# 2010 April 13
#
# 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 file is testing the operation of the library in
# "PRAGMA journal_mode=WAL" mode.
#

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

set testprefix wal

ifcapable !wal {finish_test ; return }

proc reopen_db {} {
  catch { db close }
  forcedelete test.db test.db-wal test.db-wal-summary
  sqlite3_wal db test.db
}

set ::blobcnt 0
proc blob {nByte} {
  incr ::blobcnt
  return [string range [string repeat "${::blobcnt}x" $nByte] 1 $nByte]
}

proc sqlite3_wal {args} {
  eval sqlite3 $args
  [lindex $args 0] eval { PRAGMA auto_vacuum = 0 }
  [lindex $args 0] eval { PRAGMA page_size = 1024 }
  [lindex $args 0] eval { PRAGMA journal_mode = wal }
  [lindex $args 0] eval { PRAGMA synchronous = normal }
  [lindex $args 0] function blob blob
}

proc log_deleted {logfile} {
  return [expr [file exists $logfile]==0]
}

#
# These are 'warm-body' tests used while developing the WAL code. They
# serve to prove that a few really simple cases work:
#
# wal-1.*: Read and write the database.
# wal-2.*: Test MVCC with one reader, one writer.
# wal-3.*: Test transaction rollback.
# wal-4.*: Test savepoint/statement rollback.
# wal-5.*: Test the temp database.
# wal-6.*: Test creating databases with different page sizes.
#
#
#
do_test wal-0.1 {
  execsql { PRAGMA auto_vacuum = 0 }
  execsql { PRAGMA synchronous = normal }
  execsql { PRAGMA journal_mode = wal }
} {wal}
do_test wal-0.2 {
  file size test.db
} {1024}

do_test wal-1.0 {
  execsql { 
    BEGIN;
    CREATE TABLE t1(a, b); 
  }
  list [file exists test.db-journal] \
       [file exists test.db-wal]     \
       [file size test.db]
} {0 1 1024}
do_test wal-1.1 {
  execsql COMMIT
  list [file exists test.db-journal] [file exists test.db-wal]
} {0 1}
do_test wal-1.2 {
  # There are now two pages in the log.
  file size test.db-wal
} [wal_file_size 2 1024]

do_test wal-1.3 {
  execsql { SELECT * FROM sqlite_master }
} {table t1 t1 2 {CREATE TABLE t1(a, b)}}

do_test wal-1.4 {
  execsql { INSERT INTO t1 VALUES(1, 2) }
  execsql { INSERT INTO t1 VALUES(3, 4) }
  execsql { INSERT INTO t1 VALUES(5, 6) }
  execsql { INSERT INTO t1 VALUES(7, 8) }
  execsql { INSERT INTO t1 VALUES(9, 10) }
} {}

do_test wal-1.5 {
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.1 {
  sqlite3_wal db2 ./test.db
  execsql { BEGIN; SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.2 {
  execsql { INSERT INTO t1 VALUES(11, 12) }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12}

do_test wal-2.3 {
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.4 {
  execsql { INSERT INTO t1 VALUES(13, 14) }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}

do_test wal-2.5 {
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10}

do_test wal-2.6 {
  execsql { COMMIT; SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}

do_test wal-3.1 {
  execsql { BEGIN; DELETE FROM t1 }
  execsql { SELECT * FROM t1 }
} {}
do_test wal-3.2 {
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
do_test wal-3.3 {
  execsql { ROLLBACK }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
db2 close

#-------------------------------------------------------------------------
# The following tests, wal-4.*, test that savepoints work with WAL 
# databases.
#
do_test wal-4.1 {
  execsql {
    DELETE FROM t1;
    BEGIN;
      INSERT INTO t1 VALUES('a', 'b');
      SAVEPOINT sp;
        INSERT INTO t1 VALUES('c', 'd');
        SELECT * FROM t1;
  }
} {a b c d}
do_test wal-4.2 {
  execsql {
      ROLLBACK TO sp;
      SELECT * FROM t1;
  }
} {a b}
do_test wal-4.3 {
  execsql {
    COMMIT;
    SELECT * FROM t1;
  }
} {a b}

do_test wal-4.4.1 {
  db close
  sqlite3 db test.db
  db func blob blob
  list [execsql { SELECT * FROM t1 }] [file size test.db-wal]
} {{a b} 0}
do_test wal-4.4.2 {
  execsql { PRAGMA cache_size = 10 }
  execsql {
    CREATE TABLE t2(a, b);
    INSERT INTO t2 VALUES(blob(400), blob(400));
    SAVEPOINT tr;
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  2 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  4 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  8 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 16 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 32 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  2 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  4 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  8 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 16 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 32 */
      SELECT count(*) FROM t2;
  }
} {32}
do_test wal-4.4.3 {
  execsql { ROLLBACK TO tr }
} {}
do_test wal-4.4.4 {
  set logsize [file size test.db-wal]
  execsql {
      INSERT INTO t1 VALUES('x', 'y');
    RELEASE tr;
  }
  expr { $logsize == [file size test.db-wal] }
} {1}
do_test wal-4.4.5 {
  execsql { SELECT count(*) FROM t2 }
} {1}
do_test wal-4.4.6 {
  forcecopy test.db test2.db
  forcecopy test.db-wal test2.db-wal
  sqlite3 db2 test2.db
  execsql { SELECT count(*) FROM t2 ; SELECT count(*) FROM t1 } db2
} {1 2}
do_test wal-4.4.7 {
  execsql { PRAGMA integrity_check } db2
} {ok}
db2 close

