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-rw-r--r--src/btree.c76
1 files changed, 41 insertions, 35 deletions
diff --git a/src/btree.c b/src/btree.c
index a27568344..72b2dbc60 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
** May you share freely, never taking more than you give.
**
*************************************************************************
-** $Id: btree.c,v 1.256 2005/03/29 13:17:46 drh Exp $
+** $Id: btree.c,v 1.257 2005/05/01 22:52:42 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -211,12 +211,6 @@
#include "os.h"
#include <assert.h>
-/*
-** This macro rounds values up so that if the value is an address it
-** is guaranteed to be an address that is aligned to an 8-byte boundary.
-*/
-#define FORCE_ALIGNMENT(X) (((X)+7)&~7)
-
/* The following value is the maximum cell size assuming a maximum page
** size give above.
*/
@@ -308,7 +302,6 @@ struct Btree {
u8 autoVacuum; /* True if database supports auto-vacuum */
#endif
u16 pageSize; /* Total number of bytes on a page */
- u16 psAligned; /* pageSize rounded up to a multiple of 8 */
u16 usableSize; /* Number of usable bytes on each page */
int maxLocal; /* Maximum local payload in non-LEAFDATA tables */
int minLocal; /* Minimum local payload in non-LEAFDATA tables */
@@ -714,7 +707,7 @@ static void _pageIntegrity(MemPage *pPage){
used = sqliteMallocRaw( pPage->pBt->pageSize );
if( used==0 ) return;
usableSize = pPage->pBt->usableSize;
- assert( pPage->aData==&((unsigned char*)pPage)[-pPage->pBt->psAligned] );
+ assert( pPage->aData==&((unsigned char*)pPage)[-pPage->pBt->pageSize] );
hdr = pPage->hdrOffset;
assert( hdr==(pPage->pgno==1 ? 100 : 0) );
assert( pPage->pgno==sqlite3pager_pagenumber(pPage->aData) );
@@ -1017,7 +1010,7 @@ static int initPage(
assert( pBt!=0 );
assert( pParent==0 || pParent->pBt==pBt );
assert( pPage->pgno==sqlite3pager_pagenumber(pPage->aData) );
- assert( pPage->aData == &((unsigned char*)pPage)[-pBt->psAligned] );
+ assert( pPage->aData == &((unsigned char*)pPage)[-pBt->pageSize] );
if( pPage->pParent!=pParent && (pPage->pParent!=0 || pPage->isInit) ){
/* The parent page should never change unless the file is corrupt */
return SQLITE_CORRUPT; /* bkpt-CORRUPT */
@@ -1085,7 +1078,7 @@ static void zeroPage(MemPage *pPage, int flags){
int first;
assert( sqlite3pager_pagenumber(data)==pPage->pgno );
- assert( &data[pBt->psAligned] == (unsigned char*)pPage );
+ assert( &data[pBt->pageSize] == (unsigned char*)pPage );
assert( sqlite3pager_iswriteable(data) );
memset(&data[hdr], 0, pBt->usableSize - hdr);
data[hdr] = flags;
@@ -1114,7 +1107,7 @@ static int getPage(Btree *pBt, Pgno pgno, MemPage **ppPage){
MemPage *pPage;
rc = sqlite3pager_get(pBt->pPager, pgno, (void**)&aData);
if( rc ) return rc;
- pPage = (MemPage*)&aData[pBt->psAligned];
+ pPage = (MemPage*)&aData[pBt->pageSize];
pPage->aData = aData;
pPage->pBt = pBt;
pPage->pgno = pgno;
@@ -1153,7 +1146,7 @@ static void releasePage(MemPage *pPage){
if( pPage ){
assert( pPage->aData );
assert( pPage->pBt );
- assert( &pPage->aData[pPage->pBt->psAligned]==(unsigned char*)pPage );
+ assert( &pPage->aData[pPage->pBt->pageSize]==(unsigned char*)pPage );
sqlite3pager_unref(pPage->aData);
