test/backup.test

# 2009 January 30
#
# 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 sqlite3_backup_XXX API.
#
# $Id: backup.test,v 1.6 2009/02/11 15:11:00 danielk1977 Exp $

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

#---------------------------------------------------------------------
# Test organization:
#
# backup-1.*: Warm-body tests.
#
# backup-2.*: Test backup under various conditions. To and from in-memory
#             databases. To and from empty/populated databases. etc.
#
# backup-3.*: Verify that the locking-page (pending byte page) is handled.
#
# backup-4.*: Test various error conditions.
#
# backup-5.*: Test the source database being modified during a backup.
#
# backup-6.*: Test the backup_remaining() and backup_pagecount() APIs.
#
# backup-7.*: Test SQLITE_BUSY and SQLITE_LOCKED errors.
#
# backup-8.*: Test multiple simultaneous backup operations.
#
# backup-9.*: Test that passing a negative argument to backup_step() is
#             interpreted as "copy the whole file".
#

proc data_checksum {db file} { $db one "SELECT md5sum(a, b) FROM ${file}.t1" }
proc test_contents {name db1 file1 db2 file2} {
  $db2 eval {select * from sqlite_master}
  $db1 eval {select * from sqlite_master}
  set checksum [data_checksum $db2 $file2]
  uplevel [list do_test $name [list data_checksum $db1 $file1] $checksum]
}

do_test backup-1.1 {
  execsql {
    BEGIN;
    CREATE TABLE t1(a, b);
    CREATE INDEX i1 ON t1(a, b);
    INSERT INTO t1 VALUES(1, randstr(1000,1000));
    INSERT INTO t1 VALUES(2, randstr(1000,1000));
    INSERT INTO t1 VALUES(3, randstr(1000,1000));
    INSERT INTO t1 VALUES(4, randstr(1000,1000));
    INSERT INTO t1 VALUES(5, randstr(1000,1000));
    COMMIT;
  }
} {}

# Sanity check to verify that the [test_contents] proc works.
#
test_contents backup-1.2 db main db main

# Check that it is possible to create and finish backup operations.
#
do_test backup-1.3.1 {
  file delete test2.db
  sqlite3 db2 test2.db
  sqlite3_backup B db2 main db main
} {B}
do_test backup-1.3.2 {
  B finish
} {SQLITE_OK}
do_test backup-1.3.3 {
  info commands B
} {}

# Simplest backup operation. Backup test.db to test2.db. test2.db is 
# initially empty. test.db uses the default page size.
# 
do_test backup-1.4.1 {
  sqlite3_backup B db2 main db main
} {B}
do_test backup-1.4.2 {
  B step 200
} {SQLITE_DONE}
do_test backup-1.4.3 {
  B finish
} {SQLITE_OK}
do_test backup-1.4.4 {
  info commands B
} {}
test_contents backup-1.4.5 db2 main db main
db close
db2 close
#
# End of backup-1.* tests.
#---------------------------------------------------------------------


#---------------------------------------------------------------------
# The following tests, backup-2.*, are based on the following procedure:
#
#   1) Populate the source database.
#   2) Populate the destination database.
#   3) Run the backup to completion. (backup-2.*.1)
#   4) Integrity check the destination db. (backup-2.*.2)
#   5) Check that the contents of the destination db is the same as that
#      of the source db. (backup-2.*.3)
# 
# The test is run with all possible combinations of the following
# input parameters, except that if the destination is an in-memory
# database, the only page size tested is 1024 bytes (the same as the
# source page-size).
#
#   * Source database is an in-memory database, OR
#   * Source database is a file-backed database.
#
#   * Target database is an in-memory database, OR
#   * Target database is a file-backed database.
#
#   * Destination database is a main file, OR
#   * Destination database is an attached file, OR
#   * Destination database is a temp database.
#
#   * Target database is empty (zero bytes), OR
#   * Target database is larger than the source, OR
#   * Target database is smaller than the source.
#
#   * Target database page-size is the same as the source, OR
#   * Target database page-size is larger than the source, OR
#   * Target database page-size is smaller than the source.
#
#   * Each call to step copies a single page, OR
#   * A single call to step copies the entire source database.
#
set iTest 1
foreach zSrcFile {test.db :memory:} {
foreach zDestFile {test2.db :memory:} {
foreach zOpenScript [list {
  sqlite3 db $zSrcFile
  sqlite3 db2 $zSrcFile
  db2 eval "ATTACH '$zDestFile' AS bak"
  set db_dest db2
  set file_dest bak
} {
  sqlite3 db $zSrcFile
  sqlite3 db2 $zDestFile
  set db_dest db2
  set file_dest main
} {
  sqlite3 db $zSrcFile
  sqlite3 db2 $zDestFile
  set db_dest db2
  set file_dest temp
}] {
foreach rows_dest {0 3 10} {
foreach pgsz_dest {512 1024 2048} {
foreach nPagePerStep {1 200} {

