From 7bb481fda9ecb134804b49c2ce77ca28f7eea583 Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <hans@eds.org>
Date: Fri, 30 Mar 2012 20:42:12 -0400
Subject: Imported Upstream version 2.0.3

---
 tool/restore_jrnl.tcl | 233 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 233 insertions(+)
 create mode 100644 tool/restore_jrnl.tcl

(limited to 'tool/restore_jrnl.tcl')

diff --git a/tool/restore_jrnl.tcl b/tool/restore_jrnl.tcl
new file mode 100644
index 0000000..05af4f9
--- /dev/null
+++ b/tool/restore_jrnl.tcl
@@ -0,0 +1,233 @@
+# 2010 January 7
+#
+# 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 utility functions for SQLite library.
+#
+# This file attempts to restore the header of a journal.
+# This may be useful for rolling-back the last committed 
+# transaction from a recovered journal.
+#
+
+package require sqlite3
+
+set parm_error 0
+set fix_chksums 0
+set dump_pages 0
+set db_name ""
+
+for {set i 0} {$i<$argc} {incr i} {
+  if {[lindex $argv $i] == "-fix_chksums"} {
+    set fix_chksums -1
+  } elseif {[lindex $argv $i] == "-dump_pages"} {
+    set dump_pages -1
+  } elseif {$db_name == ""} {
+    set db_name [lindex $argv $i]
+    set jrnl_name $db_name-journal
+  } else {
+    set parm_error -1
+  }
+}
+if {$parm_error || $db_name == ""} {
+  puts "USAGE: restore_jrnl.tcl \[-fix_chksums\] \[-dump_pages\] db_name"
+  puts "Example: restore_jrnl.tcl foo.sqlite"
+  return
+}
+
+# is there a way to determine this?
+set sectsz 512
+
+# Copy file $from into $to
+#
+proc copy_file {from to} {
+  file copy -force $from $to
+}
+
+# Execute some SQL
+#
+proc catchsql {sql} {
+  set rc [catch {uplevel [list db eval $sql]} msg]
+  list $rc $msg
+}
+
+# Perform a test
+#
+proc do_test {name cmd expected} {
+  puts -nonewline "$name ..."
+  set res [uplevel $cmd]
+  if {$res eq $expected} {
+    puts Ok
+  } else {
+    puts Error
+    puts "  Got: $res"
+    puts "  Expected: $expected"
+  }
+}
+
+# Calc checksum nonce from journal page data.
+#
+proc calc_nonce {jrnl_pgno} {
+  global sectsz
+  global db_pgsz
+  global jrnl_name
+  set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$jrnl_pgno)]
+  set nonce [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$db_pgsz] 4]]
+  for {set i [expr $db_pgsz-200]} {$i>0} {set i [expr $i-200]} {
+    set byte [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$i] 1]]
+    set nonce [expr $nonce-$byte]
+  }
+  return $nonce
+}
+
+# Calc checksum from journal page data.
+#
+proc calc_chksum {jrnl_pgno} {
+  global sectsz
+  global db_pgsz
+  global jrnl_name
+  global nonce
+  set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$jrnl_pgno)]
+  set chksum $nonce
+  for {set i [expr $db_pgsz-200]} {$i>0} {set i [expr $i-200]} {
+    set byte [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$i] 1]]
+    set chksum [expr $chksum+$byte]
+  }
+  return $chksum
+}
+
+# Print journal page data in hex dump form
+#
+proc dump_jrnl_page {jrnl_pgno} {
+  global sectsz
+  global db_pgsz
+  global jrnl_name
+
+  # print a header block for the page
+  puts [string repeat "-" 79]
+  set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$jrnl_pgno)]
+  set db_pgno [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset] 4]]
+  set chksum [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$db_pgsz] 4]]
+  set nonce [calc_nonce $jrnl_pgno]
+  puts [ format {jrnl_pg_offset: %08x (%d)  jrnl_pgno: %d  db_pgno: %d} \