do_test wal-4.5.1 {
  reopen_db
  db func blob blob
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES('a', 'b');
  }
  sqlite3 db test.db
  db func blob blob
  list [execsql { SELECT * FROM t1 }] [file size test.db-wal]
} {{a b} 0}
do_test wal-4.5.2 {
  execsql { PRAGMA cache_size = 10 }
  execsql {
    CREATE TABLE t2(a, b);
    BEGIN;
    INSERT INTO t2 VALUES(blob(400), blob(400));
    SAVEPOINT tr;
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  2 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  4 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /*  8 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 16 */
      INSERT INTO t2 SELECT blob(400), blob(400) FROM t2; /* 32 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  2 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  4 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /*  8 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 16 */
      INSERT INTO t1 SELECT blob(400), blob(400) FROM t1; /* 32 */
      SELECT count(*) FROM t2;
  }
} {32}
do_test wal-4.5.3 {
  execsql { ROLLBACK TO tr }
} {}
do_test wal-4.5.4 {
  set logsize [file size test.db-wal]
  execsql {
      INSERT INTO t1 VALUES('x', 'y');
    RELEASE tr;
    COMMIT;
  }
  expr { $logsize == [file size test.db-wal] }
} {1}
do_test wal-4.5.5 {
  execsql { SELECT count(*) FROM t2 ; SELECT count(*) FROM t1 }
} {1 2}
do_test wal-4.5.6 {
  forcecopy test.db test2.db
  forcecopy test.db-wal test2.db-wal
  sqlite3 db2 test2.db
  execsql { SELECT count(*) FROM t2 ; SELECT count(*) FROM t1 } db2
} {1 2}
do_test wal-4.5.7 {
  execsql { PRAGMA integrity_check } db2
} {ok}
db2 close

do_test wal-4.6.1 {
  execsql {
    DELETE FROM t2;
    PRAGMA wal_checkpoint;
    BEGIN;
      INSERT INTO t2 VALUES('w', 'x');
      SAVEPOINT save;
        INSERT INTO t2 VALUES('y', 'z');
      ROLLBACK TO save;
    COMMIT;
  }
  execsql { SELECT * FROM t2 }
} {w x}


reopen_db
do_test wal-5.1 {
  execsql {
    CREATE TEMP TABLE t2(a, b);
    INSERT INTO t2 VALUES(1, 2);
  }
} {}
do_test wal-5.2 {
  execsql {
    BEGIN;
      INSERT INTO t2 VALUES(3, 4);
      SELECT * FROM t2;
  }
} {1 2 3 4}
do_test wal-5.3 {
  execsql {
    ROLLBACK;
    SELECT * FROM t2;
  }
} {1 2}
do_test wal-5.4 {
  execsql {
    CREATE TEMP TABLE t3(x UNIQUE);
    BEGIN;
      INSERT INTO t2 VALUES(3, 4);
      INSERT INTO t3 VALUES('abc');
  }
  catchsql { INSERT INTO t3 VALUES('abc') }
} {1 {UNIQUE constraint failed: t3.x}}
do_test wal-5.5 {
  execsql {
    COMMIT;
    SELECT * FROM t2;
  }
} {1 2 3 4}
db close

foreach sector {512 4096} {
  sqlite3_simulate_device -sectorsize $sector
  foreach pgsz {512 1024 2048 4096} {
    forcedelete test.db test.db-wal
    do_test wal-6.$sector.$pgsz.1 {
      sqlite3 db test.db -vfs devsym
      execsql "
        PRAGMA page_size = $pgsz;
        PRAGMA auto_vacuum = 0;
        PRAGMA journal_mode = wal;
      "
      execsql "
        CREATE TABLE t1(a, b);
        INSERT INTO t1 VALUES(1, 2);
      "
      db close
      file size test.db
    } [expr $pgsz*2]
  
    do_test wal-6.$sector.$pgsz.2 {
      log_deleted test.db-wal
    } {1}
  }
}

do_test wal-7.1 {
  forcedelete test.db test.db-wal
  sqlite3_wal db test.db
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  }
  list [file size test.db] [file size test.db-wal]
} [list 1024 [wal_file_size 3 1024]]
do_test wal-7.2 {
  execsql { PRAGMA wal_checkpoint }
  list [file size test.db] [file size test.db-wal]
} [list 2048 [wal_file_size 3 1024]]

# Execute some transactions in auto-vacuum mode to test database file
# truncation.
#
do_test wal-8.1 {
  reopen_db
  catch { db close }
  forcedelete test.db test.db-wal

  sqlite3 db test.db
  db function blob blob
  execsql {
    PRAGMA auto_vacuum = 1;
    PRAGMA journal_mode = wal;
    PRAGMA auto_vacuum;
  }
} {wal 1}
do_test wal-8.2 {
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  4 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  8 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 16 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 32 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 64 */
    PRAGMA wal_checkpoint;
  }
  file size test.db
} [expr 68*1024]
do_test wal-8.3 {
  execsql { 
    DELETE FROM t1 WHERE rowid<54;
    PRAGMA wal_checkpoint;
  }
  file size test.db
} [expr 14*1024]

# Run some "warm-body" tests to ensure that log-summary files with more
# than 256 entries (log summaries that contain index blocks) work Ok.
#
do_test wal-9.1 {
  reopen_db
  execsql {
    PRAGMA cache_size=2000;
    CREATE TABLE t1(x PRIMARY KEY);
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 VALUES(blob(900));
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  4 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /*  8 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 16 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 32 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 64 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 128 */
    INSERT INTO t1 SELECT blob(900) FROM t1;       /* 256 */
  }
  file size test.db
} 1024
do_test wal-9.2 {
  sqlite3_wal db2 test.db
  execsql {PRAGMA integrity_check } db2
} {ok}

do_test wal-9.3 {
  forcedelete test2.db test2.db-wal
  copy_file test.db test2.db
  copy_file test.db-wal test2.db-wal
  sqlite3_wal db3 test2.db 
  execsql {PRAGMA integrity_check } db3
} {ok}
db3 close

do_test wal-9.4 {
  execsql { PRAGMA wal_checkpoint }
  db2 close
  sqlite3_wal db2 test.db
  execsql {PRAGMA integrity_check } db2
} {ok}

foreach handle {db db2 db3} { catch { $handle close } }
unset handle

#-------------------------------------------------------------------------
# The following block of tests - wal-10.* - test that the WAL locking 
# scheme works in simple cases. This block of tests is run twice. Once
# using multiple connections in the address space of the current process,
# and once with all connections except one running in external processes.
#
do_multiclient_test tn {

