/* * 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 = ginCompareAttEntries(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; }
/* * Adds array of item pointers to tuple's posting list or * creates posting tree and tuple pointed to tree in a case * of not enough space. Max size of tuple is defined in * GinFormTuple(). */ static IndexTuple addItemPointersToTuple(Relation index, GinState *ginstate, GinBtreeStack *stack, IndexTuple old, ItemPointerData *items, uint32 nitem, GinStatsData *buildStats) { Datum key = gin_index_getattr(ginstate, old); OffsetNumber attnum = gintuple_get_attrnum(ginstate, old); IndexTuple res = GinFormTuple(index, ginstate, attnum, key, NULL, nitem + GinGetNPosting(old), false); if (res) { /* good, small enough */ uint32 newnitem; newnitem = ginMergeItemPointers(GinGetPosting(res), GinGetPosting(old), GinGetNPosting(old), items, nitem); /* merge might have eliminated some duplicate items */ GinShortenTuple(res, newnitem); } else { BlockNumber postingRoot; GinPostingTreeScan *gdi; /* posting list becomes big, so we need to make posting's tree */ res = GinFormTuple(index, ginstate, attnum, key, NULL, 0, true); postingRoot = createPostingTree(index, GinGetPosting(old), GinGetNPosting(old)); GinSetPostingTree(res, postingRoot); gdi = ginPrepareScanPostingTree(index, postingRoot, FALSE); gdi->btree.isBuild = (buildStats != NULL); ginInsertItemPointer(gdi, items, nitem, buildStats); pfree(gdi); /* During index build, count the newly-added data page */ if (buildStats) buildStats->nDataPages++; } return res; }
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; }
/* * 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] = GinItemPointerGetBlockNumber(&itup->t_tid); (*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) { Datum value; OffsetNumber attnum; /* * 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)); } value = gin_index_getattr(&gvs->ginstate, itup); attnum = gintuple_get_attrnum(&gvs->ginstate, itup); itup = GinFormTuple(gvs->index, &gvs->ginstate, attnum, value, 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; }
/* * 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); }