From c2b175b94851e59765cc87243d8faf923e3d820b Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Thu, 3 Oct 2013 11:47:17 +0300
Subject: [PATCH] Minor GIN code refactoring.
It makes for cleaner code to have separate Get/Add functions for PostingItems
and ItemPointers. A few callsites that have to deal with both types need to
be duplicated because of this, but all the callers have to know which one
they're dealing with anyway. Overall, this reduces the amount of casting
required.
Extracted from Alexander Korotkov's larger patch to change the data page
format.
---
src/backend/access/gin/gindatapage.c | 121 +++++++++++++++++++--------
src/backend/access/gin/ginget.c | 12 +--
src/backend/access/gin/ginvacuum.c | 6 +-
src/backend/access/gin/ginxlog.c | 28 ++++---
src/include/access/gin_private.h | 11 ++-
5 files changed, 123 insertions(+), 55 deletions(-)
diff --git a/src/backend/access/gin/gindatapage.c b/src/backend/access/gin/gindatapage.c
index f017de0cdc8..2c6447d7faa 100644
--- a/src/backend/access/gin/gindatapage.c
+++ b/src/backend/access/gin/gindatapage.c
@@ -105,7 +105,7 @@ dataLocateItem(GinBtree btree, GinBtreeStack *stack)
{
OffsetNumber mid = low + ((high - low) / 2);
- pitem = (PostingItem *) GinDataPageGetItem(page, mid);
+ pitem = GinDataPageGetPostingItem(page, mid);
if (mid == maxoff)
{
@@ -117,7 +117,7 @@ dataLocateItem(GinBtree btree, GinBtreeStack *stack)
}
else
{
- pitem = (PostingItem *) GinDataPageGetItem(page, mid);
+ pitem = GinDataPageGetPostingItem(page, mid);
result = ginCompareItemPointers(btree->items + btree->curitem, &(pitem->key));
}
@@ -135,7 +135,7 @@ dataLocateItem(GinBtree btree, GinBtreeStack *stack)
Assert(high >= FirstOffsetNumber && high <= maxoff);
stack->off = high;
- pitem = (PostingItem *) GinDataPageGetItem(page, high);
+ pitem = GinDataPageGetPostingItem(page, high);
return PostingItemGetBlockNumber(pitem);
}
@@ -176,7 +176,8 @@ dataLocateLeafItem(GinBtree btree, GinBtreeStack *stack)
{
OffsetNumber mid = low + ((high - low) / 2);
- result = ginCompareItemPointers(btree->items + btree->curitem, (ItemPointer) GinDataPageGetItem(page, mid));
+ result = ginCompareItemPointers(btree->items + btree->curitem,
+ GinDataPageGetItemPointer(page, mid));
if (result == 0)
{
@@ -210,7 +211,7 @@ dataFindChildPtr(GinBtree btree, Page page, BlockNumber blkno, OffsetNumber stor
/* if page isn't changed, we return storedOff */
if (storedOff >= FirstOffsetNumber && storedOff <= maxoff)
{
- pitem = (PostingItem *) GinDataPageGetItem(page, storedOff);
+ pitem = GinDataPageGetPostingItem(page, storedOff);
if (PostingItemGetBlockNumber(pitem) == blkno)
return storedOff;
@@ -220,7 +221,7 @@ dataFindChildPtr(GinBtree btree, Page page, BlockNumber blkno, OffsetNumber stor
*/
for (i = storedOff + 1; i <= maxoff; i++)
{
- pitem = (PostingItem *) GinDataPageGetItem(page, i);
+ pitem = GinDataPageGetPostingItem(page, i);
if (PostingItemGetBlockNumber(pitem) == blkno)
return i;
}
@@ -231,7 +232,7 @@ dataFindChildPtr(GinBtree btree, Page page, BlockNumber blkno, OffsetNumber stor
/* last chance */
for (i = FirstOffsetNumber; i <= maxoff; i++)
{
- pitem = (PostingItem *) GinDataPageGetItem(page, i);
+ pitem = GinDataPageGetPostingItem(page, i);
if (PostingItemGetBlockNumber(pitem) == blkno)
return i;
}
@@ -251,33 +252,62 @@ dataGetLeftMostPage(GinBtree btree, Page page)
Assert(GinPageIsData(page));
Assert(GinPageGetOpaque(page)->maxoff >= FirstOffsetNumber);
- pitem = (PostingItem *) GinDataPageGetItem(page, FirstOffsetNumber);
+ pitem = GinDataPageGetPostingItem(page, FirstOffsetNumber);
return PostingItemGetBlockNumber(pitem);
}
/*
- * add ItemPointer or PostingItem to page. data should point to
- * correct value! depending on leaf or non-leaf page
+ * add ItemPointer to a leaf page.