  # Open the databases.
  catch { file delete test.db }
  catch { file delete test2.db }
  eval $zOpenScript

  # Set to true if copying to an in-memory destination. Copying to an 
  # in-memory destination is only possible if the initial destination
  # page size is the same as the source page size (in this case 1024 bytes).
  #
  set isMemDest [expr {
    $zDestFile eq ":memory:" || $file_dest eq "temp" && $TEMP_STORE==3
  }]

  if { $isMemDest==0 || $pgsz_dest == 1024 } {
    if 0 {
      puts -nonewline "Test $iTest: src=$zSrcFile dest=$zDestFile"
      puts -nonewline " (as $db_dest.$file_dest)"
      puts -nonewline " rows_dest=$rows_dest pgsz_dest=$pgsz_dest"
      puts ""
    }

    # Set up the content of the source database.
    execsql {
      PRAGMA page_size = 1024;
      BEGIN;
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a, b);
      INSERT INTO t1 VALUES(1, randstr(1000,1000));
      INSERT INTO t1 VALUES(2, randstr(1000,1000));
      INSERT INTO t1 VALUES(3, randstr(1000,1000));
      INSERT INTO t1 VALUES(4, randstr(1000,1000));
      INSERT INTO t1 VALUES(5, randstr(1000,1000));
      COMMIT;
    }
    
    

    # Set up the content of the target database.
    execsql "PRAGMA ${file_dest}.page_size = ${pgsz_dest}" $db_dest
    if {$rows_dest != 0} {
      execsql "
        BEGIN; 
        CREATE TABLE ${file_dest}.t1(a, b);
        CREATE INDEX ${file_dest}.i1 ON t1(a, b);
      " $db_dest
      for {set ii 0} {$ii < $rows_dest} {incr ii} {
        execsql "
          INSERT INTO ${file_dest}.t1 VALUES(1, randstr(1000,1000))
        " $db_dest
      }
    }
  
    # Backup the source database.
    do_test backup-2.$iTest.1 {
      sqlite3_backup B $db_dest $file_dest db main
      while {[B step $nPagePerStep]=="SQLITE_OK"} {}
      B finish
    } {SQLITE_OK}
    
    # Run integrity check on the backup.
    do_test backup-2.$iTest.2 {
      execsql "PRAGMA ${file_dest}.integrity_check" $db_dest
    } {ok}
  
    test_contents backup-2.$iTest.3 db main $db_dest $file_dest
  
  }

  db close
  catch {db2 close}
  incr iTest

} } } } } }
#
# End of backup-2.* tests.
#---------------------------------------------------------------------

#---------------------------------------------------------------------
# These tests, backup-3.*, ensure that nothing goes wrong if either 
# the source or destination database are large enough to include the
# the locking-page (the page that contains the range of bytes that
# the locks are applied to). These tests assume that the pending
# byte is at offset 0x00010000 (64KB offset), as set by tester.tcl, 
# not at the 1GB offset as it usually is.
#
# The test procedure is as follows (same procedure as used for 
# the backup-2.* tests):
#
#   1) Populate the source database.
#   2) Populate the destination database.
#   3) Run the backup to completion. (backup-3.*.1)
#   4) Integrity check the destination db. (backup-3.*.2)
#   5) Check that the contents of the destination db is the same as that
#      of the source db. (backup-3.*.3)
#
# The test procedure is run with the following parameters varied: 
#
#   * Source database includes pending-byte page.
#   * Source database does not include pending-byte page.
#
#   * Target database includes pending-byte page.
#   * Target database does not include pending-byte page.
#
#   * Target database page-size is the same as the source, OR
#   * Target database page-size is larger than the source, OR
#   * Target database page-size is smaller than the source.
#
set iTest 1
foreach nSrcPg {10 64 65 66 100} {
foreach nDestRow {10 100} {
foreach nDestPgsz {512 1024 2048 4096} {

  catch { file delete test.db }
  catch { file delete test2.db }
  sqlite3 db test.db
  sqlite3 db2 test2.db

