xref: /sqlite-3.40.0/test/pager1.test (revision ba3cbf3d)

# 2010 June 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.
#
#***********************************************************************
#

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

# Do not use a codec for tests in this file, as the database file is
# manipulated directly using tcl scripts (using the [hexio_write] command).
#
do_not_use_codec

#
# pager1-1.*: Test inter-process locking (clients in multiple processes).
#
# pager1-2.*: Test intra-process locking (multiple clients in this process).
#
# pager1-3.*: Savepoint related tests.
#
# pager1-4.*: Hot-journal related tests.
#
# pager1-5.*: Cases related to multi-file commits.
#
# pager1-6.*: Cases related to "PRAGMA max_page_count"
#
# pager1-7.*: Cases specific to "PRAGMA journal_mode=TRUNCATE"
#
# pager1-8.*: Cases using temporary and in-memory databases.
#
# pager1-9.*: Tests related to the backup API.
#
# pager1-10.*: Test that the assumed file-system sector-size is limited to
#              64KB.
#
# pager1-12.*: Tests involving "PRAGMA page_size"
#
# pager1-13.*: Cases specific to "PRAGMA journal_mode=PERSIST"
#
# pager1-14.*: Cases specific to "PRAGMA journal_mode=OFF"
#
# pager1-15.*: Varying sqlite3_vfs.szOsFile
#
# pager1-16.*: Varying sqlite3_vfs.mxPathname
#
# pager1-17.*: Tests related to "PRAGMA omit_readlock"
#
# pager1-18.*: Test that the pager layer responds correctly if the b-tree
#              requests an invalid page number (due to db corruption).
#

set a_string_counter 1
proc a_string {n} {
  global a_string_counter
  incr a_string_counter
  string range [string repeat "${a_string_counter}." $n] 1 $n
}
db func a_string a_string

do_multiclient_test tn {

  # Create and populate a database table using connection [db]. Check
  # that connections [db2] and [db3] can see the schema and content.
  #
  do_test pager1-$tn.1 {
    sql1 {
      CREATE TABLE t1(a PRIMARY KEY, b);
      CREATE INDEX i1 ON t1(b);
      INSERT INTO t1 VALUES(1, 'one'); INSERT INTO t1 VALUES(2, 'two');
    }
  } {}
  do_test pager1-$tn.2 { sql2 { SELECT * FROM t1 } } {1 one 2 two}
  do_test pager1-$tn.3 { sql3 { SELECT * FROM t1 } } {1 one 2 two}

  # Open a transaction and add a row using [db]. This puts [db] in
  # RESERVED state. Check that connections [db2] and [db3] can still
  # read the database content as it was before the transaction was
  # opened. [db] should see the inserted row.
  #
  do_test pager1-$tn.4 {
    sql1 {
      BEGIN;
        INSERT INTO t1 VALUES(3, 'three');
    }
  } {}
  do_test pager1-$tn.5 { sql2 { SELECT * FROM t1 } } {1 one 2 two}
  do_test pager1-$tn.7 { sql1 { SELECT * FROM t1 } } {1 one 2 two 3 three}

  # [db] still has an open write transaction. Check that this prevents
  # other connections (specifically [db2]) from writing to the database.
  #
  # Even if [db2] opens a transaction first, it may not write to the
  # database. After the attempt to write the db within a transaction,
  # [db2] is left with an open transaction, but not a read-lock on
  # the main database. So it does not prevent [db] from committing.
  #
  do_test pager1-$tn.8 {
    csql2 { UPDATE t1 SET a = a + 10 }
  } {1 {database is locked}}
  do_test pager1-$tn.9 {
    csql2 {
      BEGIN;
      UPDATE t1 SET a = a + 10;
    }
  } {1 {database is locked}}

  # Have [db] commit its transactions. Check the other connections can
  # now see the new database content.
  #
  do_test pager1-$tn.10 { sql1 { COMMIT } } {}
  do_test pager1-$tn.11 { sql1 { SELECT * FROM t1 } } {1 one 2 two 3 three}
  do_test pager1-$tn.12 { sql2 { SELECT * FROM t1 } } {1 one 2 two 3 three}
  do_test pager1-$tn.13 { sql3 { SELECT * FROM t1 } } {1 one 2 two 3 three}

  # Check that, as noted above, [db2] really did keep an open transaction
  # after the attempt to write the database failed.
  #
  do_test pager1-$tn.14 {
    csql2 { BEGIN }
  } {1 {cannot start a transaction within a transaction}}
  do_test pager1-$tn.15 { sql2 { ROLLBACK } } {}

  # Have [db2] open a transaction and take a read-lock on the database.
  # Check that this prevents [db] from writing to the database (outside
  # of any transaction). After this fails, check that [db3] can read
  # the db (showing that [db] did not take a PENDING lock etc.)
  #
  do_test pager1-$tn.15 {
    sql2 { BEGIN; SELECT * FROM t1; }
  } {1 one 2 two 3 three}
  do_test pager1-$tn.16 {
    csql1 { UPDATE t1 SET a = a + 10 }
  } {1 {database is locked}}
  do_test pager1-$tn.17 { sql3 { SELECT * FROM t1 } } {1 one 2 two 3 three}

  # This time, have [db] open a transaction before writing the database.
  # This works - [db] gets a RESERVED lock which does not conflict with
  # the SHARED lock [db2] is holding.
  #
  do_test pager1-$tn.18 {
    sql1 {
      BEGIN;
      UPDATE t1 SET a = a + 10;
    }
  } {}
  do_test pager1-$tn-19 {
    sql1 { PRAGMA lock_status }
  } {main reserved temp closed}
  do_test pager1-$tn-20 {
    sql2 { PRAGMA lock_status }
  } {main shared temp closed}

  # Check that all connections can still read the database. Only [db] sees
  # the updated content (as the transaction has not been committed yet).
  #
  do_test pager1-$tn.21 { sql1 { SELECT * FROM t1 } } {11 one 12 two 13 three}
  do_test pager1-$tn.22 { sql2 { SELECT * FROM t1 } } {1 one 2 two 3 three}
  do_test pager1-$tn.23 { sql3 { SELECT * FROM t1 } } {1 one 2 two 3 three}

  # Because [db2] still has the SHARED lock, [db] is unable to commit the
  # transaction. If it tries, an error is returned and the connection
  # upgrades to a PENDING lock.
  #
  # Once this happens, [db] can read the database and see the new content,
  # [db2] (still holding SHARED) can still read the old content, but [db3]
  # (not holding any lock) is prevented by [db]'s PENDING from reading
  # the database.
  #
  do_test pager1-$tn.24 { csql1 { COMMIT } } {1 {database is locked}}
  do_test pager1-$tn-25 {
    sql1 { PRAGMA lock_status }
  } {main pending temp closed}
  do_test pager1-$tn.26 { sql1 { SELECT * FROM t1  } } {11 one 12 two 13 three}
  do_test pager1-$tn.27 { sql2 { SELECT * FROM t1  } } {1 one 2 two 3 three}
  do_test pager1-$tn.28 { csql3 { SELECT * FROM t1 } } {1 {database is locked}}

  # Have [db2] commit its read transaction, releasing the SHARED lock it
  # is holding. Now, neither [db2] nor [db3] may read the database (as [db]
  # is still holding a PENDING).
  #
  do_test pager1-$tn.29 { sql2 { COMMIT } } {}
  do_test pager1-$tn.30 { csql2 { SELECT * FROM t1 } } {1 {database is locked}}
  do_test pager1-$tn.31 { csql3 { SELECT * FROM t1 } } {1 {database is locked}}

