Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Fix harmless compiler warnings in the cell-overwrite logic. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | cell-overwrite-prototype |
| Files: | files | file ages | folders |
| SHA3-256: | 3e11dc3183bc3e8ec49af244a8e8b3e0 |
| User & Date: | drh 2018-05-07 11:29:59 |
Context
|
2018-05-07
| ||
| 11:48 | On an UPDATE, try to overwrite an existing btree cell with the modified content, if the old and new cell are the same size. Use memcmp() first to avoid dirtying pages that are unchanged. check-in: 5887d8be user: drh tags: trunk | |
| 11:29 | Fix harmless compiler warnings in the cell-overwrite logic. Closed-Leaf check-in: 3e11dc31 user: drh tags: cell-overwrite-prototype | |
|
2018-05-04
| ||
| 19:18 | Merge enhancements from trunk. check-in: 9650f71b user: drh tags: cell-overwrite-prototype | |
Changes
Changes to src/btree.c.
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
....
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
|
rc = btreeOverwriteContent(pPage, pCur->info.pPayload, pX,
0, pCur->info.nLocal);
if( rc ) return rc;
if( pCur->info.nLocal==nTotal ) return SQLITE_OK;
/* Now overwrite the overflow pages */
iOffset = pCur->info.nLocal;
ovflPgno = get4byte(pCur->info.pPayload + iOffset);
pBt = pPage->pBt;
ovflPageSize = pBt->usableSize - 4;
do{
rc = btreeGetPage(pBt, ovflPgno, &pPage, 0);
if( rc ) return rc;
if( sqlite3PagerPageRefcount(pPage->pDbPage)!=1 ){
rc = SQLITE_CORRUPT_BKPT;
}else{
if( iOffset+ovflPageSize<nTotal ){
ovflPgno = get4byte(pPage->aData);
}else{
ovflPageSize = nTotal - iOffset;
}
rc = btreeOverwriteContent(pPage, pPage->aData+4, pX,
iOffset, ovflPageSize);
}
................................................................................
/* If the cursor is currently on the last row and we are appending a
** new row onto the end, set the "loc" to avoid an unnecessary
** btreeMoveto() call */
if( (pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey==pCur->info.nKey ){
/* The current is currently pointing to the entry that is to be
** overwritten */
if( pCur->info.nSize!=0 && pCur->info.nPayload==pX->nData+pX->nZero ){
return btreeOverwriteCell(pCur, pX);
}
loc = 0;
}else if( loc==0 ){
rc = sqlite3BtreeMovetoUnpacked(pCur, 0, pX->nKey, flags!=0, &loc);
if( rc ) return rc;
}
|
>
>
|
>
|
>
>
|
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
....
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
|
rc = btreeOverwriteContent(pPage, pCur->info.pPayload, pX,
0, pCur->info.nLocal);
if( rc ) return rc;
if( pCur->info.nLocal==nTotal ) return SQLITE_OK;
/* Now overwrite the overflow pages */
iOffset = pCur->info.nLocal;
assert( nTotal>=0 );
assert( iOffset>=0 );
ovflPgno = get4byte(pCur->info.pPayload + iOffset);
pBt = pPage->pBt;
ovflPageSize = pBt->usableSize - 4;
do{
rc = btreeGetPage(pBt, ovflPgno, &pPage, 0);
if( rc ) return rc;
if( sqlite3PagerPageRefcount(pPage->pDbPage)!=1 ){
rc = SQLITE_CORRUPT_BKPT;
}else{
if( iOffset+ovflPageSize<(u32)nTotal ){
ovflPgno = get4byte(pPage->aData);
}else{
ovflPageSize = nTotal - iOffset;
}
rc = btreeOverwriteContent(pPage, pPage->aData+4, pX,
iOffset, ovflPageSize);
}
................................................................................
/* If the cursor is currently on the last row and we are appending a
** new row onto the end, set the "loc" to avoid an unnecessary
** btreeMoveto() call */
if( (pCur->curFlags&BTCF_ValidNKey)!=0 && pX->nKey==pCur->info.nKey ){
/* The current is currently pointing to the entry that is to be
** overwritten */
assert( pX->nData>=0 && pX->nZero>=0 );
if( pCur->info.nSize!=0
&& pCur->info.nPayload==(u32)pX->nData+pX->nZero
){
return btreeOverwriteCell(pCur, pX);
}
loc = 0;
}else if( loc==0 ){
rc = sqlite3BtreeMovetoUnpacked(pCur, 0, pX->nKey, flags!=0, &loc);
if( rc ) return rc;
}
|