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| 1 | +#!/usr/bin/perl |
| 2 | + |
| 3 | +# |
| 4 | +# Display all commits on active branches, merging together commits from |
| 5 | +# different branches that occur close together in time and with identical |
| 6 | +# log messages. Most of the time, such commits occur in the same order |
| 7 | +# on all branches, and we print them out in that order. However, if commit |
| 8 | +# A occurs before commit B on branch X and commit B occurs before commit A |
| 9 | +# on branch Y, then there's no ordering which is consistent with both |
| 10 | +# branches. |
| 11 | +# |
| 12 | +# When we encounter a situation where there's no single "best" commit to |
| 13 | +# print next, we print the one that involves the least distortion of the |
| 14 | +# commit order, summed across all branches. In the event of a further tie, |
| 15 | +# the commit from the newer branch prints first. It is best not to sort |
| 16 | +# based on timestamp, because git timestamps aren't necessarily in order |
| 17 | +# (since the timestamp is provided by the committer's machine), even though |
| 18 | +# for the portion of the history we imported from CVS, we expect that they |
| 19 | +# will be. |
| 20 | +# |
| 21 | +# Even though we don't use timestamps to order commits, it is used to |
| 22 | +# identify which commits happened at about the same time, for the purpose |
| 23 | +# of matching up commits from different branches. |
| 24 | +# |
| 25 | + |
| 26 | +use strict; |
| 27 | +use warnings; |
| 28 | +require Date::Calc; |
| 29 | +require Getopt::Long; |
| 30 | +require IPC::Open2; |
| 31 | + |
| 32 | +my @BRANCHES = qw(master REL9_0_STABLE REL8_4_STABLE REL8_3_STABLE |
| 33 | + REL8_2_STABLE REL8_1_STABLE REL8_0_STABLE REL7_4_STABLE); |
| 34 | + |
| 35 | +my $since; |
| 36 | +Getopt::Long::GetOptions('since=s' => \$since) || usage(); |
| 37 | +usage() if @ARGV; |
| 38 | + |
| 39 | +my @git = qw(git log --date=iso); |
| 40 | +push @git, '--since=' . $since if defined $since; |
| 41 | + |
| 42 | +my %all_commits; |
| 43 | +my %all_commits_by_branch; |
| 44 | + |
| 45 | +my %commit; |
| 46 | +for my $branch (@BRANCHES) { |
| 47 | + my $commitnum = 0; |
| 48 | + IPC::Open2::open2(my $git_out, my $git_in, @git, "origin/$branch") |
| 49 | + || die "can't run @git origin/$branch: $!"; |
| 50 | + while (my $line = <$git_out>) { |
| 51 | + if ($line =~ /^commit\s+(.*)/) { |
| 52 | + push_commit(\%commit) if %commit; |
| 53 | + %commit = ( |
| 54 | + 'branch' => $branch, |
| 55 | + 'commit' => $1, |
| 56 | + 'message' => '', |
| 57 | + 'commitnum' => $commitnum++, |
| 58 | + ); |
| 59 | + } |
| 60 | + elsif ($line =~ /^Author:\s+(.*)/) { |
| 61 | + $commit{'author'} = $1; |
| 62 | + } |
| 63 | + elsif ($line =~ /^Date:\s+(.*)/) { |
| 64 | + $commit{'date'} = $1; |
| 65 | + } |
| 66 | + elsif ($line =~ /^\s+/) { |
| 67 | + $commit{'message'} .= $line; |
| 68 | + } |
| 69 | + } |
| 70 | +} |
| 71 | + |
| 72 | +my %position; |
