ikiwiki/IkiWiki/Plugin/git.pm

553 lines
15 KiB
Perl

#!/usr/bin/perl
package IkiWiki::Plugin::git;
use warnings;
use strict;
use IkiWiki;
use Encode;
use open qw{:utf8 :std};
my $sha1_pattern = qr/[0-9a-fA-F]{40}/; # pattern to validate Git sha1sums
my $dummy_commit_msg = 'dummy commit'; # message to skip in recent changes
sub import { #{{{
hook(type => "checkconfig", id => "git", call => \&checkconfig);
hook(type => "getsetup", id => "git", call => \&getsetup);
hook(type => "rcs", id => "rcs_update", call => \&rcs_update);
hook(type => "rcs", id => "rcs_prepedit", call => \&rcs_prepedit);
hook(type => "rcs", id => "rcs_commit", call => \&rcs_commit);
hook(type => "rcs", id => "rcs_commit_staged", call => \&rcs_commit_staged);
hook(type => "rcs", id => "rcs_add", call => \&rcs_add);
hook(type => "rcs", id => "rcs_remove", call => \&rcs_remove);
hook(type => "rcs", id => "rcs_rename", call => \&rcs_rename);
hook(type => "rcs", id => "rcs_recentchanges", call => \&rcs_recentchanges);
hook(type => "rcs", id => "rcs_diff", call => \&rcs_diff);
hook(type => "rcs", id => "rcs_getctime", call => \&rcs_getctime);
} #}}}
sub checkconfig () { #{{{
if (! defined $config{diffurl}) {
$config{diffurl}="";
}
if (! defined $config{gitorigin_branch}) {
$config{gitorigin_branch}="origin";
}
if (! defined $config{gitmaster_branch}) {
$config{gitmaster_branch}="master";
}
if (defined $config{git_wrapper} && length $config{git_wrapper}) {
push @{$config{wrappers}}, {
wrapper => $config{git_wrapper},
wrappermode => (defined $config{git_wrappermode} ? $config{git_wrappermode} : "06755"),
};
}
} #}}}
sub getsetup () { #{{{
return
git_wrapper => {
type => "string",
example => "/git/wiki.git/hooks/post-update",
description => "git post-update executable to generate",
safe => 0, # file
rebuild => 0,
},
git_wrappermode => {
type => "string",
example => '06755',
description => "mode for git_wrapper (can safely be made suid)",
safe => 0,
rebuild => 0,
},
historyurl => {
type => "string",
example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=history;f=[[file]]",
description => "gitweb url to show file history ([[file]] substituted)",
safe => 1,
rebuild => 1,
},
diffurl => {
type => "string",
example => "http://git.example.com/gitweb.cgi?p=wiki.git;a=blobdiff;h=[[sha1_to]];hp=[[sha1_from]];hb=[[sha1_parent]];f=[[file]]",
description => "gitweb url to show a diff ([[sha1_to]], [[sha1_from]], [[sha1_parent]], and [[file]] substituted)",
safe => 1,
rebuild => 1,
},
gitorigin_branch => {
type => "string",
example => "origin",
description => "where to pull and push changes (set to empty string to disable)",
safe => 0, # paranoia
rebuild => 0,
},
gitmaster_branch => {
type => "string",
example => "master",
description => "branch that the wiki is stored in",
safe => 0, # paranoia
rebuild => 0,
},
} #}}}
sub safe_git (&@) { #{{{
# Start a child process safely without resorting /bin/sh.
# Return command output or success state (in scalar context).
my ($error_handler, @cmdline) = @_;
my $pid = open my $OUT, "-|";
error("Cannot fork: $!") if !defined $pid;
if (!$pid) {
# In child.
# Git commands want to be in wc.
chdir $config{srcdir}
or error("Cannot chdir to $config{srcdir}: $!");
exec @cmdline or error("Cannot exec '@cmdline': $!");
}
# In parent.
my @lines;
while (<$OUT>) {
chomp;
push @lines, $_;
}
close $OUT;
$error_handler->("'@cmdline' failed: $!") if $? && $error_handler;
return wantarray ? @lines : ($? == 0);