  # Set up the content of the two databases.
  #
  execsql { PRAGMA page_size = 1024 }
  execsql "PRAGMA page_size = $nDestPgsz" db2
  foreach db {db db2} {
    execsql {
      BEGIN; 
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a, b);
      COMMIT;
    } $db
  }
  while {[file size test.db]/1024 < $nSrcPg} {
    execsql { INSERT INTO t1 VALUES($ii, randstr(200,200)) }
  }

  for {set ii 0} {$ii < $nDestRow} {incr ii} {
    execsql { INSERT INTO t1 VALUES($ii, randstr(1000,1000)) } db2
  }

  # Backup the source database.
  do_test backup-3.$iTest.1 {
    sqlite3_backup B db main db2 main
    while {[B step 10]=="SQLITE_OK"} {}
    B finish
  } {SQLITE_OK}
    
  # Run integrity check on the backup.
  do_test backup-3.$iTest.2 {
    execsql "PRAGMA integrity_check" db2
  } {ok}
  
  test_contents backup-3.$iTest.3 db main db2 main

  db close
  db2 close
  incr iTest
}
}
}
#
# End of backup-3.* tests.
#---------------------------------------------------------------------


#---------------------------------------------------------------------
# The following tests, backup-4.*, test various error conditions:
# 
# backup-4.1.*: Test invalid database names.
#
# backup-4.2.*: Test that the source database cannot be detached while 
#               a backup is in progress.
#
# backup-4.3.*: Test that the source database handle cannot be closed
#               while a backup is in progress.
#
# backup-4.4.*: Test an attempt to specify the same handle for the
#               source and destination databases.
#
# backup-4.5.*: Test that an in-memory destination with a different
#               page-size to the source database is an error.
#
sqlite3 db test.db
sqlite3 db2 test2.db

do_test backup-4.1.1 {
  catch { sqlite3_backup B db aux db2 main }
} {1}
do_test backup-4.1.2 {
  sqlite3_errmsg db
} {unknown database aux}
do_test backup-4.1.3 {
  catch { sqlite3_backup B db main db2 aux }
} {1}
do_test backup-4.1.4 {
  sqlite3_errmsg db
} {unknown database aux}

do_test backup-4.2.1 {
  catch { file delete -force test3.db }
  catch { file delete -force test4.db }
  execsql { 
    ATTACH 'test3.db' AS aux1;
    CREATE TABLE aux1.t1(a, b);
  }
  execsql { 
    ATTACH 'test4.db' AS aux2;
    CREATE TABLE aux2.t2(a, b);
  } db2
  sqlite3_backup B db aux1 db2 aux2
} {B}
do_test backup-4.2.2 {
  catchsql { DETACH aux2 } db2
} {1 {database aux2 is locked}}
do_test backup-4.2.3 {
breakpoint
  B step 50
} {SQLITE_DONE}
do_test backup-4.2.4 {
  B finish
} {SQLITE_OK}

do_test backup-4.3.1 {
  sqlite3_backup B db aux1 db2 aux2
} {B}
do_test backup-4.3.2 {
  db2 cache flush
  sqlite3_close db2
} {SQLITE_BUSY}
do_test backup-4.3.3 {
  sqlite3_errmsg db2
} {unable to close due to unfinished backup operation}
do_test backup-4.3.4 {
  B step 50
} {SQLITE_DONE}
do_test backup-4.3.5 {
  B finish
} {SQLITE_OK}

do_test backup-4.4.1 {
  set rc [catch {sqlite3_backup B db main db aux1}]
  list $rc [sqlite3_errcode db] [sqlite3_errmsg db]
} {1 SQLITE_ERROR {source and destination must be distinct}}
db close
db2 close

do_test backup-4.5.1 {
  catch { file delete -force test.db }
  sqlite3 db test.db
  sqlite3 db2 :memory:
  execsql {
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  }
  execsql {
    PRAGMA page_size = 4096;
    CREATE TABLE t2(a, b);
    INSERT INTO t2 VALUES(3, 4);
  } db2
  sqlite3_backup B db2 main db main
} {B}
do_test backup-4.5.2 {
  B step 5000
} {SQLITE_READONLY}
do_test backup-4.5.3 {
  B finish
} {SQLITE_READONLY}

db close
db2 close
#
# End of backup-5.* tests.
#---------------------------------------------------------------------