  # Initialize the database schema and contents.
  #
  do_test wal-10.$tn.1 {
    execsql {
      PRAGMA auto_vacuum = 0;
      PRAGMA journal_mode = wal;
      CREATE TABLE t1(a, b);
      INSERT INTO t1 VALUES(1, 2);
      SELECT * FROM t1;
    }
  } {wal 1 2}

  # Open a transaction and write to the database using [db]. Check that [db2]
  # is still able to read the snapshot before the transaction was opened.
  #
  do_test wal-10.$tn.2 {
    execsql { BEGIN; INSERT INTO t1 VALUES(3, 4); }
    sql2 {SELECT * FROM t1}
  } {1 2}

  # Have [db] commit the transaction. Check that [db2] is now seeing the 
  # new, updated snapshot.
  #
  do_test wal-10.$tn.3 {
    execsql { COMMIT }
    sql2 {SELECT * FROM t1}
  } {1 2 3 4}

  # Have [db2] open a read transaction. Then write to the db via [db]. Check
  # that [db2] is still seeing the original snapshot. Then read with [db3].
  # [db3] should see the newly committed data.
  #
  do_test wal-10.$tn.4 {
    sql2 { BEGIN ; SELECT * FROM t1}
  } {1 2 3 4}
  do_test wal-10.$tn.5 {
    execsql { INSERT INTO t1 VALUES(5, 6); }
    sql2 {SELECT * FROM t1}
  } {1 2 3 4}
  do_test wal-10.$tn.6 {
    sql3 {SELECT * FROM t1}
  } {1 2 3 4 5 6}
  do_test wal-10.$tn.7 {
    sql2 COMMIT
  } {}

  # Have [db2] open a write transaction. Then attempt to write to the 
  # database via [db]. This should fail (writer lock cannot be obtained).
  #
  # Then open a read-transaction with [db]. Commit the [db2] transaction
  # to disk. Verify that [db] still cannot write to the database (because
  # it is reading an old snapshot).
  #
  # Close the current [db] transaction. Open a new one. [db] can now write
  # to the database (as it is not locked and [db] is reading the latest
  # snapshot).
  #
  do_test wal-10.$tn.7 {
    sql2 { BEGIN; INSERT INTO t1 VALUES(7, 8) ; }
    catchsql { INSERT INTO t1 VALUES(9, 10) }
  } {1 {database is locked}}
  do_test wal-10.$tn.8 {
    execsql { BEGIN ; SELECT * FROM t1 }
  } {1 2 3 4 5 6}
  do_test wal-10.$tn.9 {
    sql2 COMMIT
    catchsql { INSERT INTO t1 VALUES(9, 10) }
  } {1 {database is locked}}
  do_test wal-10.$tn.10 {
    execsql { COMMIT }
    execsql { BEGIN }
    execsql { INSERT INTO t1 VALUES(9, 10) }
    execsql { COMMIT }
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10}

  # Open a read transaction with [db2]. Check that this prevents [db] from
  # checkpointing the database. But not from writing to it.
  #
  do_test wal-10.$tn.11 {
    sql2 { BEGIN; SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10}
  do_test wal-10.$tn.12 {
    catchsql { PRAGMA wal_checkpoint } 
  } {0 {0 7 7}}   ;# Reader no longer block checkpoints
  do_test wal-10.$tn.13 {
    execsql { INSERT INTO t1 VALUES(11, 12) }
    sql2 {SELECT * FROM t1}
  } {1 2 3 4 5 6 7 8 9 10}

  # Writers do not block checkpoints any more either.
  #
  do_test wal-10.$tn.14 {
    catchsql { PRAGMA wal_checkpoint } 
  } {0 {0 8 7}}

  # The following series of test cases used to verify another blocking
  # case in WAL - a case which no longer blocks.
  #
  do_test wal-10.$tn.15 {
    sql2 { COMMIT; BEGIN; SELECT * FROM t1; }
  } {1 2 3 4 5 6 7 8 9 10 11 12}
  do_test wal-10.$tn.16 {
    catchsql { PRAGMA wal_checkpoint } 
  } {0 {0 8 8}}
  do_test wal-10.$tn.17 {
    execsql { PRAGMA wal_checkpoint } 
  } {0 8 8}
  do_test wal-10.$tn.18 {
    sql3 { BEGIN; SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12}
  do_test wal-10.$tn.19 {
    catchsql { INSERT INTO t1 VALUES(13, 14) }
  } {0 {}}
  do_test wal-10.$tn.20 {
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
  do_test wal-10.$tn.21 {
    sql3 COMMIT
    sql2 COMMIT
  } {}
  do_test wal-10.$tn.22 {
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14}

  # Another series of tests that used to demonstrate blocking behavior
  # but which now work.
  #
  do_test wal-10.$tn.23 {
    execsql { PRAGMA wal_checkpoint }
  } {0 9 9}
  do_test wal-10.$tn.24 {
    sql2 { BEGIN; SELECT * FROM t1; }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
  do_test wal-10.$tn.25 {
    execsql { PRAGMA wal_checkpoint }
  } {0 9 9}
  do_test wal-10.$tn.26 {
    catchsql { INSERT INTO t1 VALUES(15, 16) }
  } {0 {}}
  do_test wal-10.$tn.27 {
    sql3 { INSERT INTO t1 VALUES(17, 18) }
  } {}
  do_test wal-10.$tn.28 {
    code3 {
      set ::STMT [sqlite3_prepare db3 "SELECT * FROM t1" -1 TAIL]
      sqlite3_step $::STMT
    }
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18}
  do_test wal-10.$tn.29 {
    execsql { INSERT INTO t1 VALUES(19, 20) }
    catchsql { PRAGMA wal_checkpoint }
  } {0 {0 3 0}}
  do_test wal-10.$tn.30 {
    code3 { sqlite3_finalize $::STMT }
    execsql { PRAGMA wal_checkpoint }
  } {0 3 0}

