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Couple additional functions to fix tree at runtime.

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Need in one more function to handle "my bits moved..."
case. FixBTree is still FALSE.
REL7_1_STABLE
Vadim B. Mikheev 25 years ago
parent ed7910ef44
commit dca0762efc
1 changed files with 324 additions and 7 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 331
      src/backend/access/nbtree/nbtinsert.c

331
src/backend/access/nbtree/nbtinsert.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.78 2001/01/29 07:28:16 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.79 2001/01/31 01:08:36 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@ -37,7 +37,9 @@ typedef struct
extern bool FixBTree;
Buffer _bt_fixroot(Relation rel, Buffer oldrootbuf, bool release);
static void _bt_fixtree(Relation rel, BlockNumber blkno, BTStack stack);
static void _bt_fixtree(Relation rel, BlockNumber blkno);
static BlockNumber _bt_fixlevel(Relation rel, Buffer buf, BlockNumber limit);
static OffsetNumber _bt_getoff(Page page, BlockNumber blkno);
static Buffer _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf);
@ -512,7 +514,7 @@ _bt_insertonpg(Relation rel,
{
blkno = lpageop->btpo_parent;
_bt_relbuf(rel, buf, BT_WRITE);
_bt_fixtree(rel, blkno, NULL);
_bt_fixtree(rel, blkno);
goto formres;
}
}
@ -561,6 +563,10 @@ _bt_insertonpg(Relation rel,
pbuf = _bt_getstackbuf(rel, stack);
if (pbuf == InvalidBuffer)
elog(ERROR, "_bt_getstackbuf: my bits moved right off the end of the world!"
"\n\tRecreate index %s.", RelationGetRelationName(rel));
/* Now we can write and unlock the children */
_bt_wrtbuf(rel, rbuf);
_bt_wrtbuf(rel, buf);
@ -1172,8 +1178,10 @@ _bt_getstackbuf(Relation rel, BTStack stack)
}
/* by here, the item we're looking for moved right at least one page */
if (P_RIGHTMOST(opaque))
elog(FATAL, "_bt_getstackbuf: my bits moved right off the end of the world!"
"\n\tRecreate index %s.", RelationGetRelationName(rel));
{
_bt_relbuf(rel, buf, BT_WRITE);
return(InvalidBuffer);
}
blkno = opaque->btpo_next;
_bt_relbuf(rel, buf, BT_WRITE);
@ -1450,6 +1458,7 @@ _bt_fixroot(Relation rel, Buffer oldrootbuf, bool release)
/* give up left buffer */
_bt_relbuf(rel, leftbuf, BT_WRITE);
pfree(btitem);
leftbuf = rightbuf;
leftpage = rightpage;
leftopaque = rightopaque;
@ -1477,10 +1486,318 @@ _bt_fixroot(Relation rel, Buffer oldrootbuf, bool release)
return(rootbuf);
}
/*
* Using blkno of leftmost page on a level inside tree this func
* checks/fixes tree from this level up to the root page.
*/
static void
_bt_fixtree(Relation rel, BlockNumber blkno, BTStack stack)
_bt_fixtree(Relation rel, BlockNumber blkno)
{
Buffer buf;
Page page;
BTPageOpaque opaque;
BlockNumber pblkno;
elog(ERROR, "bt_fixtree: unimplemented , yet (need to recreate index)");
for ( ; ; )
{
buf = _bt_getbuf(rel, blkno, BT_READ);
page = BufferGetPage(buf);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
if (! P_LEFTMOST(opaque) || P_ISLEAF(opaque))
elog(ERROR, "bt_fixtree: invalid start page (need to recreate index)");
pblkno = opaque->btpo_parent;
/* check/fix entire level */
_bt_fixlevel(rel, buf, InvalidBlockNumber);
/*
* No pins/locks are held here. Re-read start page if its
* btpo_parent pointed to meta page else go up one level.
*/
if (pblkno == BTREE_METAPAGE)
{
buf = _bt_getbuf(rel, blkno, BT_WRITE);
page = BufferGetPage(buf);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
if (P_ISROOT(opaque))
{
/* Tree is Ok now */
_bt_relbuf(rel, buf, BT_WRITE);
return;
}
pblkno = opaque->btpo_parent;
/* Call _bt_fixroot() if there is no upper level */
if (pblkno == BTREE_METAPAGE)
{
buf = _bt_fixroot(rel, buf, true);
_bt_relbuf(rel, buf, BT_WRITE);
return;
}
/* Have to go up one level */
_bt_relbuf(rel, buf, BT_WRITE);
blkno = pblkno;
}
}
}
/*
* Check/fix level starting from page in buffer buf up to block
* limit on *child* level (or till rightmost child page if limit
* is InvalidBlockNumber). Start buffer must be read locked.