#---------------------------------------------------------------------
# The following tests, backup-5.*, test that the backup works properly
# when the source database is modified during the backup. Test cases
# are organized as follows:
#
# backup-5.x.1.*: Nothing special. Modify the database mid-backup.
#
# backup-5.x.2.*: Modify the database mid-backup so that one or more
#                 pages are written out due to cache stress. Then 
#                 rollback the transaction.
#
# backup-5.x.3.*: Database is vacuumed.
#
# backup-5.x.4.*: Database is vacuumed and the page-size modified.
#
# backup-5.x.5.*: Database is shrunk via incr-vacuum.
#
# Each test is run three times, in the following configurations:
#
#   1) Backing up file-to-file. The writer writes via an external pager.
#   2) Backing up file-to-file. The writer writes via the same pager as
#      is used by the backup operation.
#   3) Backing up memory-to-file. 
#
set iTest 0
foreach {writer file} {db test.db db3 test.db db :memory:} {
  incr iTest
  catch { file delete bak.db }
  sqlite3 db2 bak.db
  catch { file delete $file }
  sqlite3 db $file
  sqlite3 db3 $file

  do_test backup-5.$iTest.1.1 {
    execsql {
      BEGIN;
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a, b);
      INSERT INTO t1 VALUES(1, randstr(1000,1000));
      INSERT INTO t1 VALUES(2, randstr(1000,1000));
      INSERT INTO t1 VALUES(3, randstr(1000,1000));
      INSERT INTO t1 VALUES(4, randstr(1000,1000));
      INSERT INTO t1 VALUES(5, randstr(1000,1000));
      COMMIT;
    }
    expr {[execsql {PRAGMA page_count}] > 10}
  } {1}
  do_test backup-5.$iTest.1.2 {
    sqlite3_backup B db2 main db main
    B step 5
  } {SQLITE_OK}
  do_test backup-5.$iTest.1.3 {
    execsql { UPDATE t1 SET a = a + 1 } $writer
    B step 50
  } {SQLITE_DONE}
  do_test backup-5.$iTest.1.4 {
    B finish
  } {SQLITE_OK} 
  integrity_check backup-5.$iTest.1.5 db2
  test_contents backup-5.$iTest.1.6 db main db2 main

  do_test backup-5.$iTest.2.1 {
    execsql {
      PRAGMA cache_size = 10;
      BEGIN;
      INSERT INTO t1 SELECT '', randstr(1000,1000) FROM t1;
      INSERT INTO t1 SELECT '', randstr(1000,1000) FROM t1;
      INSERT INTO t1 SELECT '', randstr(1000,1000) FROM t1;
      INSERT INTO t1 SELECT '', randstr(1000,1000) FROM t1;
      COMMIT;
    }
  } {}
  do_test backup-5.$iTest.2.2 {
    sqlite3_backup B db2 main db main
    B step 50
  } {SQLITE_OK}
  do_test backup-5.$iTest.2.3 {
    execsql { 
      BEGIN;
      UPDATE t1 SET a = a + 1;
      ROLLBACK;
    } $writer
    B step 5000
  } {SQLITE_DONE}
  do_test backup-5.$iTest.2.4 {
    B finish
  } {SQLITE_OK} 
  integrity_check backup-5.$iTest.2.5 db2
  test_contents backup-5.$iTest.2.6 db main db2 main

  do_test backup-5.$iTest.3.1 {
    execsql { UPDATE t1 SET b = randstr(1000,1000) }
  } {}
  do_test backup-5.$iTest.3.2 {
    sqlite3_backup B db2 main db main
    B step 50
  } {SQLITE_OK}
  do_test backup-5.$iTest.3.3 {
    execsql { VACUUM } $writer
    B step 5000
  } {SQLITE_DONE}
  do_test backup-5.$iTest.3.4 {
    B finish
  } {SQLITE_OK} 
  integrity_check backup-5.$iTest.3.5 db2
  test_contents backup-5.$iTest.3.6 db main db2 main

  do_test backup-5.$iTest.4.1 {
    execsql { UPDATE t1 SET b = randstr(1000,1000) }
  } {}
  do_test backup-5.$iTest.4.2 {
    sqlite3_backup B db2 main db main
    B step 50
  } {SQLITE_OK}
  do_test backup-5.$iTest.4.3 {
    execsql { 
      PRAGMA page_size = 2048;
      VACUUM;
    } $writer
    B step 5000
  } {SQLITE_DONE}
  do_test backup-5.$iTest.4.4 {
    B finish
  } {SQLITE_OK} 
  integrity_check backup-5.$iTest.4.5 db2
  test_contents backup-5.$iTest.4.6 db main db2 main

