update docs for darcs

Deleted all the old incomplete implementations.

Moved explanation of the two-repo system currently implemented for darcs
into rcs/details, and removed discussion from there about other methods
(including one-repo).

Wrote a rcs/darcs page, which I hope is accurate.

1 files changed, 4 insertions, 506 deletions

diff --git a/doc/todo/darcs.mdwn b/doc/todo/darcs.mdwn
index 882a41379..f721e15c5 100644
--- a/doc/todo/darcs.mdwn
+++ b/doc/todo/darcs.mdwn
@@ -1,513 +1,9 @@
-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](mailto:tschwinge@gnu.org)
-
-[[!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](bma@bmalee.eu)) 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
-
-
-
-"""]]
-
----
-
-Well, here's my version too. It only does getctime -- using a real XML parser, instead of regexp ugliness -- and maybe recentchanges, but that may be bitrotted, or maybe I never finished it, as I only need the getctime. As for actual commits, I have previously voiced my opinion, that this should be done by the plugin generating a patch bundle, and forwarding it to darcs in some way (`darcs apply` or even email to another host, possibly moderated), instead of the hacky direct modification of a working copy. It could also be faster to getctime in a batch. Just reading in all the changes the first time they're needed, might not be a big improvement in many cases, but if we got a batch request from ikiwiki, we could keep reaing the changes until all the files in this batch request have been met.  --[[tuomov]]
-
-[[!toggle text="show" id="tuomov"]]
-[[!toggleable id="tuomov" text="""
-<pre>
-#!/usr/bin/perl
-# Stubs for no revision control.
-
-use warnings;
-use strict;
-use IkiWiki;
-
-package IkiWiki;
-
-sub rcs_update () {
-}
-
-sub rcs_prepedit ($) {
-	return ""
-}
-
-sub rcs_commit ($$$) {
-	return undef # success
-}
-
-sub rcs_add ($) {
-}
-
-sub rcs_recentchanges ($) {
-	my $num=shift;
-	my @ret;
-	
-	eval q{use Date::Parse};
-	eval q{use XML::Simple};
-	
-	my $repodir=$config{srcdir};
-	
-	if (-d "$config{srcdir}/_darcs") {
-		my $child = open(LOG, "-|");
-		if (! $child) {
-			exec("darcs", "changes", "--xml", 
-			     "--repodir", "$repodir",
-			     "--last", "$num")
-			|| error("darcs changes failed to run");
-		}
-		my $data=<LOG>;
-		close LOG;
-		
-		my $log = XMLin($data, ForceArray => 1);
-		
-		foreach my $patch ($log->{patch}) {
-			my $date=$patch->{local_date};
-			my $hash=$patch->{hash};
-			my $when=concise(ago(time - str2time($date)));
-			my @pages;
-			
-			my $child = open(SUMMARY, "-|");
-			if (! $child) {
-				exec("darcs", "annotate", "-s", "--xml", 
-				     "--match", "hash: $hash",
-				     "--repodir", "$repodir")
-				|| error("darcs annotate failed to run");
-			}
-			my $data=<SUMMARY>;
-			close SUMMARY;
-		
-			my $summary = XMLin("<lame>$data</lame>", ForceArray => 1);
-
-			# TODO: find @pages
-			
-			push @ret, {
-				#rev => $rev,
-				user => $patch->{author},
-				#committype => $committype,
-				when => $when, 
-				#message => [@message],
-				pages => [@pages],
-			}; # if @pages;
-			return @ret if @ret >= $num;
-		}
-	}
-	
-	return @ret;
-}
-
-sub rcs_notify () {
-}
-
-sub rcs_getctime ($) {
-	my $file=shift;
-	
-	eval q{use Date::Parse};
-	eval q{use XML::Simple};
-	local $/=undef;
-	
-	# Sigh... doing things the hard way again
-	my $repodir=$config{srcdir};
-	
-	my $filer=substr($file, length($repodir));
-	$filer =~ s:^[/]+::;
-	
-	my $child = open(LOG, "-|");
-	if (! $child) {
-		exec("darcs", "changes", "--xml", "--reverse",
-		     "--repodir", "$repodir", "$filer")
-		|| error("darcs changes $filer failed to run");
-	}
-	
-	my $data=<LOG>;
-	close LOG;
-	
-	my $log = XMLin($data, ForceArray => 1);
-	
-	my $datestr=$log->{patch}[0]->{local_date};
-	
-	if (! defined $datestr) {
-		warn "failed to get ctime for $filer";
-		return 0;
-	}
-	
-	my $date=str2time($datestr);
-	
-	debug("found ctime ".localtime($date)." for $file");
-	
-	return $date;
-}
-
-1
-</pre>
-"""]]
-
----
-
-I merged the two versions above and made some fixes; it is recording my web edits in darcs and showing a recent changes page.
-It is in a [darcs repository](http://joyful.com/darcsweb/darcsweb.cgi?r=ikiwiki-darcs), please send patches. --[[Simon_Michael]]
-
-> I'd like to see at least the following fixed before I commit this: --[[Joey]]
-> * Running `darcs record $filename` in backticks is not good (security)
->   The thing to do is to open stdout to /dev/null before execing darcs.
-> * Get `rcs_recentchanges_xml` working, parsing xml with regexps does
->   not seem like a maintenance win.
-> * `rcs_notify` should be removed, it's no longer used.
-> * Some form of conflict handling. Using darcs to attempt to merge
->   the changes is I gusss optional (although every other rcs backend,
->   including svn manages to do this), but it needs to at *least* detect
->   conflicts and return a page with conflict markers for the user to fix
->   the conflict.
-
-I have addressed the recentchanges bit, you can find my hacked up darcs.pm at <http://web.mornfall.net/stuff/web-root/IkiWiki/Rcs/darcs.pm>.
-
-It's got couple of FIXMEs, and a very site-specific filter for recentchanges. Not sure how to do that better though. I will eventually add web commits, probably of my own (and mention it here).
-
----
-
-And here's yet another one, including an updated `ikiwiki-makerepo`. :)
-
 <http://khjk.org/~pesco/ikiwiki-darcs/> (now a darcs repo)
 
