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Modifications to reduce memory consumption. (CVS 2422)

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FossilOrigin-Name: 0fd5ce4eefdc429ce0493f15d0dba9e8a3a0b0e2
This commit is contained in:
danielk1977
2005-03-28 08:44:07 +00:00
parent dd5b2fa5f2
commit 634f298c89
6 changed files with 218 additions and 66 deletions
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67
src/btree.c
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@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.253 2005/03/21 04:04:02 danielk1977 Exp $
** $Id: btree.c,v 1.254 2005/03/28 08:44:07 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -3757,7 +3757,8 @@ static int balance_quick(MemPage *pPage, MemPage *pParent){
static int balance_nonroot(MemPage *pPage){
MemPage *pParent; /* The parent of pPage */
Btree *pBt; /* The whole database */
int nCell = 0; /* Number of cells in aCell[] */
int nCell = 0; /* Number of cells in apCell[] */
int nMaxCells = 0; /* Allocated size of apCell, szCell, aFrom. */
int nOld; /* Number of pages in apOld[] */
int nNew; /* Number of pages in apNew[] */
int nDiv; /* Number of cells in apDiv[] */
@@ -3771,7 +3772,6 @@ static int balance_nonroot(MemPage *pPage){
int pageFlags; /* Value of pPage->aData[0] */
int subtotal; /* Subtotal of bytes in cells on one page */
int iSpace = 0; /* First unused byte of aSpace[] */
int mxCellPerPage; /* Maximum number of cells in one page */
MemPage *apOld[NB]; /* pPage and up to two siblings */
Pgno pgnoOld[NB]; /* Page numbers for each page in apOld[] */
MemPage *apCopy[NB]; /* Private copies of apOld[] pages */
@@ -3825,31 +3825,6 @@ static int balance_nonroot(MemPage *pPage){
}
#endif
/*
** Allocate space for memory structures
*/
mxCellPerPage = MX_CELL(pBt);
apCell = sqliteMallocRaw(
(mxCellPerPage+2)*NB*(sizeof(u8*)+sizeof(int))
+ sizeof(MemPage)*NB
+ pBt->psAligned*(5+NB)
+ (ISAUTOVACUUM ? (mxCellPerPage+2)*NN*2 : 0)
);
if( apCell==0 ){
return SQLITE_NOMEM;
}
szCell = (int*)&apCell[(mxCellPerPage+2)*NB];
aCopy[0] = (u8*)&szCell[(mxCellPerPage+2)*NB];
for(i=1; i<NB; i++){
aCopy[i] = &aCopy[i-1][pBt->psAligned+sizeof(MemPage)];
}
aSpace = &aCopy[NB-1][pBt->psAligned+sizeof(MemPage)];
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum ){
aFrom = &aSpace[5*pBt->psAligned];
}
#endif
/*
** Find the cell in the parent page whose left child points back
** to pPage. The "idx" variable is the index of that cell. If pPage
@@ -3910,8 +3885,35 @@ static int balance_nonroot(MemPage *pPage){
apCopy[i] = 0;
assert( i==nOld );
nOld++;
nMaxCells += 1+apOld[i]->nCell+apOld[i]->nOverflow;
}
/*
** Allocate space for memory structures
*/
apCell = sqliteMallocRaw(
nMaxCells*sizeof(u8*) /* apCell */
+ nMaxCells*sizeof(int) /* szCell */
+ sizeof(MemPage)*NB /* aCopy */
+ pBt->psAligned*(5+NB) /* aSpace */
+ (ISAUTOVACUUM ? nMaxCells : 0) /* aFrom */
);
if( apCell==0 ){
rc = SQLITE_NOMEM;
goto balance_cleanup;
}
szCell = (int*)&apCell[nMaxCells];
aCopy[0] = (u8*)&szCell[nMaxCells];
for(i=1; i<NB; i++){
aCopy[i] = &aCopy[i-1][pBt->psAligned+sizeof(MemPage)];
}
aSpace = &aCopy[NB-1][pBt->psAligned+sizeof(MemPage)];
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum ){
aFrom = &aSpace[5*pBt->psAligned];
}
#endif
/*
** Make copies of the content of pPage and its siblings into aOld[].
** The rest of this function will use data from the copies rather
@@ -3948,6 +3950,7 @@ static int balance_nonroot(MemPage *pPage){
MemPage *pOld = apCopy[i];
int limit = pOld->nCell+pOld->nOverflow;
for(j=0; j<limit; j++){
assert( nCell<nMaxCells );
apCell[nCell] = findOverflowCell(pOld, j);
szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
#ifndef SQLITE_OMIT_AUTOVACUUM
@@ -3975,6 +3978,7 @@ static int balance_nonroot(MemPage *pPage){
dropCell(pParent, nxDiv, sz);
}else{
u8 *pTemp;
assert( nCell<nMaxCells );
szCell[nCell] = sz;
pTemp = &aSpace[iSpace];
iSpace += sz;
@@ -4020,6 +4024,7 @@ static int balance_nonroot(MemPage *pPage){
*/
usableSpace = pBt->usableSize - 12 + leafCorrection;
for(subtotal=k=i=0; i<nCell; i++){
assert( i<nMaxCells );
subtotal += szCell[i] + 2;
if( subtotal > usableSpace ){
szNew[k] = subtotal - szCell[i];
@@ -4051,6 +4056,8 @@ static int balance_nonroot(MemPage *pPage){
r = cntNew[i-1] - 1;
d = r + 1 - leafData;
assert( d<nMaxCells );
assert( r<nMaxCells );
while( szRight==0 || szRight+szCell[d]+2<=szLeft-(szCell[r]+2) ){
szRight += szCell[d] + 2;
szLeft -= szCell[r] + 2;
@@ -4146,6 +4153,7 @@ static int balance_nonroot(MemPage *pPage){
j = 0;
for(i=0; i<nNew; i++){
/* Assemble the new sibling page. */
assert( j<nMaxCells );
MemPage *pNew = apNew[i];
assert( pNew->pgno==pgnoNew[i] );
assemblePage(pNew, cntNew[i]-j, &apCell[j], &szCell[j]);
@@ -4160,6 +4168,7 @@ static int balance_nonroot(MemPage *pPage){
*/
if( pBt->autoVacuum ){
for(k=j; k<cntNew[i]; k++){
assert( k<nMaxCells );
if( aFrom[k]==0xFF || apCopy[aFrom[k]]->pgno!=pNew->pgno ){
rc = ptrmapPutOvfl(pNew, k-j);
if( rc!=SQLITE_OK ){
@@ -4179,6 +4188,8 @@ static int balance_nonroot(MemPage *pPage){
u8 *pCell;
u8 *pTemp;
int sz;
assert( j<nMaxCells );
pCell = apCell[j];
sz = szCell[j] + leafCorrection;
if( !pNew->leaf ){