}
# Convenient wrappers.
sub run_or_die ($@) { safe_git(\&error, @_) }
sub run_or_cry ($@) { safe_git(sub { warn @_ }, @_) }
sub run_or_non ($@) { safe_git(undef, @_) }
#}}}
sub merge_past ($$$) { #{{{
# Unlike with Subversion, Git cannot make a 'svn merge -rN:M file'.
# Git merge commands work with the committed changes, except in the
# implicit case of '-m' of git checkout(1). So we should invent a
# kludge here. In principle, we need to create a throw-away branch
# in preparing for the merge itself. Since branches are cheap (and
# branching is fast), this shouldn't cost high.
#
# The main problem is the presence of _uncommitted_ local changes. One
# possible approach to get rid of this situation could be that we first
# make a temporary commit in the master branch and later restore the
# initial state (this is possible since Git has the ability to undo a
# commit, i.e. 'git reset --soft HEAD^'). The method can be summarized
# as follows:
#
# - create a diff of HEAD:current-sha1
# - dummy commit
# - create a dummy branch and switch to it
# - rewind to past (reset --hard to the current-sha1)
# - apply the diff and commit
# - switch to master and do the merge with the dummy branch
# - make a soft reset (undo the last commit of master)
#
# The above method has some drawbacks: (1) it needs a redundant commit
# just to get rid of local changes, (2) somewhat slow because of the
# required system forks. Until someone points a more straight method
# (which I would be grateful) I have implemented an alternative method.
# In this approach, we hide all the modified files from Git by renaming
# them (using the 'rename' builtin) and later restore those files in
# the throw-away branch (that is, we put the files themselves instead
# of applying a patch).
my ($sha1, $file, $message) = @_;
my @undo; # undo stack for cleanup in case of an error
my $conflict; # file content with conflict markers
eval {
# Hide local changes from Git by renaming the modified file.
# Relative paths must be converted to absolute for renaming.
my ($target, $hidden) = (
"$config{srcdir}/${file}", "$config{srcdir}/${file}.${sha1}"
);
rename($target, $hidden)
or error("rename '$target' to '$hidden' failed: $!");
# Ensure to restore the renamed file on error.
push @undo, sub {
return if ! -e "$hidden"; # already renamed
rename($hidden, $target)
or warn "rename '$hidden' to '$target' failed: $!";
};
my $branch = "throw_away_${sha1}"; # supposed to be unique
# Create a throw-away branch and rewind backward.
push @undo, sub { run_or_cry('git', 'branch', '-D', $branch) };
run_or_die('git', 'branch', $branch, $sha1);
# Switch to throw-away branch for the merge operation.
push @undo, sub {
if (!run_or_cry('git', 'checkout', $config{gitmaster_branch})) {
run_or_cry('git', 'checkout','-f',$config{gitmaster_branch});
}
};
run_or_die('git', 'checkout', $branch);
# Put the modified file in _this_ branch.
rename($hidden, $target)
or error("rename '$hidden' to '$target' failed: $!");
# _Silently_ commit all modifications in the current branch.
run_or_non('git', 'commit', '-m', $message, '-a');
# ... and re-switch to master.
run_or_die('git', 'checkout', $config{gitmaster_branch});
# Attempt to merge without complaining.
if (!run_or_non('git', 'pull', '--no-commit', '.', $branch)) {
$conflict = readfile($target);
run_or_die('git', 'reset', '--hard');
}
};
my $failure = $@;
# Process undo stack (in reverse order). By policy cleanup
# actions should normally print a warning on failure.
while (my $handle = pop @undo) {
$handle->();
}
error("Git merge failed!\n$failure\n") if $failure;
return $conflict;
} #}}}
sub parse_diff_tree ($@) { #{{{
# Parse the raw diff tree chunk and return the info hash.
# See git-diff-tree(1) for the syntax.
my ($prefix, $dt_ref) = @_;
# End of stream?
return if !defined @{ $dt_ref } ||
!defined @{ $dt_ref }[0] || !length @{ $dt_ref }[0];
my %ci;
# Header line.
while (my $line = shift @{ $dt_ref }) {
return if $line !~ m/^(.+) ($sha1_pattern)/;
my $sha1 = $2;
$ci{'sha1'} = $sha1;
last;