  # At one point, if a reader failed to upgrade to a writer because it
  # was reading an old snapshot, the write-locks were not being released.
  # Test that this bug has been fixed.
  #
  do_test wal-10.$tn.31 {
    sql2 COMMIT
    execsql { BEGIN ; SELECT * FROM t1 }
    sql2 { INSERT INTO t1 VALUES(21, 22) }
    catchsql { INSERT INTO t1 VALUES(23, 24) }
  } {1 {database is locked}}
  do_test wal-10.$tn.32 {
    # This statement would fail when the bug was present.
    sql2 { INSERT INTO t1 VALUES(23, 24) }
  } {}
  do_test wal-10.$tn.33 {
    execsql { SELECT * FROM t1 ; COMMIT }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20}
  do_test wal-10.$tn.34 {
    execsql { SELECT * FROM t1 }
  } {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24}

  # Test that if a checkpointer cannot obtain the required locks, it
  # releases all locks before returning a busy error.
  #
  do_test wal-10.$tn.35 {
    execsql { 
      DELETE FROM t1;
      INSERT INTO t1 VALUES('a', 'b');
      INSERT INTO t1 VALUES('c', 'd');
    }
    sql2 {
      BEGIN;
        SELECT * FROM t1;
    }
  } {a b c d}
  do_test wal-10.$tn.36 {
    catchsql { PRAGMA wal_checkpoint }
  } {0 {0 8 8}}
  do_test wal-10.$tn.36 {
    sql3 { INSERT INTO t1 VALUES('e', 'f') }
    sql2 { SELECT * FROM t1 }
  } {a b c d}
  do_test wal-10.$tn.37 {
    sql2 COMMIT
    execsql { PRAGMA wal_checkpoint }
  } {0 9 9}
}

#-------------------------------------------------------------------------
# This block of tests, wal-11.*, test that nothing goes terribly wrong
# if frames must be written to the log file before a transaction is
# committed (in order to free up memory).
#
do_test wal-11.1 {
  reopen_db
  execsql {
    PRAGMA cache_size = 10;
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x PRIMARY KEY);
  }
  list [expr [file size test.db]/1024] [expr [file size test.db-wal]/1044]
} {1 3}
do_test wal-11.2 {
  execsql { PRAGMA wal_checkpoint }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [wal_file_size 3 1024]]
do_test wal-11.3 {
  execsql { INSERT INTO t1 VALUES( blob(900) ) }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [wal_file_size 4 1024]]

do_test wal-11.4 {
  execsql { 
    BEGIN;
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 2
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 4
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 8
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 16
  }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [wal_file_size 32 1024]]
do_test wal-11.5 {
  execsql { 
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {16 ok}
do_test wal-11.6 {
  execsql COMMIT
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 3 [wal_file_size 41 1024]]
do_test wal-11.7 {
  execsql { 
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {16 ok}
do_test wal-11.8 {
  execsql { PRAGMA wal_checkpoint }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [wal_file_size 41 1024]]
do_test wal-11.9 {
  db close
  list [expr [file size test.db]/1024] [log_deleted test.db-wal]
} {37 1}
sqlite3_wal db test.db
set nWal 39
if {[permutation]!="mmap"} {set nWal 37}
ifcapable !mmap {set nWal 37}
do_test wal-11.10 {
  execsql {
    PRAGMA cache_size = 10;
    BEGIN;
      INSERT INTO t1 SELECT blob(900) FROM t1;   -- 32
      SELECT count(*) FROM t1;
  }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [wal_file_size $nWal 1024]]
do_test wal-11.11 {
  execsql {
      SELECT count(*) FROM t1;
    ROLLBACK;
    SELECT count(*) FROM t1;
  }
} {32 16}
do_test wal-11.12 {
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [wal_file_size $nWal 1024]]
do_test wal-11.13 {
  execsql {
    INSERT INTO t1 VALUES( blob(900) );
    SELECT count(*) FROM t1;
    PRAGMA integrity_check;
  }
} {17 ok}
do_test wal-11.14 {
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 37 [wal_file_size $nWal 1024]]


#-------------------------------------------------------------------------
# This block of tests, wal-12.*, tests the fix for a problem that 
# could occur if a log that is a prefix of an older log is written 
# into a reused log file.
#
reopen_db
do_test wal-12.1 {
  execsql {
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x, y);
    CREATE TABLE t2(x, y);
    INSERT INTO t1 VALUES('A', 1);
  }
  list [expr [file size test.db]/1024] [file size test.db-wal]
} [list 1 [wal_file_size 5 1024]]
do_test wal-12.2 {
  db close
  sqlite3 db test.db
  execsql {
    PRAGMA synchronous = normal;
    UPDATE t1 SET y = 0 WHERE x = 'A';
  }
  list [expr [file size test.db]/1024] [expr [file size test.db-wal]/1044]
} {3 1}
do_test wal-12.3 {
  execsql { INSERT INTO t2 VALUES('B', 1) }
  list [expr [file size test.db]/1024] [expr [file size test.db-wal]/1044]
} {3 2}
do_test wal-12.4 {
  forcecopy test.db test2.db
  forcecopy test.db-wal test2.db-wal
  sqlite3_wal db2 test2.db
  execsql { SELECT * FROM t2 } db2
} {B 1}
db2 close
do_test wal-12.5 {
  execsql {
    PRAGMA wal_checkpoint;
    UPDATE t2 SET y = 2 WHERE x = 'B'; 
    PRAGMA wal_checkpoint;
    UPDATE t1 SET y = 1 WHERE x = 'A';
    PRAGMA wal_checkpoint;
    UPDATE t1 SET y = 0 WHERE x = 'A';
  }
  execsql {  SELECT * FROM t2 }
} {B 2}
do_test wal-12.6 {
  forcecopy test.db test2.db
  forcecopy test.db-wal test2.db-wal
  sqlite3_wal db2 test2.db
  execsql { SELECT * FROM t2 } db2
} {B 2}
db2 close
db close

