3 # The author disclaims copyright to this source code. In place of
4 # a legal notice, here is a blessing:
6 # May you do good and not evil.
7 # May you find forgiveness for yourself and forgive others.
8 # May you share freely, never taking more than you give.
10 #***********************************************************************
11 # This file implements utility functions for SQLite library.
13 # This file attempts to restore the header of a journal.
14 # This may be useful for rolling-back the last committed
15 # transaction from a recovered journal.
18 package require sqlite3
25 for {set i 0} {$i<$argc} {incr i} {
26 if {[lindex $argv $i] == "-fix_chksums"} {
28 } elseif {[lindex $argv $i] == "-dump_pages"} {
30 } elseif {$db_name == ""} {
31 set db_name [lindex $argv $i]
32 set jrnl_name $db_name-journal
37 if {$parm_error || $db_name == ""} {
38 puts "USAGE: restore_jrnl.tcl \[-fix_chksums\] \[-dump_pages\] db_name"
39 puts "Example: restore_jrnl.tcl foo.sqlite"
43 # is there a way to determine this?
46 # Copy file $from into $to
48 proc copy_file {from to} {
49 file copy -force $from $to
55 set rc [catch {uplevel [list db eval $sql]} msg]
61 proc do_test {name cmd expected} {
62 puts -nonewline "$name ..."
63 set res [uplevel $cmd]
64 if {$res eq $expected} {
69 puts " Expected: $expected"
73 # Calc checksum nonce from journal page data.
75 proc calc_nonce {jrnl_pgno} {
79 set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$jrnl_pgno)]
80 set nonce [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$db_pgsz] 4]]
81 for {set i [expr $db_pgsz-200]} {$i>0} {set i [expr $i-200]} {
82 set byte [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$i] 1]]
83 set nonce [expr $nonce-$byte]
88 # Calc checksum from journal page data.
90 proc calc_chksum {jrnl_pgno} {
95 set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$jrnl_pgno)]
97 for {set i [expr $db_pgsz-200]} {$i>0} {set i [expr $i-200]} {
98 set byte [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$i] 1]]
99 set chksum [expr $chksum+$byte]
104 # Print journal page data in hex dump form
106 proc dump_jrnl_page {jrnl_pgno} {
111 # print a header block for the page
112 puts [string repeat "-" 79]
113 set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$jrnl_pgno)]
114 set db_pgno [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset] 4]]
115 set chksum [hexio_get_int [hexio_read $jrnl_name [expr $jrnl_pg_offset+4+$db_pgsz] 4]]
116 set nonce [calc_nonce $jrnl_pgno]
117 puts [ format {jrnl_pg_offset: %08x (%d) jrnl_pgno: %d db_pgno: %d} \
\r
118 $jrnl_pg_offset $jrnl_pg_offset \
\r
119 $jrnl_pgno $db_pgno]
\r
120 puts [ format {nonce: %08x chksum: %08x} \
\r
123 # now hex dump the data
124 # This is derived from the Tcler's WIKI
\r
125 set fid [open $jrnl_name r]
\r
126 fconfigure $fid -translation binary -encoding binary
\r
127 seek $fid [expr $jrnl_pg_offset+4]
\r
128 set data [read $fid $db_pgsz]
\r
130 for {set addr 0} {$addr<$db_pgsz} {set addr [expr $addr+16]} {
131 # get 16 bytes of data
\r
132 set s [string range $data $addr [expr $addr+16]]
\r
134 # Convert the data to hex and to characters.
\r
135 binary scan $s H*@0a* hex ascii
\r
137 # Replace non-printing characters in the data.
\r
138 regsub -all -- {[^[:graph:] ]} $ascii {.} ascii
\r
140 # Split the 16 bytes into two 8-byte chunks
\r
141 regexp -- {(.{16})(.{0,16})} $hex -> hex1 hex2
\r
143 # Convert the hex to pairs of hex digits
\r
144 regsub -all -- {..} $hex1 {& } hex1
\r
145 regsub -all -- {..} $hex2 {& } hex2
\r
147 # Print the hex and ascii data
\r
148 puts [ format {%08x %-24s %-24s %-16s} \
\r
149 $addr $hex1 $hex2 $ascii ]
\r
153 # Setup for the tests. Make a backup copy of the files.
155 if [file exist $db_name.org] {
156 puts "ERROR: during back-up: $db_name.org exists already."
159 if [file exist $jrnl_name.org] {
160 puts "ERROR: during back-up: $jrnl_name.org exists already."
163 copy_file $db_name $db_name.org
164 copy_file $jrnl_name $jrnl_name.org
166 set db_fsize [file size $db_name]
167 set db_pgsz [hexio_get_int [hexio_read $db_name 16 2]]
168 set db_npage [expr {$db_fsize / $db_pgsz}]
170 set jrnl_fsize [file size $jrnl_name]
171 set jrnl_npage [expr {($jrnl_fsize - $sectsz) / (4 + $db_pgsz + 4)}]
173 # calculate checksum nonce for first page
174 set nonce [calc_nonce 0]
176 # verify all the pages in the journal use the same nonce
177 for {set i 1} {$i<$jrnl_npage} {incr i} {
178 set tnonce [calc_nonce $i]
179 if {$tnonce != $nonce} {
180 puts "WARNING: different nonces: 0=$nonce $i=$tnonce"
182 set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$i)]
183 set tchksum [calc_chksum $i]
184 hexio_write $jrnl_name [expr $jrnl_pg_offset+4+$db_pgsz] [format %08x $tchksum]
185 puts "INFO: fixing chksum: $i=$tchksum"
190 # verify all the page numbers in the journal
191 for {set i 0} {$i<$jrnl_npage} {incr i} {
192 set jrnl_pg_offset [expr $sectsz+((4+$db_pgsz+4)*$i)]
193 set db_pgno [hexio_get_int [hexio_read $jrnl_name $jrnl_pg_offset 4]]
195 puts "WARNING: page number < 1: $i=$db_pgno"
197 if {$db_pgno >= $db_npage} {
198 puts "WARNING: page number >= $db_npage: $i=$db_pgno"
204 for {set i 0} {$i<$jrnl_npage} {incr i} {
209 # write the 8 byte magic string
210 hexio_write $jrnl_name 0 d9d505f920a163d7
212 # write -1 for number of records
213 hexio_write $jrnl_name 8 ffffffff
215 # write 00 for checksum nonce
216 hexio_write $jrnl_name 12 [format %08x $nonce]
219 hexio_write $jrnl_name 16 [format %08x $db_npage]
222 hexio_write $jrnl_name 20 [format %08x $sectsz]
225 hexio_write $jrnl_name 24 [format %08x $db_pgsz]
227 # check the integrity of the database with the patched journal
229 do_test restore_jrnl-1.0 {
230 catchsql {PRAGMA integrity_check}