*/
void
-GinDataPageAddItem(Page page, void *data, OffsetNumber offset)
+GinDataPageAddItemPointer(Page page, ItemPointer data, OffsetNumber offset)
{
OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
char *ptr;
+ Assert(GinPageIsLeaf(page));
+
+ if (offset == InvalidOffsetNumber)
+ {
+ ptr = (char *) GinDataPageGetItemPointer(page, maxoff + 1);
+ }
+ else
+ {
+ ptr = (char *) GinDataPageGetItemPointer(page, offset);
+ if (maxoff + 1 - offset != 0)
+ memmove(ptr + sizeof(ItemPointerData),
+ ptr,
+ (maxoff - offset + 1) * sizeof(ItemPointerData));
+ }
+ memcpy(ptr, data, sizeof(ItemPointerData));
+
+ GinPageGetOpaque(page)->maxoff++;
+}
+
+/*
+ * add PostingItem to a non-leaf page.
+ */
+void
+GinDataPageAddPostingItem(Page page, PostingItem *data, OffsetNumber offset)
+{
+ OffsetNumber maxoff = GinPageGetOpaque(page)->maxoff;
+ char *ptr;
+
+ Assert(!GinPageIsLeaf(page));
+
if (offset == InvalidOffsetNumber)
{
- ptr = GinDataPageGetItem(page, maxoff + 1);
+ ptr = (char *) GinDataPageGetPostingItem(page, maxoff + 1);
}
else
{
- ptr = GinDataPageGetItem(page, offset);
+ ptr = (char *) GinDataPageGetPostingItem(page, offset);
if (maxoff + 1 - offset != 0)
- memmove(ptr + GinSizeOfDataPageItem(page),
+ memmove(ptr + sizeof(PostingItem),
ptr,
- (maxoff - offset + 1) * GinSizeOfDataPageItem(page));
+ (maxoff - offset + 1) * sizeof(PostingItem));
}
- memcpy(ptr, data, GinSizeOfDataPageItem(page));
+ memcpy(ptr, data, sizeof(PostingItem));
GinPageGetOpaque(page)->maxoff++;
}
@@ -294,7 +324,8 @@ GinPageDeletePostingItem(Page page, OffsetNumber offset)
Assert(offset >= FirstOffsetNumber && offset <= maxoff);
if (offset != maxoff)
- memmove(GinDataPageGetItem(page, offset), GinDataPageGetItem(page, offset + 1),
+ memmove(GinDataPageGetPostingItem(page, offset),
+ GinDataPageGetPostingItem(page, offset + 1),
sizeof(PostingItem) * (maxoff - offset));
GinPageGetOpaque(page)->maxoff--;
@@ -342,7 +373,7 @@ dataPrepareData(GinBtree btree, Page page, OffsetNumber off)
if (!GinPageIsLeaf(page) && btree->rightblkno != InvalidBlockNumber)
{
- PostingItem *pitem = (PostingItem *) GinDataPageGetItem(page, off);
+ PostingItem *pitem = GinDataPageGetPostingItem(page, off);
PostingItemSetBlockNumber(pitem, btree->rightblkno);
ret = btree->rightblkno;
@@ -418,7 +449,7 @@ dataPlaceToPage(GinBtree btree, Buffer buf, OffsetNumber off, XLogRecData **prda
while (btree->curitem < btree->nitem)
{
- GinDataPageAddItem(page, btree->items + btree->curitem, off);
+ GinDataPageAddItemPointer(page, btree->items + btree->curitem, off);
off++;
btree->curitem++;
}
@@ -427,12 +458,12 @@ dataPlaceToPage(GinBtree btree, Buffer buf, OffsetNumber off, XLogRecData **prda
}
else
{
- GinDataPageAddItem(page, btree->items + btree->curitem, off);