  # [db] is now able to commit the transaction. Once the transaction is
  # committed, all three connections can read the new content.
  #
  do_test pager1-$tn.25 { sql1 { UPDATE t1 SET a = a+10 } } {}
  do_test pager1-$tn.26 { sql1 { COMMIT } } {}
  do_test pager1-$tn.27 { sql1 { SELECT * FROM t1 } } {21 one 22 two 23 three}
  do_test pager1-$tn.27 { sql2 { SELECT * FROM t1 } } {21 one 22 two 23 three}
  do_test pager1-$tn.28 { sql3 { SELECT * FROM t1 } } {21 one 22 two 23 three}

  # Install a busy-handler for connection [db].
  #
  set ::nbusy [list]
  proc busy {n} {
    lappend ::nbusy $n
    if {$n>5} { sql2 COMMIT }
    return 0
  }
  db busy busy

  do_test pager1-$tn.29 {
    sql1 { BEGIN ; INSERT INTO t1 VALUES('x', 'y') }
  } {}
  do_test pager1-$tn.30 {
    sql2 { BEGIN ; SELECT * FROM t1 }
  } {21 one 22 two 23 three}
  do_test pager1-$tn.31 { sql1 COMMIT } {}
  do_test pager1-$tn.32 { set ::nbusy } {0 1 2 3 4 5 6}
}

#-------------------------------------------------------------------------
# Savepoint related test cases.
#
# pager1-3.1.2.*: Force a savepoint rollback to cause the database file
#                 to grow.
#
# pager1-3.1.3.*: Use a journal created in synchronous=off mode as part
#                 of a savepoint rollback.
#
do_test pager1-3.1.1 {
  faultsim_delete_and_reopen
  execsql {
    CREATE TABLE t1(a PRIMARY KEY, b);
    CREATE TABLE counter(
      i CHECK (i<5),
      u CHECK (u<10)
    );
    INSERT INTO counter VALUES(0, 0);
    CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
      UPDATE counter SET i = i+1;
    END;
    CREATE TRIGGER tr2 AFTER UPDATE ON t1 BEGIN
      UPDATE counter SET u = u+1;
    END;
  }
  execsql { SELECT * FROM counter }
} {0 0}

do_execsql_test pager1-3.1.2 {
  PRAGMA cache_size = 10;
  BEGIN;
    INSERT INTO t1 VALUES(1, randomblob(1500));
    INSERT INTO t1 VALUES(2, randomblob(1500));
    INSERT INTO t1 VALUES(3, randomblob(1500));
    SELECT * FROM counter;
} {3 0}
do_catchsql_test pager1-3.1.3 {
    INSERT INTO t1 SELECT a+3, randomblob(1500) FROM t1
} {1 {constraint failed}}
do_execsql_test pager1-3.4 { SELECT * FROM counter } {3 0}
do_execsql_test pager1-3.5 { SELECT a FROM t1 } {1 2 3}
do_execsql_test pager1-3.6 { COMMIT } {}

foreach {tn sql tcl} {
  7  { PRAGMA synchronous = NORMAL ; PRAGMA temp_store = 0 } {
    testvfs tv -default 1
    tv devchar safe_append
  }
  8  { PRAGMA synchronous = NORMAL ; PRAGMA temp_store = 2 } {
    testvfs tv -default 1
    tv devchar sequential
  }
  9  { PRAGMA synchronous = FULL } { }
  10 { PRAGMA synchronous = NORMAL } { }
  11 { PRAGMA synchronous = OFF } { }
  12 { PRAGMA synchronous = FULL ; PRAGMA fullfsync = 1 } { }
  13 { PRAGMA synchronous = FULL } {
    testvfs tv -default 1
    tv devchar sequential
  }
} {
  do_test pager1-3.$tn.1 {
    eval $tcl
    faultsim_delete_and_reopen
    db func a_string a_string
    execsql $sql
    execsql {
      PRAGMA auto_vacuum = 2;
      PRAGMA cache_size = 10;
      CREATE TABLE z(x INTEGER PRIMARY KEY, y);
      BEGIN;
        INSERT INTO z VALUES(NULL, a_string(800));
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --   2
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --   4
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --   8
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --  16
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --  32
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --  64
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     -- 128
        INSERT INTO z SELECT NULL, a_string(800) FROM z;     -- 256
      COMMIT;
    }
    execsql { PRAGMA auto_vacuum }
  } {2}
  do_execsql_test pager1-3.$tn.2 {
    BEGIN;
      INSERT INTO z VALUES(NULL, a_string(800));
      INSERT INTO z VALUES(NULL, a_string(800));
      SAVEPOINT one;
        UPDATE z SET y = NULL WHERE x>256;
        PRAGMA incremental_vacuum;
        SELECT count(*) FROM z WHERE x < 100;
      ROLLBACK TO one;
    COMMIT;
  } {99}

  do_execsql_test pager1-3.$tn.3 {
    BEGIN;
      SAVEPOINT one;
        UPDATE z SET y = y||x;
      ROLLBACK TO one;
    COMMIT;
    SELECT count(*) FROM z;
  } {258}

  do_execsql_test pager1-3.$tn.4 {
    SAVEPOINT one;
      UPDATE z SET y = y||x;
    ROLLBACK TO one;
  } {}
  do_execsql_test pager1-3.$tn.5 {
    SELECT count(*) FROM z;
    RELEASE one;
    PRAGMA integrity_check;
  } {258 ok}

  db close
  catch { tv delete }
}

#-------------------------------------------------------------------------
# Hot journal rollback related test cases.
#
# pager1.4.1.*: Test that the pager module deletes very small invalid
#               journal files.
#
# pager1.4.2.*: Test that if the master journal pointer at the end of a
#               hot-journal file appears to be corrupt (checksum does not
#               compute) the associated journal is rolled back (and no
#               xAccess() call to check for the presence of any master
#               journal file is made).
#
# pager1.4.3.*: Test that the contents of a hot-journal are ignored if the
#               page-size or sector-size in the journal header appear to
#               be invalid (too large, too small or not a power of 2).
#
# pager1.4.4.*: Test hot-journal rollback of journal file with a master
#               journal pointer generated in various "PRAGMA synchronous"
#               modes.
#
# pager1.4.5.*: Test that hot-journal rollback stops if it encounters a
#               journal-record for which the checksum fails.
#
# pager1.4.6.*: Test that when rolling back a hot-journal that contains a
#               master journal pointer, the master journal file is deleted
#               after all the hot-journals that refer to it are deleted.
#
# pager1.4.7.*: Test that if a hot-journal file exists but a client can
#               open it for reading only, the database cannot be accessed and
#               SQLITE_CANTOPEN is returned.
#
do_test pager1.4.1.1 {
  faultsim_delete_and_reopen
  execsql {
    CREATE TABLE x(y, z);
    INSERT INTO x VALUES(1, 2);
  }
  set fd [open test.db-journal w]
  puts -nonewline $fd "helloworld"
  close $fd
  file exists test.db-journal
} {1}
do_test pager1.4.1.2 { execsql { SELECT * FROM x } } {1 2}
do_test pager1.4.1.3 { file exists test.db-journal } {0}

