Add git-annotate, a tool for assigning blame.

Signed-off-by: Ryan Anderson <ryan@michonline.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 321 insertions, 0 deletions

diff --git a/git-annotate.perl b/git-annotate.perl
new file mode 100755
index 000000000..8f984318a
--- /dev/null
+++ b/git-annotate.perl
@@ -0,0 +1,321 @@
+#!/usr/bin/perl
+# Copyright 2006, Ryan Anderson <ryan@michonline.com>
+#
+# GPL v2 (See COPYING)
+#
+# This file is licensed under the GPL v2, or a later version
+# at the discretion of Linus Torvalds.
+
+use warnings;
+use strict;
+
+my $filename = shift @ARGV;
+
+
+my @stack = (
+	{
+		'rev' => "HEAD",
+		'filename' => $filename,
+	},
+);
+
+our (@lineoffsets, @pendinglineoffsets);
+our @filelines = ();
+open(F,"<",$filename)
+	or die "Failed to open filename: $!";
+
+while(<F>) {
+	chomp;
+	push @filelines, $_;
+}
+close(F);
+our $leftover_lines = @filelines;
+our %revs;
+our @revqueue;
+our $head;
+
+my $revsprocessed = 0;
+while (my $bound = pop @stack) {
+	my @revisions = git_rev_list($bound->{'rev'}, $bound->{'filename'});
+	foreach my $revinst (@revisions) {
+		my ($rev, @parents) = @$revinst;
+		$head ||= $rev;
+
+		$revs{$rev}{'filename'} = $bound->{'filename'};
+		if (scalar @parents > 0) {
+			$revs{$rev}{'parents'} = \@parents;
+			next;
+		}
+
+		my $newbound = find_parent_renames($rev, $bound->{'filename'});
+		if ( exists $newbound->{'filename'} && $newbound->{'filename'} ne $bound->{'filename'}) {
+			push @stack, $newbound;
+			$revs{$rev}{'parents'} = [$newbound->{'rev'}];
+		}
+	}
+}
+push @revqueue, $head;
+init_claim($head);
+$revs{$head}{'lineoffsets'} = {};
+handle_rev();
+
+
+my $i = 0;
+foreach my $l (@filelines) {
+	my ($output, $rev, $committer, $date);
+	if (ref $l eq 'ARRAY') {
+		($output, $rev, $committer, $date) = @$l;
+		if (length($rev) > 8) {
+			$rev = substr($rev,0,8);
+		}
+	} else {
+		$output = $l;
+		($rev, $committer, $date) = ('unknown', 'unknown', 'unknown');
+	}
+
+	printf("(%8s %10s %10s %d)%s\n", $rev, $committer, $date, $i++, $output);
+}
+
+sub init_claim {
+	my ($rev) = @_;
+	my %revinfo = git_commit_info($rev);
+	for (my $i = 0; $i < @filelines; $i++) {
+		$filelines[$i] = [ $filelines[$i], '', '', '', 1];
+			# line,
+			# rev,
+			# author,
+			# date,
+			# 1 <-- belongs to the original file.
+	}
+	$revs{$rev}{'lines'} = \@filelines;
+}
+
+
+sub handle_rev {
+	my $i = 0;
+	while (my $rev = shift @revqueue) {
+
+		my %revinfo = git_commit_info($rev);
+
+		foreach my $p (@{$revs{$rev}{'parents'}}) {
+
+			git_diff_parse($p, $rev, %revinfo);
+			push @revqueue, $p;
+		}
+
+
+		if (scalar @{$revs{$rev}{parents}} == 0) {
+			# We must be at the initial rev here, so claim everything that is left.
+			for (my $i = 0; $i < @{$revs{$rev}{lines}}; $i++) {
+				if (ref ${$revs{$rev}{lines}}[$i] eq '' || ${$revs{$rev}{lines}}[$i][1] eq '') {
+					claim_line($i, $rev, $revs{$rev}{lines}, %revinfo);
+				}
+			}
+		}
+	}
+}
+
+
+sub git_rev_list {
+	my ($rev, $file) = @_;
+
+	open(P,"-|","git-rev-list","--parents","--remove-empty",$rev,"--",$file)
+		or die "Failed to exec git-rev-list: $!";
+
+	my @revs;
+	while(my $line = <P>) {
+		chomp $line;
+		my ($rev, @parents) = split /\s+/, $line;
+		push @revs, [ $rev, @parents ];
+	}
+	close(P);
+
+	printf("0 revs found for rev %s (%s)\n", $rev, $file) if (@revs == 0);
+	return @revs;
+}
+
+sub find_parent_renames {
+	my ($rev, $file) = @_;
+
+	open(P,"-|","git-diff-tree", "-M50", "-r","--name-status", "-z","$rev")
+		or die "Failed to exec git-diff: $!";
+
+	local $/ = "\0";
+	my %bound;
+	my $junk = <P>;
+	while (my $change = <P>) {
+		chomp $change;
+		my $filename = <P>;
+		chomp $filename;
+
+		if ($change =~ m/^[AMD]$/ ) {
+			next;
+		} elsif ($change =~ m/^R/ ) {
+			my $oldfilename = $filename;
+			$filename = <P>;
+			chomp $filename;
+			if ( $file eq $filename ) {
+				my $parent = git_find_parent($rev, $oldfilename);
+				@bound{'rev','filename'} = ($parent, $oldfilename);
+				last;
+			}
+		}
+	}
+	close(P);
+
+	return \%bound;
+}
+
+
+sub git_find_parent {
+	my ($rev, $filename) = @_;
+
+	open(REVPARENT,"-|","git-rev-list","--remove-empty", "--parents","--max-count=1","$rev","--",$filename)
+		or die "Failed to open git-rev-list to find a single parent: $!";
+
+	my $parentline = <REVPARENT>;
+	chomp $parentline;
+	my ($revfound,$parent) = split m/\s+/, $parentline;
+
+	close(REVPARENT);
+
+	return $parent;
+}
+
+
+# Get a diff between the current revision and a parent.
