/* Comparator function for rbtree.c */
static int
cmpEntryAccumulator(const RBNode *a, const RBNode *b, void *arg)
{
const EntryAccumulator *ea = (const EntryAccumulator *) a;
const EntryAccumulator *eb = (const EntryAccumulator *) b;
BuildAccumulator *accum = (BuildAccumulator *) arg;
return compareAttEntries(accum->ginstate, ea->attnum, ea->value,
eb->attnum, eb->value);
}
/*
* Searches correct position for value on leaf page.
* Page should be corrrectly choosen.
* Returns true if value found on page.
*/
static bool
entryLocateLeafEntry(GinBtree btree, GinBtreeStack *stack)
{
Page page = BufferGetPage(stack->buffer);
OffsetNumber low,
high;
IndexTuple itup;
Assert(GinPageIsLeaf(page));
Assert(!GinPageIsData(page));
if (btree->fullScan)
{
stack->off = FirstOffsetNumber;
return TRUE;
}
low = FirstOffsetNumber;
high = PageGetMaxOffsetNumber(page);
if (high < low)
{
stack->off = FirstOffsetNumber;
return false;
}
high++;
while (high > low)
{
OffsetNumber mid = low + ((high - low) / 2);
int result;
itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, mid));
result = 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;
return true;
}
else if (result > 0)
low = mid + 1;
else
high = mid;
}
stack->off = high;
return false;
}
static bool
entryIsMoveRight(GinBtree btree, Page page)
{
IndexTuple itup;
if (GinPageRightMost(page))
return FALSE;
itup = getRightMostTuple(page);
if (compareAttEntries(btree->ginstate,
btree->entryAttnum, btree->entryValue,
gintuple_get_attrnum(btree->ginstate, itup),
gin_index_getattr(btree->ginstate, itup)) > 0)
return TRUE;
return FALSE;
}
/*
* 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);
}
