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Reduce the number of paths in btreeCopyFile(). (CVS 6124)

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FossilOrigin-Name: df2c285cb99ac188c96dd1a4e6a30f689195a150
This commit is contained in:
danielk1977
2009-01-06 18:21:08 +00:00
parent cd1cbff38b
commit 076dce5336
3 changed files with 64 additions and 70 deletions
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120
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 1.555 2009/01/02 21:08:09 drh Exp $
** $Id: btree.c,v 1.556 2009/01/06 18:21:09 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
@@ -7290,76 +7290,70 @@ static int btreeCopyFile(Btree *pTo, Btree *pFrom){
** bytes and 9 pages, then the file needs to be truncated to 9KB.
*/
if( rc==SQLITE_OK ){
if( nFromPageSize!=nToPageSize ){
sqlite3_file *pFile = sqlite3PagerFile(pBtTo->pPager);
i64 iSize = (i64)nFromPageSize * (i64)nFromPage;
i64 iNow = (i64)((nToPage>nNewPage)?nToPage:nNewPage) * (i64)nToPageSize;
i64 iPending = ((i64)PENDING_BYTE_PAGE(pBtTo)-1) *(i64)nToPageSize;
assert( iSize<=iNow );
/* Commit phase one syncs the journal file associated with pTo
** containing the original data. It does not sync the database file
** itself. After doing this it is safe to use OsTruncate() and other
** file APIs on the database file directly.
*/
pBtTo->db = pTo->db;
rc = sqlite3PagerCommitPhaseOne(pBtTo->pPager, 0, 1);
if( iSize<iNow && rc==SQLITE_OK ){
rc = sqlite3OsTruncate(pFile, iSize);
}
/* The loop that copied data from database pFrom to pTo did not
** populate the locking page of database pTo. If the page-size of
** pFrom is smaller than that of pTo, this means some data will
** not have been copied.
**
** This block copies the missing data from database pFrom to pTo
** using file APIs. This is safe because at this point we know that
** all of the original data from pTo has been synced into the
** journal file. At this point it would be safe to do anything at
** all to the database file except truncate it to zero bytes.
*/
if( rc==SQLITE_OK && nFromPageSize<nToPageSize && iSize>iPending){
i64 iOff;
for(
iOff=iPending;
rc==SQLITE_OK && iOff<(iPending+nToPageSize);
iOff += nFromPageSize
){
DbPage *pFromPage = 0;
Pgno iFrom = (Pgno)(iOff/nFromPageSize)+1;
if( iFrom==PENDING_BYTE_PAGE(pBtFrom) || iFrom>nFromPage ){
continue;
}
rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
if( rc==SQLITE_OK ){
char *zFrom = sqlite3PagerGetData(pFromPage);
rc = sqlite3OsWrite(pFile, zFrom, nFromPageSize, iOff);
sqlite3PagerUnref(pFromPage);
}
sqlite3_file *pFile = sqlite3PagerFile(pBtTo->pPager);
i64 iSize = (i64)nFromPageSize * (i64)nFromPage;
i64 iNow = (i64)((nToPage>nNewPage)?nToPage:nNewPage) * (i64)nToPageSize;
i64 iPending = ((i64)PENDING_BYTE_PAGE(pBtTo)-1) *(i64)nToPageSize;
assert( iSize<=iNow );
/* Commit phase one syncs the journal file associated with pTo
** containing the original data. It does not sync the database file
** itself. After doing this it is safe to use OsTruncate() and other
** file APIs on the database file directly.
*/
pBtTo->db = pTo->db;
rc = sqlite3PagerCommitPhaseOne(pBtTo->pPager, 0, 1);
if( iSize<iNow && rc==SQLITE_OK ){
rc = sqlite3OsTruncate(pFile, iSize);
}
/* The loop that copied data from database pFrom to pTo did not
** populate the locking page of database pTo. If the page-size of
** pFrom is smaller than that of pTo, this means some data will
** not have been copied.
**
** This block copies the missing data from database pFrom to pTo
** using file APIs. This is safe because at this point we know that
** all of the original data from pTo has been synced into the
** journal file. At this point it would be safe to do anything at
** all to the database file except truncate it to zero bytes.
*/
if( rc==SQLITE_OK && nFromPageSize<nToPageSize && iSize>iPending){
i64 iOff;
for(
iOff=iPending;
rc==SQLITE_OK && iOff<(iPending+nToPageSize);
iOff += nFromPageSize
){
DbPage *pFromPage = 0;
Pgno iFrom = (Pgno)(iOff/nFromPageSize)+1;
if( iFrom==PENDING_BYTE_PAGE(pBtFrom) || iFrom>nFromPage ){
continue;
}
rc = sqlite3PagerGet(pBtFrom->pPager, iFrom, &pFromPage);
if( rc==SQLITE_OK ){
char *zFrom = sqlite3PagerGetData(pFromPage);
rc = sqlite3OsWrite(pFile, zFrom, nFromPageSize, iOff);
sqlite3PagerUnref(pFromPage);
}
}
/* Sync the database file */
if( rc==SQLITE_OK ){
rc = sqlite3PagerSync(pBtTo->pPager);
}
}else{
rc = sqlite3PagerTruncate(pBtTo->pPager, nNewPage);
}
if( rc==SQLITE_OK ){
pBtTo->pageSizeFixed = 0;
}
}
if( rc ){
/* Sync the database file */
if( rc==SQLITE_OK ){
rc = sqlite3PagerSync(pBtTo->pPager);
}
if( rc==SQLITE_OK ){
pBtTo->pageSizeFixed = 0;
}else{
sqlite3BtreeRollback(pTo);
}
return rc;
return rc;
}
int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
int rc;