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Overview
Comment:Change pager_truncate() to a different method for extending files while also ensuring that writes are page-size and page-aligned.
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SHA1: 874bc8844f6494cdbf700bd884dee67d40f11fc0
User & Date: drh 2011-01-28 15:46:14.305
Context
2011-01-28
17:02
Bogus release candidate. (Closed-Leaf check-in: 38ca1daa23 user: drh tags: mistake)
16:45
Add test script pagerfault3.test. No changes to code or existing tests. (check-in: 682fe41efd user: dan tags: trunk)
15:46
Change pager_truncate() to a different method for extending files while also ensuring that writes are page-size and page-aligned. (check-in: 874bc8844f user: drh tags: trunk)
15:07
When extending a database file, do so by writing one or more page-size chunks of data to the file, instead of just a single byte to the end. (check-in: 58577135a8 user: dan tags: trunk)
Changes
Side-by-Side Diff Ignore Whitespace Patch
Changes to src/pager.c.
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  assert( pPager->eState!=PAGER_ERROR );
  assert( pPager->eState!=PAGER_READER );
  
  if( isOpen(pPager->fd) 
   && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN) 
  ){
    i64 currentSize, newSize;
    int szPage = pPager->pageSize;
    assert( pPager->eLock==EXCLUSIVE_LOCK );
    /* TODO: Is it safe to use Pager.dbFileSize here? */
    rc = sqlite3OsFileSize(pPager->fd, &currentSize);
    newSize = pPager->pageSize*(i64)nPage;
    newSize = szPage*(i64)nPage;
    if( rc==SQLITE_OK && currentSize!=newSize ){
      if( currentSize>newSize ){
        rc = sqlite3OsTruncate(pPager->fd, newSize);
      }else{
        char *pTmp = pPager->pTmpSpace;
        memset(pTmp, 0, pPager->pageSize);
        while( currentSize<newSize ){
          rc = sqlite3OsWrite(pPager->fd, pTmp, pPager->pageSize, currentSize);
        memset(pTmp, 0, szPage);
        testcase( (newSize-szPage) <  currentSize );
        testcase( (newSize-szPage) == currentSize );
        testcase( (newSize-szPage) >  currentSize );
        rc = sqlite3OsWrite(pPager->fd, pTmp, szPage, newSize-szPage);
          currentSize += pPager->pageSize;
        }
      }
      if( rc==SQLITE_OK ){
        pPager->dbFileSize = nPage;
      }
    }
  }
  return rc;
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