}
}
@@ -1164,7 +1157,9 @@ static void releasePage(MemPage *pPage){
** happens.
*/
static void pageDestructor(void *pData, int pageSize){
- MemPage *pPage = (MemPage*)&((char*)pData)[FORCE_ALIGNMENT(pageSize)];
+ MemPage *pPage;
+ assert( (pageSize & 7)==0 );
+ pPage = (MemPage*)&((char*)pData)[pageSize];
if( pPage->pParent ){
MemPage *pParent = pPage->pParent;
pPage->pParent = 0;
@@ -1182,7 +1177,9 @@ static void pageDestructor(void *pData, int pageSize){
** page to agree with the restored data.
*/
static void pageReinit(void *pData, int pageSize){
- MemPage *pPage = (MemPage*)&((char*)pData)[FORCE_ALIGNMENT(pageSize)];
+ MemPage *pPage;
+ assert( (pageSize & 7)==0 );
+ pPage = (MemPage*)&((char*)pData)[pageSize];
if( pPage->isInit ){
pPage->isInit = 0;
initPage(pPage, pPage->pParent);
@@ -1238,7 +1235,8 @@ int sqlite3BtreeOpen(
pBt->readOnly = sqlite3pager_isreadonly(pBt->pPager);
sqlite3pager_read_fileheader(pBt->pPager, sizeof(zDbHeader), zDbHeader);
pBt->pageSize = get2byte(&zDbHeader[16]);
- if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE ){
+ if( pBt->pageSize<512 || pBt->pageSize>SQLITE_MAX_PAGE_SIZE
+ || ((pBt->pageSize-1)&pBt->pageSize)!=0 ){
pBt->pageSize = SQLITE_DEFAULT_PAGE_SIZE;
pBt->maxEmbedFrac = 64; /* 25% */
pBt->minEmbedFrac = 32; /* 12.5% */
@@ -1270,7 +1268,7 @@ int sqlite3BtreeOpen(
#endif
}
pBt->usableSize = pBt->pageSize - nReserve;
- pBt->psAligned = FORCE_ALIGNMENT(pBt->pageSize);
+ assert( (pBt->pageSize & 7)==0 ); /* 8-byte alignment of pageSize */
sqlite3pager_set_pagesize(pBt->pPager, pBt->pageSize);
*ppBtree = pBt;
return SQLITE_OK;
@@ -1357,8 +1355,8 @@ int sqlite3BtreeSetPageSize(Btree *pBt, int pageSize, int nReserve){
}
if( pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE &&
((pageSize-1)&pageSize)==0 ){
+ assert( (pageSize & 7)==0 );
pBt->pageSize = pageSize;
- pBt->psAligned = FORCE_ALIGNMENT(pageSize);
sqlite3pager_set_pagesize(pBt->pPager, pageSize);
}
pBt->usableSize = pBt->pageSize - nReserve;
@@ -1418,7 +1416,7 @@ int sqlite3BtreeGetAutoVacuum(Btree *pBt){
** if there is a locking protocol violation.
*/
static int lockBtree(Btree *pBt){
- int rc;
+ int rc, pageSize;
MemPage *pPage1;
if( pBt->pPage1 ) return SQLITE_OK;
rc = getPage(pBt, 1, &pPage1);
@@ -1437,12 +1435,16 @@ static int lockBtree(Btree *pBt){
if( page1[18]>1 || page1[19]>1 ){
goto page1_init_failed;
}
- pBt->pageSize = get2byte(&page1[16]);
- pBt->usableSize = pBt->pageSize - page1[20];
+ pageSize = get2byte(&page1[16]);
+ if( ((pageSize-1)&pageSize)!=0 ){
+ goto page1_init_failed;
+ }
+ assert( (pageSize & 7)==0 );
+ pBt->pageSize = pageSize;
+ pBt->usableSize = pageSize - page1[20];
if( pBt->usableSize<500 ){
goto page1_init_failed;
}
- pBt->psAligned = FORCE_ALIGNMENT(pBt->pageSize);
pBt->maxEmbedFrac = page1[21];
pBt->minEmbedFrac = page1[22];
pBt->minLeafFrac = page1[23];
@@ -1509,7 +1511,7 @@ static void unlockBtreeIfUnused(Btree *pBt){
if( pBt->inTrans==TRANS_NONE && pBt->pCursor==0 && pBt->pPage1!=0 ){