  catch { file delete bak.db }
  sqlite3 db2 bak.db
  catch { file delete $file }
  sqlite3 db $file
  sqlite3 db3 $file
  do_test backup-5.$iTest.5.1 {
    execsql {
      PRAGMA auto_vacuum = incremental;
      BEGIN;
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a, b);
      INSERT INTO t1 VALUES(1, randstr(1000,1000));
      INSERT INTO t1 VALUES(2, randstr(1000,1000));
      INSERT INTO t1 VALUES(3, randstr(1000,1000));
      INSERT INTO t1 VALUES(4, randstr(1000,1000));
      INSERT INTO t1 VALUES(5, randstr(1000,1000));
      COMMIT;
    }
  } {}
  do_test backup-5.$iTest.5.2 {
    sqlite3_backup B db2 main db main
    B step 8
  } {SQLITE_OK}
  do_test backup-5.$iTest.5.3 {
    execsql { 
      DELETE FROM t1;
      PRAGMA incremental_vacuum;
    } $writer
    B step 50
  } {SQLITE_DONE}
  do_test backup-5.$iTest.5.4 {
    B finish
  } {SQLITE_OK} 
  integrity_check backup-5.$iTest.5.5 db2
  test_contents backup-5.$iTest.5.6 db main db2 main
}
catch {db close}
catch {db2 close}
catch {db3 close}
#
# End of backup-5.* tests.
#---------------------------------------------------------------------

#---------------------------------------------------------------------
# Test the sqlite3_backup_remaining() and backup_pagecount() APIs.
#
do_test backup-6.1 {
  catch { file delete -force test.db }
  catch { file delete -force test2.db }
  sqlite3 db test.db
  sqlite3 db2 test2.db
  execsql {
    BEGIN;
    CREATE TABLE t1(a, b);
    CREATE INDEX i1 ON t1(a, b);
    INSERT INTO t1 VALUES(1, randstr(1000,1000));
    INSERT INTO t1 VALUES(2, randstr(1000,1000));
    INSERT INTO t1 VALUES(3, randstr(1000,1000));
    INSERT INTO t1 VALUES(4, randstr(1000,1000));
    INSERT INTO t1 VALUES(5, randstr(1000,1000));
    COMMIT;
  }
} {}
do_test backup-6.2 {
  set nTotal [expr {[file size test.db]/1024}]
  sqlite3_backup B db2 main db main
  B step 1
} {SQLITE_OK}
do_test backup-6.3 {
  B pagecount
} $nTotal
do_test backup-6.4 {
  B remaining
} [expr $nTotal-1]
do_test backup-6.5 {
  B step 5
  list [B remaining] [B pagecount]
} [list [expr $nTotal-6] $nTotal]
do_test backup-6.6 {
  execsql { CREATE TABLE t2(a PRIMARY KEY, b) }
  B step 1
  list [B remaining] [B pagecount]
} [list [expr $nTotal-5] [expr $nTotal+2]]

do_test backup-6.X {
  B finish
} {SQLITE_OK}



#---------------------------------------------------------------------
# Test cases backup-7.* test that SQLITE_BUSY and SQLITE_LOCKED errors
# are returned correctly:
#
# backup-7.1.*: Source database is externally locked (return SQLITE_BUSY).
#
# backup-7.2.*: Attempt to step the backup process while a 
#               write-transaction is underway on the source pager (return
#               SQLITE_LOCKED).
#
# backup-7.3.*: Destination database is externally locked (return SQLITE_BUSY).
#
do_test backup-7.0 {
  catch { file delete -force test.db }
  catch { file delete -force test2.db }
  sqlite3 db2 test2.db
  sqlite3 db test.db
  execsql {
    CREATE TABLE t1(a, b);
    CREATE INDEX i1 ON t1(a, b);
    INSERT INTO t1 VALUES(1, randstr(1000,1000));
    INSERT INTO t1 SELECT a+ 1, randstr(1000,1000) FROM t1;
    INSERT INTO t1 SELECT a+ 2, randstr(1000,1000) FROM t1;
    INSERT INTO t1 SELECT a+ 4, randstr(1000,1000) FROM t1;
    INSERT INTO t1 SELECT a+ 8, randstr(1000,1000) FROM t1;
    INSERT INTO t1 SELECT a+16, randstr(1000,1000) FROM t1;
    INSERT INTO t1 SELECT a+32, randstr(1000,1000) FROM t1;
    INSERT INTO t1 SELECT a+64, randstr(1000,1000) FROM t1;
  }
} {}