* No pins/locks are held on exit. Returns block number of last
* visited/pointing-to-limit page on *check/fix* level.
*/
static BlockNumber
_bt_fixlevel(Relation rel, Buffer buf, BlockNumber limit)
{
BlockNumber blkno = BufferGetBlockNumber(buf);
BlockNumber pblkno = blkno;
Page page;
BTPageOpaque opaque;
BlockNumber cblkno[3];
OffsetNumber coff[3];
Buffer cbuf[3];
Page cpage[3];
BTPageOpaque copaque[3];
BTItem btitem;
int cidx, i;
bool goodbye = false;
char tbuf[BLCKSZ];
page = BufferGetPage(buf);
/* copy page to temp storage */
memmove(tbuf, page, PageGetPageSize(page));
_bt_relbuf(rel, buf, BT_READ);
page = (Page)tbuf;
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
/* Initialize first child data */
coff[0] = P_FIRSTDATAKEY(opaque);
if (coff[0] > PageGetMaxOffsetNumber(page))
elog(ERROR, "bt_fixlevel: invalid maxoff on start page (need to recreate index)");
btitem = (BTItem) PageGetItem(page, PageGetItemId(page, coff[0]));
cblkno[0] = ItemPointerGetBlockNumber(&(btitem->bti_itup.t_tid));
cbuf[0] = _bt_getbuf(rel, cblkno[0], BT_READ);
cpage[0] = BufferGetPage(cbuf[0]);
copaque[0] = (BTPageOpaque) PageGetSpecialPointer(cpage[0]);
if (P_LEFTMOST(opaque) && ! P_LEFTMOST(copaque[0]))
elog(ERROR, "bt_fixtlevel: non-leftmost child page of leftmost parent (need to recreate index)");
/* caller should take care and avoid this */
if (P_RIGHTMOST(copaque[0]))
elog(ERROR, "bt_fixtlevel: invalid start child (need to recreate index)");
for ( ; ; )
{
/*
* Read up to 2 more child pages and look for pointers
* to them in *saved* parent page
*/
coff[1] = coff[2] = InvalidOffsetNumber;
for (cidx = 0; cidx < 2; )
{
cidx++;
cblkno[cidx] = (copaque[cidx - 1])->btpo_next;
cbuf[cidx] = _bt_getbuf(rel, cblkno[cidx], BT_READ);
cpage[cidx] = BufferGetPage(cbuf[cidx]);
copaque[cidx] = (BTPageOpaque) PageGetSpecialPointer(cpage[cidx]);
coff[cidx] = _bt_getoff(page, cblkno[cidx]);
/* sanity check */
if (coff[cidx] != InvalidOffsetNumber)
{
for (i = cidx - 1; i >= 0; i--)
{
if (coff[i] == InvalidOffsetNumber)
continue;
if (coff[cidx] != coff[i] + 1)
elog(ERROR, "bt_fixlevel: invalid item order(1) (need to recreate index)");
break;
}
}
if (P_RIGHTMOST(copaque[cidx]))
break;
}
/*
* Read parent page and insert missed pointers.
*/
if (coff[1] == InvalidOffsetNumber ||
(cidx == 2 && coff[2] == InvalidOffsetNumber))
{
Buffer newbuf;
Page newpage;
BTPageOpaque newopaque;
BTItem ritem;
Size itemsz;
OffsetNumber newitemoff;
BlockNumber parblk[3];
BTStackData stack;
stack.bts_parent = NULL;
stack.bts_blkno = pblkno;
stack.bts_offset = InvalidOffsetNumber;
ItemPointerSet(&(stack.bts_btitem.bti_itup.t_tid),
cblkno[0], P_HIKEY);
buf = _bt_getstackbuf(rel, &stack);
if (buf == InvalidBuffer)
elog(ERROR, "bt_fixlevel: pointer disappeared (need to recreate index)");
page = BufferGetPage(buf);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
coff[0] = stack.bts_offset;
pblkno = BufferGetBlockNumber(buf);
parblk[0] = pblkno;
if (cblkno[0] == limit)
blkno = pblkno; /* where we have seen pointer to limit */
/* Check/insert missed pointers */
for (i = 1; i <= cidx; i++)
{
coff[i] = _bt_getoff(page, cblkno[i]);
/* sanity check */
parblk[i] = BufferGetBlockNumber(buf);
if (coff[i] != InvalidOffsetNumber)
{
if (parblk[i] == parblk[i - 1] &&
coff[i] != coff[i - 1] + 1)
elog(ERROR, "bt_fixlevel: invalid item order(2) (need to recreate index)");