}
# Identification lines for the commit.
while (my $line = shift @{ $dt_ref }) {
# Regexps are semi-stolen from gitweb.cgi.
if ($line =~ m/^tree ([0-9a-fA-F]{40})$/) {
$ci{'tree'} = $1;
}
elsif ($line =~ m/^parent ([0-9a-fA-F]{40})$/) {
# XXX: collecting in reverse order
push @{ $ci{'parents'} }, $1;
}
elsif ($line =~ m/^(author|committer) (.*) ([0-9]+) (.*)$/) {
my ($who, $name, $epoch, $tz) =
($1, $2, $3, $4 );
$ci{ $who } = $name;
$ci{ "${who}_epoch" } = $epoch;
$ci{ "${who}_tz" } = $tz;
if ($name =~ m/^[^<]+\s+<([^@>]+)/) {
$ci{"${who}_username"} = $1;
}
elsif ($name =~ m/^([^<]+)\s+<>$/) {
$ci{"${who}_username"} = $1;
}
else {
$ci{"${who}_username"} = $name;
}
}
elsif ($line =~ m/^$/) {
# Trailing empty line signals next section.
last;
}
}
debug("No 'tree' seen in diff-tree output") if !defined $ci{'tree'};
if (defined $ci{'parents'}) {
$ci{'parent'} = @{ $ci{'parents'} }[0];
}
else {
$ci{'parent'} = 0 x 40;
}
# Commit message (optional).
while ($dt_ref->[0] =~ /^ /) {
my $line = shift @{ $dt_ref };
$line =~ s/^ //;
push @{ $ci{'comment'} }, $line;
}
shift @{ $dt_ref } if $dt_ref->[0] =~ /^$/;
# Modified files.
while (my $line = shift @{ $dt_ref }) {
if ($line =~ m{^
(:+) # number of parents
([^\t]+)\t # modes, sha1, status
(.*) # file names
$}xo) {
my $num_parents = length $1;
my @tmp = split(" ", $2);
my ($file, $file_to) = split("\t", $3);
my @mode_from = splice(@tmp, 0, $num_parents);
my $mode_to = shift(@tmp);
my @sha1_from = splice(@tmp, 0, $num_parents);
my $sha1_to = shift(@tmp);
my $status = shift(@tmp);
if ($file =~ m/^"(.*)"$/) {
($file=$1) =~ s/\\([0-7]{1,3})/chr(oct($1))/eg;
}
$file =~ s/^\Q$prefix\E//;
if (length $file) {
push @{ $ci{'details'} }, {
'file' => decode_utf8($file),
'sha1_from' => $sha1_from[0],
'sha1_to' => $sha1_to,
};
}
next;
};
last;
}
return \%ci;
} #}}}
sub git_commit_info ($;$) { #{{{
# Return an array of commit info hashes of num commits (default: 1)
# starting from the given sha1sum.
my ($sha1, $num) = @_;
$num ||= 1;
my @raw_lines = run_or_die('git', 'log', "--max-count=$num",
'--pretty=raw', '--raw', '--abbrev=40', '--always', '-c',
'-r', $sha1, '--', '.');
my ($prefix) = run_or_die('git', 'rev-parse', '--show-prefix');
my @ci;
while (my $parsed = parse_diff_tree(($prefix or ""), \@raw_lines)) {
push @ci, $parsed;
}
warn "Cannot parse commit info for '$sha1' commit" if !@ci;
return wantarray ? @ci : $ci[0];
} #}}}
sub git_sha1 (;$) { #{{{
# Return head sha1sum (of given file).
my $file = shift || q{--};
# Ignore error since a non-existing file might be given.
my ($sha1) = run_or_non('git', 'rev-list', '--max-count=1', 'HEAD',
'--', $file);
if ($sha1) {
($sha1) = $sha1 =~ m/($sha1_pattern)/; # sha1 is untainted now
} else { debug("Empty sha1sum for '$file'.") }
return defined $sha1 ? $sha1 : q{};
} #}}}
sub rcs_update () { #{{{
# Update working directory.
if (length $config{gitorigin_branch}) {
run_or_cry('git', 'pull', $config{gitorigin_branch});