do_test backup-7.1.1 {
  sqlite3_backup B db2 main db main
  B step 5
} {SQLITE_OK}
do_test backup-7.1.2 {
  sqlite3 db3 test.db
  execsql { BEGIN EXCLUSIVE } db3
  B step 5
} {SQLITE_BUSY}
do_test backup-7.1.3 {
  execsql { ROLLBACK } db3
  B step 5
} {SQLITE_OK}
do_test backup-7.2.1 {
  execsql { 
    BEGIN;
    INSERT INTO t1 VALUES(1, 4);
  }
} {}
do_test backup-7.2.2 {
  B step 5000
} {SQLITE_LOCKED}
do_test backup-7.2.3 {
  execsql { ROLLBACK }
  B step 5000
} {SQLITE_DONE}
do_test backup-7.2.4 {
  B finish
} {SQLITE_OK}
test_contents backup-7.2.5 db main db2 main
integrity_check backup-7.3.6 db2

do_test backup-7.3.1 {
  db2 close
  db3 close
  file delete -force test2.db
  sqlite3 db2 test2.db
  sqlite3 db3 test2.db

  sqlite3_backup B db2 main db main
  execsql { BEGIN ; CREATE TABLE t2(a, b); } db3

  B step 5
} {SQLITE_BUSY}
do_test backup-7.3.2 {
  execsql { COMMIT } db3
  B step 5000
} {SQLITE_DONE}
do_test backup-7.3.3 {
  B finish
} {SQLITE_OK}
test_contents backup-7.3.4 db main db2 main
integrity_check backup-7.3.5 db2
catch { db2 close }
catch { db3 close }

#-----------------------------------------------------------------------
# The following tests, backup-8.*, test attaching multiple backup
# processes to the same source database. Also, reading from the source
# database while a read transaction is active.
#
# These tests reuse the database "test.db" left over from backup-7.*.
#
do_test backup-8.1 {
  catch { file delete -force test2.db }
  catch { file delete -force test3.db }
  sqlite3 db2 test2.db
  sqlite3 db3 test3.db

  sqlite3_backup B2 db2 main db main
  sqlite3_backup B3 db3 main db main
  list [B2 finish] [B3 finish]
} {SQLITE_OK SQLITE_OK}
do_test backup-8.2 {
  sqlite3_backup B3 db3 main db main
  sqlite3_backup B2 db2 main db main
  list [B2 finish] [B3 finish]
} {SQLITE_OK SQLITE_OK}
do_test backup-8.3 {
  sqlite3_backup B2 db2 main db main
  sqlite3_backup B3 db3 main db main
  B2 step 5
} {SQLITE_OK}
do_test backup-8.4 {
  execsql {
    BEGIN;
    SELECT * FROM sqlite_master;
  }
  B3 step 5
} {SQLITE_OK}
do_test backup-8.5 {
  list [B3 step 5000] [B3 finish]
} {SQLITE_DONE SQLITE_OK}
do_test backup-8.6 {
  list [B2 step 5000] [B2 finish]
} {SQLITE_DONE SQLITE_OK}
test_contents backup-8.7 db main db2 main
test_contents backup-8.8 db main db3 main
do_test backup-8.9 {
  execsql { PRAGMA lock_status }
} {main shared temp closed}
do_test backup-8.10 {
  execsql COMMIT
} {}
catch { db2 close }
catch { db3 close }

#-----------------------------------------------------------------------
# The following tests, backup-9.*, test that:
# 
#   * Passing 0 as an argument to sqlite3_backup_step() means no pages
#     are backed up (backup-9.1.*), and 
#   * Passing a negative value as an argument to sqlite3_backup_step() means 
#     all pages are backed up (backup-9.2.*).
#
# These tests reuse the database "test.db" left over from backup-7.*.
# 
do_test backup-9.1.1 {
  sqlite3 db2 test2.db
  sqlite3_backup B db2 main db main
  B step 1
} {SQLITE_OK}
do_test backup-9.1.2 {
  set nRemaining [B remaining]
  expr {$nRemaining>100}
} {1}
do_test backup-9.1.3 {
  B step 0
} {SQLITE_OK}
do_test backup-9.1.4 {
  B remaining
} $nRemaining

do_test backup-9.2.1 {
  B step -1
} {SQLITE_DONE}
do_test backup-9.2.2 {
  B remaining
} {0}
do_test backup-9.2.3 {
  B finish
} {SQLITE_OK}
catch {db2 close}

finish_test