# Set up a [testvfs] to snapshot the file-system just before SQLite
# deletes the master-journal to commit a multi-file transaction.
#
# In subsequent test cases, invoking [faultsim_restore_and_reopen] sets
# up the file system to contain two databases, two hot-journal files and
# a master-journal.
#
do_test pager1.4.2.1 {
  testvfs tstvfs -default 1
  tstvfs filter xDelete
  tstvfs script xDeleteCallback
  proc xDeleteCallback {method file args} {
    set file [file tail $file]
    if { [string match *mj* $file] } { faultsim_save }
  }
  faultsim_delete_and_reopen
  db func a_string a_string
  execsql {
    ATTACH 'test.db2' AS aux;
    PRAGMA journal_mode = DELETE;
    PRAGMA main.cache_size = 10;
    PRAGMA aux.cache_size = 10;
    CREATE TABLE t1(a UNIQUE, b UNIQUE);
    CREATE TABLE aux.t2(a UNIQUE, b UNIQUE);
    INSERT INTO t1 VALUES(a_string(200), a_string(300));
    INSERT INTO t1 SELECT a_string(200), a_string(300) FROM t1;
    INSERT INTO t1 SELECT a_string(200), a_string(300) FROM t1;
    INSERT INTO t2 SELECT * FROM t1;
    BEGIN;
      INSERT INTO t1 SELECT a_string(201), a_string(301) FROM t1;
      INSERT INTO t1 SELECT a_string(202), a_string(302) FROM t1;
      INSERT INTO t1 SELECT a_string(203), a_string(303) FROM t1;
      INSERT INTO t1 SELECT a_string(204), a_string(304) FROM t1;
      REPLACE INTO t2 SELECT * FROM t1;
    COMMIT;
  }
  db close
  tstvfs delete
} {}
do_test pager1.4.2.2 {
  faultsim_restore_and_reopen
  execsql {
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {4 ok}
do_test pager1.4.2.3 {
  faultsim_restore_and_reopen
  foreach f [glob test.db-mj*] { file delete -force $f }
  execsql {
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {64 ok}
do_test pager1.4.2.4 {
  faultsim_restore_and_reopen
  hexio_write test.db-journal [expr [file size test.db-journal]-20] 123456
  execsql {
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {4 ok}
do_test pager1.4.2.5 {
  faultsim_restore_and_reopen
  hexio_write test.db-journal [expr [file size test.db-journal]-20] 123456
  foreach f [glob test.db-mj*] { file delete -force $f }
  execsql {
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {4 ok}

do_test pager1.4.3.1 {
  testvfs tstvfs -default 1
  tstvfs filter xSync
  tstvfs script xSyncCallback
  proc xSyncCallback {method file args} {
    set file [file tail $file]
    if { 0==[string match *journal $file] } { faultsim_save }
  }
  faultsim_delete_and_reopen
  execsql {
    PRAGMA journal_mode = DELETE;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
  }
  db close
  tstvfs delete
} {}

foreach {tn ofst value result} {
          2   20    31       {1 2 3 4}
          3   20    32       {1 2 3 4}
          4   20    33       {1 2 3 4}
          5   20    65536    {1 2 3 4}
          6   20    131072   {1 2 3 4}

          7   24    511      {1 2 3 4}
          8   24    513      {1 2 3 4}
          9   24    65536    {1 2 3 4}

         10   32    65536    {1 2}
} {
  do_test pager1.4.3.$tn {
    faultsim_restore_and_reopen
    hexio_write test.db-journal $ofst [format %.8x $value]
    execsql { SELECT * FROM t1 }
  } $result
}
db close

# Set up a VFS that snapshots the file-system just before a master journal
# file is deleted to commit a multi-file transaction. Specifically, the
# file-system is saved just before the xDelete() call to remove the
# master journal file from the file-system.
#
testvfs tv -default 1
tv script copy_on_mj_delete
set ::mj_filename_length 0
proc copy_on_mj_delete {method filename args} {
  if {[string match *mj* [file tail $filename]]} {
    set ::mj_filename_length [string length $filename]
    faultsim_save
  }
  return SQLITE_OK
}

set pwd [pwd]
foreach {tn1 tcl} {
  1 { set prefix "test.db" }
  2 {
    # This test depends on the underlying VFS being able to open paths
    # 512 bytes in length. The idea is to create a hot-journal file that
    # contains a master-journal pointer so large that it could contain
    # a valid page record (if the file page-size is 512 bytes). So as to
    # make sure SQLite doesn't get confused by this.
    #
    set nPadding [expr 511 - $::mj_filename_length]

    # We cannot just create a really long database file name to open, as
    # Linux limits a single component of a path to 255 bytes by default
    # (and presumably other systems have limits too). So create a directory
    # hierarchy to work in.
    #
    set dirname "d123456789012345678901234567890/"
    set nDir [expr $nPadding / 32]
    if { $nDir } {
      set p [string repeat $dirname $nDir]
      file mkdir $p
      cd $p
    }

    set padding [string repeat x [expr $nPadding %32]]
    set prefix "test.db${padding}"
  }
} {
  eval $tcl
  foreach {tn2 sql} {
    o {
      PRAGMA main.synchronous=OFF;
      PRAGMA aux.synchronous=OFF;
    }
    o512 {
      PRAGMA main.synchronous=OFF;
      PRAGMA aux.synchronous=OFF;
      PRAGMA main.page_size = 512;
      PRAGMA aux.page_size = 512;
    }
    n {
      PRAGMA main.synchronous=NORMAL;
      PRAGMA aux.synchronous=NORMAL;
    }
    f {
      PRAGMA main.synchronous=FULL;
      PRAGMA aux.synchronous=FULL;
    }
  } {

    set tn "${tn1}.${tn2}"

    # Set up a connection to have two databases, test.db (main) and
    # test.db2 (aux). Then run a multi-file transaction on them. The
    # VFS will snapshot the file-system just before the master-journal
    # file is deleted to commit the transaction.
    #
    tv filter xDelete
    do_test pager1-4.4.$tn.1 {
      faultsim_delete_and_reopen $prefix
      execsql "
        ATTACH '${prefix}2' AS aux;
        $sql
        CREATE TABLE a(x);
        CREATE TABLE aux.b(x);
        INSERT INTO a VALUES('double-you');
        INSERT INTO a VALUES('why');
        INSERT INTO a VALUES('zed');
        INSERT INTO b VALUES('won');
        INSERT INTO b VALUES('too');
        INSERT INTO b VALUES('free');
      "
      execsql {
        BEGIN;
          INSERT INTO a SELECT * FROM b WHERE rowid<=3;
          INSERT INTO b SELECT * FROM a WHERE rowid<=3;
        COMMIT;
      }
    } {}
    tv filter {}

    # Check that the transaction was committed successfully.
    #
    do_execsql_test pager1-4.4.$tn.2 {
      SELECT * FROM a
    } {double-you why zed won too free}
    do_execsql_test pager1-4.4.$tn.3 {
      SELECT * FROM b
    } {won too free double-you why zed}

    # Restore the file-system and reopen the databases. Check that it now
    # appears that the transaction was not committed (because the file-system
    # was restored to the state where it had not been).
    #
    do_test pager1-4.4.$tn.4 {
      faultsim_restore_and_reopen $prefix
      execsql "ATTACH '${prefix}2' AS aux"
    } {}
    do_execsql_test pager1-4.4.$tn.5 {SELECT * FROM a} {double-you why zed}
    do_execsql_test pager1-4.4.$tn.6 {SELECT * FROM b} {won too free}