| 73 | +for my $branch (@BRANCHES) { |
| 74 | + $position{$branch} = 0; |
| 75 | +} |
| 76 | +while (1) { |
| 77 | + my $best_branch; |
| 78 | + my $best_inversions; |
| 79 | + for my $branch (@BRANCHES) { |
| 80 | + my $leader = $all_commits_by_branch{$branch}->[$position{$branch}]; |
| 81 | + next if !defined $leader; |
| 82 | + my $inversions = 0; |
| 83 | + for my $branch2 (@BRANCHES) { |
| 84 | + if (defined $leader->{'branch_position'}{$branch2}) { |
| 85 | + $inversions += $leader->{'branch_position'}{$branch2} |
| 86 | + - $position{$branch2}; |
| 87 | + } |
| 88 | + } |
| 89 | + if (!defined $best_inversions || $inversions < $best_inversions) { |
| 90 | + $best_branch = $branch; |
| 91 | + $best_inversions = $inversions; |
| 92 | + } |
| 93 | + } |
| 94 | + last if !defined $best_branch; |
| 95 | + my $winner = |
| 96 | + $all_commits_by_branch{$best_branch}->[$position{$best_branch}]; |
| 97 | + print $winner->{'header'}; |
| 98 | + print "Commit-Order-Inversions: $best_inversions\n" |
| 99 | + if $best_inversions != 0; |
| 100 | + print $winner->{'message'}; |
| 101 | + $winner->{'done'} = 1; |
| 102 | + for my $branch (@BRANCHES) { |
| 103 | + my $leader = $all_commits_by_branch{$branch}->[$position{$branch}]; |
| 104 | + if (defined $leader && $leader->{'done'}) { |
| 105 | + ++$position{$branch}; |
| 106 | + redo; |
| 107 | + } |
| 108 | + } |
| 109 | +} |
| 110 | + |
| 111 | +sub push_commit { |
| 112 | + my ($c) = @_; |
| 113 | + my $ht = hash_commit($c); |
| 114 | + my $ts = parse_datetime($c->{'date'}); |
| 115 | + my $cc; |
| 116 | + for my $candidate (@{$all_commits{$ht}}) { |
| 117 | + if (abs($ts - $candidate->{'timestamp'}) < 600 |
| 118 | + && !exists $candidate->{'branch_position'}{$c->{'branch'}}) |
| 119 | + { |
| 120 | + $cc = $candidate; |
| 121 | + last; |
| 122 | + } |
| 123 | + } |
| 124 | + if (!defined $cc) { |
| 125 | + $cc = { |
| 126 | + 'header' => sprintf("Author: %s\n", $c->{'author'}), |
| 127 | + 'message' => $c->{'message'}, |
| 128 | + 'timestamp' => $ts |
| 129 | + }; |
| 130 | + push @{$all_commits{$ht}}, $cc; |
| 131 | + } |
| 132 | + $cc->{'header'} .= sprintf "Branch: %s [%s] %s\n", |
| 133 | + $c->{'branch'}, substr($c->{'commit'}, 0, 9), $c->{'date'}; |
| 134 | + push @{$all_commits_by_branch{$c->{'branch'}}}, $cc; |
| 135 | + $cc->{'branch_position'}{$c->{'branch'}} = |
| 136 | + -1+@{$all_commits_by_branch{$c->{'branch'}}}; |
| 137 | +} |
| 138 | + |
| 139 | +sub hash_commit { |
| 140 | + my ($c) = @_; |
| 141 | + return $c->{'author'} . "\0" . $c->{'message'}; |
| 142 | +} |
| 143 | + |
| 144 | +sub parse_datetime { |
| 145 | + my ($dt) = @_; |
| 146 | + $dt =~ /^(\d\d\d\d)-(\d\d)-(\d\d)\s+(\d\d):(\d\d):(\d\d)/; |
| 147 | + return Date::Calc::Mktime($1, $2, $3, $4, $5, $6); |
| 148 | +} |
| 149 | + |
| 150 | +sub usage { |
| 151 | + print STDERR <<EOM; |
| 152 | +Usage: git-topo-order [--since=SINCE] |
| 153 | +EOM |
| 154 | + exit 1; |
| 155 | +} |
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