+      $jrnl_pg_offset $jrnl_pg_offset \
+      $jrnl_pgno $db_pgno]
+  puts [ format {nonce: %08x chksum: %08x} \
+      $nonce $chksum]
+
+  # now hex dump the data
+  # This is derived from the Tcler's WIKI
+  set fid [open $jrnl_name r]
+  fconfigure $fid -translation binary -encoding binary
+  seek $fid [expr $jrnl_pg_offset+4]
+  set data [read $fid $db_pgsz]
+  close $fid
+  for {set addr 0} {$addr<$db_pgsz} {set addr [expr $addr+16]} {
+    # get 16 bytes of data
+    set s [string range $data $addr [expr $addr+16]]
+    
+    # Convert the data to hex and to characters.
+    binary scan $s H*@0a* hex ascii
+
+    # Replace non-printing characters in the data.
+    regsub -all -- {[^[:graph:] ]} $ascii {.} ascii
+
+    # Split the 16 bytes into two 8-byte chunks
+    regexp -- {(.{16})(.{0,16})} $hex -> hex1 hex2
+
+    # Convert the hex to pairs of hex digits
+    regsub -all -- {..} $hex1 {& } hex1
+    regsub -all -- {..} $hex2 {& } hex2
+
+    # Print the hex and ascii data
+    puts [ format {%08x %-24s %-24s %-16s} \
+        $addr $hex1 $hex2 $ascii ]
+  }
+}
+
+# Setup for the tests.  Make a backup copy of the files.
+#
+if [file exist $db_name.org] {
+  puts "ERROR: during back-up: $db_name.org exists already."
+  return;
+}
+if [file exist $jrnl_name.org] {
+  puts "ERROR: during back-up: $jrnl_name.org exists already."
+  return
+}
+copy_file $db_name $db_name.org
+copy_file $jrnl_name $jrnl_name.org
+
+set db_fsize [file size $db_name]
+set db_pgsz [hexio_get_int [hexio_read $db_name 16 2]]
+set db_npage [expr {$db_fsize / $db_pgsz}]
+
+set jrnl_fsize [file size $jrnl_name]
+set jrnl_npage [expr {($jrnl_fsize - $sectsz) / (4 + $db_pgsz + 4)}]
+
+# calculate checksum nonce for first page
+set nonce [calc_nonce 0]
+
+# verify all the pages in the journal use the same nonce
+for {set i 1} {$i<$jrnl_npage} {incr i} {
+  set tnonce [calc_nonce $i]
+  if {$tnonce != $nonce} {
+    puts "WARNING: different nonces: 0=$nonce $i=$tnonce"
+    if {$fix_chksums } {
+      set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$i)]
+      set tchksum [calc_chksum $i]
+      hexio_write $jrnl_name [expr $jrnl_pg_offset+4+$db_pgsz] [format %08x $tchksum]
+      puts "INFO: fixing chksum: $i=$tchksum"
+    }
+  }
+}
+
+# verify all the page numbers in the journal
+for {set i 0} {$i<$jrnl_npage} {incr i} {
+  set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$i)]
+  set db_pgno [hexio_get_int [hexio_read $jrnl_name $jrnl_pg_offset 4]]
+  if {$db_pgno < 1} {
+    puts "WARNING: page number < 1: $i=$db_pgno"
+  }
+  if {$db_pgno >= $db_npage} {
+    puts "WARNING: page number >= $db_npage: $i=$db_pgno"
+  }
+}
+
+# dump page data
+if {$dump_pages} {
+  for {set i 0} {$i<$jrnl_npage} {incr i} {
+    dump_jrnl_page $i
+  }
+}
+
+# write the 8 byte magic string
+hexio_write $jrnl_name 0 d9d505f920a163d7
+
+# write -1 for number of records
+hexio_write $jrnl_name 8 ffffffff
+
+# write 00 for checksum nonce
+hexio_write $jrnl_name 12 [format %08x $nonce]
+
+# write page count
+hexio_write $jrnl_name 16 [format %08x $db_npage]
+
+# write sector size
+hexio_write $jrnl_name 20 [format %08x $sectsz]
+
+# write page size
+hexio_write $jrnl_name 24 [format %08x $db_pgsz]
+
+# check the integrity of the database with the patched journal
+sqlite3 db $db_name
+do_test restore_jrnl-1.0 {
+  catchsql {PRAGMA integrity_check}
+} {0 ok}
+db close
+
-- 
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