SQLite

**
**     0: Magic number.  0x377f0682 or 0x377f0683
**     4: File format version.  Currently 3007000
**     8: Database page size.  Example: 1024
**    12: Checkpoint sequence number
**    16: Salt-1, random integer incremented with each checkpoint
**    20: Salt-2, a different random integer changing with each ckpt
**    24: Checksum-1 (first part of checksum for first 24 bytes of header).
**    28: Checksum-2 (second part of checksum for first 24 bytes of header).
**
** Immediately following the wal-header are zero or more frames. Each
** frame consists of a 24-byte frame-header followed by a <page-size> bytes
** of page data. The frame-header is broken into 6 big-endian 32-bit unsigned 
** integer values, as follows:
**
**     0: Page number.

#if defined(SQLITE_TEST) && defined(SQLITE_DEBUG)
int sqlite3WalTrace = 0;
# define WALTRACE(X)  if(sqlite3WalTrace) sqlite3DebugPrintf X
#else
# define WALTRACE(X)
#endif

/*
** The maximum (and only) versions of the wal and wal-index formats
** that may be interpreted by this version of SQLite.
**
** If a client begins recovering a WAL file and finds that (a) the checksum
** values in the wal-header are correct and (b) the version field is not
** WAL_MAX_VERSION, recovery fails and SQLite returns SQLITE_CANTOPEN.
**
** Similarly, if a client successfully reads a wal-index header (i.e. the 
** checksum test is successful) and finds that the version field is not
** WALINDEX_MAX_VERSION, then no read-transaction is opened and SQLite
** returns SQLITE_CANTOPEN.
*/
#define WAL_MAX_VERSION      3007000
#define WALINDEX_MAX_VERSION 3007000

/*
** Indices of various locking bytes.   WAL_NREADER is the number
** of available reader locks and should be at least 3.
*/
#define WAL_WRITE_LOCK         0
#define WAL_ALL_BUT_WRITE      1

/*
** The following object holds a copy of the wal-index header content.
**
** The actual header in the wal-index consists of two copies of this
** object.
*/
struct WalIndexHdr {
  u32 iVersion;                   /* Wal-index version */
  u32 unused;                     /* Unused (padding) field */
  u32 iChange;                    /* Counter incremented each transaction */
  u8 isInit;                      /* 1 when initialized */
  u8 bigEndCksum;                 /* True if checksums in WAL are big-endian */
  u16 szPage;                     /* Database page size in bytes */
  u32 mxFrame;                    /* Index of last valid frame in the WAL */
  u32 nPage;                      /* Size of database in pages */
  u32 aFrameCksum[2];             /* Checksum of last frame in log */

#define WALINDEX_LOCK_OFFSET   (sizeof(WalIndexHdr)*2 + sizeof(WalCkptInfo))
#define WALINDEX_LOCK_RESERVED 16
#define WALINDEX_HDR_SIZE      (WALINDEX_LOCK_OFFSET+WALINDEX_LOCK_RESERVED)

/* Size of header before each frame in wal */
#define WAL_FRAME_HDRSIZE 24

/* Size of write ahead log header, including checksum. */
/* #define WAL_HDRSIZE 24 */
#define WAL_HDRSIZE 32

/* WAL magic value. Either this value, or the same value with the least
** significant bit also set (WAL_MAGIC | 0x00000001) is stored in 32-bit
** big-endian format in the first 4 bytes of a WAL file.
**
** If the LSB is set, then the checksums for each frame within the WAL
** file are calculated by treating all data as an array of 32-bit 

*/
static void walIndexWriteHdr(Wal *pWal){
  volatile WalIndexHdr *aHdr = walIndexHdr(pWal);
  const int nCksum = offsetof(WalIndexHdr, aCksum);

  assert( pWal->writeLock );
  pWal->hdr.isInit = 1;
  pWal->hdr.iVersion = WALINDEX_MAX_VERSION;
  walChecksumBytes(1, (u8*)&pWal->hdr, nCksum, 0, pWal->hdr.aCksum);
  memcpy((void *)&aHdr[1], (void *)&pWal->hdr, sizeof(WalIndexHdr));
  sqlite3OsShmBarrier(pWal->pDbFd);
  memcpy((void *)&aHdr[0], (void *)&pWal->hdr, sizeof(WalIndexHdr));
}

