SQLite

# 2007 March 24
#
# 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.
#
# $Id: exclusive2.test,v 1.6 2007/06/16 14:43:52 danielk1977 Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return

#        is still the same. This is because it uses the in-memory cache.
#        It can't tell the db has changed because we reset the change-counter.
# 9:     Increment the change-counter.
# 10:    Ensure that the first connection now sees the updated database. It
#        sees the change-counter has been incremented and discards the 
#        invalid in-memory cache.
#
# This will only work if the database cache is large enough to hold 
# the entire database. In the case of 1024 byte pages, this means
# the cache size must be at least 17. Otherwise, some pages will be
# loaded from the database file in step 8.
#
do_test exclusive2-1.1 {
  execsql {
    BEGIN;
    CREATE TABLE t1(a, b);
    INSERT INTO t1(a) VALUES(randstr(10, 400));
    INSERT INTO t1(a) VALUES(randstr(10, 400));
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    COMMIT;
    SELECT count(*) FROM t1;
  }
} {64}
do_test exclusive2-1.2.1 {
  # Make sure the pager cache is large enough to store the 
  # entire database.
  set nPage [expr [file size test.db]/1024]
  if {$::SQLITE_DEFAULT_CACHE_SIZE < $nPage} {
    execsql "PRAGMA cache_size = $nPage"
  }
  expr {[execsql {PRAGMA cache_size}] >= $nPage}
} {1}
do_test exclusive2-1.2 {
  set ::sig [t1sig]
  pagerChangeCounter test.db
} {1}
do_test exclusive2-1.3 {
  t1sig
} $::sig

#        still works. It should be accessing the in-memory cache.
# 5-6:   Modify the dataase change-counter. Connection 1 still works
#        entirely from in-memory cache, because it doesn't check the
#        change-counter.
# 7-8    Set the locking-mode back to normal. After the db is unlocked,
#        SQLite detects the modified change-counter and discards the
#        in-memory cache. Then it finds the corruption caused in step 4....
#
# As above, this test is only applicable if the pager cache is
# large enough to hold the entire database. With 1024 byte pages,
# this means 19 pages.
#
do_test exclusive2-2.1 {
  execsql {PRAGMA locking_mode = exclusive;}
  execsql {
    BEGIN;
    DELETE FROM t1;
    INSERT INTO t1(a) VALUES(randstr(10, 400));
    INSERT INTO t1(a) VALUES(randstr(10, 400));
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    INSERT INTO t1(a) SELECT randstr(10, 400) FROM t1;
    COMMIT;
    SELECT count(*) FROM t1;
  }
} {64}
do_test exclusive2-2.2.1 {
  # Make sure the pager cache is large enough to store the 
  # entire database.
  set nPage [expr [file size test.db]/1024]
  if {$::SQLITE_DEFAULT_CACHE_SIZE < $nPage} {
    execsql "PRAGMA cache_size = $nPage"
  }
  expr {[execsql {PRAGMA cache_size}] >= $nPage}
} {1}
do_test exclusive2-2.2 {
  set ::sig [t1sig]
  pagerChangeCounter test.db
} {3}
do_test exclusive2-2.3 {
  t1sig
} $::sig