    # Restore the file-system again. This time, before reopening the databases,
    # delete the master-journal file from the file-system. It now appears that
    # the transaction was committed (no master-journal file == no rollback).
    #
    do_test pager1-4.4.$tn.7 {
      faultsim_restore_and_reopen $prefix
      foreach f [glob ${prefix}-mj*] { file delete -force $f }
      execsql "ATTACH '${prefix}2' AS aux"
    } {}
    do_execsql_test pager1-4.4.$tn.8 {
      SELECT * FROM a
    } {double-you why zed won too free}
    do_execsql_test pager1-4.4.$tn.9 {
      SELECT * FROM b
    } {won too free double-you why zed}
  }

  cd $pwd
}
db close
tv delete
file delete -force $dirname


# Set up a VFS to make a copy of the file-system just before deleting a
# journal file to commit a transaction. The transaction modifies exactly
# two database pages (and page 1 - the change counter).
#
testvfs tv -default 1
tv sectorsize 512
tv script copy_on_journal_delete
tv filter xDelete
proc copy_on_journal_delete {method filename args} {
  if {[string match *journal $filename]} faultsim_save
  return SQLITE_OK
}
faultsim_delete_and_reopen
do_execsql_test pager1.4.5.1 {
  PRAGMA page_size = 1024;
  CREATE TABLE t1(a, b);
  CREATE TABLE t2(a, b);
  INSERT INTO t1 VALUES('I', 'II');
  INSERT INTO t2 VALUES('III', 'IV');
  BEGIN;
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t2 VALUES(3, 4);
  COMMIT;
} {}
tv filter {}

# Check the transaction was committed:
#
do_execsql_test pager1.4.5.2 {
  SELECT * FROM t1;
  SELECT * FROM t2;
} {I II 1 2 III IV 3 4}

# Now try four tests:
#
#  pager1-4.5.3: Restore the file-system. Check that the whole transaction
#                is rolled back.
#
#  pager1-4.5.4: Restore the file-system. Corrupt the first record in the
#                journal. Check the transaction is not rolled back.
#
#  pager1-4.5.5: Restore the file-system. Corrupt the second record in the
#                journal. Check that the first record in the transaction is
#                played back, but not the second.
#
#  pager1-4.5.6: Restore the file-system. Try to open the database with a
#                readonly connection. This should fail, as a read-only
#                connection cannot roll back the database file.
#
faultsim_restore_and_reopen
do_execsql_test pager1.4.5.3 {
  SELECT * FROM t1;
  SELECT * FROM t2;
} {I II III IV}
faultsim_restore_and_reopen
hexio_write test.db-journal [expr 512+4+1024 - 202] 0123456789ABCDEF
do_execsql_test pager1.4.5.4 {
  SELECT * FROM t1;
  SELECT * FROM t2;
} {I II 1 2 III IV 3 4}
faultsim_restore_and_reopen
hexio_write test.db-journal [expr 512+4+1024+4+4+1024 - 202] 0123456789ABCDEF
do_execsql_test pager1.4.5.5 {
  SELECT * FROM t1;
  SELECT * FROM t2;
} {I II III IV 3 4}

faultsim_restore_and_reopen
db close
sqlite3 db test.db -readonly 1
do_catchsql_test pager1.4.5.6 {
  SELECT * FROM t1;
  SELECT * FROM t2;
} {1 {disk I/O error}}
db close

# Snapshot the file-system just before multi-file commit. Save the name
# of the master journal file in $::mj_filename.
#
tv script copy_on_mj_delete
tv filter xDelete
proc copy_on_mj_delete {method filename args} {
  if {[string match *mj* [file tail $filename]]} {
    set ::mj_filename $filename
    faultsim_save
  }
  return SQLITE_OK
}
do_test pager1.4.6.1 {
  faultsim_delete_and_reopen
  execsql {
    ATTACH 'test.db2' AS two;
    CREATE TABLE t1(a, b);
    CREATE TABLE two.t2(a, b);
    INSERT INTO t1 VALUES(1, 't1.1');
    INSERT INTO t2 VALUES(1, 't2.1');
    BEGIN;
      UPDATE t1 SET b = 't1.2';
      UPDATE t2 SET b = 't2.2';
    COMMIT;
  }
  tv filter {}
  db close
} {}

faultsim_restore_and_reopen
do_execsql_test pager1.4.6.2 { SELECT * FROM t1 }           {1 t1.1}
do_test         pager1.4.6.3 { file exists $::mj_filename } {1}
do_execsql_test pager1.4.6.4 {
  ATTACH 'test.db2' AS two;
  SELECT * FROM t2;
} {1 t2.1}
do_test pager1.4.6.5 { file exists $::mj_filename } {0}

faultsim_restore_and_reopen
db close
do_test pager1.4.6.8 {
  set ::mj_filename1 $::mj_filename
  tv filter xDelete
  sqlite3 db test.db2
  execsql {
    ATTACH 'test.db3' AS three;
    CREATE TABLE three.t3(a, b);
    INSERT INTO t3 VALUES(1, 't3.1');
    BEGIN;
      UPDATE t2 SET b = 't2.3';
      UPDATE t3 SET b = 't3.3';
    COMMIT;
  }
  expr {$::mj_filename1 != $::mj_filename}
} {1}
faultsim_restore_and_reopen
tv filter {}

# The file-system now contains:
#
#   * three databases
#   * three hot-journal files
#   * two master-journal files.
#
# The hot-journals associated with test.db2 and test.db3 point to
# master journal $::mj_filename. The hot-journal file associated with
# test.db points to master journal $::mj_filename1. So reading from
# test.db should delete $::mj_filename1.
#
do_test pager1.4.6.9 {
  lsort [glob test.db*]
} [lsort [list                                           \
  test.db test.db2 test.db3                              \
  test.db-journal test.db2-journal test.db3-journal      \
  [file tail $::mj_filename] [file tail $::mj_filename1]
]]

# The master-journal $::mj_filename1 contains pointers to test.db and
# test.db2. However the hot-journal associated with test.db2 points to
# a different master-journal. Therefore, reading from test.db only should
# be enough to cause SQLite to delete $::mj_filename1.
#
do_test         pager1.4.6.10 { file exists $::mj_filename  } {1}
do_test         pager1.4.6.11 { file exists $::mj_filename1 } {1}
do_execsql_test pager1.4.6.12 { SELECT * FROM t1 } {1 t1.1}
do_test         pager1.4.6.13 { file exists $::mj_filename  } {1}
do_test         pager1.4.6.14 { file exists $::mj_filename1 } {0}

do_execsql_test pager1.4.6.12 {
  ATTACH 'test.db2' AS two;
  SELECT * FROM t2;
} {1 t2.1}
do_test         pager1.4.6.13 { file exists $::mj_filename }  {1}
do_execsql_test pager1.4.6.14 {
  ATTACH 'test.db3' AS three;
  SELECT * FROM t3;
} {1 t3.1}
do_test         pager1.4.6.15 { file exists $::mj_filename }  {0}

db close
tv delete

testvfs tv -default 1
tv sectorsize 512
tv script copy_on_journal_delete
tv filter xDelete
proc copy_on_journal_delete {method filename args} {
  if {[string match *journal $filename]} faultsim_save
  return SQLITE_OK
}
faultsim_delete_and_reopen
do_execsql_test pager1.4.7.1 {
  CREATE TABLE t1(x PRIMARY KEY, y);
  CREATE INDEX i1 ON t1(y);
  INSERT INTO t1 VALUES('I',   'one');
  INSERT INTO t1 VALUES('II',  'four');
  INSERT INTO t1 VALUES('III', 'nine');
  BEGIN;
    INSERT INTO t1 VALUES('IV', 'sixteen');
    INSERT INTO t1 VALUES('V' , 'twentyfive');
  COMMIT;
} {}
tv filter {}
db close
tv delete
do_test pager1.4.7.2 {
  faultsim_restore_and_reopen
  catch {file attributes test.db-journal -permissions r--------}
  catch {file attributes test.db-journal -readonly 1}
  catchsql { SELECT * FROM t1 }
} {1 {unable to open database file}}
do_test pager1.4.7.3 {
  db close
  catch {file attributes test.db-journal -permissions rw-rw-rw-}
  catch {file attributes test.db-journal -readonly 0}
  file delete test.db-journal
  file exists test.db-journal
} {0}

