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Here's Thomas Schwinge unfinished darcs support for ikiwiki.

(Finishing this has been suggested as a [[soc]] project.)

I haven't been working on this for months and also won't in the near future. Feel free to use what I have done so far and bring it into an usable state! Also, feel free to contact me if there are questions.

-- Thomas Schwinge

[[toggle text="show"]] [[toggleable text=""" # Support for the darcs rcs, URL:http://darcs.net/. # Copyright (C) 2006 Thomas Schwinge tschwinge@gnu.org # # This program is free software; you can redistribute it and/or modify it # under the terms of the GNU General Public License as published by the # Free Software Foundation; either version 2 of the License, or (at your # option) any later version. # # This program is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program; if not, write to the Free Software Foundation, Inc., # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

# We're guaranteed to be the only instance of ikiwiki running at a given
# time.  It is essential that only ikiwiki is working on a particular
# repository.  That means one instance of ikiwiki and it also means that
# you must not `darcs push' into this repository, as this might create
# race conditions, as I understand it.


use warnings;
use strict;
use IkiWiki;

package IkiWiki;


# Which darcs executable to use.
my $darcs = ($ENV{DARCS} or 'darcs');


# Internal functions.

sub darcs_info ($$$) {
    my $field = shift;
    my $repodir = shift;
    my $file = shift; # Relative to the repodir.

    my $child = open(DARCS_CHANGES, "-|");
    if (! $child) {
	exec($darcs, 'changes', '--repo=' . $repodir, '--xml-output', $file) or
	    error('failed to run `darcs changes\'');
    }

    # Brute force for now.  :-/
    while (<DARCS_CHANGES>) {
	last if /^<\/created_as>$/;
    }
    ($_) = <DARCS_CHANGES> =~ /$field=\'([^\']+)/;
    $field eq 'hash' and s/\.gz//; # Strip away the `.gz' from `hash'es.

    close(DARCS_CHANGES) or error('`darcs changes\' exited ' . $?);

    return $_;
}


# Exported functions.

sub rcs_update () {
    # Not needed.
}

sub rcs_prepedit ($) {
    # Prepares to edit a file under revision control.  Returns a token that
    # must be passed to rcs_commit() when the file is to be commited.  For us,
    # this token the hash value of the latest patch that modifies the file,
    # i.e. something like its current revision.  If the file is not yet added
    # to the repository, we return TODO: the empty string.

    my $file = shift; # Relative to the repodir.

    my $hash = darcs_info('hash', $config{srcdir}, $file);
    return defined $hash ? $hash : "";
}

sub rcs_commit ($$$) {
    # Commit the page.  Returns `undef' on success and a version of the page
    # with conflict markers on failure.

    my $file = shift; # Relative to the repodir.
    my $message = shift;
    my $rcstoken = shift;

    # Compute if the ``revision'' of $file changed.
    my $changed = darcs_info('hash', $config{srcdir}, $file) ne $rcstoken;

    # Yes, the following is a bit convoluted.
    if ($changed) {
	# TODO.  Invent a better, non-conflicting name.
	rename("$config{srcdir}/$file", "$config{srcdir}/$file.save") or
	    error("failed to rename $file to $file.save: $!");

	# Roll the repository back to $rcstoken.

	# TODO.  Can we be sure that no changes are lost?  I think that
	# we can, if we make sure that the `darcs push' below will always
	# succeed.

	# We need to revert everything as `darcs obliterate' might choke
	# otherwise.
        # TODO: `yes | ...' needed?  Doesn't seem so.
	system($darcs, "revert", "--repodir=" . $config{srcdir}, "--all") and
	    error("`darcs revert' failed");
	# Remove all patches starting at $rcstoken.
	# TODO.  Something like `yes | darcs obliterate ...' seems to be needed.
	system($darcs, "obliterate", "--quiet", "--repodir" . $config{srcdir},
	       "--match", "hash " . $rcstoken) and
		   error("`darcs obliterate' failed");
	# Restore the $rcstoken one.
	system($darcs, "pull", "--quiet", "--repodir=" . $config{srcdir},
	       "--match", "hash " . $rcstoken, "--all") and
		   error("`darcs pull' failed");

	# We're back at $rcstoken.  Re-install the modified file.
	rename("$config{srcdir}/$file.save", "$config{srcdir}/$file") or
	    error("failed to rename $file.save to $file: $!");
    }

    # Record the changes.
    # TODO: What if $message is empty?
    writefile("$file.log", $config{srcdir}, $message);
    system($darcs, 'record', '--repodir=' . $config{srcdir}, '--all',
	   '--logfile=' . "$config{srcdir}/$file.log",
	   '--author=' . 'web commit <web-hurd@gnu.org>', $file) and
	       error('`darcs record\' failed');

    # Update the repository by pulling from the default repository, which is
    # master repository.
    system($darcs, "pull", "--quiet", "--repodir=" . $config{srcdir},
	   "--all") and error("`darcs pull' failed\n");

    # If this updating yields any conflicts, we'll record them now to resolve
    # them.  If nothing is recorded, there are no conflicts.
    $rcstoken = darcs_info('hash', $config{srcdir}, $file);
    # TODO: Use only the first line here, i.e. only the patch name?
    writefile("$file.log", $config{srcdir}, 'resolve conflicts: ' . $message);
    system($darcs, 'record', '--repodir=' . $config{srcdir}, '--all',
	   '--logfile=' . "$config{srcdir}/$file.log",
	   '--author=' . 'web commit <web-hurd@gnu.org>', $file) and
	       error('`darcs record\' failed');
    my $conflicts = darcs_info('hash', $config{srcdir}, $file) ne $rcstoken;
    unlink("$config{srcdir}/$file.log") or
	error("failed to remove `$file.log'");

    # Push the changes to the main repository.
    system($darcs, 'push', '--quiet', '--repodir=' . $config{srcdir}, '--all')
	and error('`darcs push\' failed');
    # TODO: darcs send?

    if ($conflicts) {
	my $document = readfile("$config{srcdir}/$file");
	# Try to leave everything in a consistent state.
        # TODO: `yes | ...' needed?  Doesn't seem so.
	system($darcs, "revert", "--repodir=" . $config{srcdir}, "--all") and
	    warn("`darcs revert' failed.\n");
	return $document;
    } else {
	return undef;
    }
}

sub rcs_add ($) {
    my $file = shift; # Relative to the repodir.

