Merge branch 'performance'

Conflicts:
	faster-dupemerge

diff --combined faster-dupemerge
index 0b43a3c7a2bd26ce6f36377311c66bdb885f70f2,6223ab0adc2d7cacb4dee7e7c4f4e71a2aa3a1d4..d35f591a442a9c7bb6c52ea160bed284825089b0
--- 1/faster-dupemerge
--- 2/faster-dupemerge
+++ b/faster-dupemerge
@@@ -4,7 -4,7 +4,7 @@@ use Fcntl qw(:DEFAULT :flock)
  use File::Compare;
  use File::Temp;
  
 -# Copyright (C) 2003-2006 Zygo Blaxell <zblaxell@feedme.hungrycats.org>
 +# Copyright (C) 2003-2009 Zygo Blaxell <faster-dupemerge@mailtoo.hungrycats.org>
  
  # This program is free software; you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
@@@ -238,7 -238,7 +238,7 @@@ my @find_command = ('find', @directorie
  my $printf_string = '%s ' .
        ($collapse_access    ? '0 0 0 ' : '%U %G %m ') .
        ($collapse_timestamp ? '0 '     : '%T@ ') .
-       '%i %p\0';
+       '%D:%i %p\0';
  
  push(@find_command, '!', '-empty') unless $collapse_zero;
  push(@find_command, '-printf', $printf_string);
@@@ -305,14 -305,14 +305,14 @@@ sub merge_files 
        }
  
        print STDERR "Merging...\n" if $debug;
-       foreach my $candidate (@candidate_list) {
+       foreach my $candidate (sort @candidate_list) {
                print STDERR "\tDigesting candidate $candidate\n" if $debug;
                my $ok = 0;
                my $digest;
  
  hash_file:
  
-               foreach my $filename (keys(%{$inode_to_file_name{$candidate}})) {
+               foreach my $filename (sort keys(%{$inode_to_file_name{$candidate}})) {
                        print STDERR "\t\tDigesting file $filename\n" if $debug;
                        if ((-l $filename) || ! -f _) {
                                warn "Bogon file " . tick_quote($filename);
@@@ -333,9 -333,8 +333,9 @@@
                if ($ok) {
                        print STDERR "\t\tDigest is $digest\n" if $debug;
  
 -                      my $incumbent = $hash_to_inode{$digest};
 -                      if (defined($incumbent)) {
 +                      my $incumbent_list = ($hash_to_inode{$digest} ||= []);
 +                      my $incumbent_matched = 0;
 +                      for my $incumbent (@$incumbent_list) {
                                print STDERR "\t\tInodes $incumbent and $candidate have same hash\n" if $debug;
  
                                my $finished = 0;
@@@ -343,9 -342,9 +343,9 @@@
  link_start:
  
                                until ($finished) {
-                                       my @incumbent_names = keys(%{$inode_to_file_name{$incumbent}});
-                                       my @candidate_names = keys(%{$inode_to_file_name{$candidate}});
+                                       my @incumbent_names = sort keys(%{$inode_to_file_name{$incumbent}});
+                                       my @candidate_names = sort keys(%{$inode_to_file_name{$candidate}});
 -                                      print STDERR "\t\tLinks to $incumbent:",   join("\n\t\t\t", '', @incumbent_names),   "\n" if $debug;
 +                                      print STDERR "\t\tLinks to $incumbent:", join("\n\t\t\t", '', @incumbent_names), "\n" if $debug;
                                        print STDERR "\t\tLinks to $candidate:", join("\n\t\t\t", '', @candidate_names), "\n" if $debug;
  
  incumbent_file:
@@@ -412,7 -411,6 +412,7 @@@ candidate_file
                                                                                print STDERR "$quoted_incumbent_file and $quoted_candidate_file have same hash but do not compare equal!\n" unless $skip_hashes;
                                                                        } else {
                                                                                $identical = 1;
 +                                                                              $incumbent_matched = 1;
                                                                        }
                                                                        $compare_count++;
                                                                        $compare_bytes += $incumbent_size;
@@@ -443,6 -441,12 +443,12 @@@
                                                                        my $link_done = 0;
  
                                                                        my ($from_file, $to_file, $from_inode, $to_inode, $from_nlink, $to_nlink);
+ 
+                                                                       # If the candidate has more links than incumbent, replace incumbent with candidate.
+                                                                       # If the incumbent has more links than candidate, replace candidate with incumbent.
+                                                                       # If the link counts are equal, we saw incumbent first, so keep the incumbent.
+                                                                       # "We saw incumbent first" is significant because we explicitly sort the inodes.
+                                                                       # Thank Johannes Niess for this idea.
                                                                        if ($candidate_nlink > $incumbent_nlink) {
                                                                                $from_file = $candidate_file;
                                                                                $to_file = $incumbent_file;
@@@ -489,9 -493,13 +495,9 @@@
                                                                        # My random number generator chooses the incumbent's size.
  
                                                                        if ($link_done) {
 -                                                                              # Since we're in a dry run, the filesystem doesn't change.
 -                                                                              # Our notion of what the filesystem should look like should not change either.
                                                                                delete $inode_to_file_name{$to_inode}->{$to_file};
 -                                                                              unless ($dry_run) {
 -                                                                                      $inode_to_file_name{$from_inode}->{$to_file} = undef;
 -                                                                                      $hash_to_inode{$digest} = $from_inode;
 -                                                                              }
 +                                                                              $inode_to_file_name{$from_inode}->{$to_file} = undef;
 +                                                                              $hash_to_inode{$digest} = [ $from_inode ];
  
                                                                                $hard_links++;
                                                                                if ($to_nlink == 1) {
@@@ -519,10 -527,9 +525,10 @@@
                                        }
                                        $finished = 1;
                                }
 -                      } else {
 +                      }
 +                      unless ($incumbent_matched) {
                                print STDERR "\t\tNew hash entered\n" if $debug;
 -                              $hash_to_inode{$digest} = $candidate;
 +                              push(@$incumbent_list, $candidate);
                        }
                } else {
                        warn "No digests found for inode $candidate\n";
@@@ -537,7 -544,7 +543,7 @@@ end_merge
  }
  
  while (<FIND>) {
-       my ($weak_key, $inode, $name) = m/^(\d+ \d+ \d+ \d+ -?[\d.]+) (\d+) (.+)\0$/so;
 -      my ($weak_key, $inode, $name) = m/^(\d+ \d+ \d+ \d+ -?\d+) (\d+:\d+) (.+)\0$/so;
++      my ($weak_key, $inode, $name) = m/^(\d+ \d+ \d+ \d+ -?[\d.]+) (\d+:\d+) (.+)\0$/so;
        die "read error: $!\nLast input line was '$_'" unless defined($name);
  
        print STDERR "weak_key=$weak_key inode=$inode name=$name\n" if $debug;