+ GinDataPageAddItemPointer(page, btree->items + btree->curitem, off);
btree->curitem++;
}
}
else
- GinDataPageAddItem(page, &(btree->pitem), off);
+ GinDataPageAddPostingItem(page, &(btree->pitem), off);
}
/*
@@ -448,6 +479,7 @@ dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRe
OffsetNumber separator;
ItemPointer bound;
Page lpage = PageGetTempPageCopy(BufferGetPage(lbuf));
+ bool isleaf = GinPageIsLeaf(lpage);
ItemPointerData oldbound = *GinDataPageGetRightBound(lpage);
int sizeofitem = GinSizeOfDataPageItem(lpage);
OffsetNumber maxoff = GinPageGetOpaque(lpage)->maxoff;
@@ -469,10 +501,20 @@ dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRe
InvalidOffsetNumber : PostingItemGetBlockNumber(&(btree->pitem));
data.updateBlkno = dataPrepareData(btree, lpage, off);
- memcpy(vector, GinDataPageGetItem(lpage, FirstOffsetNumber),
- maxoff * sizeofitem);
+ if (isleaf)
+ {
+ memcpy(vector,
+ GinDataPageGetItemPointer(lpage, FirstOffsetNumber),
+ maxoff * sizeof(ItemPointerData));
+ }
+ else
+ {
+ memcpy(vector,
+ GinDataPageGetPostingItem(lpage, FirstOffsetNumber),
+ maxoff * sizeof(PostingItem));
+ }
- if (GinPageIsLeaf(lpage) && GinPageRightMost(lpage) && off > GinPageGetOpaque(lpage)->maxoff)
+ if (isleaf && GinPageRightMost(lpage) && off > GinPageGetOpaque(lpage)->maxoff)
{
nCopied = 0;
while (btree->curitem < btree->nitem &&
@@ -491,7 +533,7 @@ dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRe
ptr = vector + (off - 1) * sizeofitem;
if (maxoff + 1 - off != 0)
memmove(ptr + sizeofitem, ptr, (maxoff - off + 1) * sizeofitem);
- if (GinPageIsLeaf(lpage))
+ if (isleaf)
{
memcpy(ptr, btree->items + btree->curitem, sizeofitem);
btree->curitem++;
@@ -514,19 +556,32 @@ dataSplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogRe
GinInitPage(rpage, GinPageGetOpaque(lpage)->flags, pageSize);
GinInitPage(lpage, GinPageGetOpaque(rpage)->flags, pageSize);
- memcpy(GinDataPageGetItem(lpage, FirstOffsetNumber), vector, separator * sizeofitem);
+ if (isleaf)
+ memcpy(GinDataPageGetItemPointer(lpage, FirstOffsetNumber),
+ vector, separator * sizeof(ItemPointerData));
+ else
+ memcpy(GinDataPageGetPostingItem(lpage, FirstOffsetNumber),
+ vector, separator * sizeof(PostingItem));
+
GinPageGetOpaque(lpage)->maxoff = separator;
- memcpy(GinDataPageGetItem(rpage, FirstOffsetNumber),
- vector + separator * sizeofitem, (maxoff - separator) * sizeofitem);
+ if (isleaf)
+ memcpy(GinDataPageGetItemPointer(rpage, FirstOffsetNumber),
+ vector + separator * sizeof(ItemPointerData),
+ (maxoff - separator) * sizeof(ItemPointerData));
+ else
+ memcpy(GinDataPageGetPostingItem(rpage, FirstOffsetNumber),
+ vector + separator * sizeof(PostingItem),
+ (maxoff - separator) * sizeof(PostingItem));
+
GinPageGetOpaque(rpage)->maxoff = maxoff - separator;