#-------------------------------------------------------------------------
# The following tests deal with multi-file commits.
#
# pager1-5.1.*: The case where a multi-file cannot be committed because
#               another connection is holding a SHARED lock on one of the
#               files. After the SHARED lock is removed, the COMMIT succeeds.
#
# pager1-5.2.*: Multi-file commits with journal_mode=memory.
#
# pager1-5.3.*: Multi-file commits with journal_mode=memory.
#
# pager1-5.4.*: Check that with synchronous=normal, the master-journal file
#               name is added to a journal file immediately after the last
#               journal record. But with synchronous=full, extra unused space
#               is allocated between the last journal record and the
#               master-journal file name so that the master-journal file
#               name does not lie on the same sector as the last journal file
#               record.
#
# pager1-5.5.*: Check that in journal_mode=PERSIST mode, a journal file is
#               truncated to zero bytes when a multi-file transaction is
#               committed (instead of the first couple of bytes being zeroed).
#
#
do_test pager1-5.1.1 {
  faultsim_delete_and_reopen
  execsql {
    ATTACH 'test.db2' AS aux;
    CREATE TABLE t1(a, b);
    CREATE TABLE aux.t2(a, b);
    INSERT INTO t1 VALUES(17, 'Lenin');
    INSERT INTO t1 VALUES(22, 'Stalin');
    INSERT INTO t1 VALUES(53, 'Khrushchev');
  }
} {}
do_test pager1-5.1.2 {
  execsql {
    BEGIN;
      INSERT INTO t1 VALUES(64, 'Brezhnev');
      INSERT INTO t2 SELECT * FROM t1;
  }
  sqlite3 db2 test.db2
  execsql {
    BEGIN;
      SELECT * FROM t2;
  } db2
} {}
do_test pager1-5.1.3 {
  catchsql COMMIT
} {1 {database is locked}}
do_test pager1-5.1.4 {
  execsql COMMIT db2
  execsql COMMIT
  execsql { SELECT * FROM t2 } db2
} {17 Lenin 22 Stalin 53 Khrushchev 64 Brezhnev}
do_test pager1-5.1.5 {
  db2 close
} {}

do_test pager1-5.2.1 {
  execsql {
    PRAGMA journal_mode = memory;
    BEGIN;
      INSERT INTO t1 VALUES(84, 'Andropov');
      INSERT INTO t2 VALUES(84, 'Andropov');
    COMMIT;
  }
} {memory}
do_test pager1-5.3.1 {
  execsql {
    PRAGMA journal_mode = off;
    BEGIN;
      INSERT INTO t1 VALUES(85, 'Gorbachev');
      INSERT INTO t2 VALUES(85, 'Gorbachev');
    COMMIT;
  }
} {off}

do_test pager1-5.4.1 {
  db close
  testvfs tv
  sqlite3 db test.db -vfs tv
  execsql { ATTACH 'test.db2' AS aux }

  tv filter xDelete
  tv script max_journal_size
  tv sectorsize 512
  set ::max_journal 0
  proc max_journal_size {method args} {
    set sz 0
    catch { set sz [file size test.db-journal] }
    if {$sz > $::max_journal} {
      set ::max_journal $sz
    }
    return SQLITE_OK
  }
  execsql {
    PRAGMA journal_mode = DELETE;
    PRAGMA synchronous = NORMAL;
    BEGIN;
      INSERT INTO t1 VALUES(85, 'Gorbachev');
      INSERT INTO t2 VALUES(85, 'Gorbachev');
    COMMIT;
  }
  set ::max_journal
} [expr 2615+[string length [pwd]]]
do_test pager1-5.4.2 {
  set ::max_journal 0
  execsql {
    PRAGMA synchronous = full;
    BEGIN;
      DELETE FROM t1 WHERE b = 'Lenin';
      DELETE FROM t2 WHERE b = 'Lenin';
    COMMIT;
  }
  set ::max_journal
} [expr 3111+[string length [pwd]]]
db close
tv delete

do_test pager1-5.5.1 {
  sqlite3 db test.db
  execsql {
    ATTACH 'test.db2' AS aux;
    PRAGMA journal_mode = PERSIST;
    CREATE TABLE t3(a, b);
    INSERT INTO t3 SELECT randomblob(1500), randomblob(1500) FROM t1;
    UPDATE t3 SET b = randomblob(1500);
  }
  expr [file size test.db-journal] > 15000
} {1}
do_test pager1-5.5.2 {
  execsql {
    PRAGMA synchronous = full;
    BEGIN;
      DELETE FROM t1 WHERE b = 'Stalin';
      DELETE FROM t2 WHERE b = 'Stalin';
    COMMIT;
  }
  file size test.db-journal
} {0}


#-------------------------------------------------------------------------
# The following tests work with "PRAGMA max_page_count"
#
do_test pager1-6.1 {
  faultsim_delete_and_reopen
  execsql {
    PRAGMA max_page_count = 10;
    CREATE TABLE t2(a, b);
    CREATE TABLE t3(a, b);
    CREATE TABLE t4(a, b);
    CREATE TABLE t5(a, b);
    CREATE TABLE t6(a, b);
    CREATE TABLE t7(a, b);
    CREATE TABLE t8(a, b);
    CREATE TABLE t9(a, b);
    CREATE TABLE t10(a, b);
  }
} {10}
do_catchsql_test pager1-6.2 {
  CREATE TABLE t11(a, b)
} {1 {database or disk is full}}
do_execsql_test pager1-6.4 { PRAGMA max_page_count      } {10}
do_execsql_test pager1-6.5 { PRAGMA max_page_count = 15 } {15}
do_execsql_test pager1-6.6 { CREATE TABLE t11(a, b)     } {}
do_execsql_test pager1-6.7 {
  BEGIN;
    INSERT INTO t11 VALUES(1, 2);
    PRAGMA max_page_count = 13;
} {13}
do_execsql_test pager1-6.8 {
    INSERT INTO t11 VALUES(3, 4);
    PRAGMA max_page_count = 10;
} {11}
do_execsql_test pager1-6.9 { COMMIT } {}


#-------------------------------------------------------------------------
# The following tests work with "PRAGMA journal_mode=TRUNCATE" and
# "PRAGMA locking_mode=EXCLUSIVE".
#
# Each test is specified with 5 variables. As follows:
#
#   $tn:  Test Number. Used as part of the [do_test] test names.
#   $sql: SQL to execute.
#   $res: Expected result of executing $sql.
#   $js:  The expected size of the journal file, in bytes, after executing
#         the SQL script. Or -1 if the journal is not expected to exist.
#   $ws:  The expected size of the WAL file, in bytes, after executing
#         the SQL script. Or -1 if the WAL is not expected to exist.
#
ifcapable wal {
  faultsim_delete_and_reopen
  foreach {tn sql res js ws} [subst {