/*

    u8 *aFrame = 0;               /* Malloc'd buffer to load entire frame */
    int szFrame;                  /* Number of bytes in buffer aFrame[] */
    u8 *aData;                    /* Pointer to data part of aFrame buffer */
    int iFrame;                   /* Index of last frame read */
    i64 iOffset;                  /* Next offset to read from log file */
    int szPage;                   /* Page size according to the log */
    u32 magic;                    /* Magic value read from WAL header */
    u32 version;                  /* Magic value read from WAL header */

    /* Read in the WAL header. */
    rc = sqlite3OsRead(pWal->pWalFd, aBuf, WAL_HDRSIZE, 0);
    if( rc!=SQLITE_OK ){
      goto recovery_error;
    }

      goto finished;
    }
    pWal->hdr.bigEndCksum = (magic&0x00000001);
    pWal->szPage = szPage;
    pWal->nCkpt = sqlite3Get4byte(&aBuf[12]);
    memcpy(&pWal->hdr.aSalt, &aBuf[16], 8);
    walChecksumBytes(pWal->hdr.bigEndCksum==SQLITE_BIGENDIAN, 
        aBuf, WAL_HDRSIZE-2*4, 0, pWal->hdr.aFrameCksum
    );

    if( pWal->hdr.aFrameCksum[0]!=sqlite3Get4byte(&aBuf[24])
     || pWal->hdr.aFrameCksum[1]!=sqlite3Get4byte(&aBuf[28])
    ){
      goto finished;
    }

    version = sqlite3Get4byte(&aBuf[4]);
    if( version!=WAL_MAX_VERSION ){
      rc = SQLITE_CANTOPEN_BKPT;
      goto finished;
    }

    /* Malloc a buffer to read frames into. */
    szFrame = szPage + WAL_FRAME_HDRSIZE;
    aFrame = (u8 *)sqlite3_malloc(szFrame);
    if( !aFrame ){
      rc = SQLITE_NOMEM;
      goto recovery_error;

  /* If the first page of the wal-index has been mapped, try to read the
  ** wal-index header immediately, without holding any lock. This usually
  ** works, but may fail if the wal-index header is corrupt or currently 
  ** being modified by another user.
  */
  badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);
  if( badHdr==0 && pWal->hdr.iVersion!=WALINDEX_MAX_VERSION ){
    rc = SQLITE_CANTOPEN_BKPT;
  }

  /* If the first attempt failed, it might have been due to a race
  ** with a writer.  So get a WRITE lock and try again.
  */
  assert( badHdr==0 || pWal->writeLock==0 );
  if( badHdr && SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
    pWal->writeLock = 1;

  /* If this is the first frame written into the log, write the WAL
  ** header to the start of the WAL file. See comments at the top of
  ** this source file for a description of the WAL header format.
  */
  iFrame = pWal->hdr.mxFrame;
  if( iFrame==0 ){
    u8 aWalHdr[WAL_HDRSIZE];      /* Buffer to assemble wal-header in */
    u32 aCksum[2];                /* Checksum for wal-header */

    sqlite3Put4byte(&aWalHdr[0], (WAL_MAGIC | SQLITE_BIGENDIAN));
    sqlite3Put4byte(&aWalHdr[4], WAL_MAX_VERSION);
    sqlite3Put4byte(&aWalHdr[8], szPage);
    sqlite3Put4byte(&aWalHdr[12], pWal->nCkpt);
    memcpy(&aWalHdr[16], pWal->hdr.aSalt, 8);
    walChecksumBytes(1, aWalHdr, WAL_HDRSIZE-2*4, 0, aCksum);
    sqlite3Put4byte(&aWalHdr[24], aCksum[0]);
    sqlite3Put4byte(&aWalHdr[28], aCksum[1]);
    
    pWal->szPage = szPage;
    pWal->hdr.bigEndCksum = SQLITE_BIGENDIAN;
    pWal->hdr.aFrameCksum[0] = aCksum[0];
    pWal->hdr.aFrameCksum[1] = aCksum[1];

    rc = sqlite3OsWrite(pWal->pWalFd, aWalHdr, sizeof(aWalHdr), 0);
    WALTRACE(("WAL%p: wal-header write %s\n", pWal, rc ? "failed" : "ok"));
    if( rc!=SQLITE_OK ){
      return rc;
    }

