+++ /dev/null
-#!/usr/bin/perl
-#
-# REuse REcorded REsolve. This tool records a conflicted automerge
-# result and its hand resolution, and helps to resolve future
-# automerge that results in the same conflict.
-#
-# To enable this feature, create a directory 'rr-cache' under your
-# .git/ directory.
-
-use Digest;
-use File::Path;
-use File::Copy;
-
-my $git_dir = $::ENV{GIT_DIR} || ".git";
-my $rr_dir = "$git_dir/rr-cache";
-my $merge_rr = "$git_dir/rr-cache/MERGE_RR";
-
-my %merge_rr = ();
-
-sub read_rr {
- if (!-f $merge_rr) {
- %merge_rr = ();
- return;
- }
- my $in;
- local $/ = "\0";
- open $in, "<$merge_rr" or die "$!: $merge_rr";
- while (<$in>) {
- chomp;
- my ($name, $path) = /^([0-9a-f]{40})\t(.*)$/s;
- $merge_rr{$path} = $name;
- }
- close $in;
-}
-
-sub write_rr {
- my $out;
- open $out, ">$merge_rr" or die "$!: $merge_rr";
- for my $path (sort keys %merge_rr) {
- my $name = $merge_rr{$path};
- print $out "$name\t$path\0";
- }
- close $out;
-}
-
-sub compute_conflict_name {
- my ($path) = @_;
- my @side = ();
- my $in;
- open $in, "<$path" or die "$!: $path";
-
- my $sha1 = Digest->new("SHA-1");
- my $hunk = 0;
- while (<$in>) {
- if (/^<<<<<<< .*/) {
- $hunk++;
- @side = ([], undef);
- }
- elsif (/^=======$/) {
- $side[1] = [];
- }
- elsif (/^>>>>>>> .*/) {
- my ($one, $two);
- $one = join('', @{$side[0]});
- $two = join('', @{$side[1]});
- if ($two le $one) {
- ($one, $two) = ($two, $one);
- }
- $sha1->add($one);
- $sha1->add("\0");
- $sha1->add($two);
- $sha1->add("\0");
- @side = ();
- }
- elsif (@side == 0) {
- next;
- }
- elsif (defined $side[1]) {
- push @{$side[1]}, $_;
- }
- else {
- push @{$side[0]}, $_;
- }
- }
- close $in;
- return ($sha1->hexdigest, $hunk);
-}
-
-sub record_preimage {
- my ($path, $name) = @_;
- my @side = ();
- my ($in, $out);
- open $in, "<$path" or die "$!: $path";
- open $out, ">$name" or die "$!: $name";
-
- while (<$in>) {
- if (/^<<<<<<< .*/) {
- @side = ([], undef);
- }
- elsif (/^=======$/) {
- $side[1] = [];
- }
- elsif (/^>>>>>>> .*/) {
- my ($one, $two);
- $one = join('', @{$side[0]});
- $two = join('', @{$side[1]});
- if ($two le $one) {
- ($one, $two) = ($two, $one);
- }
- print $out "<<<<<<<\n";
- print $out $one;
- print $out "=======\n";
- print $out $two;
- print $out ">>>>>>>\n";
- @side = ();
- }
- elsif (@side == 0) {
- print $out $_;
- }
- elsif (defined $side[1]) {
- push @{$side[1]}, $_;
- }
- else {
- push @{$side[0]}, $_;
- }
- }
- close $out;
- close $in;
-}
-
-sub find_conflict {
- my $in;
- local $/ = "\0";
- my $pid = open($in, '-|');
- die "$!" unless defined $pid;
- if (!$pid) {
- exec(qw(git ls-files -z -u)) or die "$!: ls-files";
- }
- my %path = ();
- my @path = ();
- while (<$in>) {
- chomp;
- my ($mode, $sha1, $stage, $path) =
- /^([0-7]+) ([0-9a-f]{40}) ([123])\t(.*)$/s;
- $path{$path} |= (1 << $stage);
- }
- close $in;
- while (my ($path, $status) = each %path) {
- if ($status == 14) { push @path, $path; }
- }
- return @path;
-}
-
-sub merge {
- my ($name, $path) = @_;
- record_preimage($path, "$rr_dir/$name/thisimage");
- unless (system('git', 'merge-file', map { "$rr_dir/$name/${_}image" }
- qw(this pre post))) {
- my $in;
- open $in, "<$rr_dir/$name/thisimage" or
- die "$!: $name/thisimage";
- my $out;
- open $out, ">$path" or die "$!: $path";
- while (<$in>) { print $out $_; }
- close $in;
- close $out;
- return 1;
- }
- return 0;
-}
-
-sub garbage_collect_rerere {
- # We should allow specifying these from the command line and
- # that is why the caller gives @ARGV to us, but I am lazy.