    1  {
      CREATE TABLE t1(a, b);
      PRAGMA auto_vacuum=OFF;
      PRAGMA synchronous=NORMAL;
      PRAGMA page_size=1024;
      PRAGMA locking_mode=EXCLUSIVE;
      PRAGMA journal_mode=TRUNCATE;
      INSERT INTO t1 VALUES(1, 2);
    } {exclusive truncate} 0 -1

    2  {
      BEGIN IMMEDIATE;
        SELECT * FROM t1;
      COMMIT;
    } {1 2} 0 -1

    3  {
      BEGIN;
        SELECT * FROM t1;
      COMMIT;
    } {1 2} 0 -1

    4  { PRAGMA journal_mode = WAL }    wal    -1 -1
    5  { INSERT INTO t1 VALUES(3, 4) }  {}     -1 [wal_file_size 1 1024]
    6  { PRAGMA locking_mode = NORMAL } normal -1 [wal_file_size 1 1024]
    7  { INSERT INTO t1 VALUES(5, 6); } {}     -1 [wal_file_size 2 1024]

    8  { PRAGMA journal_mode = TRUNCATE } truncate          0 -1
    9  { INSERT INTO t1 VALUES(7, 8) }    {}                0 -1
    10 { SELECT * FROM t1 }               {1 2 3 4 5 6 7 8} 0 -1

  }] {
    do_execsql_test pager1-7.1.$tn.1 $sql $res
    catch { set J -1 ; set J [file size test.db-journal] }
    catch { set W -1 ; set W [file size test.db-wal] }
    do_test pager1-7.1.$tn.2 { list $J $W } [list $js $ws]
  }
}

#-------------------------------------------------------------------------
# The following tests, pager1-8.*, test that the special filenames
# ":memory:" and "" open temporary databases.
#
foreach {tn filename} {
  1 :memory:
  2 ""
} {
  do_test pager1-8.$tn.1 {
    faultsim_delete_and_reopen
    db close
    sqlite3 db $filename
    execsql {
      PRAGMA auto_vacuum = 1;
      CREATE TABLE x1(x);
      INSERT INTO x1 VALUES('Charles');
      INSERT INTO x1 VALUES('James');
      INSERT INTO x1 VALUES('Mary');
      SELECT * FROM x1;
    }
  } {Charles James Mary}

  do_test pager1-8.$tn.2 {
    sqlite3 db2 $filename
    catchsql { SELECT * FROM x1 } db2
  } {1 {no such table: x1}}

  do_execsql_test pager1-8.$tn.3 {
    BEGIN;
      INSERT INTO x1 VALUES('William');
      INSERT INTO x1 VALUES('Anne');
    ROLLBACK;
  } {}
}

#-------------------------------------------------------------------------
# The next block of tests - pager1-9.* - deal with interactions between
# the pager and the backup API. Test cases:
#
#   pager1-9.1.*: Test that a backup completes successfully even if the
#                 source db is written to during the backup op.
#
#   pager1-9.2.*: Test that a backup completes successfully even if the
#                 source db is written to and then rolled back during a
#                 backup operation.
#
do_test pager1-9.0.1 {
  faultsim_delete_and_reopen
  db func a_string a_string
  execsql {
    PRAGMA cache_size = 10;
    BEGIN;
      CREATE TABLE ab(a, b, UNIQUE(a, b));
      INSERT INTO ab VALUES( a_string(200), a_string(300) );
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
    COMMIT;
  }
} {}
do_test pager1-9.0.2 {
  sqlite3 db2 test.db2
  db2 eval { PRAGMA cache_size = 10 }
  sqlite3_backup B db2 main db main
  list [B step 10000] [B finish]
} {SQLITE_DONE SQLITE_OK}
do_test pager1-9.0.3 {
 db one {SELECT md5sum(a, b) FROM ab}
} [db2 one {SELECT md5sum(a, b) FROM ab}]

do_test pager1-9.1.1 {
  execsql { UPDATE ab SET a = a_string(201) }
  sqlite3_backup B db2 main db main
  B step 30
} {SQLITE_OK}
do_test pager1-9.1.2 {
  execsql { UPDATE ab SET b = a_string(301) }
  list [B step 10000] [B finish]
} {SQLITE_DONE SQLITE_OK}
do_test pager1-9.1.3 {
 db one {SELECT md5sum(a, b) FROM ab}
} [db2 one {SELECT md5sum(a, b) FROM ab}]
do_test pager1-9.1.4 { execsql { SELECT count(*) FROM ab } } {128}

do_test pager1-9.2.1 {
  execsql { UPDATE ab SET a = a_string(202) }
  sqlite3_backup B db2 main db main
  B step 30
} {SQLITE_OK}
do_test pager1-9.2.2 {
  execsql {
    BEGIN;
      UPDATE ab SET b = a_string(301);
    ROLLBACK;
  }
  list [B step 10000] [B finish]
} {SQLITE_DONE SQLITE_OK}
do_test pager1-9.2.3 {
 db one {SELECT md5sum(a, b) FROM ab}
} [db2 one {SELECT md5sum(a, b) FROM ab}]
do_test pager1-9.2.4 { execsql { SELECT count(*) FROM ab } } {128}
db close
db2 close

#-------------------------------------------------------------------------
# Test that regardless of the value returned by xSectorSize(), the
# minimum effective sector-size is 512 and the maximum 65536 bytes.
#
testvfs tv -default 1
foreach sectorsize {
    32   64   128   256   512   1024   2048
    4096 8192 16384 32768 65536 131072 262144
} {
  tv sectorsize $sectorsize
  set eff $sectorsize
  if {$sectorsize < 512}   { set eff 512 }
  if {$sectorsize > 65536} { set eff 65536 }

  do_test pager1-10.$sectorsize {
    faultsim_delete_and_reopen
    execsql {
      PRAGMA journal_mode = PERSIST;
      PRAGMA page_size = 1024;
      CREATE TABLE t1(a, b);
    }
    file size test.db-journal
  } [expr $sectorsize > 65536 ? 65536 : $sectorsize]
}
db close
tv delete

testvfs tv -default 1
faultsim_delete_and_reopen
db func a_string a_string
do_execsql_test pager1-11.1 {
  PRAGMA cache_size = 10;
  BEGIN;
    CREATE TABLE zz(top PRIMARY KEY);
    INSERT INTO zz VALUES(a_string(222));
    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
  COMMIT;
  BEGIN;
    UPDATE zz SET top = a_string(345);
} {}

proc lockout {method args} { return SQLITE_IOERR }
tv script lockout
tv filter {xWrite xTruncate xSync}
do_catchsql_test pager1-11.2 { COMMIT } {1 {disk I/O error}}

tv script {}
do_test pager1-11.3 {
  sqlite3 db2 test.db
  execsql {
    PRAGMA journal_mode = TRUNCATE;
    PRAGMA integrity_check;
  } db2
} {truncate ok}
do_test pager1-11.4 {
  db2 close
  file size test.db-journal
} {0}
do_execsql_test pager1-11.5 { SELECT count(*) FROM zz } {32}
db close
tv delete

#-------------------------------------------------------------------------
# Test "PRAGMA page_size"
#
foreach pagesize {
    512   1024   2048 4096 8192 16384 32768
} {
  faultsim_delete_and_reopen

  do_test pager1-12.$pagesize.1 {
    sqlite3 db2 test.db
    execsql "
      PRAGMA page_size = $pagesize;
      CREATE VIEW v AS SELECT * FROM sqlite_master;
    " db2
    file size test.db
  } $pagesize
  do_test pager1-12.$pagesize.2 {
    sqlite3 db2 test.db
    execsql {
      SELECT count(*) FROM v;
      PRAGMA main.page_size;
    } db2
  } [list 1 $pagesize]
  do_test pager1-12.$pagesize.3 {
    execsql {
      SELECT count(*) FROM v;
      PRAGMA main.page_size;
    }
  } [list 1 $pagesize]
  db2 close
}