if( pBt->pPage1->aData==0 ){
MemPage *pPage = pBt->pPage1;
- pPage->aData = &((char*)pPage)[-pBt->psAligned];
+ pPage->aData = &((char*)pPage)[-pBt->pageSize];
pPage->pBt = pBt;
pPage->pgno = 1;
}
@@ -3381,7 +3383,7 @@ static int reparentPage(Btree *pBt, Pgno pgno, MemPage *pNewParent, int idx){
assert( pBt->pPager!=0 );
aData = sqlite3pager_lookup(pBt->pPager, pgno);
if( aData ){
- pThis = (MemPage*)&aData[pBt->psAligned];
+ pThis = (MemPage*)&aData[pBt->pageSize];
assert( pThis->aData==aData );
if( pThis->isInit ){
if( pThis->pParent!=pNewParent ){
@@ -3895,7 +3897,7 @@ static int balance_nonroot(MemPage *pPage){
nMaxCells*sizeof(u8*) /* apCell */
+ nMaxCells*sizeof(int) /* szCell */
+ sizeof(MemPage)*NB /* aCopy */
- + pBt->psAligned*(5+NB) /* aSpace */
+ + pBt->pageSize*(5+NB) /* aSpace */
+ (ISAUTOVACUUM ? nMaxCells : 0) /* aFrom */
);
if( apCell==0 ){
@@ -3905,12 +3907,12 @@ static int balance_nonroot(MemPage *pPage){
szCell = (int*)&apCell[nMaxCells];
aCopy[0] = (u8*)&szCell[nMaxCells];
for(i=1; i<NB; i++){
- aCopy[i] = &aCopy[i-1][pBt->psAligned+sizeof(MemPage)];
+ aCopy[i] = &aCopy[i-1][pBt->pageSize+sizeof(MemPage)];
}
- aSpace = &aCopy[NB-1][pBt->psAligned+sizeof(MemPage)];
+ aSpace = &aCopy[NB-1][pBt->pageSize+sizeof(MemPage)];
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum ){
- aFrom = &aSpace[5*pBt->psAligned];
+ aFrom = &aSpace[5*pBt->pageSize];
}
#endif
@@ -3921,10 +3923,14 @@ static int balance_nonroot(MemPage *pPage){
** process of being overwritten.
*/
for(i=0; i<nOld; i++){
- MemPage *p = apCopy[i] = (MemPage*)&aCopy[i][pBt->psAligned];
- p->aData = &((u8*)p)[-pBt->psAligned];
- memcpy(p->aData, apOld[i]->aData, pBt->psAligned + sizeof(MemPage));
- p->aData = &((u8*)p)[-pBt->psAligned];
+ MemPage *p = apCopy[i] = (MemPage*)&aCopy[i][pBt->pageSize];
+ assert( (((long long unsigned int)p) & 7)==0 );
+ p->aData = &((u8*)p)[-pBt->pageSize];
+ memcpy(p->aData, apOld[i]->aData, pBt->pageSize + sizeof(MemPage));
+ /* The memcpy() above changes the value of p->aData so we have to
+ ** set it again. */
+ assert( (((long long unsigned int)p) & 7)==0 );
+ p->aData = &((u8*)p)[-pBt->pageSize];
}
/*
@@ -3982,7 +3988,7 @@ static int balance_nonroot(MemPage *pPage){
szCell[nCell] = sz;
pTemp = &aSpace[iSpace];
iSpace += sz;
- assert( iSpace<=pBt->psAligned*5 );
+ assert( iSpace<=pBt->pageSize*5 );
memcpy(pTemp, apDiv[i], sz);
apCell[nCell] = pTemp+leafCorrection;
#ifndef SQLITE_OMIT_AUTOVACUUM
@@ -4207,13 +4213,13 @@ static int balance_nonroot(MemPage *pPage){
pCell = &aSpace[iSpace];
fillInCell(pParent, pCell, 0, info.nKey, 0, 0, &sz);
iSpace += sz;
- assert( iSpace<=pBt->psAligned*5 );
+ assert( iSpace<=pBt->pageSize*5 );
pTemp = 0;
}else{
pCell -= 4;
pTemp = &aSpace[iSpace];
iSpace += sz;
- assert( iSpace<=pBt->psAligned*5 );
+ assert( iSpace<=pBt->pageSize*5 );
}
rc = insertCell(pParent, nxDiv, pCell, sz, pTemp, 4);
if( rc!=SQLITE_OK ) goto balance_cleanup;
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-21 08:13:38 +0000