/*
* Form a non-leaf entry tuple by copying the key data from the given tuple,
* which can be either a leaf or non-leaf entry tuple.
*
* Any posting list in the source tuple is not copied. The specified child
* block number is inserted into t_tid.
*/
static IndexTuple
GinFormInteriorTuple(IndexTuple itup, Page page, BlockNumber childblk)
{
IndexTuple nitup;
if (GinPageIsLeaf(page) && !GinIsPostingTree(itup))
{
/* Tuple contains a posting list, just copy stuff before that */
uint32 origsize = GinGetPostingOffset(itup);
origsize = MAXALIGN(origsize);
nitup = (IndexTuple) palloc(origsize);
memcpy(nitup, itup, origsize);
/* ... be sure to fix the size header field ... */
nitup->t_info &= ~INDEX_SIZE_MASK;
nitup->t_info |= origsize;
}
else
{
/* Copy the tuple as-is */
nitup = (IndexTuple) palloc(IndexTupleSize(itup));
memcpy(nitup, itup, IndexTupleSize(itup));
}
/* Now insert the correct downlink */
GinSetDownlink(nitup, childblk);
return nitup;
}
/*
* Inserts only one entry to the index, but it can add more than 1 ItemPointer.
*/
static void
ginEntryInsert(Relation index, GinState *ginstate, Datum value, ItemPointerData *items, uint32 nitem, bool isBuild)
{
GinBtreeData btree;
GinBtreeStack *stack;
IndexTuple itup;
Page page;
prepareEntryScan(&btree, index, value, ginstate);
stack = ginFindLeafPage(&btree, NULL);
page = BufferGetPage(stack->buffer);
if (btree.findItem(&btree, stack))
{
/* found entry */
itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stack->off));
if (GinIsPostingTree(itup))
{
/* lock root of posting tree */
GinPostingTreeScan *gdi;
BlockNumber rootPostingTree = GinGetPostingTree(itup);
/* release all stack */
LockBuffer(stack->buffer, GIN_UNLOCK);
freeGinBtreeStack(stack);
/* insert into posting tree */
gdi = prepareScanPostingTree(index, rootPostingTree, FALSE);
gdi->btree.isBuild = isBuild;
insertItemPointer(gdi, items, nitem);
return;
}
itup = addItemPointersToTuple(index, ginstate, stack, itup, items, nitem, isBuild);
btree.isDelete = TRUE;
}
else
{
/* We suppose, that tuple can store at list one itempointer */
itup = GinFormTuple(ginstate, value, items, 1);
if (itup == NULL || IndexTupleSize(itup) >= GinMaxItemSize)
elog(ERROR, "huge tuple");
if (nitem > 1)
{
IndexTuple previtup = itup;
itup = addItemPointersToTuple(index, ginstate, stack, previtup, items + 1, nitem - 1, isBuild);
pfree(previtup);
}
}
btree.entry = itup;
ginInsertValue(&btree, stack);
pfree(itup);
}
/*
* Insert one or more heap TIDs associated with the given key value.
* This will either add a single key entry, or enlarge a pre-existing entry.
*
* During an index build, buildStats is non-null and the counters
* it contains should be incremented as needed.
*/
void
ginEntryInsert(GinState *ginstate,
OffsetNumber attnum, Datum key, GinNullCategory category,
ItemPointerData *items, uint32 nitem,
GinStatsData *buildStats)
{
GinBtreeData btree;
GinBtreeStack *stack;
IndexTuple itup;
Page page;
/* During index build, count the to-be-inserted entry */
if (buildStats)
buildStats->nEntries++;
ginPrepareEntryScan(&btree, attnum, key, category, ginstate);
stack = ginFindLeafPage(&btree, GIN_ROOT_BLKNO, false);
page = BufferGetPage(stack->buffer);
if (btree.findItem(&btree, stack))
{
/* found pre-existing entry */
itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stack->off));
if (GinIsPostingTree(itup))
{
/* add entries to existing posting tree */
BlockNumber rootPostingTree = GinGetPostingTree(itup);
/* release all stack */
LockBuffer(stack->buffer, GIN_UNLOCK);
freeGinBtreeStack(stack);
/* insert into posting tree */
ginInsertItemPointers(ginstate->index, rootPostingTree,
items, nitem,
buildStats);
return;
}
/* modify an existing leaf entry */
itup = addItemPointersToLeafTuple(ginstate, itup,
items, nitem, buildStats);
btree.isDelete = TRUE;
}
else
{
/* no match, so construct a new leaf entry */
itup = buildFreshLeafTuple(ginstate, attnum, key, category,
items, nitem, buildStats);
}
/* Insert the new or modified leaf tuple */
btree.entry = itup;
ginInsertValue(&btree, stack, buildStats);
pfree(itup);
}
/*
* Returns new tuple with copied value from source tuple.
* New tuple will not store posting list
*/
static IndexTuple
copyIndexTuple(IndexTuple itup, Page page)
{
IndexTuple nitup;
if (GinPageIsLeaf(page) && !GinIsPostingTree(itup))
{
nitup = (IndexTuple) palloc(MAXALIGN(GinGetOrigSizePosting(itup)));
memcpy(nitup, itup, GinGetOrigSizePosting(itup));
nitup->t_info &= ~INDEX_SIZE_MASK;
nitup->t_info |= GinGetOrigSizePosting(itup);
}
else
{
nitup = (IndexTuple) palloc(MAXALIGN(IndexTupleSize(itup)));
memcpy(nitup, itup, IndexTupleSize(itup));
}
return nitup;
}
/*
* 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;
}
/*
* Start* functions setup state of searches: find correct buffer and locks it,
* Stop* functions unlock buffer (but don't release!)