PostingItemSetBlockNumber(&(btree->pitem), BufferGetBlockNumber(lbuf));
if (GinPageIsLeaf(lpage))
- btree->pitem.key = *(ItemPointerData *) GinDataPageGetItem(lpage,
+ btree->pitem.key = *GinDataPageGetItemPointer(lpage,
GinPageGetOpaque(lpage)->maxoff);
else
- btree->pitem.key = ((PostingItem *) GinDataPageGetItem(lpage,
- GinPageGetOpaque(lpage)->maxoff))->key;
+ btree->pitem.key = GinDataPageGetPostingItem(lpage,
+ GinPageGetOpaque(lpage)->maxoff)->key;
btree->rightblkno = BufferGetBlockNumber(rbuf);
/* set up right bound for left page */
@@ -576,11 +631,11 @@ ginDataFillRoot(GinBtree btree, Buffer root, Buffer lbuf, Buffer rbuf)
li.key = *GinDataPageGetRightBound(lpage);
PostingItemSetBlockNumber(&li, BufferGetBlockNumber(lbuf));
- GinDataPageAddItem(page, &li, InvalidOffsetNumber);
+ GinDataPageAddPostingItem(page, &li, InvalidOffsetNumber);
ri.key = *GinDataPageGetRightBound(rpage);
PostingItemSetBlockNumber(&ri, BufferGetBlockNumber(rbuf));
- GinDataPageAddItem(page, &ri, InvalidOffsetNumber);
+ GinDataPageAddPostingItem(page, &ri, InvalidOffsetNumber);
}
void
diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c
index cb17d383bc8..cb779aa7f74 100644
--- a/src/backend/access/gin/ginget.c
+++ b/src/backend/access/gin/ginget.c
@@ -83,7 +83,7 @@ findItemInPostingPage(Page page, ItemPointer item, OffsetNumber *off)
*/
for (*off = FirstOffsetNumber; *off <= maxoff; (*off)++)
{
- res = ginCompareItemPointers(item, (ItemPointer) GinDataPageGetItem(page, *off));
+ res = ginCompareItemPointers(item, GinDataPageGetItemPointer(page, *off));
if (res <= 0)
return true;
@@ -154,7 +154,7 @@ scanPostingTree(Relation index, GinScanEntry scanEntry,
GinPageGetOpaque(page)->maxoff >= FirstOffsetNumber)
{
tbm_add_tuples(scanEntry->matchBitmap,
- (ItemPointer) GinDataPageGetItem(page, FirstOffsetNumber),
+ GinDataPageGetItemPointer(page, FirstOffsetNumber),
GinPageGetOpaque(page)->maxoff, false);
scanEntry->predictNumberResult += GinPageGetOpaque(page)->maxoff;
}
@@ -467,7 +467,8 @@ restartScanEntry:
*/
entry->list = (ItemPointerData *) palloc(BLCKSZ);
entry->nlist = GinPageGetOpaque(page)->maxoff;
- memcpy(entry->list, GinDataPageGetItem(page, FirstOffsetNumber),
+ memcpy(entry->list,
+ GinDataPageGetItemPointer(page, FirstOffsetNumber),
GinPageGetOpaque(page)->maxoff * sizeof(ItemPointerData));
LockBuffer(entry->buffer, GIN_UNLOCK);
@@ -587,8 +588,9 @@ entryGetNextItem(GinState *ginstate, GinScanEntry entry)
* Found position equal to or greater than stored
*/
entry->nlist = GinPageGetOpaque(page)->maxoff;
- memcpy(entry->list, GinDataPageGetItem(page, FirstOffsetNumber),
- GinPageGetOpaque(page)->maxoff * sizeof(ItemPointerData));
+ memcpy(entry->list,
+ GinDataPageGetItemPointer(page, FirstOffsetNumber),
+ GinPageGetOpaque(page)->maxoff * sizeof(ItemPointerData));