  }
  assert( pWal->szPage==szPage );

  /* Write the log file. */
  for(p=pList; p; p=p->pDirty){
    u32 nDbsize;                  /* Db-size field for frame header */
    i64 iOffset;                  /* Write offset in log file */

# of the TCL interface - methods which are based on the
# sqlite3_backup_XXX API.
#
# $Id: backup2.test,v 1.4 2009/04/07 14:14:23 danielk1977 Exp $

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

do_not_use_codec

ifcapable !trigger||!view { finish_test ; return }

# Fill a database with test data.
#
do_test backup2-1 {
  db eval {

# Test for issues reported by BareFeet (list.sql at tandb.com.au)
# on mailing list on 2008-06-12.
#
# Put a floating point number in the database so that we can manipulate
# raw bits using the hexio interface.
#
if {0==[sqlite3 -has-codec]} {
  do_test date-14.1 {
    execsql {
      PRAGMA auto_vacuum=OFF;
      PRAGMA page_size = 1024;
      CREATE TABLE t1(x);
      INSERT INTO t1 VALUES(1.1);
    }
    db close
    hexio_write test.db 2040 4142ba32bffffff9
    sqlite3 db test.db
    db eval {SELECT * FROM t1}
  } {2454629.5}
  
  # Changing the least significant byte of the floating point value between
  # 00 and FF should always generate a time of either 23:59:59 or 00:00:00,
  # never 24:00:00
  #
  for {set i 0} {$i<=255} {incr i} {
    db close
    hexio_write test.db 2047 [format %02x $i]
    sqlite3 db test.db
    do_test date-14.2.$i {
      set date [db one {SELECT datetime(x) FROM t1}]
      expr {$date eq "2008-06-12 00:00:00" || $date eq "2008-06-11 23:59:59"}
    } {1}
  }
}
finish_test

#  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
tv delete

#-------------------------------------------------------------------------
# The following tests deal with multi-file commits.
#

# "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

ifcapable !wal {finish_test ; return }

proc reopen_db {} {
  catch { db close }
  file delete -force test.db test.db-wal test.db-wal-summary
  sqlite3_wal db test.db

  [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:

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) }

  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 }

    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
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 37 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 37 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 37 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';
  }

  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 {

      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 16 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 16 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]
" {
  file delete -force 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;

    INSERT INTO t1 VALUES(5, 6);          -- frames 5 and 6
  }

  file copy -force test.db testX.db
  file copy -force 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}

      #
      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
  

  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);

# 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

ifcapable !wal {finish_test ; return }

proc set_tvfs_hdr {file args} {

  # Set $nHdr to the number of bytes in the wal-index header:
  set nHdr 48
  set nInt [expr {$nHdr/4}]

  if {[llength $args]>2} {
    error {wrong # args: should be "set_tvfs_hdr fileName ?val1? ?val2?"}
  }

  set blob [tvfs shm $file]

foreach {tn hdr1 hdr2 res} [list                                            \
  3  $wih(1)                $wih(1)                {Barton Deakin}          \
  4  $wih(1)                $wih(2)                {Barton Deakin Watson}   \
  5  $wih(2)                $wih(1)                {Barton Deakin Watson}   \
  6  $wih(2)                $wih(2)                {Barton Deakin Watson}   \
  7  $wih(1)                $wih(1)                {Barton Deakin}          \
  8  {0 0 0 0 0 0 0 0 0 0 0 0} {0 0 0 0 0 0 0 0 0 0 0 0} {Barton Deakin Watson}
] {
  do_test wal2-9.$tn {
    set_tvfs_hdr $::filename $hdr1 $hdr2
    execsql { SELECT * FROM x } db2
  } $res
}