*/
static void
startScanEntry(Relation index, GinState *ginstate, GinScanEntry entry)
{
GinBtreeData btreeEntry;
GinBtreeStack *stackEntry;
Page page;
bool needUnlock = TRUE;
if (entry->master != NULL)
{
entry->isFinished = entry->master->isFinished;
return;
}
/*
* We should find entry, and begin scan of posting tree
* or just store posting list in memory
*/
prepareEntryScan(&btreeEntry, index, entry->entry, ginstate);
btreeEntry.searchMode = TRUE;
stackEntry = ginFindLeafPage(&btreeEntry, NULL);
page = BufferGetPage(stackEntry->buffer);
entry->isFinished = TRUE;
entry->buffer = InvalidBuffer;
entry->offset = InvalidOffsetNumber;
entry->list = NULL;
entry->nlist = 0;
entry->reduceResult = FALSE;
entry->predictNumberResult = 0;
if (btreeEntry.findItem(&btreeEntry, stackEntry))
{
IndexTuple itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stackEntry->off));
if (GinIsPostingTree(itup))
{
BlockNumber rootPostingTree = GinGetPostingTree(itup);
GinPostingTreeScan *gdi;
Page page;
LockBuffer(stackEntry->buffer, GIN_UNLOCK);
needUnlock = FALSE;
gdi = prepareScanPostingTree(index, rootPostingTree, TRUE);
entry->buffer = scanBeginPostingTree(gdi);
/*
* We keep buffer pinned because we need to prevent deletition
* page during scan. See GIN's vacuum implementation. RefCount
* is increased to keep buffer pinned after freeGinBtreeStack() call.
*/
IncrBufferRefCount(entry->buffer);
page = BufferGetPage(entry->buffer);
entry->predictNumberResult = gdi->stack->predictNumber * GinPageGetOpaque(page)->maxoff;
/*
* Keep page content in memory to prevent durable page locking
*/
entry->list = (ItemPointerData *) palloc( BLCKSZ );
entry->nlist = GinPageGetOpaque(page)->maxoff;
memcpy( entry->list, GinDataPageGetItem(page, FirstOffsetNumber),
GinPageGetOpaque(page)->maxoff * sizeof(ItemPointerData) );
LockBuffer(entry->buffer, GIN_UNLOCK);
freeGinBtreeStack(gdi->stack);
pfree(gdi);
entry->isFinished = FALSE;
}
else if (GinGetNPosting(itup) > 0)
{
entry->nlist = GinGetNPosting(itup);
entry->list = (ItemPointerData *) palloc(sizeof(ItemPointerData) * entry->nlist);
memcpy(entry->list, GinGetPosting(itup), sizeof(ItemPointerData) * entry->nlist);
entry->isFinished = FALSE;
}
}
if (needUnlock)
LockBuffer(stackEntry->buffer, GIN_UNLOCK);
freeGinBtreeStack(stackEntry);
}
/*
* Inserts only one entry to the index, but it can add more than 1 ItemPointer.
*
* During an index build, buildStats is non-null and the counters
* it contains should be incremented as needed.
*/
void
ginEntryInsert(Relation index, GinState *ginstate,
OffsetNumber attnum, Datum value,
ItemPointerData *items, uint32 nitem,
GinStatsData *buildStats)
{
GinBtreeData btree;
GinBtreeStack *stack;
IndexTuple itup;
Page page;
/* During index build, count the to-be-inserted entry */
if (buildStats)
buildStats->nEntries++;
ginPrepareEntryScan(&btree, index, attnum, value, ginstate);
stack = ginFindLeafPage(&btree, NULL);
page = BufferGetPage(stack->buffer);
if (btree.findItem(&btree, stack))
{
/* found entry */
itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stack->off));
if (GinIsPostingTree(itup))
{
/* lock root of posting tree */
GinPostingTreeScan *gdi;
BlockNumber rootPostingTree = GinGetPostingTree(itup);
/* release all stack */
LockBuffer(stack->buffer, GIN_UNLOCK);
freeGinBtreeStack(stack);
/* insert into posting tree */
gdi = ginPrepareScanPostingTree(index, rootPostingTree, FALSE);
gdi->btree.isBuild = (buildStats != NULL);
ginInsertItemPointer(gdi, items, nitem, buildStats);
pfree(gdi);
return;
}
itup = addItemPointersToTuple(index, ginstate, stack, itup,
items, nitem, buildStats);
btree.isDelete = TRUE;
}
else
{
/* We suppose that tuple can store at least one itempointer */
itup = GinFormTuple(index, ginstate, attnum, value, items, 1, true);
if (nitem > 1)
{
/* Add the rest, making a posting tree if necessary */
IndexTuple previtup = itup;
itup = addItemPointersToTuple(index, ginstate, stack, previtup,
items + 1, nitem - 1, buildStats);
pfree(previtup);
}
}
btree.entry = itup;
ginInsertValue(&btree, stack, buildStats);
pfree(itup);
}
