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-rwxr-xr-xgit-relink.perl173
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diff --git a/git-relink.perl b/git-relink.perl
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+++ b/git-relink.perl
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+#!/usr/bin/env perl
+# Copyright 2005, Ryan Anderson <ryan@michonline.com>
+# Distribution permitted under the GPL v2, as distributed
+# by the Free Software Foundation.
+# Later versions of the GPL at the discretion of Linus Torvalds
+#
+# Scan two git object-trees, and hardlink any common objects between them.
+
+use 5.006;
+use strict;
+use warnings;
+use Getopt::Long;
+
+sub get_canonical_form($);
+sub do_scan_directory($$$);
+sub compare_two_files($$);
+sub usage();
+sub link_two_files($$);
+
+# stats
+my $total_linked = 0;
+my $total_already = 0;
+my ($linked,$already);
+
+my $fail_on_different_sizes = 0;
+my $help = 0;
+GetOptions("safe" => \$fail_on_different_sizes,
+ "help" => \$help);
+
+usage() if $help;
+
+my (@dirs) = @ARGV;
+
+usage() if (!defined $dirs[0] || !defined $dirs[1]);
+
+$_ = get_canonical_form($_) foreach (@dirs);
+
+my $master_dir = pop @dirs;
+
+opendir(D,$master_dir . "objects/")
+ or die "Failed to open $master_dir/objects/ : $!";
+
+my @hashdirs = grep !/^\.{1,2}$/, readdir(D);
+
+foreach my $repo (@dirs) {
+ $linked = 0;
+ $already = 0;
+ printf("Searching '%s' and '%s' for common objects and hardlinking them...\n",
+ $master_dir,$repo);
+
+ foreach my $hashdir (@hashdirs) {
+ do_scan_directory($master_dir, $hashdir, $repo);
+ }
+
+ printf("Linked %d files, %d were already linked.\n",$linked, $already);
+
+ $total_linked += $linked;
+ $total_already += $already;
+}
+
+printf("Totals: Linked %d files, %d were already linked.\n",
+ $total_linked, $total_already);
+
+
+sub do_scan_directory($$$) {
+ my ($srcdir, $subdir, $dstdir) = @_;
+
+ my $sfulldir = sprintf("%sobjects/%s/",$srcdir,$subdir);
+ my $dfulldir = sprintf("%sobjects/%s/",$dstdir,$subdir);
+
+ opendir(S,$sfulldir)
+ or die "Failed to opendir $sfulldir: $!";
+
+ foreach my $file (grep(!/\.{1,2}$/, readdir(S))) {
+ my $sfilename = $sfulldir . $file;
+ my $dfilename = $dfulldir . $file;
+
+ compare_two_files($sfilename,$dfilename);
+
+ }
+ closedir(S);
+}
+
+sub compare_two_files($$) {
+ my ($sfilename, $dfilename) = @_;
+
+ # Perl's stat returns relevant information as follows:
+ # 0 = dev number
+ # 1 = inode number
+ # 7 = size
+ my @sstatinfo = stat($sfilename);
+ my @dstatinfo = stat($dfilename);
+
+ if (@sstatinfo == 0 && @dstatinfo == 0) {
+ die sprintf("Stat of both %s and %s failed: %s\n",$sfilename, $dfilename, $!);
+
+ } elsif (@dstatinfo == 0) {
+ return;
+ }
+
+ if ( ($sstatinfo[0] == $dstatinfo[0]) &&
+ ($sstatinfo[1] != $dstatinfo[1])) {
+ if ($sstatinfo[7] == $dstatinfo[7]) {
+ link_two_files($sfilename, $dfilename);
+
+ } else {
+ my $err = sprintf("ERROR: File sizes are not the same, cannot relink %s to %s.\n",
+ $sfilename, $dfilename);
+ if ($fail_on_different_sizes) {
+ die $err;
+ } else {
+ warn $err;
+ }
+ }
+
+ } elsif ( ($sstatinfo[0] == $dstatinfo[0]) &&
+ ($sstatinfo[1] == $dstatinfo[1])) {
+ $already++;
+ }
+}
+
+sub get_canonical_form($) {
+ my $dir = shift;
+ my $original = $dir;
+
+ die "$dir is not a directory." unless -d $dir;
+
+ $dir .= "/" unless $dir =~ m#/$#;
+ $dir .= ".git/" unless $dir =~ m#\.git/$#;
+
+ die "$original does not have a .git/ subdirectory.\n" unless -d $dir;
+
+ return $dir;
+}
+
+sub link_two_files($$) {
+ my ($sfilename, $dfilename) = @_;
+ my $tmpdname = sprintf("%s.old",$dfilename);
+ rename($dfilename,$tmpdname)
+ or die sprintf("Failure renaming %s to %s: %s",
+ $dfilename, $tmpdname, $!);
+
+ if (! link($sfilename,$dfilename)) {
+ my $failtxt = "";
+ unless (rename($tmpdname,$dfilename)) {
+ $failtxt = sprintf(
+ "Git Repository containing %s is probably corrupted, " .
+ "please copy '%s' to '%s' to fix.\n",
+ $tmpdname, $dfilename);
+ }
+
+ die sprintf("Failed to link %s to %s: %s\n%s" .
+ $sfilename, $dfilename,
+ $!, $dfilename, $failtxt);
+ }
+
+ unlink($tmpdname)
+ or die sprintf("Unlink of %s failed: %s\n",
+ $dfilename, $!);
+
+ $linked++;
+}
+
+
+sub usage() {
+ print("Usage: $0 [--safe] <dir> [<dir> ...] <master_dir> \n");
+ print("All directories should contain a .git/objects/ subdirectory.\n");
+ print("Options\n");
+ print("\t--safe\t" .
+ "Stops if two objects with the same hash exist but " .
+ "have different sizes. Default is to warn and continue.\n");
+ exit(1);
+}