db2 close
db close

#-------------------------------------------------------------------------
# This block of tests - wal2-10.* - focus on the libraries response to
# new versions of the wal or wal-index formats. 
#
#   wal2-10.1.*: Test that the library refuses to "recover" a new WAL 
#                format.
#
#   wal2-10.2.*: Test that the library refuses to read or write a database
#                if the wal-index version is newer than it understands.
#
# At time of writing, the only versions of the wal and wal-index formats
# that exist are versions 3007000 (corresponding to SQLite version 3.7.0,
# the first version of SQLite to feature wal mode).
#
do_test wal2-10.1.1 {
  faultsim_delete_and_reopen
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(a, b);
    PRAGMA wal_checkpoint;
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
  }
  faultsim_save_and_close
} {}
do_test wal2-10.1.2 {
  faultsim_restore_and_reopen
  execsql { SELECT * FROM t1 }
} {1 2 3 4}
do_test wal2-10.1.3 {
  faultsim_restore_and_reopen
  set hdr [wal_set_walhdr test.db-wal]
  lindex $hdr 1
} {3007000}
do_test wal2-10.1.4 {
  lset hdr 1 3007001
  wal_set_walhdr test.db-wal $hdr
  catchsql { SELECT * FROM t1 }
} {1 {unable to open database file}}

testvfs tvfs -default 1
do_test wal2-10.2.1 {
  faultsim_restore_and_reopen
  execsql { SELECT * FROM t1 }
} {1 2 3 4}
do_test wal2-10.2.2 { 
  set hdr [set_tvfs_hdr $::filename] 
  lindex $hdr 0 
} {3007000}
breakpoint
do_test wal2-10.2.3 { 
  lset hdr 0 3007001
  wal_fix_walindex_cksum hdr 
  set_tvfs_hdr $::filename $hdr
  catchsql { SELECT * FROM t1 }
} {1 {unable to open database file}}

finish_test

#***********************************************************************
#
# This file contains common code used by many different malloc tests
# within the test suite.
#

proc wal_file_size {nFrame pgsz} {
  expr {32 + ($pgsz+24)*$nFrame}
}

proc wal_frame_count {zFile pgsz} {
  set f [file size $zFile]
  expr {($f - 32) / ($pgsz+24)}
}

proc wal_cksum_intlist {ckv1 ckv2 intlist} {
  upvar $ckv1 c1
  upvar $ckv2 c2
  foreach {v1 v2} $intlist {
    set c1 [expr {($c1 + $v1 + $c2)&0xFFFFFFFF}]
    set c2 [expr {($c2 + $v2 + $c1)&0xFFFFFFFF}]
  }
}


# This proc calculates checksums in the same way as those used by SQLite 
# in WAL files. If the $endian argument is "big", then checksums are
# calculated by interpreting data as an array of big-endian integers. If
# it is "little", data is interpreted as an array of little-endian integers.
#
proc wal_cksum {endian ckv1 ckv2 blob} {
  upvar $ckv1 c1
  upvar $ckv2 c2

  if {$endian!="big" && $endian!="little"} {
    return -error "Bad value \"$endian\" - must be \"big\" or \"little\""
  }
  set scanpattern I*
  if {$endian == "little"} { set scanpattern i* }

  binary scan $blob $scanpattern values
  wal_cksum_intlist c1 c2 $values
}

proc wal_set_walhdr {filename {intlist {}}} {
  if {[llength $intlist]==6} {
    set blob [binary format I6 $intlist]
    set endian little
    if {[lindex $intlist 0] & 0x00000001} { set endian big }
    set c1 0
    set c2 0
    wal_cksum $endian c1 c2 $blob
    append blob [binary format II $c1 $c2]

    set fd [open $filename r+]
    fconfigure $fd -translation binary
    fconfigure $fd -encoding binary
    seek $fd 0
    puts -nonewline $fd $blob
    close $fd
  }

  set fd [open $filename]
  fconfigure $fd -translation binary
  fconfigure $fd -encoding binary
  set blob [read $fd 24]

  binary scan $blob I6 ints
  set ints
}

proc wal_fix_walindex_cksum {hdrvar} {
  upvar $hdrvar hdr
  set c1 0
  set c2 0
  wal_cksum_intlist c1 c2 [lrange $hdr 0 9]
  lset hdr 10 $c1
  lset hdr 11 $c2
}