#-------------------------------------------------------------------------
# Test specal "PRAGMA journal_mode=PERSIST" test cases.
#
# pager1-13.1.*: This tests a special case encountered in persistent
#                journal mode: If the journal associated with a transaction
#                is smaller than the journal file (because a previous
#                transaction left a very large non-hot journal file in the
#                file-system), then SQLite has to be careful that there is
#                not a journal-header left over from a previous transaction
#                immediately following the journal content just written.
#                If there is, and the process crashes so that the journal
#                becomes a hot-journal and must be rolled back by another
#                process, there is a danger that the other process may roll
#                back the aborted transaction, then continue copying data
#                from an older transaction from the remainder of the journal.
#                See the syncJournal() function for details.
#
# pager1-13.2.*: Same test as the previous. This time, throw an index into
#                the mix to make the integrity-check more likely to catch
#                errors.
#
testvfs tv -default 1
tv script xSyncCb
tv filter xSync
proc xSyncCb {method filename args} {
  set t [file tail $filename]
  if {$t == "test.db"} faultsim_save
  return SQLITE_OK
}
faultsim_delete_and_reopen
db func a_string a_string

# The UPDATE statement at the end of this test case creates a really big
# journal. Since the cache-size is only 10 pages, the journal contains
# frequent journal headers.
#
do_execsql_test pager1-13.1.1 {
  PRAGMA page_size = 1024;
  PRAGMA journal_mode = PERSIST;
  PRAGMA cache_size = 10;
  BEGIN;
    CREATE TABLE t1(a INTEGER PRIMARY KEY, b BLOB);
    INSERT INTO t1 VALUES(NULL, a_string(400));
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*   2 */
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*   4 */
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*   8 */
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*  16 */
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*  32 */
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*  64 */
    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /* 128 */
  COMMIT;
  UPDATE t1 SET b = a_string(400);
} {persist}

# Run transactions of increasing sizes. Eventually, one (or more than one)
# of these will write just enough content that one of the old headers created
# by the transaction in the block above lies immediately after the content
# journalled by the current transaction.
#
for {set nUp 1} {$nUp<64} {incr nUp} {
  do_execsql_test pager1-13.1.2.$nUp.1 {
    UPDATE t1 SET b = a_string(399) WHERE a <= $nUp
  } {}
  do_execsql_test pager1-13.1.2.$nUp.2 { PRAGMA integrity_check } {ok}

  # Try to access the snapshot of the file-system.
  #
  sqlite3 db2 sv_test.db
  do_test pager1-13.1.2.$nUp.3 {
    execsql { SELECT sum(length(b)) FROM t1 } db2
  } [expr {128*400 - ($nUp-1)}]
  do_test pager1-13.1.2.$nUp.4 {
    execsql { PRAGMA integrity_check } db2
  } {ok}
  db2 close
}

# Same test as above. But this time with an index on the table.
#
do_execsql_test pager1-13.2.1 {
  CREATE INDEX i1 ON t1(b);
  UPDATE t1 SET b = a_string(400);
} {}
for {set nUp 1} {$nUp<64} {incr nUp} {
  do_execsql_test pager1-13.2.2.$nUp.1 {
    UPDATE t1 SET b = a_string(399) WHERE a <= $nUp
  } {}
  do_execsql_test pager1-13.2.2.$nUp.2 { PRAGMA integrity_check } {ok}
  sqlite3 db2 sv_test.db
  do_test pager1-13.2.2.$nUp.3 {
    execsql { SELECT sum(length(b)) FROM t1 } db2
  } [expr {128*400 - ($nUp-1)}]
  do_test pager1-13.2.2.$nUp.4 {
    execsql { PRAGMA integrity_check } db2
  } {ok}
  db2 close
}

db close
tv delete

#-------------------------------------------------------------------------
# Test specal "PRAGMA journal_mode=OFF" test cases.
#
faultsim_delete_and_reopen
do_execsql_test pager1-14.1.1 {
  PRAGMA journal_mode = OFF;
  CREATE TABLE t1(a, b);
  BEGIN;
    INSERT INTO t1 VALUES(1, 2);
  COMMIT;
  SELECT * FROM t1;
} {off 1 2}
do_catchsql_test pager1-14.1.2 {
  BEGIN;
    INSERT INTO t1 VALUES(3, 4);
  ROLLBACK;
} {0 {}}
do_execsql_test pager1-14.1.3 {
  SELECT * FROM t1;
} {1 2 3 4}
do_catchsql_test pager1-14.1.4 {
  BEGIN;
    INSERT INTO t1(rowid, a, b) SELECT a+3, b, b FROM t1;
    INSERT INTO t1(rowid, a, b) SELECT a+3, b, b FROM t1;
} {1 {PRIMARY KEY must be unique}}
do_execsql_test pager1-14.1.5 {
  COMMIT;
  SELECT * FROM t1;
} {1 2 3 4 2 2 4 4}

#-------------------------------------------------------------------------
# Test opening and closing the pager sub-system with different values
# for the sqlite3_vfs.szOsFile variable.
#
faultsim_delete_and_reopen
do_execsql_test pager1-15.0 {
  CREATE TABLE tx(y, z);
  INSERT INTO tx VALUES('Ayutthaya', 'Beijing');
  INSERT INTO tx VALUES('London', 'Tokyo');
} {}
db close
for {set i 0} {$i<513} {incr i 3} {
  testvfs tv -default 1 -szosfile $i
  sqlite3 db test.db
  do_execsql_test pager1-15.$i.1 {
    SELECT * FROM tx;
  } {Ayutthaya Beijing London Tokyo}
  db close
  tv delete
}

#-------------------------------------------------------------------------
# Check that it is not possible to open a database file if the full path
# to the associated journal file will be longer than sqlite3_vfs.mxPathname.
#
testvfs tv -default 1
tv script xOpenCb
tv filter xOpen
proc xOpenCb {method filename} {
  set ::file_len [string length $filename]
}
sqlite3 db test.db
db close
tv delete

for {set ii [expr $::file_len-5]} {$ii < [expr $::file_len+20]} {incr ii} {
  testvfs tv -default 1 -mxpathname $ii

  # The length of the full path to file "test.db-journal" is ($::file_len+8).
  # If the configured sqlite3_vfs.mxPathname value greater than or equal to
  # this, then the file can be opened. Otherwise, it cannot.
  #
  if {$ii >= [expr $::file_len+8]} {
    set res {0 {}}
  } else {
    set res {1 {unable to open database file}}
  }

  do_test pager1-16.1.$ii {
    list [catch { sqlite3 db test.db } msg] $msg
  } $res

  catch {db close}
  tv delete
}

#-------------------------------------------------------------------------
# Test "PRAGMA omit_readlock".
#
#   pager1-17.$tn.1.*: Test that if a second connection has an open
#                      read-transaction, it is not usually possible to write
#                      the database.
#
#   pager1-17.$tn.2.*: Test that if the second connection was opened with
#                      the SQLITE_OPEN_READONLY flag, and
#                      "PRAGMA omit_readlock = 1" is executed before attaching
#                      the database and opening a read-transaction on it, it is
#                      possible to write the db.
#
#   pager1-17.$tn.3.*: Test that if the second connection was *not* opened with
#                      the SQLITE_OPEN_READONLY flag, executing
#                      "PRAGMA omit_readlock = 1" has no effect.
#
do_multiclient_test tn {
  do_test pager1-17.$tn.1.1 {
    sql1 {
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
    }
    sql2 {
      BEGIN;
      SELECT * FROM t1;
    }
  } {1 2}
  do_test pager1-17.$tn.1.2 {
    csql1 { INSERT INTO t1 VALUES(3, 4) }
  } {1 {database is locked}}
  do_test pager1-17.$tn.1.3 {
    sql2 { COMMIT }
    sql1 { INSERT INTO t1 VALUES(3, 4) }
  } {}

