mirror of https://github.com/sqlite/sqlite
Reduce the stack usage of balance_quick(). (CVS 6715)
FossilOrigin-Name: e7ad68e93b19b59cb16205c4b48fd9d6492dbb02
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danielk1977
parent
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commit
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14
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14
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@ -1,5 +1,5 @@
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C Minor\supdates\sto\scomments\sin\stest\sscripts.\s(CVS\s6714)
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D 2009-06-04T02:47:04
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C Reduce\sthe\sstack\susage\sof\sbalance_quick().\s(CVS\s6715)
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D 2009-06-04T14:46:08
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F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
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F Makefile.in 8b8fb7823264331210cddf103831816c286ba446
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F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
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@ -106,7 +106,7 @@ F src/auth.c 98db07c2088455797678eb1031f42d4d94d18a71
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F src/backup.c ff50af53184a5fd7bdee4d620b5dabef74717c79
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F src/bitvec.c 0ef0651714728055d43de7a4cdd95e703fac0119
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F src/btmutex.c 9b899c0d8df3bd68f527b0afe03088321b696d3c
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F src/btree.c 708b9373d573aeb6c61899ed2fcc498a98a20b12
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F src/btree.c ca83629673417074c919b9dc4a2003d69d52de9f
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F src/btree.h f70b694e8c163227369a66863b01fbff9009f323
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F src/btreeInt.h df64030d632f8c8ac217ed52e8b6b3eacacb33a5
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F src/build.c 20e02fd72249159ff6829009f3029d16d59cdff5
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@ -733,7 +733,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
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F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
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F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
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F tool/vdbe-compress.tcl 672f81d693a03f80f5ae60bfefacd8a349e76746
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P bc6c2d894b711361808a19b673803186d3a28369
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R 9dd9dd8b1b74bf1fededc820a0a5d128
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U shane
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Z 1d673d399a0b5a991b96f6d097baa1ce
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P 453ff88f73a01a54ff464563effdb63014b1972c
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R 10cf14b6134b53081d5b29cc87d78754
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U danielk1977
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Z ea544126f0e51edd041f5bf4bda237c8
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@ -1 +1 @@
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453ff88f73a01a54ff464563effdb63014b1972c
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e7ad68e93b19b59cb16205c4b48fd9d6492dbb02
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83
src/btree.c
83
src/btree.c
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@ -9,7 +9,7 @@
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** May you share freely, never taking more than you give.
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**
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*************************************************************************
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** $Id: btree.c,v 1.613 2009/06/04 00:11:56 drh Exp $
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** $Id: btree.c,v 1.614 2009/06/04 14:46:08 danielk1977 Exp $
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**
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** This file implements a external (disk-based) database using BTrees.
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** See the header comment on "btreeInt.h" for additional information.
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@ -1173,7 +1173,6 @@ int sqlite3BtreeInitPage(MemPage *pPage){
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}
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#endif
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/* Compute the total free space on the page */
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pc = get2byte(&data[hdr+1]);
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nFree = data[hdr+7] + top;
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@ -5198,55 +5197,61 @@ static int balance(BtCursor*, int);
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** which is also the right-most entry on the page.
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*/
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static int balance_quick(BtCursor *pCur){
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int rc;
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MemPage *pNew = 0;
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Pgno pgnoNew;
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u8 *pCell;
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u16 szCell;
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CellInfo info;
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MemPage *pPage = pCur->apPage[pCur->iPage];
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MemPage *pParent = pCur->apPage[pCur->iPage-1];
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BtShared *pBt = pPage->pBt;
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int parentIdx = pParent->nCell; /* pParent new divider cell index */
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int parentSize; /* Size of new divider cell */
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u8 parentCell[64]; /* Space for the new divider cell */
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MemPage *const pPage = pCur->apPage[pCur->iPage];
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BtShared *const pBt = pCur->pBt;
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MemPage *pNew = 0; /* Newly allocated page */
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int rc; /* Return Code */
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Pgno pgnoNew; /* Page number of pNew */
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assert( sqlite3_mutex_held(pPage->pBt->mutex) );
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assert( pPage->nCell>0 );
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/* Allocate a new page. Insert the overflow cell from pPage
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** into it. Then remove the overflow cell from pPage.
