4 use Digest::SHA1 qw(sha1 sha1_hex sha1_base64);
5 use Fcntl qw(:DEFAULT :flock);
11 # Copyright (C) 2010 Zygo Blaxell <dm5@mailtoo.hungrycats.org>
13 # This program is free software; you can redistribute it and/or modify
14 # it under the terms of the GNU General Public License as published by
15 # the Free Software Foundation; either version 2 of the License, or
16 # (at your option) any later version.
18 # This program is distributed in the hope that it will be useful,
19 # but WITHOUT ANY WARRANTY; without even the implied warranty of
20 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 # GNU General Public License for more details.
23 # You should have received a copy of the GNU General Public License
24 # along with this program; if not, write to the Free Software
25 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 my ($filename) = (@_);
29 die "'$filename' is not a plain file" if (-l $filename) || ! (-f _);
30 my $ctx = Digest::SHA1->new;
31 sysopen(FILE, $filename, O_RDONLY|O_NONBLOCK) or die "open: $filename: $!";
32 binmode(FILE); # FIXME: Necessary? Probably harmless...
33 $ctx->addfile(\*FILE);
34 close(FILE) or die "close: $filename: $!";
35 return $ctx->b64digest;
41 Hashes a NUL-separated list of files on stdin into link-dir.
49 my ($from, $to) = (@_);
54 $inode_dir =~ s:[^/]*$::o;
55 $inode_base =~ s:^.*/::os;
56 my $tmp_to = File::Temp::tempnam($inode_dir, ".$inode_base.");
58 link($from, $tmp_to) or die "link: $from -> $tmp_to: $!";
60 unless (rename($tmp_to, $to)) {
63 unlink($tmp_to) or warn "unlink: $tmp_to: $!"; # Try, possibly in vain, to clean up
64 die "rename: $tmp_to -> $from: $saved_bang";
69 my $link_dir = shift @ARGV;
70 (-d $link_dir) or usage;
72 my $prefix_length = 3;
76 $file .= '_' x (length($file) + 1 - $prefix_length) if length($file) + 1 < $prefix_length;
77 my $prefix = substr($file, 0, $prefix_length);
78 my $suffix = substr($file, $prefix_length);
79 $prefix =~ s:(.):$1/:osg;
81 return ($prefix, $suffix);
85 my ($link_dir, $file) = @_;
86 my ($prefix, $suffix) = slash_prefix($file);
87 my $parent = "$link_dir/$prefix";
89 mkpath($parent, { verbose => 0 });
91 die "mkpath: $parent: $!" unless -d $parent;
92 return "$parent/$suffix";
95 # ext3 cannot handle more than 32000 links to a file. Leave some headroom.
96 my $link_count_max = 31990;
107 my $st = lstat($file);
108 die "lstat: $file: $!" unless $st;
113 # Skip the file if it has far too many links already
114 next if ($st->nlink > $link_count_max);
116 # Check link to inode
117 my $inode_link = prepare_parents("$link_dir/inode", $st->ino);
119 my $inode_st = lstat($inode_link);
122 my $inode_dev = $inode_st->dev;
123 my $inode_ino = $inode_st->ino;
124 my $file_dev = $st->dev;
125 my $file_ino = $st->ino;
126 if ($inode_ino != $file_ino || $inode_dev != $file_dev) {
127 warn "inode link '$inode_link' is wrong (inode $inode_ino should be $file_ino)" if $inode_ino != $file_ino;
128 warn "inode link '$inode_link' is wrong (dev $inode_dev should be $file_dev)" if $inode_dev != $file_dev;
136 # If neither criteria for updating link is met, leave it as-is
137 next unless $update_links;
141 my $digest = digest($file);
144 # Base64 uses /, we prefer _
147 # Check link to digest
148 my $digest_link = prepare_parents("$link_dir/digest", $digest);
150 my $digest_st = lstat($digest_link);
152 my $digest_nlink = $digest_st->nlink;
153 if ($digest_nlink > 31990) {
155 unlink($digest_link) or die "unlink: $digest_link: $!";
161 # Which file are we keeping?
164 # If digest link exists, link it to file
167 die "NOT identical!" if compare($digest_link, $file);
169 # Old, replace input with old file
171 link_files($digest_link, $file);
172 $keep_file = $digest_link;
174 # New, add input to digest
176 link_files($file, $digest_link);
180 # A link to the inode indicates we are done, so do it last
182 link_files($keep_file, $inode_link);
186 warn "$file: $@" if $@;
190 print STDERR "\nGarbage collection in '$link_dir'...";
191 chdir($link_dir) || die "chdir: $link_dir: $!";
192 print STDERR "\nRemoving files with link count < 3...";
193 system("find digest inode -type f -links -3 -print0 | xargs -0 rm -f") and die "system: exit status $?";
194 print STDERR "\nRemoving empty directories...";
195 system("find digest inode -type d -empty -print0 | xargs -0r rmdir -p --ignore-fail-on-non-empty") and die "system: exit status $?";
196 print STDERR "\nDone.\n";
202 #################################################################################
203 # GNU GENERAL PUBLIC LICENSE #
204 # Version 2, June 1991 #
206 # Copyright (C) 1989, 1991 Free Software Foundation, Inc. #
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482 # END OF TERMS AND CONDITIONS #
484 # How to Apply These Terms to Your New Programs #
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487 # possible use to the public, the best way to achieve this is to make it #
488 # free software which everyone can redistribute and change under these terms. #
490 # To do so, attach the following notices to the program. It is safest #
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501 # (at your option) any later version. #
503 # This program is distributed in the hope that it will be useful, #
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505 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
506 # GNU General Public License for more details. #
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518 # Gnomovision version 69, Copyright (C) year name of author #
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520 # This is free software, and you are welcome to redistribute it #
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528 # You should also get your employer (if you work as a programmer) or your #
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532 # Yoyodyne, Inc., hereby disclaims all copyright interest in the program #
533 # `Gnomovision' (which makes passes at compilers) written by James Hacker. #
535 # <signature of Ty Coon>, 1 April 1989 #
536 # Ty Coon, President of Vice #
538 # This General Public License does not permit incorporating your program into #
539 # proprietary programs. If your program is a subroutine library, you may #
540 # consider it more useful to permit linking proprietary applications with the #
541 # library. If this is what you want to do, use the GNU Library General #
542 # Public License instead of this License. #
543 #################################################################################