LockBuffer(entry->buffer, GIN_UNLOCK);
diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index b84d3a30de3..bda9c60279a 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -210,7 +210,7 @@ ginVacuumPostingTreeLeaves(GinVacuumState *gvs, BlockNumber blkno, bool isRoot,
for (i = FirstOffsetNumber; i <= GinPageGetOpaque(page)->maxoff; i++)
{
- PostingItem *pitem = (PostingItem *) GinDataPageGetItem(page, i);
+ PostingItem *pitem = GinDataPageGetPostingItem(page, i);
if (ginVacuumPostingTreeLeaves(gvs, PostingItemGetBlockNumber(pitem), FALSE, NULL))
isChildHasVoid = TRUE;
@@ -283,7 +283,7 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
#ifdef USE_ASSERT_CHECKING
do
{
- PostingItem *tod = (PostingItem *) GinDataPageGetItem(parentPage, myoff);
+ PostingItem *tod = GinDataPageGetPostingItem(parentPage, myoff);
Assert(PostingItemGetBlockNumber(tod) == deleteBlkno);
} while (0);
@@ -422,7 +422,7 @@ ginScanToDelete(GinVacuumState *gvs, BlockNumber blkno, bool isRoot, DataPageDel
me->blkno = blkno;
for (i = FirstOffsetNumber; i <= GinPageGetOpaque(page)->maxoff; i++)
{
- PostingItem *pitem = (PostingItem *) GinDataPageGetItem(page, i);
+ PostingItem *pitem = GinDataPageGetPostingItem(page, i);
if (ginScanToDelete(gvs, PostingItemGetBlockNumber(pitem), FALSE, me, i))
i--;
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c
index 5daabb0eef9..4d0ccb876f2 100644
--- a/src/backend/access/gin/ginxlog.c
+++ b/src/backend/access/gin/ginxlog.c
@@ -189,7 +189,7 @@ ginRedoInsert(XLogRecPtr lsn, XLogRecord *record)
Assert(data->updateBlkno == InvalidBlockNumber);
for (i = 0; i < data->nitem; i++)
- GinDataPageAddItem(page, items + i, data->offset + i);
+ GinDataPageAddItemPointer(page, &items[i], data->offset + i);
}
else
{
@@ -200,13 +200,13 @@ ginRedoInsert(XLogRecPtr lsn, XLogRecord *record)
if (data->updateBlkno != InvalidBlockNumber)
{
/* update link to right page after split */
- pitem = (PostingItem *) GinDataPageGetItem(page, data->offset);
+ pitem = GinDataPageGetPostingItem(page, data->offset);
PostingItemSetBlockNumber(pitem, data->updateBlkno);
}
pitem = (PostingItem *) (XLogRecGetData(record) + sizeof(ginxlogInsert));
- GinDataPageAddItem(page, pitem, data->offset);
+ GinDataPageAddPostingItem(page, pitem, data->offset);
}
}
else
@@ -286,22 +286,28 @@ ginRedoSplit(XLogRecPtr lsn, XLogRecord *record)
for (i = 0; i < data->separator; i++)
{
- GinDataPageAddItem(lpage, ptr, InvalidOffsetNumber);
+ if (data->isLeaf)
+ GinDataPageAddItemPointer(lpage, (ItemPointer) ptr, InvalidOffsetNumber);
+ else
+ GinDataPageAddPostingItem(lpage, (PostingItem *) ptr, InvalidOffsetNumber);
ptr += sizeofitem;
}
for (i = data->separator; i < data->nitem; i++)
{
- GinDataPageAddItem(rpage, ptr, InvalidOffsetNumber);
+ if (data->isLeaf)