#-------------------------------------------------------------------------
# Test large log summaries.
#
# In this case "large" usually means a log file that requires a wal-index
# mapping larger than 64KB (the default initial allocation). A 64KB wal-index
# is large enough for a log file that contains approximately 13100 frames.
# So the following tests create logs containing at least this many frames.
#
# wal-13.1.*: This test case creates a very large log file within the
#             file-system (around 200MB). The log file does not contain
#             any valid frames. Test that the database file can still be
#             opened and queried, and that the invalid log file causes no 
#             problems.
#
# wal-13.2.*: Test that a process may create a large log file and query
#             the database (including the log file that it itself created).
#
# wal-13.3.*: Test that if a very large log file is created, and then a
#             second connection is opened on the database file, it is possible
#             to query the database (and the very large log) using the
#             second connection.
#
# wal-13.4.*: Same test as wal-13.3.*. Except in this case the second
#             connection is opened by an external process.
#
do_test wal-13.1.1 {
  list [file exists test.db] [file exists test.db-wal]
} {1 0}
do_test wal-13.1.2 {
  set fd [open test.db-wal w]
  seek $fd [expr 200*1024*1024]
  puts $fd ""
  close $fd
  sqlite3 db test.db
  execsql { SELECT * FROM t2 }
} {B 2}
do_test wal-13.1.3 {
  db close
  file exists test.db-wal
} {0}

do_test wal-13.2.1 {
  sqlite3 db test.db
  execsql { SELECT count(*) FROM t2 }
} {1}
do_test wal-13.2.2 {
  db function blob blob
  for {set i 0} {$i < 16} {incr i} {
    execsql { INSERT INTO t2 SELECT blob(400), blob(400) FROM t2 }
  }
  execsql { SELECT count(*) FROM t2 }
} [expr int(pow(2, 16))]
do_test wal-13.2.3 {
  expr [file size test.db-wal] > [wal_file_size 33000 1024]
} 1

do_multiclient_test tn {
  incr tn 2

  do_test wal-13.$tn.0 {
    sql1 {
      PRAGMA journal_mode = WAL;
      CREATE TABLE t1(x);
      INSERT INTO t1 SELECT randomblob(800);
    }
    sql1 { SELECT count(*) FROM t1 }
  } {1}

  for {set ii 1} {$ii<16} {incr ii} {
    do_test wal-13.$tn.$ii.a {
      sql2 { INSERT INTO t1 SELECT randomblob(800) FROM t1 }
      sql2 { SELECT count(*) FROM t1 }
    } [expr (1<<$ii)]
    do_test wal-13.$tn.$ii.b {
      sql1 { SELECT count(*) FROM t1 }
    } [expr (1<<$ii)]
    do_test wal-13.$tn.$ii.c {
      sql1 { SELECT count(*) FROM t1 }
    } [expr (1<<$ii)]
    do_test wal-13.$tn.$ii.d {
      sql1 { PRAGMA integrity_check }
    } {ok}
  }
}

#-------------------------------------------------------------------------
# Check a fun corruption case has been fixed.
#
# The problem was that after performing a checkpoint using a connection
# that had an out-of-date pager-cache, the next time the connection was
# used it did not realize the cache was out-of-date and proceeded to
# operate with an inconsistent cache. Leading to corruption.
#
catch { db close }
catch { db2 close }
catch { db3 close }
forcedelete test.db test.db-wal
sqlite3 db test.db
sqlite3 db2 test.db
do_test wal-14 {
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a PRIMARY KEY, b);
    INSERT INTO t1 VALUES(randomblob(10), randomblob(100));
    INSERT INTO t1 SELECT randomblob(10), randomblob(100) FROM t1;
    INSERT INTO t1 SELECT randomblob(10), randomblob(100) FROM t1;
    INSERT INTO t1 SELECT randomblob(10), randomblob(100) FROM t1;
  }

  db2 eval { 
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
    INSERT INTO t1 SELECT randomblob(10), randomblob(100);
  }

  # After executing the "PRAGMA wal_checkpoint", connection [db] was being
  # left with an inconsistent cache. Running the CREATE INDEX statement
  # in this state led to database corruption.
  catchsql { 
    PRAGMA wal_checkpoint;
    CREATE INDEX i1 on t1(b);
  }
   
  db2 eval { PRAGMA integrity_check }
} {ok}

catch { db close }
catch { db2 close }

#-------------------------------------------------------------------------
# The following block of tests - wal-15.* - focus on testing the 
# implementation of the sqlite3_wal_checkpoint() interface.
#
forcedelete test.db test.db-wal
sqlite3 db test.db
do_test wal-15.1 {
  execsql {
    PRAGMA auto_vacuum = 0;
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = WAL;
  }
  execsql {
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  }
} {}

# Test that an error is returned if the database name is not recognized
#
do_test wal-15.2.1 {
  sqlite3_wal_checkpoint db aux
} {SQLITE_ERROR}
do_test wal-15.2.2 {
  sqlite3_errcode db
} {SQLITE_ERROR}
do_test wal-15.2.3 {
  sqlite3_errmsg db
} {unknown database: aux}

# Test that an error is returned if an attempt is made to checkpoint
# if a transaction is open on the database.
#
do_test wal-15.3.1 {
  execsql {
    BEGIN;
    INSERT INTO t1 VALUES(3, 4);
  }
  sqlite3_wal_checkpoint db main
} {SQLITE_LOCKED}
do_test wal-15.3.2 {
  sqlite3_errcode db
} {SQLITE_LOCKED}
do_test wal-15.3.3 {
  sqlite3_errmsg db
} {database table is locked}

# Earlier versions returned an error is returned if the db cannot be 
# checkpointed because of locks held by another connection. Check that
# this is no longer the case.
#
sqlite3 db2 test.db
do_test wal-15.4.1 {
  execsql {
    BEGIN;
    SELECT * FROM t1;
  } db2
} {1 2}
do_test wal-15.4.2 {
  execsql { COMMIT }
  sqlite3_wal_checkpoint db
} {SQLITE_OK}
do_test wal-15.4.3 {
  sqlite3_errmsg db
} {not an error}