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*/
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/* Allocate a new page. This page will become the right-sibling of pPage */
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rc = allocateBtreePage(pBt, &pNew, &pgnoNew, 0, 0);
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if( rc==SQLITE_OK ){
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pCell = pPage->aOvfl[0].pCell;
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szCell = cellSizePtr(pPage, pCell);
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/* The parentCell buffer is used to store a temporary copy of the divider
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** cell that will be inserted into pParent. Such a cell consists of a 4
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** byte page number followed by a variable length integer. In other
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** words, at most 13 bytes. Hence the parentCell buffer must be at
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** least 13 bytes in size.
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*/
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MemPage * const pParent = pCur->apPage[pCur->iPage-1];
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u8 parentCell[13];
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u8 *pOut = &parentCell[4];
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u8 *pCell = pPage->aOvfl[0].pCell;
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u16 szCell = cellSizePtr(pPage, pCell);
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u8 *pStop;
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assert( sqlite3PagerIswriteable(pNew->pDbPage) );
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zeroPage(pNew, pPage->aData[0]);
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assemblePage(pNew, 1, &pCell, &szCell);
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pPage->nOverflow = 0;
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/* pPage is currently the right-child of pParent. Change this
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** so that the right-child is the new page allocated above and
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** pPage is the next-to-right child.
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/* Create a divider cell to insert into pParent. The divider cell
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** consists of a 4-byte page number (the page number of pPage) and
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** a variable length key value (which must be the same value as the
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** largest key on pPage).
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**
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** Ignore the return value of the call to fillInCell(). fillInCell()
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** may only return other than SQLITE_OK if it is required to allocate
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** one or more overflow pages. Since an internal table B-Tree cell
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** may never spill over onto an overflow page (it is a maximum of
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** 13 bytes in size), it is not neccessary to check the return code.
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**
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** Similarly, the insertCell() function cannot fail if the page
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** being inserted into is already writable and the cell does not
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** contain an overflow pointer. So ignore this return code too.
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** To find the largest key value on pPage, first find the right-most
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** cell on pPage. The first two fields of this cell are the
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** record-length (a variable length integer at most 32-bits in size)
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** and the key value (a variable length integer, may have any value).
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** The first of the while(...) loops below skips over the record-length
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** field. The second while(...) loop copies the key value from the
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** cell on pPage into the parentCell buffer.
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*/
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assert( pPage->nCell>0 );
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put4byte(parentCell, pPage->pgno);
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pCell = findCell(pPage, pPage->nCell-1);
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sqlite3BtreeParseCellPtr(pPage, pCell, &info);
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fillInCell(pParent, parentCell, 0, info.nKey, 0, 0, 0, &parentSize);
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assert( parentSize<64 );
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assert( sqlite3PagerIswriteable(pParent->pDbPage) );
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insertCell(pParent, parentIdx, parentCell, parentSize, 0, 4);
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put4byte(findOverflowCell(pParent,parentIdx), pPage->pgno);
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pStop = &pCell[9];
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while( (*(pCell++)&0x80) && pCell<pStop );
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pStop = &pCell[9];
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while( ((*(pOut++) = *(pCell++))&0x80) && pCell<pStop );
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/* Insert the new divider cell into pParent */
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insertCell(pParent, pParent->nCell, parentCell, pOut-parentCell, 0, 0);
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/* Set the right-child pointer of pParent to point to the new page. */
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put4byte(&pParent->aData[pParent->hdrOffset+8], pgnoNew);
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/* If this is an auto-vacuum database, update the pointer map
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@ -5642,7 +5647,7 @@ static int balance_nonroot(BtCursor *pCur){
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szNew[i-1] = szLeft;
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}
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/* Either we found one or more cells (cntnew[0])>0) or we are the
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/* Either we found one or more cells (cntnew[0])>0) or pPage is
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** a virtual root page. A virtual root page is when the real root
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** page is page 1 and we are the only child of that page.
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*/
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