if (cblkno[i] == limit)
blkno = parblk[i];
continue;
}
/* Have to check next page ? */
if ((! P_RIGHTMOST(opaque)) &&
coff[i - 1] == PageGetMaxOffsetNumber(page)) /* yes */
{
newbuf = _bt_getbuf(rel, opaque->btpo_next, BT_WRITE);
newpage = BufferGetPage(newbuf);
newopaque = (BTPageOpaque) PageGetSpecialPointer(newpage);
coff[i] = _bt_getoff(newpage, cblkno[i]);
if (coff[i] != InvalidOffsetNumber) /* found ! */
{
if (coff[i] != P_FIRSTDATAKEY(newopaque))
elog(ERROR, "bt_fixlevel: invalid item order(3) (need to recreate index)");
_bt_relbuf(rel, buf, BT_WRITE);
buf = newbuf;
page = newpage;
opaque = newopaque;
pblkno = BufferGetBlockNumber(buf);
parblk[i] = pblkno;
if (cblkno[i] == limit)
blkno = pblkno;
continue;
}
/* unfound - need to insert on current page */
_bt_relbuf(rel, newbuf, BT_WRITE);
}
/* insert pointer */
ritem = (BTItem) PageGetItem(cpage[i - 1],
PageGetItemId(cpage[i - 1], P_HIKEY));
btitem = _bt_formitem(&(ritem->bti_itup));
ItemPointerSet(&(btitem->bti_itup.t_tid), cblkno[i], P_HIKEY);
itemsz = IndexTupleDSize(btitem->bti_itup)
+ (sizeof(BTItemData) - sizeof(IndexTupleData));
itemsz = MAXALIGN(itemsz);
newitemoff = coff[i - 1] + 1;
if (PageGetFreeSpace(page) < itemsz)
{
OffsetNumber firstright;
OffsetNumber itup_off;
BlockNumber itup_blkno;
bool newitemonleft;
firstright = _bt_findsplitloc(rel, page,
newitemoff, itemsz, &newitemonleft);
newbuf = _bt_split(rel, buf, firstright,
newitemoff, itemsz, btitem, newitemonleft,
&itup_off, &itup_blkno);
/* what buffer we need in ? */
if (newitemonleft)
_bt_relbuf(rel, newbuf, BT_WRITE);
else
{
_bt_relbuf(rel, buf, BT_WRITE);
buf = newbuf;
page = BufferGetPage(buf);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
}
pblkno = BufferGetBlockNumber(buf);
coff[i] = itup_off;
}
else
{
_bt_insertuple(rel, buf, itemsz, btitem, newitemoff);
coff[i] = newitemoff;
}
pfree(btitem);
parblk[i] = pblkno;
if (cblkno[i] == limit)
blkno = pblkno;
}
/* copy page with pointer to cblkno[cidx] to temp storage */
memmove(tbuf, page, PageGetPageSize(page));
_bt_relbuf(rel, buf, BT_WRITE);
page = (Page)tbuf;
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
if (limit == InvalidBlockNumber)
blkno = pblkno; /* last visited page */
}
/* Continue if current check/fix level page is rightmost */
if (P_RIGHTMOST(opaque))
goodbye = false;
/* Pointers to child pages are Ok - right end of child level ? */
_bt_relbuf(rel, cbuf[0], BT_READ);
_bt_relbuf(rel, cbuf[1], BT_READ);
if (cidx == 1 ||
(cidx == 2 && (P_RIGHTMOST(copaque[2]) || goodbye)))
{
if (cidx == 2)
_bt_relbuf(rel, cbuf[2], BT_READ);
return(blkno);
}
if (cblkno[0] == limit || cblkno[1] == limit)
goodbye = true;
cblkno[0] = cblkno[2];
cbuf[0] = cbuf[2];
cpage[0] = cpage[2];
copaque[0] = copaque[2];
coff[0] = coff[2];
}
}
static OffsetNumber
_bt_getoff(Page page, BlockNumber blkno)
{
elog(ERROR, "bt_fixtree: unimplemented , yet");
BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
OffsetNumber offnum = P_FIRSTDATAKEY(opaque);
BlockNumber curblkno;
ItemId itemid;
BTItem item;
for ( ; offnum <= maxoff; offnum++)
{
itemid = PageGetItemId(page, offnum);
item = (BTItem) PageGetItem(page, itemid);
curblkno = ItemPointerGetBlockNumber(&(item->bti_itup.t_tid));
if (curblkno == blkno)
return(offnum);
}
return(InvalidOffsetNumber);
}
/*

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