-
- my $cutoff_noresolve = 15; # two weeks
- my $cutoff_resolve = 60; # two months
- my @to_remove;
- while (<$rr_dir/*/preimage>) {
- my ($dir) = /^(.*)\/preimage$/;
- my $cutoff = ((-f "$dir/postimage")
- ? $cutoff_resolve
- : $cutoff_noresolve);
- my $age = -M "$_";
- if ($cutoff <= $age) {
- push @to_remove, $dir;
- }
- }
- if (@to_remove) {
- rmtree(\@to_remove);
- }
-}
-
--d "$rr_dir" || exit(0);
-
-read_rr();
-
-if (@ARGV) {
- my $arg = shift @ARGV;
- if ($arg eq 'clear') {
- for my $path (keys %merge_rr) {
- my $name = $merge_rr{$path};
- if (-d "$rr_dir/$name" &&
- ! -f "$rr_dir/$name/postimage") {
- rmtree(["$rr_dir/$name"]);
- }
- }
- unlink $merge_rr;
- }
- elsif ($arg eq 'status') {
- for my $path (keys %merge_rr) {
- print $path, "\n";
- }
- }
- elsif ($arg eq 'diff') {
- for my $path (keys %merge_rr) {
- my $name = $merge_rr{$path};
- system('diff', ((@ARGV == 0) ? ('-u') : @ARGV),
- '-L', "a/$path", '-L', "b/$path",
- "$rr_dir/$name/preimage", $path);
- }
- }
- elsif ($arg eq 'gc') {
- garbage_collect_rerere(@ARGV);
- }
- else {
- die "$0 unknown command: $arg\n";
- }
- exit 0;
-}
-
-my %conflict = map { $_ => 1 } find_conflict();
-
-# MERGE_RR records paths with conflicts immediately after merge
-# failed. Some of the conflicted paths might have been hand resolved
-# in the working tree since then, but the initial run would catch all
-# and register their preimages.
-
-for my $path (keys %conflict) {
- # This path has conflict. If it is not recorded yet,
- # record the pre-image.
- if (!exists $merge_rr{$path}) {
- my ($name, $hunk) = compute_conflict_name($path);
- next unless ($hunk);
- $merge_rr{$path} = $name;
- if (! -d "$rr_dir/$name") {
- mkpath("$rr_dir/$name", 0, 0777);
- print STDERR "Recorded preimage for '$path'\n";
- record_preimage($path, "$rr_dir/$name/preimage");
- }
- }
-}
-
-# Now some of the paths that had conflicts earlier might have been
-# hand resolved. Others may be similar to a conflict already that
-# was resolved before.
-
-for my $path (keys %merge_rr) {
- my $name = $merge_rr{$path};
-
- # We could resolve this automatically if we have images.
- if (-f "$rr_dir/$name/preimage" &&
- -f "$rr_dir/$name/postimage") {
- if (merge($name, $path)) {
- print STDERR "Resolved '$path' using previous resolution.\n";
- # Then we do not have to worry about this path
- # anymore.
- delete $merge_rr{$path};
- next;
- }
- }
-
- # Let's see if we have resolved it.
- (undef, my $hunk) = compute_conflict_name($path);
- next if ($hunk);
-
- print STDERR "Recorded resolution for '$path'.\n";
- copy($path, "$rr_dir/$name/postimage");
- # And we do not have to worry about this path anymore.
- delete $merge_rr{$path};
-}
-
-# Write out the rest.
-write_rr();