/*
* Searches correct position for value on leaf page.
* Page should be correctly chosen.
* Returns true if value found on page.
*/
static bool
entryLocateLeafEntry(GinBtree btree, GinBtreeStack *stack)
{
Page page = BufferGetPage(stack->buffer);
OffsetNumber low,
high;
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);
IndexTuple itup;
OffsetNumber attnum;
Datum key;
GinNullCategory category;
int result;
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;
return true;
}
else if (result > 0)
low = mid + 1;
else
high = mid;
}
stack->off = high;
return false;
}
/*
* Collect data from a pending-list page in preparation for insertion into
* the main index.
*
* Go through all tuples >= startoff on page and collect values in accum
*
* Note that ka is just workspace --- it does not carry any state across
* calls.
*/
static void
processPendingPage(BuildAccumulator *accum, KeyArray *ka,
Page page, OffsetNumber startoff)
{
ItemPointerData heapptr;
OffsetNumber i,
maxoff;
OffsetNumber attrnum;
/* reset *ka to empty */
ka->nvalues = 0;
maxoff = PageGetMaxOffsetNumber(page);
Assert(maxoff >= FirstOffsetNumber);
ItemPointerSetInvalid(&heapptr);
attrnum = 0;
for (i = startoff; i <= maxoff; i = OffsetNumberNext(i))
{
IndexTuple itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, i));
OffsetNumber curattnum;
Datum curkey;
GinNullCategory curcategory;
/* Check for change of heap TID or attnum */
curattnum = gintuple_get_attrnum(accum->ginstate, itup);
if (!ItemPointerIsValid(&heapptr))
{
heapptr = itup->t_tid;
attrnum = curattnum;
}
else if (!(ItemPointerEquals(&heapptr, &itup->t_tid) &&
curattnum == attrnum))
{
/*
* ginInsertBAEntries can insert several datums per call, but only
* for one heap tuple and one column. So call it at a boundary,
* and reset ka.
*/
ginInsertBAEntries(accum, &heapptr, attrnum,
ka->keys, ka->categories, ka->nvalues);
ka->nvalues = 0;
heapptr = itup->t_tid;
attrnum = curattnum;
}
/* Add key to KeyArray */
curkey = gintuple_get_key(accum->ginstate, itup, &curcategory);
addDatum(ka, curkey, curcategory);
}
/* Dump out all remaining keys */
ginInsertBAEntries(accum, &heapptr, attrnum,
ka->keys, ka->categories, ka->nvalues);
}
static bool
entryIsMoveRight(GinBtree btree, Page page)
{
IndexTuple itup;
OffsetNumber attnum;
Datum key;
GinNullCategory category;
if (GinPageRightMost(page))
return FALSE;
itup = getRightMostTuple(page);
attnum = gintuple_get_attrnum(btree->ginstate, itup);
key = gintuple_get_key(btree->ginstate, itup, &category);
if (ginCompareAttEntries(btree->ginstate,
btree->entryAttnum, btree->entryKey, btree->entryCategory,
attnum, key, category) > 0)
return TRUE;
return FALSE;
}
/*
* Adds array of item pointers to tuple's posting list, or
* creates posting tree and tuple pointing to tree in case
* of not enough space. Max size of tuple is defined in
* GinFormTuple(). Returns a new, modified index tuple.
* items[] must be in sorted order with no duplicates.
*/
static IndexTuple
addItemPointersToLeafTuple(GinState *ginstate,
IndexTuple old,
ItemPointerData *items, uint32 nitem,
GinStatsData *buildStats, Buffer buffer)
{
OffsetNumber attnum;
Datum key;
GinNullCategory category;
IndexTuple res;
ItemPointerData *newItems,
*oldItems;
int oldNPosting,
newNPosting;
GinPostingList *compressedList;
Assert(!GinIsPostingTree(old));
attnum = gintuple_get_attrnum(ginstate, old);
key = gintuple_get_key(ginstate, old, &category);
/* merge the old and new posting lists */
oldItems = ginReadTuple(ginstate, attnum, old, &oldNPosting);
newItems = ginMergeItemPointers(items, nitem,
oldItems, oldNPosting,
&newNPosting);
/* Compress the posting list, and try to a build tuple with room for it */
res = NULL;
compressedList = ginCompressPostingList(newItems, newNPosting, GinMaxItemSize,
NULL);
pfree(newItems);
if (compressedList)
{
res = GinFormTuple(ginstate, attnum, key, category,
(char *) compressedList,
SizeOfGinPostingList(compressedList),
newNPosting,
false);
pfree(compressedList);
}
if (!res)
{
/* posting list would be too big, convert to posting tree */
BlockNumber postingRoot;
/*
* Initialize posting tree with the old tuple's posting list. It's
* surely small enough to fit on one posting-tree page, and should
* already be in order with no duplicates.
