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Make sure all data structures have 8-byte alignment - necessary for the

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sparc architecture and helpful on other 64-bit platforms.  Ticket #1232.
Also update some comments in build.c. (CVS 2452)

FossilOrigin-Name: d9418851cebc1605d8d62aad7987c0d61a905e81
This commit is contained in:
drh
2005-05-03 12:30:33 +00:00
parent 07d183da90
commit c96d8530ca
5 changed files with 34 additions and 24 deletions
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21
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 1.257 2005/05/01 22:52:42 drh Exp $
** $Id: btree.c,v 1.258 2005/05/03 12:30:34 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
@@ -211,6 +211,12 @@
#include "os.h"
#include <assert.h>
/* Round up a number to the next larger multiple of 8. This is used
** to force 8-byte alignment on 64-bit architectures.
*/
#define ROUND8(x) ((x+7)&~7)
/* The following value is the maximum cell size assuming a maximum page
** size give above.
*/
@@ -3896,9 +3902,9 @@ static int balance_nonroot(MemPage *pPage){
apCell = sqliteMallocRaw(
nMaxCells*sizeof(u8*) /* apCell */
+ nMaxCells*sizeof(int) /* szCell */
+ sizeof(MemPage)*NB /* aCopy */
+ ROUND8(sizeof(MemPage))*NB /* aCopy */
+ pBt->pageSize*(5+NB) /* aSpace */
+ (ISAUTOVACUUM ? nMaxCells : 0) /* aFrom */
+ (ISAUTOVACUUM ? nMaxCells : 0) /* aFrom */
);
if( apCell==0 ){
rc = SQLITE_NOMEM;
@@ -3906,10 +3912,13 @@ static int balance_nonroot(MemPage *pPage){
}
szCell = (int*)&apCell[nMaxCells];
aCopy[0] = (u8*)&szCell[nMaxCells];
assert( ((aCopy[0] - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
for(i=1; i<NB; i++){
aCopy[i] = &aCopy[i-1][pBt->pageSize+sizeof(MemPage)];
aCopy[i] = &aCopy[i-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
assert( ((aCopy[i] - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
}
aSpace = &aCopy[NB-1][pBt->pageSize+sizeof(MemPage)];
aSpace = &aCopy[NB-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
assert( ((aSpace - (u8*)apCell) & 7)==0 ); /* 8-byte alignment required */
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pBt->autoVacuum ){
aFrom = &aSpace[5*pBt->pageSize];
@@ -3924,12 +3933,10 @@ static int balance_nonroot(MemPage *pPage){
*/
for(i=0; i<nOld; i++){
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];
}