# After [db2] drops its lock, [db] may checkpoint the db.
#
do_test wal-15.4.4 {
  execsql { COMMIT } db2
  sqlite3_wal_checkpoint db
} {SQLITE_OK}
do_test wal-15.4.5 {
  sqlite3_errmsg db
} {not an error}
do_test wal-15.4.6 {
  file size test.db
} [expr 1024*2]

catch { db2 close }
catch { db close }

#-------------------------------------------------------------------------
# The following block of tests - wal-16.* - test that if a NULL pointer or
# an empty string is passed as the second argument of the wal_checkpoint()
# API, an attempt is made to checkpoint all attached databases.
#
foreach {tn ckpt_cmd ckpt_res ckpt_main ckpt_aux} {
  1 {sqlite3_wal_checkpoint db}              SQLITE_OK     1 1
  2 {sqlite3_wal_checkpoint db ""}           SQLITE_OK     1 1
  3 {db eval "PRAGMA wal_checkpoint"}        {0 10 10}     1 1

  4 {sqlite3_wal_checkpoint db main}         SQLITE_OK     1 0
  5 {sqlite3_wal_checkpoint db aux}          SQLITE_OK     0 1
  6 {sqlite3_wal_checkpoint db temp}         SQLITE_OK     0 0
  7 {db eval "PRAGMA main.wal_checkpoint"}   {0 10 10}     1 0
  8 {db eval "PRAGMA aux.wal_checkpoint"}    {0 13 13}     0 1
  9 {db eval "PRAGMA temp.wal_checkpoint"}   {0 -1 -1}     0 0
} {
  do_test wal-16.$tn.1 {
    forcedelete test2.db test2.db-wal test2.db-journal
    forcedelete test.db test.db-wal test.db-journal

    sqlite3 db test.db
    execsql {
      ATTACH 'test2.db' AS aux;
      PRAGMA main.auto_vacuum = 0;
      PRAGMA aux.auto_vacuum = 0;
      PRAGMA main.journal_mode = WAL;
      PRAGMA aux.journal_mode = WAL;
      PRAGMA main.synchronous = NORMAL;
      PRAGMA aux.synchronous = NORMAL;
    }
  } {wal wal}

  do_test wal-16.$tn.2 {
    execsql {
      CREATE TABLE main.t1(a, b, PRIMARY KEY(a, b));
      CREATE TABLE aux.t2(a, b, PRIMARY KEY(a, b));

      INSERT INTO t2 VALUES(1, randomblob(1000));
      INSERT INTO t2 VALUES(2, randomblob(1000));
      INSERT INTO t1 SELECT * FROM t2;
    }
  
    list [file size test.db] [file size test.db-wal]
  } [list [expr 1*1024] [wal_file_size 10 1024]]
  do_test wal-16.$tn.3 {
    list [file size test2.db] [file size test2.db-wal]
  } [list [expr 1*1024] [wal_file_size 13 1024]]
  
  do_test wal-16.$tn.4 [list eval $ckpt_cmd] $ckpt_res
  
  do_test wal-16.$tn.5 {
    list [file size test.db] [file size test.db-wal]
  } [list [expr ($ckpt_main ? 7 : 1)*1024] [wal_file_size 10 1024]]

  do_test wal-16.$tn.6 {
    list [file size test2.db] [file size test2.db-wal]
  } [list [expr ($ckpt_aux ? 7 : 1)*1024] [wal_file_size 13 1024]]

  catch { db close }
}

#-------------------------------------------------------------------------
# The following tests - wal-17.* - attempt to verify that the correct
# number of "padding" frames are appended to the log file when a transaction
# is committed in synchronous=FULL mode.
# 
# Do this by creating a database that uses 512 byte pages. Then writing
# a transaction that modifies 171 pages. In synchronous=NORMAL mode, this
# produces a log file of:
#
#   32 + (24+512)*171 = 90312 bytes.
#
# Slightly larger than 11*8192 = 90112 bytes.
#
# Run the test using various different sector-sizes. In each case, the
# WAL code should write the 90300 bytes of log file containing the 
# transaction, then append as may frames as are required to extend the
# log file so that no part of the next transaction will be written into
# a disk-sector used by transaction just committed.
#
set old_pending_byte [sqlite3_test_control_pending_byte 0x10000000]
catch { db close }
foreach {tn sectorsize logsize} "
  1   128  [wal_file_size 172 512]
  2   256  [wal_file_size 172 512]
  3   512  [wal_file_size 172 512] 
  4  1024  [wal_file_size 172 512]
  5  2048  [wal_file_size 172 512]
  6  4096  [wal_file_size 176 512]
  7  8192  [wal_file_size 184 512]
" {
  forcedelete test.db test.db-wal test.db-journal
  sqlite3_simulate_device -sectorsize $sectorsize
  sqlite3 db test.db -vfs devsym

  do_test wal-17.$tn.1 {
    execsql {
      PRAGMA auto_vacuum = 0;
      PRAGMA page_size = 512;
      PRAGMA cache_size = -2000;
      PRAGMA journal_mode = WAL;
      PRAGMA synchronous = FULL;
    }
    execsql {
      BEGIN;
      CREATE TABLE t(x);
    }
    for {set i 0} {$i<166} {incr i} {
      execsql { INSERT INTO t VALUES(randomblob(400)) }
    }
    execsql COMMIT

    file size test.db-wal
  } $logsize

  do_test wal-17.$tn.2 {
    file size test.db
  } 512

  do_test wal-17.$tn.3 {
    db close
    file size test.db
  } [expr 512*171]
}
sqlite3_test_control_pending_byte $old_pending_byte

#-------------------------------------------------------------------------
# This test - wal-18.* - verifies a couple of specific conditions that
# may be encountered while recovering a log file are handled correctly:
#
#   wal-18.1.* When the first 32-bits of a frame checksum is correct but 
#              the second 32-bits are false, and
#
#   wal-18.2.* When the page-size field that occurs at the start of a log
#              file is a power of 2 greater than 16384 or smaller than 512.
#
forcedelete test.db test.db-wal test.db-journal
do_test wal-18.0 {
  sqlite3 db test.db
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA auto_vacuum = 0;
    PRAGMA journal_mode = WAL;
    PRAGMA synchronous = OFF;

    CREATE TABLE t1(a, b, UNIQUE(a, b));
    INSERT INTO t1 VALUES(0, 0);
    PRAGMA wal_checkpoint;

