citadel

git-contacts (4513B)

---

 #!/usr/bin/env perl
 
 # List people who might be interested in a patch.  Useful as the argument to
 # git-send-email --cc-cmd option, and in other situations.
 #
 # Usage: git contacts <file | rev-list option> ...
 
 use strict;
 use warnings;
 use IPC::Open2;
 
 my $since = '5-years-ago';
 my $min_percent = 10;
 my $labels_rx = qr/Signed-off-by|Reviewed-by|Acked-by|Cc|Reported-by/i;
 my %seen;
 
 sub format_contact {
 	my ($name, $email) = @_;
 	return "$name <$email>";
 }
 
 sub parse_commit {
 	my ($commit, $data) = @_;
 	my $contacts = $commit->{contacts};
 	my $inbody = 0;
 	for (split(/^/m, $data)) {
 		if (not $inbody) {
 			if (/^author ([^<>]+) <(\S+)> .+$/) {
 				$contacts->{format_contact($1, $2)} = 1;
 			} elsif (/^$/) {
 				$inbody = 1;
 			}
 		} elsif (/^$labels_rx:\s+([^<>]+)\s+<(\S+?)>$/o) {
 			$contacts->{format_contact($1, $2)} = 1;
 		}
 	}
 }
 
 sub import_commits {
 	my ($commits) = @_;
 	return unless %$commits;
 	my $pid = open2 my $reader, my $writer, qw(git cat-file --batch);
 	for my $id (keys(%$commits)) {
 		print $writer "$id\n";
 		my $line = <$reader>;
 		if ($line =~ /^([0-9a-f]{40}) commit (\d+)/) {
 			my ($cid, $len) = ($1, $2);
 			die "expected $id but got $cid\n" unless $id eq $cid;
 			my $data;
 			# cat-file emits newline after data, so read len+1
 			read $reader, $data, $len + 1;
 			parse_commit($commits->{$id}, $data);
 		}
 	}
 	close $reader;
 	close $writer;
 	waitpid($pid, 0);
 	die "git-cat-file error: $?\n" if $?;
 }
 
 sub get_blame {
 	my ($commits, $source, $from, $ranges) = @_;
 	return unless @$ranges;
 	open my $f, '-|',
 		qw(git blame --porcelain -C),
 		map({"-L$_->[0],+$_->[1]"} @$ranges),
 		'--since', $since, "$from^", '--', $source or die;
 	while (<$f>) {
 		if (/^([0-9a-f]{40}) \d+ \d+ \d+$/) {
 			my $id = $1;
 			$commits->{$id} = { id => $id, contacts => {} }
 				unless $seen{$id};
 			$seen{$id} = 1;
 		}
 	}
 	close $f;
 }
 
 sub blame_sources {
 	my ($sources, $commits) = @_;
 	for my $s (keys %$sources) {
 		for my $id (keys %{$sources->{$s}}) {
 			get_blame($commits, $s, $id, $sources->{$s}{$id});
 		}
 	}
 }
 
 sub scan_patches {
 	my ($sources, $id, $f) = @_;
 	my $source;
 	while (<$f>) {
 		if (/^From ([0-9a-f]{40}) Mon Sep 17 00:00:00 2001$/) {
 			$id = $1;
 			$seen{$id} = 1;
 		}
 		next unless $id;
 		if (m{^--- (?:a/(.+)|/dev/null)$}) {
 			$source = $1;
 		} elsif (/^@@ -(\d+)(?:,(\d+))?/ && $source) {
 			my $len = defined($2) ? $2 : 1;
 			push @{$sources->{$source}{$id}}, [$1, $len] if $len;
 		}
 	}
 }
 
 sub scan_patch_file {
 	my ($commits, $file) = @_;
 	open my $f, '<', $file or die "read failure: $file: $!\n";
 	scan_patches($commits, undef, $f);
 	close $f;
 }
 
 sub parse_rev_args {
 	my @args = @_;
 	open my $f, '-|',
 		qw(git rev-parse --revs-only --default HEAD --symbolic), @args
 		or die;
 	my @revs;
 	while (<$f>) {
 		chomp;
 		push @revs, $_;
 	}
 	close $f;
 	return @revs if scalar(@revs) != 1;
 	return "^$revs[0]", 'HEAD' unless $revs[0] =~ /^-/;
 	return $revs[0], 'HEAD';
 }
 
 sub scan_rev_args {
 	my ($commits, $args) = @_;
 	my @revs = parse_rev_args(@$args);
 	open my $f, '-|', qw(git rev-list --reverse), @revs or die;
 	while (<$f>) {
 		chomp;
 		my $id = $_;
 		$seen{$id} = 1;
 		open my $g, '-|', qw(git show -C --oneline), $id or die;
 		scan_patches($commits, $id, $g);
 		close $g;
 	}
 	close $f;
 }
 
 sub mailmap_contacts {
 	my ($contacts) = @_;
 	my %mapped;
 	my $pid = open2 my $reader, my $writer, qw(git check-mailmap --stdin);
 	for my $contact (keys(%$contacts)) {
 		print $writer "$contact\n";
 		my $canonical = <$reader>;
 		chomp $canonical;
 		$mapped{$canonical} += $contacts->{$contact};
 	}
 	close $reader;
 	close $writer;
 	waitpid($pid, 0);
 	die "git-check-mailmap error: $?\n" if $?;
 	return \%mapped;
 }
 
 if (!@ARGV) {
 	die "No input revisions or patch files\n";
 }
 
 my (@files, @rev_args);
 for (@ARGV) {
 	if (-e) {
 		push @files, $_;
 	} else {
 		push @rev_args, $_;
 	}
 }
 
 my %sources;
 for (@files) {
 	scan_patch_file(\%sources, $_);
 }
 if (@rev_args) {
 	scan_rev_args(\%sources, \@rev_args)
 }
 
 my $toplevel = `git rev-parse --show-toplevel`;
 chomp $toplevel;
 chdir($toplevel) or die "chdir failure: $toplevel: $!\n";
 
 my %commits;
 blame_sources(\%sources, \%commits);
 import_commits(\%commits);
 
 my $contacts = {};
 for my $commit (values %commits) {
 	for my $contact (keys %{$commit->{contacts}}) {
 		$contacts->{$contact}++;
 	}
 }
 $contacts = mailmap_contacts($contacts);
 
 my $ncommits = scalar(keys %commits);
 for my $contact (keys %$contacts) {
 	my $percent = $contacts->{$contact} * 100 / $ncommits;
 	next if $percent < $min_percent;
 	print "$contact\n";
 }