    # Intermediate directories will be added automagically.
    system($darcs, 'add', '--quiet', '--repodir=' . $config{srcdir},
	   '--boring', $file) and error('`darcs add\' failed');
}

sub rcs_recentchanges ($) {
    warn('rcs_recentchanges() is not implemented');
    return 'rcs_recentchanges() is not implemented';
}

sub rcs_notify () {
    warn('rcs_notify() is not implemented');
}

sub rcs_getctime () {
    warn('rcs_getctime() is not implemented');
}

1

"""]]

This is my (bma) darcs.pm - it's messy (my Perl isn't up to much) but seems to work. It uses just one repo, like the mercurial plugin (unlike the above version, which AIUI uses two).

rcs_commit() uses backticks instead of system(), to prevent darcs' output being sent to the browser and mucking with the HTTP headers (darcs record has no --quiet option). And rcs_recentchanges() uses regexes rather than parsing darcs' XML output.

[[toggle text="show" id="bma"]] [[toggleable id="bma" text="""

#!/usr/bin/perl

use warnings;
use strict;
use IkiWiki;
use Date::Parse;
use open qw{:utf8 :std};

package IkiWiki;

sub rcs_update () { #{{{
	# Do nothing - there's nowhere to update *from*.
} #}}}

sub rcs_prepedit ($) { #{{{
} #}}}

sub rcs_commit ($$$;$$) { #{{{
	my ($file, $message, $rcstoken, $user, $ipaddr) = @_;

	# $user should probably be a name and an email address, by darcs
	# convention.
	if (defined $user) {
		$user = possibly_foolish_untaint($user);
	}
	elsif (defined $ipaddr) {
		$user = "Anonymous from $ipaddr";
	}
	else {
		$user = "Anonymous";
	}

	$message = possibly_foolish_untaint($message);
	
	# BUG: this outputs one line of text, and there's not a -q or --quiet
	# option. Redirecting output to /dev/null works, but I still get the
	# HTTP status and location headers displayed in the browser - is that
	# darcs' fault or ikiwiki's?
	# Doing it in backticks *works*, but I'm sure it could be done better.
	my @cmdline = ("darcs", "record", "--repodir", "$config{srcdir}",
	               "-a", "-m", "$message", "--author", "$user", $file);
	`darcs record --repodir "$config{srcdir}" -a -m "$message" --author "$user" $file`; # Return value? Output? Who needs 'em?
	#if (system(@cmdline) != 0) {
	#	warn "'@cmdline' failed: $!";
	#}

	return undef; # success
	
sub rcs_add ($) { # {{{
	my ($file) = @_;

	my @cmdline = ("darcs", "add", "--repodir", "$config{srcdir}", "-a", "-q", "$file");
	if (system(@cmdline) != 0) {
		warn "'@cmdline' failed: $!";
	}
} #}}}

sub rcs_recentchanges ($) { #{{{
	# TODO: This is horrible code. It doesn't work perfectly, and uses regexes
	# rather than parsing Darcs' XML output.
	my $num=shift;
	my @ret;
	
	return unless -d "$config{srcdir}/_darcs";

	my $changelog = `darcs changes --xml --summary --repodir "$config{srcdir}"`;
	$changelog = join("", split(/\s*\n\s*/, $changelog));
	my @changes = split(/<\/patch>.*?<patch/m, $changelog);


	foreach my $change (@changes) {
		$change =~ m/hash='(.*?)'/;
		my $rev = $1;
		$change =~ m/author='(.*?)'/;
		my $user = $1."\n";
		my $committype = "web";
		if($user =~ m/&lt;/) {
			# Author fields generated by darcs include an email address: look for the "<".
			$committype = "darcs";
			use HTML::Entities;
			$user = decode_entities $user;
		}
		$change =~ m/local_date='(.*?)'/;
		my $when = $1;
		$when=time - str2time($when, 'UTC');
		$change =~ m/<name>(.*?)<\/name>/g;
		my @message = {line => $1};
		foreach my $match ($change =~ m/<comment>(.*?)<\/comment>/gm) {
			push @message, {line => $1};
		}

		my @pages;
		foreach my $match ($change =~ m/<.*?_(file|directory)>(.*?)(<(added|removed)_lines.*\/>)*<\/.*?_(file|directory)>/g) {
			# My perl-fu is weak. I'm probably going about this all wrong, anyway.
			push @pages, {page => pagename($match)} if ( -f $config{srcdir}."/".$match || -d $config{srcdir}."/".$match) and not $match =~ m/^$/;
		}
		push @ret, { rev => $rev,
				user => $user,
				committype => $committype,
				when => $when,
				message => [@message],
				pages => [@pages],
			}
	}
	return @ret;
} #}}}

sub rcs_notify () { #{{{
	# TODO
} #}}}

sub rcs_getctime ($) { #{{{
	error gettext("getctime not implemented");
} #}}}

1

"""]]