+# Record the commit information that results.
+sub git_diff_parse {
+	my ($parent, $rev, %revinfo) = @_;
+
+	my ($ri, $pi) = (0,0);
+	open(DIFF,"-|","git-diff-tree","-M","-p",$rev,$parent,"--",
+			$revs{$rev}{'filename'}, $revs{$parent}{'filename'})
+		or die "Failed to call git-diff for annotation: $!";
+
+	my $slines = $revs{$rev}{'lines'};
+	my @plines;
+
+	my $gotheader = 0;
+	my ($remstart, $remlength, $addstart, $addlength);
+	my ($hunk_start, $hunk_index, $hunk_adds);
+	while(<DIFF>) {
+		chomp;
+		if (m/^@@ -(\d+),(\d+) \+(\d+),(\d+)/) {
+			($remstart, $remlength, $addstart, $addlength) = ($1, $2, $3, $4);
+			# Adjust for 0-based arrays
+			$remstart--;
+			$addstart--;
+			# Reinit hunk tracking.
+			$hunk_start = $remstart;
+			$hunk_index = 0;
+			$gotheader = 1;
+
+			for (my $i = $ri; $i < $remstart; $i++) {
+				$plines[$pi++] = $slines->[$i];
+				$ri++;
+			}
+			next;
+		} elsif (!$gotheader) {
+			next;
+		}
+
+		if (m/^\+(.*)$/) {
+			my $line = $1;
+			$plines[$pi++] = [ $line, '', '', '', 0 ];
+			next;
+
+		} elsif (m/^-(.*)$/) {
+			my $line = $1;
+			if (get_line($slines, $ri) eq $line) {
+				# Found a match, claim
+				claim_line($ri, $rev, $slines, %revinfo);
+			} else {
+				die sprintf("Sync error: %d/%d\n|%s\n|%s\n%s => %s\n",
+						$ri, $hunk_start + $hunk_index,
+						$line,
+						get_line($slines, $ri),
+						$rev, $parent);
+			}
+			$ri++;
+
+		} else {
+			if (substr($_,1) ne get_line($slines,$ri) ) {
+				die sprintf("Line %d (%d) does not match:\n|%s\n|%s\n%s => %s\n",
+						$hunk_start + $hunk_index, $ri,
+						substr($_,1),
+						get_line($slines,$ri),
+						$rev, $parent);
+			}
+			$plines[$pi++] = $slines->[$ri++];
+		}
+		$hunk_index++;
+	}
+	close(DIFF);
+	for (my $i = $ri; $i < @{$slines} ; $i++) {
+		push @plines, $slines->[$ri++];
+	}
+
+	$revs{$parent}{lines} = \@plines;
+	return;
+}
+
+sub get_line {
+	my ($lines, $index) = @_;
+
+	return ref $lines->[$index] ne '' ? $lines->[$index][0] : $lines->[$index];
+}
+
+sub git_cat_file {
+	my ($parent, $filename) = @_;
+	return () unless defined $parent && defined $filename;
+	my $blobline = `git-ls-tree $parent $filename`;
+	my ($mode, $type, $blob, $tfilename) = split(/\s+/, $blobline, 4);
+
+	open(C,"-|","git-cat-file", "blob", $blob)
+		or die "Failed to git-cat-file blob $blob (rev $parent, file $filename): " . $!;
+
+	my @lines;
+	while(<C>) {
+		chomp;
+		push @lines, $_;
+	}
+	close(C);
+
+	return @lines;
+}
+
+
+sub claim_line {
+	my ($floffset, $rev, $lines, %revinfo) = @_;
+	my $oline = get_line($lines, $floffset);
+	@{$lines->[$floffset]} = ( $oline, $rev,
+		$revinfo{'author'}, $revinfo{'author_date'} );
+	#printf("Claiming line %d with rev %s: '%s'\n",
+	#		$floffset, $rev, $oline) if 1;
+}
+
+sub git_commit_info {
+	my ($rev) = @_;
+	open(COMMIT, "-|","git-cat-file", "commit", $rev)
+		or die "Failed to call git-cat-file: $!";
+
+	my %info;
+	while(<COMMIT>) {
+		chomp;
+		last if (length $_ == 0);
+
+		if (m/^author (.*) <(.*)> (.*)$/) {
+			$info{'author'} = $1;
+			$info{'author_email'} = $2;
+			$info{'author_date'} = $3;
+		} elsif (m/^committer (.*) <(.*)> (.*)$/) {
+			$info{'committer'} = $1;
+			$info{'committer_email'} = $2;
+			$info{'committer_date'} = $3;
+		}
+	}
+	close(COMMIT);
+
+	return %info;
+}