and newrpage, which are pointers to palloc'd pages, not associated
* with buffers. stack->buffer is not touched yet.
*/
Buffer rbuffer;
BlockNumber savedRightLink;
ginxlogSplit data;
Buffer lbuffer = InvalidBuffer;
Page newrootpg = NULL;
/* Get a new index page to become the right page */
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;
/* Begin setting up WAL record (which we might not use) */
data.node = btree->index->rd_node;
data.rblkno = BufferGetBlockNumber(rbuffer);
data.flags = xlflags;
if (BufferIsValid(childbuf))
{
data.leftChildBlkno = BufferGetBlockNumber(childbuf);
data.rightChildBlkno = GinPageGetOpaque(childpage)->rightlink;
}
else
data.leftChildBlkno = data.rightChildBlkno = InvalidBlockNumber;
if (stack->parent == NULL)
{
/*
* splitting the root, so we need to allocate new left page and
* place pointers to left and right page on root page.
*/
lbuffer = GinNewBuffer(btree->index);
/* During index build, count the new left 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(newrpage)->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 rather than
* overwriting the original page directly, since we're not in the
* critical section yet.)
*/
newrootpg = PageGetTempPage(newrpage);
GinInitPage(newrootpg, GinPageGetOpaque(newlpage)->flags & ~(GIN_LEAF | GIN_COMPRESSED), BLCKSZ);
btree->fillRoot(btree, newrootpg,
BufferGetBlockNumber(lbuffer), newlpage,
BufferGetBlockNumber(rbuffer), newrpage);
}
else
{
/* splitting a non-root page */
data.rrlink = savedRightLink;
data.lblkno = BufferGetBlockNumber(stack->buffer);
GinPageGetOpaque(newrpage)->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 likewise for the new contents of the
* newly-allocated right block. 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.
*/
START_CRIT_SECTION();
MarkBufferDirty(rbuffer);
MarkBufferDirty(stack->buffer);
/*
* Restore the temporary copies over the real buffers.
*/
if (stack->parent == NULL)
{
/* Splitting the root, three pages to update */
MarkBufferDirty(lbuffer);
memcpy(page, newrootpg, BLCKSZ);
memcpy(BufferGetPage(lbuffer), newlpage, BLCKSZ);
memcpy(BufferGetPage(rbuffer), newrpage, BLCKSZ);
}
else
{
/* Normal split, only two pages to update */
memcpy(page, newlpage, BLCKSZ);
memcpy(BufferGetPage(rbuffer), newrpage, BLCKSZ);
}
/* We also clear childbuf's INCOMPLETE_SPLIT flag, if passed */
if (BufferIsValid(childbuf))
{
GinPageGetOpaque(childpage)->flags &= ~GIN_INCOMPLETE_SPLIT;
MarkBufferDirty(childbuf);
}
/* write WAL record */
if (RelationNeedsWAL(btree->index))
{
XLogRecData rdata[2];
XLogRecPtr recptr;
rdata[0].buffer = InvalidBuffer;
rdata[0].data = (char *) &data;
rdata[0].len = sizeof(ginxlogSplit);
if (BufferIsValid(childbuf))
{
rdata[0].next = &rdata[1];
rdata[1].buffer = childbuf;
rdata[1].buffer_std = true;
rdata[1].data = NULL;
rdata[1].len = 0;
rdata[1].next = payloadrdata;
}
else
rdata[0].next = payloadrdata;
recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_SPLIT, rdata);
PageSetLSN(page, recptr);
PageSetLSN(BufferGetPage(rbuffer), recptr);
if (stack->parent == NULL)
PageSetLSN(BufferGetPage(lbuffer), recptr);
if (BufferIsValid(childbuf))
PageSetLSN(childpage, recptr);
}
END_CRIT_SECTION();
/*
* We can release the locks/pins on the new pages now, but keep
* stack->buffer locked. childbuf doesn't get unlocked either.
*/
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.
*/
result = (stack->parent == NULL);
}
else
{
elog(ERROR, "invalid return code from GIN placeToPage method: %d", rc);
result = false; /* keep compiler quiet */
}
/* Clean up temp context */
MemoryContextSwitchTo(oldCxt);
MemoryContextDelete(tmpCxt);
return result;
}
/*
* Find correct tuple in non-leaf page. It supposed that
* page correctly choosen 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->getLeftMostPage(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
{
itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
result = compareAttEntries(btree->ginstate,
btree->entryAttnum, btree->entryValue,
gintuple_get_attrnum(btree->ginstate, itup),
gin_index_getattr(btree->ginstate, itup));
}
if (result == 0)
{
stack->off = mid;
Assert(GinItemPointerGetBlockNumber(&(itup)->t_tid) != GIN_ROOT_BLKNO);
return GinItemPointerGetBlockNumber(&(itup)->t_tid);
}
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(GinItemPointerGetBlockNumber(&(itup)->t_tid) != GIN_ROOT_BLKNO);
return GinItemPointerGetBlockNumber(&(itup)->t_tid);
}