}
} #}}}
sub rcs_prepedit ($) { #{{{
# Return the commit sha1sum of the file when editing begins.
# This will be later used in rcs_commit if a merge is required.
my ($file) = @_;
return git_sha1($file);
} #}}}
sub rcs_commit ($$$;$$) { #{{{
# Try to commit the page; returns undef on _success_ and
# a version of the page with the rcs's conflict markers on
# failure.
my ($file, $message, $rcstoken, $user, $ipaddr) = @_;
# Check to see if the page has been changed by someone else since
# rcs_prepedit was called.
my $cur = git_sha1($file);
my ($prev) = $rcstoken =~ /^($sha1_pattern)$/; # untaint
if (defined $cur && defined $prev && $cur ne $prev) {
my $conflict = merge_past($prev, $file, $dummy_commit_msg);
return $conflict if defined $conflict;
}
rcs_add($file);
return rcs_commit_staged($message, $user, $ipaddr);
} #}}}
sub rcs_commit_staged ($$$) {
# Commits all staged changes. Changes can be staged using rcs_add,
# rcs_remove, and rcs_rename.
my ($message, $user, $ipaddr)=@_;
# Set the commit author and email to the web committer.
my %env=%ENV;
if (defined $user || defined $ipaddr) {
my $u=defined $user ? $user : $ipaddr;
$ENV{GIT_AUTHOR_NAME}=$u;
$ENV{GIT_AUTHOR_EMAIL}="$u\@web";
}
# git commit returns non-zero if file has not been really changed.
# so we should ignore its exit status (hence run_or_non).
$message = IkiWiki::possibly_foolish_untaint($message);
if (run_or_non('git', 'commit', '--cleanup=verbatim',
'-q', '-m', $message)) {
if (length $config{gitorigin_branch}) {
run_or_cry('git', 'push', $config{gitorigin_branch});
}
}
%ENV=%env;
return undef; # success
}
sub rcs_add ($) { # {{{
# Add file to archive.
my ($file) = @_;
run_or_cry('git', 'add', $file);
} #}}}
sub rcs_remove ($) { # {{{
# Remove file from archive.
my ($file) = @_;
run_or_cry('git', 'rm', '-f', $file);
} #}}}
sub rcs_rename ($$) { # {{{
my ($src, $dest) = @_;
run_or_cry('git', 'mv', '-f', $src, $dest);
} #}}}
sub rcs_recentchanges ($) { #{{{
# List of recent changes.
my ($num) = @_;
eval q{use Date::Parse};
error($@) if $@;
my @rets;
foreach my $ci (git_commit_info('HEAD', $num)) {
# Skip redundant commits.
next if ($ci->{'comment'} && @{$ci->{'comment'}}[0] eq $dummy_commit_msg);
my ($sha1, $when) = (
$ci->{'sha1'},
$ci->{'author_epoch'}
);
my @pages;
foreach my $detail (@{ $ci->{'details'} }) {
my $file = $detail->{'file'};
my $diffurl = $config{'diffurl'};
$diffurl =~ s/\[\[file\]\]/$file/go;
$diffurl =~ s/\[\[sha1_parent\]\]/$ci->{'parent'}/go;
$diffurl =~ s/\[\[sha1_from\]\]/$detail->{'sha1_from'}/go;
$diffurl =~ s/\[\[sha1_to\]\]/$detail->{'sha1_to'}/go;
push @pages, {
page => pagename($file),
diffurl => $diffurl,
};
}
my @messages;
my $pastblank=0;
foreach my $line (@{$ci->{'comment'}}) {
$pastblank=1 if $line eq '';
next if $pastblank && $line=~m/^ *(signed[ \-]off[ \-]by[ :]|acked[ \-]by[ :]|cc[ :])/i;
push @messages, { line => $line };
}
my $user=$ci->{'author_username'};
my $web_commit = ($ci->{'author'} =~ /\@web>/);
# compatability code for old web commit messages
if (! $web_commit &&
defined $messages[0] &&
$messages[0]->{line} =~ m/$config{web_commit_regexp}/) {
$user = defined $2 ? "$2" : "$3";
$messages[0]->{line} = $4;
$web_commit=1;
}
push @rets, {
rev => $sha1,
user => $user,
committype => $web_commit ? "web" : "git",
when => $when,
message => [@messages],
pages => [@pages],
} if @pages;
last if @rets >= $num;
}
return @rets;
} #}}}
sub rcs_diff ($) { #{{{
my $rev=shift;
my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
my @lines;
foreach my $line (run_or_non("git", "show", $sha1)) {
if (@lines || $line=~/^diff --git/) {
push @lines, $line."\n";
}
}
if (wantarray) {
return @lines;
}
else {
return join("", @lines);
}
} #}}}
sub rcs_getctime ($) { #{{{
my $file=shift;
# Remove srcdir prefix
$file =~ s/^\Q$config{srcdir}\E\/?//;
my $sha1 = git_sha1($file);
my $ci = git_commit_info($sha1);
my $ctime = $ci->{'author_epoch'};
debug("ctime for '$file': ". localtime($ctime));
return $ctime;
} #}}}
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