*/
postingRoot = createPostingTree(ginstate->index,
oldItems,
oldNPosting,
buildStats,
buffer);
/* Now insert the TIDs-to-be-added into the posting tree */
ginInsertItemPointers(ginstate->index, postingRoot,
items, nitem,
buildStats);
/* And build a new posting-tree-only result tuple */
res = GinFormTuple(ginstate, attnum, key, category, NULL, 0, 0, true);
GinSetPostingTree(res, postingRoot);
}
pfree(oldItems);
return res;
}
/*
* returns modified page or NULL if page isn't modified.
* Function works with original page until first change is occurred,
* then page is copied into temporary one.
*/
static Page
ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint32 *nroot)
{
Page origpage = BufferGetPage(buffer),
tmppage;
OffsetNumber i,
maxoff = PageGetMaxOffsetNumber(origpage);
tmppage = origpage;
*nroot = 0;
for (i = FirstOffsetNumber; i <= maxoff; i++)
{
IndexTuple itup = (IndexTuple) PageGetItem(tmppage, PageGetItemId(tmppage, i));
if (GinIsPostingTree(itup))
{
/*
* store posting tree's roots for further processing, we can't
* vacuum it just now due to risk of deadlocks with scans/inserts
*/
roots[*nroot] = GinGetDownlink(itup);
(*nroot)++;
}
else if (GinGetNPosting(itup) > 0)
{
/*
* if we already create temporary page, we will make changes in
* place
*/
ItemPointerData *cleaned = (tmppage == origpage) ? NULL : GinGetPosting(itup);
uint32 newN = ginVacuumPostingList(gvs, GinGetPosting(itup), GinGetNPosting(itup), &cleaned);
if (GinGetNPosting(itup) != newN)
{
OffsetNumber attnum;
Datum key;
GinNullCategory category;
/*
* Some ItemPointers was deleted, so we should remake our
* tuple
*/
if (tmppage == origpage)
{
/*
* On first difference we create temporary page in memory
* and copies content in to it.
*/
tmppage = PageGetTempPageCopy(origpage);
if (newN > 0)
{
Size pos = ((char *) GinGetPosting(itup)) - ((char *) origpage);
memcpy(tmppage + pos, cleaned, sizeof(ItemPointerData) * newN);
}
pfree(cleaned);
/* set itup pointer to new page */
itup = (IndexTuple) PageGetItem(tmppage, PageGetItemId(tmppage, i));
}
attnum = gintuple_get_attrnum(&gvs->ginstate, itup);
key = gintuple_get_key(&gvs->ginstate, itup, &category);
itup = GinFormTuple(&gvs->ginstate, attnum, key, category,
GinGetPosting(itup), newN, true);
PageIndexTupleDelete(tmppage, i);
if (PageAddItem(tmppage, (Item) itup, IndexTupleSize(itup), i, false, false) != i)
elog(ERROR, "failed to add item to index page in \"%s\"",
RelationGetRelationName(gvs->index));
pfree(itup);
}
}
}
return (tmppage == origpage) ? NULL : tmppage;
}
/*
* Adds array of item pointers to tuple's posting list, or
* creates posting tree and tuple pointing to tree in case
* of not enough space. Max size of tuple is defined in
* GinFormTuple(). Returns a new, modified index tuple.
* items[] must be in sorted order with no duplicates.