+ GinDataPageAddItemPointer(rpage, (ItemPointer) ptr, InvalidOffsetNumber);
+ else
+ GinDataPageAddPostingItem(rpage, (PostingItem *) ptr, InvalidOffsetNumber);
ptr += sizeofitem;
}
/* set up right key */
bound = GinDataPageGetRightBound(lpage);
if (data->isLeaf)
- *bound = *(ItemPointerData *) GinDataPageGetItem(lpage, GinPageGetOpaque(lpage)->maxoff);
+ *bound = *GinDataPageGetItemPointer(lpage, GinPageGetOpaque(lpage)->maxoff);
else
- *bound = ((PostingItem *) GinDataPageGetItem(lpage, GinPageGetOpaque(lpage)->maxoff))->key;
+ *bound = GinDataPageGetPostingItem(lpage, GinPageGetOpaque(lpage)->maxoff)->key;
bound = GinDataPageGetRightBound(rpage);
*bound = data->rightbound;
@@ -803,11 +809,11 @@ ginContinueSplit(ginIncompleteSplit *split)
PostingItemSetBlockNumber(&(btree.pitem), split->leftBlkno);
if (GinPageIsLeaf(page))
- btree.pitem.key = *(ItemPointerData *) GinDataPageGetItem(page,
- GinPageGetOpaque(page)->maxoff);
+ btree.pitem.key = *GinDataPageGetItemPointer(page,
+ GinPageGetOpaque(page)->maxoff);
else
- btree.pitem.key = ((PostingItem *) GinDataPageGetItem(page,
- GinPageGetOpaque(page)->maxoff))->key;
+ btree.pitem.key = GinDataPageGetPostingItem(page,
+ GinPageGetOpaque(page)->maxoff)->key;
}
btree.rightblkno = split->rightBlkno;
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index c603521c957..7af3a870c75 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -232,10 +232,14 @@ typedef signed char GinNullCategory;
#define GinDataPageGetRightBound(page) ((ItemPointer) PageGetContents(page))
#define GinDataPageGetData(page) \
(PageGetContents(page) + MAXALIGN(sizeof(ItemPointerData)))
+/* non-leaf pages contain PostingItems */
+#define GinDataPageGetPostingItem(page, i) \
+ ((PostingItem *) (GinDataPageGetData(page) + ((i)-1) * sizeof(PostingItem)))
+/* leaf pages contain ItemPointers */
+#define GinDataPageGetItemPointer(page, i) \
+ ((ItemPointer) (GinDataPageGetData(page) + ((i)-1) * sizeof(ItemPointerData)))
#define GinSizeOfDataPageItem(page) \
(GinPageIsLeaf(page) ? sizeof(ItemPointerData) : sizeof(PostingItem))
-#define GinDataPageGetItem(page,i) \
- (GinDataPageGetData(page) + ((i)-1) * GinSizeOfDataPageItem(page))
#define GinDataPageGetFreeSpace(page) \
(BLCKSZ - MAXALIGN(SizeOfPageHeaderData) \
@@ -534,7 +538,8 @@ extern uint32 ginMergeItemPointers(ItemPointerData *dst,
ItemPointerData *a, uint32 na,
ItemPointerData *b, uint32 nb);
-extern void GinDataPageAddItem(Page page, void *data, OffsetNumber offset);
+extern void GinDataPageAddItemPointer(Page page, ItemPointer data, OffsetNumber offset);
+extern void GinDataPageAddPostingItem(Page page, PostingItem *data, OffsetNumber offset);
extern void GinPageDeletePostingItem(Page page, OffsetNumber offset);
typedef struct
--
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