 > Note that there's a 'darcs' branch in git that I'm keeping a copy of your
 > code in. Just in case. :-)
 
-I've taken all the good stuff from the above and added the missing hooks. The code hasn't seen a lot of testing, so some bugs are likely yet to surface. Also, I'm not experienced with perl and don't know where I should have used the function `possibly_foolish_untaint`.
-
-Regarding the repository layout: There are two darcs repositories. One is the `srcdir`, the other we'll call `master`.
-
- *  HTML is generated from `srcdir`.
- *  CGI edits happen in `srcdir`.
- *  The backend pulls updates from `master` into `srcdir`, i.e. darcs commits should happen to `master`.
- *  `master` calls ikiwiki (through a wrapper) in its apply posthook, i.e. `master/_darcs/prefs/defaults` should look like this:
-
-        apply posthook ikiwrap
-        apply run-posthook
-
-    (I'm not sure, should/could it be `ikiwrap --refresh` above?)
- *  The backend pushes CGI edits from `srcdir` back into `master` (triggering the apply hook).
- *  The working copies in `srcdir` and `master` should *not* be touched by the user, only by the CGI or darcs, respectively.
+I've taken all the good stuff from the above (now deleted --[[Joey]]) and added the missing hooks. The code hasn't seen a lot of testing, so some bugs are likely yet to surface. Also, I'm not experienced with perl and don't know where I should have used the function `possibly_foolish_untaint`.
 
 > Review of this one:
 > 
@@ -523,7 +19,7 @@ Regarding the repository layout: There are two darcs repositories. One is the `s
 > * `rcs_remove` just calls "rm"? Does darcs record notice the file was removed
 >    and automatically commit the removal? (And why `system("rm")` and not
 >    `unlink`?)
-> * Is the the darcs info in [[details]] still up-to-date re this version?
+> * Is the the darcs info in [[rcs/details]] still up-to-date re this version?
 > --[[Joey]]
 
 > Update:
@@ -537,6 +33,8 @@ Regarding the repository layout: There are two darcs repositories. One is the `s
 > this version works. It's similar, but the details differ slightly.
 > You could copy my description above to replace it.
 >
+>> done --[[Joey]] 
+> 
 > There is still some ironing to do, for instance the current version doesn't allow for
 > modifying attachments by re-uploading them via CGI ("darcs add failed"). Am I assuming
 > correctly that "adding" a file that's already in the repo should just be a no-op?