    INSERT INTO t1 VALUES(1, 2);          -- frames 1 and 2
    INSERT INTO t1 VALUES(3, 4);          -- frames 3 and 4
    INSERT INTO t1 VALUES(5, 6);          -- frames 5 and 6
  }

  forcecopy test.db testX.db
  forcecopy test.db-wal testX.db-wal
  db close
  list [file size testX.db] [file size testX.db-wal]
} [list [expr 3*1024] [wal_file_size 6 1024]]

unset -nocomplain nFrame result
foreach {nFrame result} {
         0      {0 0}
         1      {0 0}
         2      {0 0 1 2}
         3      {0 0 1 2}
         4      {0 0 1 2 3 4}
         5      {0 0 1 2 3 4}
         6      {0 0 1 2 3 4 5 6}
} {
  do_test wal-18.1.$nFrame {
    forcecopy testX.db test.db
    forcecopy testX.db-wal test.db-wal

    hexio_write test.db-wal [expr 24 + $nFrame*(24+1024) + 20] 00000000

    sqlite3 db test.db
    execsql { 
      SELECT * FROM t1;
      PRAGMA integrity_check; 
    }
  } [concat $result ok]
  db close
} 

proc randomblob {pgsz} {
  sqlite3 rbdb :memory:
  set blob [rbdb one {SELECT randomblob($pgsz)}]
  rbdb close
  set blob
}

proc logcksum {ckv1 ckv2 blob} {
  upvar $ckv1 c1
  upvar $ckv2 c2

  # Since the magic number at the start of the -wal file header is
  # 931071618 that indicates that the content should always be read as
  # little-endian.
  # 
  set scanpattern i*

  binary scan $blob $scanpattern values
  foreach {v1 v2} $values {
    set c1 [expr {($c1 + $v1 + $c2)&0xFFFFFFFF}]
    set c2 [expr {($c2 + $v2 + $c1)&0xFFFFFFFF}]
  }
}

forcecopy test.db testX.db
foreach {tn pgsz works} { 
  1    128    0
  2    256    0
  3    512    1
  4   1024    1
  5   2048    1
  6   4096    1
  7   8192    1
  8  16384    1
  9  32768    1
 10  65536    1
 11 131072    0
 11   1016    0
} {

  if {$::SQLITE_MAX_PAGE_SIZE < $pgsz} {
    set works 0
  }

  for {set pg 1} {$pg <= 3} {incr pg} {
    forcecopy testX.db test.db
    forcedelete test.db-wal
  
    # Check that the database now exists and consists of three pages. And
    # that there is no associated wal file.
    #
    do_test wal-18.2.$tn.$pg.1 { file exists test.db-wal } 0
    do_test wal-18.2.$tn.$pg.2 { file exists test.db } 1
    do_test wal-18.2.$tn.$pg.3 { file size test.db } [expr 1024*3]
  
    do_test wal-18.2.$tn.$pg.4 {

      # Create a wal file that contains a single frame (database page
      # number $pg) with the commit flag set. The frame checksum is
      # correct, but the contents of the database page are corrupt.
      #
      # The page-size in the log file header is set to $pgsz. If the
      # WAL code considers $pgsz to be a valid SQLite database file page-size,
      # the database will be corrupt (because the garbage frame contents
      # will be treated as valid content). If $pgsz is invalid (too small
      # or too large), the db will not be corrupt as the log file will
      # be ignored.
      #
      set walhdr [binary format IIIIII 931071618 3007000 $pgsz 1234 22 23]
      set framebody [randomblob $pgsz]
      set framehdr  [binary format IIII $pg 5 22 23]
      set c1 0
      set c2 0
      logcksum c1 c2 $walhdr

      append walhdr [binary format II $c1 $c2]
      logcksum c1 c2 [string range $framehdr 0 7]
      logcksum c1 c2 $framebody
      set framehdr [binary format IIIIII $pg 5 22 23 $c1 $c2]

      set fd [open test.db-wal w]
      fconfigure $fd -encoding binary -translation binary
      puts -nonewline $fd $walhdr
      puts -nonewline $fd $framehdr
      puts -nonewline $fd $framebody
      close $fd
  
      file size test.db-wal
    } [wal_file_size 1 $pgsz]
  
    do_test wal-18.2.$tn.$pg.5 {
      sqlite3 db test.db
      set rc [catch { db one {PRAGMA integrity_check} } msg]
      expr { $rc!=0 || $msg!="ok" }
    } $works
  
    db close
  }
}

#-------------------------------------------------------------------------
# The following test - wal-19.* - fixes a bug that was present during
# development.
#
# When a database connection in WAL mode is closed, it attempts an
# EXCLUSIVE lock on the database file. If the lock is obtained, the
# connection knows that it is the last connection to disconnect from
# the database, so it runs a checkpoint operation. The bug was that
# the connection was not updating its private copy of the wal-index 
# header before doing so, meaning that it could checkpoint an old
# snapshot.
#
do_test wal-19.1 {
  forcedelete test.db test.db-wal test.db-journal
  sqlite3 db test.db
  sqlite3 db2 test.db
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
  }
  execsql { SELECT * FROM t1 } db2
} {1 2 3 4}
do_test wal-19.2 {
  execsql {
    INSERT INTO t1 VALUES(5, 6);
    SELECT * FROM t1;
  }
} {1 2 3 4 5 6}
do_test wal-19.3 {
  db close
  db2 close
  file exists test.db-wal
} {0}
do_test wal-19.4 {
  # When the bug was present, the following was returning {1 2 3 4} only,
  # as [db2] had an out-of-date copy of the wal-index header when it was
  # closed.
  #
  sqlite3 db test.db
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6}