# 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/wal_common.tcl

do_not_use_codec

ifcapable !wal {finish_test ; return }





# Test organization:
# 
#   walback-1.*: Simple tests.
#   walback-2.*: Test backups when the source db is modified mid-backup.
#

  execsql { 
    VACUUM;
    PRAGMA main.journal_mode;
  }
} {wal}
do_test walbak-1.5 {
  list [file size test.db] [file size test.db-wal]
} [list 1024 [wal_file_size 6 1024]]
do_test walbak-1.6 {
  execsql { PRAGMA wal_checkpoint }
  list [file size test.db] [file size test.db-wal]
} [list [expr 3*1024] [wal_file_size 6 1024]]
do_test walbak-1.7 {
  execsql { 
    CREATE TABLE t2(a, b);
    INSERT INTO t2 SELECT * FROM t1;
    DROP TABLE t1;
  }
  list [file size test.db] [file size test.db-wal]
} [list [expr 3*1024] [wal_file_size 6 1024]]
do_test walbak-1.8 {
  execsql { VACUUM }
  list [file size test.db] [file size test.db-wal]
} [list [expr 3*1024] [wal_file_size 8 1024]]
do_test walbak-1.9 {
  execsql { PRAGMA wal_checkpoint }
  list [file size test.db] [file size test.db-wal]
} [list [expr 2*1024] [wal_file_size 8 1024]]

#-------------------------------------------------------------------------
# Backups when the source db is modified mid-backup.
#
proc sig {{db db}} {
  $db eval { 
    PRAGMA integrity_check;

#
#***********************************************************************
#

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

ifcapable !wal {finish_test ; return }



























# Read and return the contents of file $filename. Treat the content as
# binary data.
#
proc readfile {filename} {
  set fd [open $filename]
  fconfigure $fd -encoding binary
  fconfigure $fd -translation binary

  binary scan [string range $data $offset [expr $offset+7]] II expect1 expect2
  set expect1 [expr $expect1&0xFFFFFFFF]
  set expect2 [expr $expect2&0xFFFFFFFF]

  expr {$c1==$expect1 && $c2==$expect2}
}


# File $filename must be a WAL file on disk. Compute the checksum for frame
# $iFrame in the file by interpreting data as $endian-endian integers 
# ($endian must be either "big" or "little"). Then write the computed 
# checksum into the file.
#
proc log_checksum_write {filename iFrame endian} {
  set data [readfile $filename]

  foreach {offset c1 c2} [log_checksum_calc $data $iFrame $endian] {}

  set bin [binary format II $c1 $c2]
  set fd [open $filename r+]
  fconfigure $fd -encoding binary
  fconfigure $fd -translation binary
  seek $fd $offset
  puts -nonewline $fd $bin
  close $fd
}

# Calculate and return the checksum for a particular frame in a WAL.
#
# Arguments are:
#
#   $data         Blob containing the entire contents of a WAL.
#
#   $iFrame       Frame number within the $data WAL. Frames are numbered 
#                 starting at 1.
#
#   $endian       One of "big" or "little".
#
# Returns a list of three elements, as follows:
#
#   * The byte offset of the checksum belonging to frame $iFrame in the WAL.
#   * The first integer in the calculated version of the checksum.
#   * The second integer in the calculated version of the checksum.
#
proc log_checksum_calc {data iFrame endian} {
  
  binary scan [string range $data 8 11] I pgsz
  if {$iFrame > 1} {
    set n [wal_file_size [expr $iFrame-2] $pgsz]
    binary scan [string range $data [expr $n+16] [expr $n+23]] II c1 c2
  } else {
    set c1 0
    set c2 0
    wal_cksum $endian c1 c2 [string range $data 0 23]
  }

  set n [wal_file_size [expr $iFrame-1] $pgsz]
  wal_cksum $endian c1 c2 [string range $data $n [expr $n+7]]
  wal_cksum $endian c1 c2 [string range $data [expr $n+24] [expr $n+24+$pgsz-1]]

  list [expr $n+16] $c1 $c2
}

#
# File $filename must be a WAL file on disk. Set the 'magic' field of the
# WAL header to indicate that checksums are $endian-endian ($endian must be
# either "big" or "little").
#
# Also update the wal header checksum (since the wal header contents may
# have changed).
#
proc log_checksum_writemagic {filename endian} {
  set val [expr {0x377f0682 | ($endian == "big" ? 1 : 0)}]
  set bin [binary format I $val]
  set fd [open $filename r+]
  fconfigure $fd -encoding binary
  fconfigure $fd -translation binary
  puts -nonewline $fd $bin

  seek $fd 0
  set blob [read $fd 24]
  set c1 0
  set c2 0
  wal_cksum $endian c1 c2 $blob 
  seek $fd 24
  puts -nonewline $fd [binary format II $c1 $c2]

  close $fd
}

#-------------------------------------------------------------------------
# Test cases walcksum-1.* attempt to verify the following:
#
#   * That both native and non-native order checksum log files can 