*/
static IndexTuple
addItemPointersToLeafTuple(GinState *ginstate,
IndexTuple old,
ItemPointerData *items, uint32 nitem,
GinStatsData *buildStats)
{
OffsetNumber attnum;
Datum key;
GinNullCategory category;
IndexTuple res;
Assert(!GinIsPostingTree(old));
attnum = gintuple_get_attrnum(ginstate, old);
key = gintuple_get_key(ginstate, old, &category);
/* try to build tuple with room for all the items */
res = GinFormTuple(ginstate, attnum, key, category,
NULL, nitem + GinGetNPosting(old),
false);
if (res)
{
/* good, small enough */
uint32 newnitem;
/* fill in the posting list with union of old and new TIDs */
newnitem = ginMergeItemPointers(GinGetPosting(res),
GinGetPosting(old),
GinGetNPosting(old),
items, nitem);
/* merge might have eliminated some duplicate items */
GinShortenTuple(res, newnitem);
}
else
{
/* posting list would be too big, convert to posting tree */
BlockNumber postingRoot;
/*
* Initialize posting tree with the old tuple's posting list. It's
* surely small enough to fit on one posting-tree page, and should
* already be in order with no duplicates.
*/
postingRoot = createPostingTree(ginstate->index,
GinGetPosting(old),
GinGetNPosting(old),
buildStats);
/* Now insert the TIDs-to-be-added into the posting tree */
ginInsertItemPointers(ginstate->index, postingRoot,
items, nitem,
buildStats);
/* And build a new posting-tree-only result tuple */
res = GinFormTuple(ginstate, attnum, key, category, NULL, 0, true);
GinSetPostingTree(res, postingRoot);
}
return res;
}
/*
* returns modified page or NULL if page isn't modified.
* Function works with original page until first change is occurred,
* then page is copied into temporary one.
*/
static Page
ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint32 *nroot)
{
Page origpage = BufferGetPage(buffer),
tmppage;
OffsetNumber i,
maxoff = PageGetMaxOffsetNumber(origpage);
tmppage = origpage;
*nroot = 0;
for (i = FirstOffsetNumber; i <= maxoff; i++)
{
IndexTuple itup = (IndexTuple) PageGetItem(tmppage, PageGetItemId(tmppage, i));
if (GinIsPostingTree(itup))
{
/*
* store posting tree's roots for further processing, we can't
* vacuum it just now due to risk of deadlocks with scans/inserts
*/
roots[*nroot] = GinGetDownlink(itup);
(*nroot)++;
}
else if (GinGetNPosting(itup) > 0)
{
int nitems;
ItemPointer items_orig;
bool free_items_orig;
ItemPointer items;
/* Get list of item pointers from the tuple. */
if (GinItupIsCompressed(itup))
{
items_orig = ginPostingListDecode((GinPostingList *) GinGetPosting(itup), &nitems);
free_items_orig = true;
}
else
{
items_orig = (ItemPointer) GinGetPosting(itup);
nitems = GinGetNPosting(itup);
free_items_orig = false;
}
/* Remove any items from the list that need to be vacuumed. */
items = ginVacuumItemPointers(gvs, items_orig, nitems, &nitems);
if (free_items_orig)
pfree(items_orig);
/* If any item pointers were removed, recreate the tuple. */
if (items)
{
OffsetNumber attnum;
Datum key;
GinNullCategory category;
GinPostingList *plist;
int plistsize;
if (nitems > 0)
{
plist = ginCompressPostingList(items, nitems, GinMaxItemSize, NULL);
plistsize = SizeOfGinPostingList(plist);
}
else
{
plist = NULL;
plistsize = 0;
}
/*
* if we already created a temporary page, make changes in
* place
*/
if (tmppage == origpage)
{
/*
* On first difference, create a temporary copy of the
* page and copy the tuple's posting list to it.
*/
tmppage = PageGetTempPageCopy(origpage);
/* set itup pointer to new page */
itup = (IndexTuple) PageGetItem(tmppage, PageGetItemId(tmppage, i));
}
attnum = gintuple_get_attrnum(&gvs->ginstate, itup);
key = gintuple_get_key(&gvs->ginstate, itup, &category);
itup = GinFormTuple(&gvs->ginstate, attnum, key, category,
(char *) plist, plistsize,
nitems, true);
if (plist)
pfree(plist);
PageIndexTupleDelete(tmppage, i);
if (PageAddItem(tmppage, (Item) itup, IndexTupleSize(itup), i, false, false) != i)
elog(ERROR, "failed to add item to index page in \"%s\"",
RelationGetRelationName(gvs->index));
pfree(itup);
pfree(items);
}
}
}
return (tmppage == origpage) ? NULL : tmppage;
}
/*
* 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);
}
