pager3.test

一个小型的嵌入式数据库

# 2001 September 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is page cache subsystem.
#
# $Id: pager3.test,v 1.2 2004/11/04 14:47:13 drh Exp $


set testdir [file dirname $argv0]
source $testdir/tester.tcl

# This test makes sure the database file is truncated back to the correct
# length on a rollback.
#
# After some preliminary setup, a transaction is start at NOTE (1).
# The create table on the following line allocates an additional page
# at the end of the database file.  But that page is not written because
# the database still has a RESERVED lock, not an EXCLUSIVE lock.  The
# new page is held in memory and the size of the file is unchanged.
# The insert at NOTE (2) begins adding additional pages.  Then it hits
# a constraint error and aborts.  The abort causes sqlite3OsTruncate()
# to be called to restore the file to the same length as it was after
# the create table.  But the create table results had not yet been
# written so the file is actually lengthened by this truncate.  Finally,
# the rollback at NOTE (3) is called to undo all the changes since the
# begin.  This rollback should truncate the database again.
# 
# This test was added because the second truncate at NOTE (3) was not
# occurring on early versions of SQLite 3.0.
#
do_test pager3-1.1 {
  execsql {
    create table t1(a unique, b);
    insert into t1 values(1, 'abcdefghijklmnopqrstuvwxyz');
    insert into t1 values(2, 'abcdefghijklmnopqrstuvwxyz');
    update t1 set b=b||a||b;
    update t1 set b=b||a||b;
    update t1 set b=b||a||b;
    update t1 set b=b||a||b;
    update t1 set b=b||a||b;
    update t1 set b=b||a||b;
    create temp table t2 as select * from t1;
    begin;                  ------- NOTE (1)
    create table t3(x);
  }
  catchsql {
    insert into t1 select 4-a, b from t2;  ----- NOTE (2)
  }
  execsql {
    rollback;  ------- NOTE (3)
  }
  db close
  sqlite3 db test.db
  set r ok
  ifcapable {integrityck} {
    set r [execsql {
      pragma integrity_check;
    }]
  }
  set r
} ok

finish_test