    }

    file copy -force test.db test2.db
    file copy -force test.db-wal test2.db-wal
    db close

    list [file size test2.db] [file size test2.db-wal]
  } [list [expr 1024*3] [wal_file_size 6 1024]]

  # Verify that the checksums are valid for all frames and that they
  # are calculated by interpreting data in native byte-order.
  #
  for {set f 1} {$f <= 6} {incr f} {
    do_test walcksum-1.$endian.2.$f {
      log_checksum_verify test2.db-wal $f $native

  #
  do_test walcksum-1.$endian.5.0 {
    execsql { 
      PRAGMA synchronous = NORMAL;
      INSERT INTO t1 VALUES(34, 'thirtyfour');
    }
    list [file size test.db] [file size test.db-wal]
  } [list [expr 1024*3] [wal_file_size 8 1024]]
  for {set f 1} {$f <= 8} {incr f} {
    do_test walcksum-1.$endian.5.$f {
      log_checksum_verify test.db-wal $f $endian
    } {1}
  }

  # Now connect a second connection to the database. Check that this one

  } {ok 1 2 3 5 8 13 21 34}
  do_test walcksum-1.$endian.7.0 {
    execsql { 
      PRAGMA synchronous = NORMAL;
      INSERT INTO t1 VALUES(55, 'fiftyfive');
    } db2
    list [file size test.db] [file size test.db-wal]
  } [list [expr 1024*3] [wal_file_size 10 1024]]
  for {set f 1} {$f <= 10} {incr f} {
    do_test walcksum-1.$endian.7.$f {
      log_checksum_verify test.db-wal $f $endian
    } {1}
  }

  # Now that both the recoverer and non-recoverer have added frames to the

    INSERT INTO t1 VALUES(1, randomblob(300));
    INSERT INTO t1 VALUES(2, randomblob(300));
    PRAGMA journal_mode = WAL;
    INSERT INTO t1 VALUES(3, randomblob(300));
  }

  file size test.db-wal
} [wal_file_size 1 1024]
do_test walcksum-3.2 {
  file copy -force test.db-wal test2.db-wal
  file copy -force test.db test2.db
  sqlite3 db2 test2.db
  execsql { SELECT a FROM t1 } db2
} {1 2 3}
db2 close
file copy -force test.db test2.db


foreach incr {1 2 3 20 40 60 80 100 120 140 160 180 200 220 240 253 254 255} {
  do_test walcksum-3.3.$incr {
    set FAIL 0
    for {set iOff 0} {$iOff < [wal_file_size 1 1024]} {incr iOff} {

      file copy -force test.db-wal test2.db-wal
      set fd [open test2.db-wal r+]
      fconfigure $fd -encoding binary
      fconfigure $fd -translation binary
  
      seek $fd $iOff

#***********************************************************************
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl
source $testdir/lock_common.tcl
source $testdir/wal_common.tcl
ifcapable !wal {finish_test ; return }





#-------------------------------------------------------------------------
# This test case demonstrates a flaw in the wal-index manipulation that
# existed at one point: If a process crashes mid-transaction, it may have
# already added some entries to one of the hash-tables in the wal-index.
# If the transaction were to be explicitly rolled back at this point, the
# hash-table entries would be removed as part of the rollback. However,

# More specifically, this file contains regression tests for the 
# sqlite3_wal_hook() mechanism, including the sqlite3_wal_autocheckpoint()
# and "PRAGMA wal_autocheckpoint" convenience interfaces.
#

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

ifcapable !wal {finish_test ; return }





set ::wal_hook [list]
proc wal_hook {zDb nEntry} {
  lappend ::wal_hook $zDb $nEntry
  return 0
}
db wal_hook wal_hook

  7 "INSERT INTO t4 VALUES(3, 'three')"   6   9
  8 "INSERT INTO t4 VALUES(4, 'four')"    8  11
  9 "INSERT INTO t4 VALUES(5, 'five')"    8  11
} {
  do_test walhook-2.$tn {
    execsql $sql
    list [file size test.db] [file size test.db-wal]
  } [list [expr $dbpages*1024] [wal_file_size $logpages 1024]]
}

catch { db2 close }
catch { db close }
finish_test