  do_test pager1-17.$tn.2.1 {
    code2 {
      db2 close
      sqlite3 db2 :memory: -readonly 1
    }
    sql2 {
      PRAGMA omit_readlock = 1;
      ATTACH 'test.db' AS two;
      BEGIN;
      SELECT * FROM t1;
    }
  } {1 2 3 4}
  do_test pager1-17.$tn.2.2 { sql1 "INSERT INTO t1 VALUES(5, 6)" } {}
  do_test pager1-17.$tn.2.3 { sql2 "SELECT * FROM t1" }            {1 2 3 4}
  do_test pager1-17.$tn.2.4 { sql2 "COMMIT ; SELECT * FROM t1" }   {1 2 3 4 5 6}

  do_test pager1-17.$tn.3.1 {
    code2 {
      db2 close
      sqlite3 db2 :memory:
    }
    sql2 {
      PRAGMA omit_readlock = 1;
      ATTACH 'test.db' AS two;
      BEGIN;
      SELECT * FROM t1;
    }
  } {1 2 3 4 5 6}
  do_test pager1-17.$tn.3.2 {
    csql1 { INSERT INTO t1 VALUES(3, 4) }
  } {1 {database is locked}}
  do_test pager1-17.$tn.3.3 { sql2 COMMIT } {}
}

#-------------------------------------------------------------------------
# Test the pagers response to the b-tree layer requesting illegal page
# numbers:
#
#   + The locking page,
#   + Page 0,
#   + A page with a page number greater than (2^31-1).
#
do_test pager1-18.1 {
  faultsim_delete_and_reopen
  db func a_string a_string
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(a_string(500), a_string(200));
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
  }
} {}
do_test pager1-18.2 {
  set root [db one "SELECT rootpage FROM sqlite_master"]
  set lockingpage [expr (0x10000/1024) + 1]
  execsql {
    PRAGMA writable_schema = 1;
    UPDATE sqlite_master SET rootpage = $lockingpage;
  }
  sqlite3 db2 test.db
  catchsql { SELECT count(*) FROM t1 } db2
} {1 {database disk image is malformed}}
db2 close
do_test pager1-18.3 {
  execsql {
    CREATE TABLE t2(x);
    INSERT INTO t2 VALUES(a_string(5000));
  }
  set pgno [expr ([file size test.db] / 1024)-2]
  hexio_write test.db [expr ($pgno-1)*1024] 00000000
  sqlite3 db2 test.db
  catchsql { SELECT length(x) FROM t2 } db2
} {1 {database disk image is malformed}}
db2 close
do_test pager1-18.4 {
  hexio_write test.db [expr ($pgno-1)*1024] 90000000
  sqlite3 db2 test.db
  catchsql { SELECT length(x) FROM t2 } db2
} {1 {database disk image is malformed}}
db2 close
do_test pager1-18.5 {
  sqlite3 db ""
  execsql {
    CREATE TABLE t1(a, b);
    CREATE TABLE t2(a, b);
    PRAGMA writable_schema = 1;
    UPDATE sqlite_master SET rootpage=5 WHERE tbl_name = 't1';
    PRAGMA writable_schema = 0;
    ALTER TABLE t1 RENAME TO x1;
  }
  catchsql { SELECT * FROM x1 }
} {1 {database disk image is malformed}}
db close

do_test pager1-18.6 {
  faultsim_delete_and_reopen
  db func a_string a_string
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(a_string(800));
    INSERT INTO t1 VALUES(a_string(800));
  }

  set root [db one "SELECT rootpage FROM sqlite_master"]
  db close

  hexio_write test.db [expr ($root-1)*1024 + 8] 00000000
  sqlite3 db test.db
  catchsql { SELECT length(x) FROM t1 }
} {1 {database disk image is malformed}}

do_test pager1-19.1 {
  sqlite3 db ""
  db func a_string a_string
  execsql {
    PRAGMA page_size = 512;
    PRAGMA auto_vacuum = 1;
    CREATE TABLE t1(aa, ab, ac, ad, ae, af, ag, ah, ai, aj, ak, al, am, an,
                    ba, bb, bc, bd, be, bf, bg, bh, bi, bj, bk, bl, bm, bn,
                    ca, cb, cc, cd, ce, cf, cg, ch, ci, cj, ck, cl, cm, cn,
                    da, db, dc, dd, de, df, dg, dh, di, dj, dk, dl, dm, dn,
                    ea, eb, ec, ed, ee, ef, eg, eh, ei, ej, ek, el, em, en,
                    fa, fb, fc, fd, fe, ff, fg, fh, fi, fj, fk, fl, fm, fn,
                    ga, gb, gc, gd, ge, gf, gg, gh, gi, gj, gk, gl, gm, gn,
                    ha, hb, hc, hd, he, hf, hg, hh, hi, hj, hk, hl, hm, hn,
                    ia, ib, ic, id, ie, if, ig, ih, ii, ij, ik, il, im, ix,
                    ja, jb, jc, jd, je, jf, jg, jh, ji, jj, jk, jl, jm, jn,
                    ka, kb, kc, kd, ke, kf, kg, kh, ki, kj, kk, kl, km, kn,
                    la, lb, lc, ld, le, lf, lg, lh, li, lj, lk, ll, lm, ln,
                    ma, mb, mc, md, me, mf, mg, mh, mi, mj, mk, ml, mm, mn
    );
    CREATE TABLE t2(aa, ab, ac, ad, ae, af, ag, ah, ai, aj, ak, al, am, an,
                    ba, bb, bc, bd, be, bf, bg, bh, bi, bj, bk, bl, bm, bn,
                    ca, cb, cc, cd, ce, cf, cg, ch, ci, cj, ck, cl, cm, cn,
                    da, db, dc, dd, de, df, dg, dh, di, dj, dk, dl, dm, dn,
                    ea, eb, ec, ed, ee, ef, eg, eh, ei, ej, ek, el, em, en,
                    fa, fb, fc, fd, fe, ff, fg, fh, fi, fj, fk, fl, fm, fn,
                    ga, gb, gc, gd, ge, gf, gg, gh, gi, gj, gk, gl, gm, gn,
                    ha, hb, hc, hd, he, hf, hg, hh, hi, hj, hk, hl, hm, hn,
                    ia, ib, ic, id, ie, if, ig, ih, ii, ij, ik, il, im, ix,
                    ja, jb, jc, jd, je, jf, jg, jh, ji, jj, jk, jl, jm, jn,
                    ka, kb, kc, kd, ke, kf, kg, kh, ki, kj, kk, kl, km, kn,
                    la, lb, lc, ld, le, lf, lg, lh, li, lj, lk, ll, lm, ln,
                    ma, mb, mc, md, me, mf, mg, mh, mi, mj, mk, ml, mm, mn
    );
    INSERT INTO t1(aa) VALUES( a_string(100000) );
    INSERT INTO t2(aa) VALUES( a_string(100000) );
    VACUUM;
  }
} {}

finish_test