#-------------------------------------------------------------------------
# This test - wal-20.* - uses two connections. One in this process and
# the other in an external process. The procedure is:
#
#   1. Using connection 1, create the database schema.
#
#   2. Using connection 2 (in an external process), add so much
#      data to the database without checkpointing that a wal-index 
#      larger than 64KB is required.
#
#   3. Using connection 1, checkpoint the database. Make sure all
#      the data is present and the database is not corrupt.
#
# At one point, SQLite was failing to grow the mapping of the wal-index
# file in step 3 and the checkpoint was corrupting the database file.
#
do_test wal-20.1 {
  catch {db close}
  forcedelete test.db test.db-wal test.db-journal
  sqlite3 db test.db
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(randomblob(900));
    SELECT count(*) FROM t1;
  }
} {wal 1}
do_test wal-20.2 {
  set ::buddy [launch_testfixture]
  testfixture $::buddy {
    sqlite3 db test.db
    db transaction { db eval {
      PRAGMA wal_autocheckpoint = 0;
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 2 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 4 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 8 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 16 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 32 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 64 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 128 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 256 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 512 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 1024 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 2048 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 4096 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 8192 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 16384 */
    } }
  }
} {0}
do_test wal-20.3 {
  close $::buddy
  execsql { PRAGMA wal_checkpoint }
  execsql { SELECT count(*) FROM t1 }
} {16384}
do_test wal-20.4 {
  db close
  sqlite3 db test.db
  execsql { SELECT count(*) FROM t1 }
} {16384}
integrity_check wal-20.5

catch { db2 close }
catch { db close }

do_test wal-21.1 {
  faultsim_delete_and_reopen
  execsql { 
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
    INSERT INTO t1 VALUES(5, 6);
    INSERT INTO t1 VALUES(7, 8);
    INSERT INTO t1 VALUES(9, 10);
    INSERT INTO t1 VALUES(11, 12);
  }
} {wal}
do_test wal-21.2 {
  execsql { 
    PRAGMA cache_size = 10;
    PRAGMA wal_checkpoint;
    BEGIN;
      SAVEPOINT s;
        INSERT INTO t1 SELECT randomblob(900), randomblob(900) FROM t1;
      ROLLBACK TO s;
    COMMIT;
  }
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6 7 8 9 10 11 12}
do_test wal-21.3 {
  execsql { PRAGMA integrity_check }
} {ok}

#-------------------------------------------------------------------------
# Test reading and writing of databases with different page-sizes.
#
foreach pgsz {512 1024 2048 4096 8192 16384 32768 65536} {
  do_multiclient_test tn [string map [list %PGSZ% $pgsz] {
    do_test wal-22.%PGSZ%.$tn.1 {
      sql1 {
        PRAGMA main.page_size = %PGSZ%;
        PRAGMA auto_vacuum = 0;
        PRAGMA journal_mode = WAL;
        CREATE TABLE t1(x UNIQUE);
        INSERT INTO t1 SELECT randomblob(800);
        INSERT INTO t1 SELECT randomblob(800);
        INSERT INTO t1 SELECT randomblob(800);
      }
    } {wal}
    do_test wal-22.%PGSZ%.$tn.2 { sql2 { PRAGMA integrity_check } } {ok}
    do_test wal-22.%PGSZ%.$tn.3 {
      sql1 {PRAGMA wal_checkpoint}
      expr {[file size test.db] % %PGSZ%}
    } {0}
  }]
}

#-------------------------------------------------------------------------
# Test that when 1 or more pages are recovered from a WAL file, 
# sqlite3_log() is invoked to report this to the user.
#
ifcapable curdir {
  set walfile [file nativename [file join [get_pwd] test.db-wal]]
} else {
  set walfile test.db-wal
}
catch {db close}
forcedelete test.db
do_test wal-23.1 {
  faultsim_delete_and_reopen
  execsql {
    CREATE TABLE t1(a, b);
    PRAGMA journal_mode = WAL;
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
  }
  faultsim_save_and_close

  sqlite3_shutdown
  test_sqlite3_log [list lappend ::log]
  set ::log [list]
  sqlite3 db test.db
  execsql { SELECT * FROM t1 }
} {1 2 3 4}
do_test wal-23.2 { set ::log } {}

do_test wal-23.3 {
  db close
  set ::log [list]
  faultsim_restore_and_reopen
  execsql { SELECT * FROM t1 }
} {1 2 3 4}
do_test wal-23.4 { 
  set ::log 
} [list SQLITE_NOTICE_RECOVER_WAL \
    "recovered 2 frames from WAL file $walfile"]


ifcapable autovacuum {
  # This block tests that if the size of a database is reduced by a 
  # transaction (because of an incremental or auto-vacuum), that no
  # data is written to the WAL file for the truncated pages as part
  # of the commit. e.g. if a transaction reduces the size of a database
  # to N pages, data for page N+1 should not be written to the WAL file 
  # when committing the transaction. At one point such data was being 
  # written.
  #
  catch {db close}
  forcedelete test.db
  sqlite3 db test.db
  do_execsql_test 24.1 {
    PRAGMA auto_vacuum = 2;
    PRAGMA journal_mode = WAL;
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(randomblob(5000));
    INSERT INTO t1 SELECT * FROM t1;
    INSERT INTO t1 SELECT * FROM t1;
    INSERT INTO t1 SELECT * FROM t1;
    INSERT INTO t1 SELECT * FROM t1;
  } {wal}
  do_test 24.2 { 
    execsql {
      DELETE FROM t1;
      PRAGMA wal_checkpoint;
    }
    db close
    sqlite3 db test.db
    file exists test.db-wal
  } 0
  do_test 24.3 {
    file size test.db
  } [expr 84 * 1024]
  do_test 24.4 {
    execsql { 
      PRAGMA cache_size = 200;
      PRAGMA incremental_vacuum;
      PRAGMA wal_checkpoint;
    }
    file size test.db
  } [expr 3 * 1024]

  # WAL file now contains a single frame - the new root page for table t1.
  # It would be two frames (the new root page and a padding frame) if the
  # ZERO_DAMAGE flag were not set.
  do_test 24.5 {
    file size test.db-wal
  } [wal_file_size 1 1024]
}

db close
sqlite3_shutdown
test_sqlite3_log
sqlite3_initialize

# Make sure PRAGMA journal_mode=WAL works with ATTACHED databases in
# all journal modes.
#
foreach mode {OFF MEMORY PERSIST DELETE TRUNCATE WAL} {
  delete_file test.db test2.db
  sqlite3 db test.db
  do_test wal-25.$mode {
    db eval "PRAGMA journal_mode=$mode"
    db eval {ATTACH 'test2.db' AS t2; PRAGMA journal_mode=WAL;}
  } {wal}
  db close
}

finish_test