diff options
| -rw-r--r-- | doc/rcs/darcs.mdwn | 15 | ||||
| -rw-r--r-- | doc/rcs/details.mdwn | 98 | ||||
| -rw-r--r-- | doc/todo/darcs.mdwn | 510 |
3 files changed, 29 insertions, 594 deletions
diff --git a/doc/rcs/darcs.mdwn b/doc/rcs/darcs.mdwn new file mode 100644 index 000000000..7f66d0808 --- /dev/null +++ b/doc/rcs/darcs.mdwn @@ -0,0 +1,15 @@ +[Darcs](http://darcs.new) is a distributed revison control +system. Ikiwiki supports storing a wiki in a +Darcs repository. + +An Ikiwiki wrapper is run by the `posthook` to update a wiki whenever commits +or remote pushes come in. When running as a [[cgi]] with Darcs, ikiwiki +automatically commits edited pages, and uses the Darcs history to generate the +[[RecentChanges]] page. + +Example for a `_darcs/prefs/defaults` file in `$SRCDIR`: + + apply posthook /path/to/repository/_darcs/ikiwrapper + apply run-posthook + +See also [[todo/darcs|todo/darcs]] diff --git a/doc/rcs/details.mdwn b/doc/rcs/details.mdwn index 089221cab..00559a4dd 100644 --- a/doc/rcs/details.mdwn +++ b/doc/rcs/details.mdwn @@ -32,98 +32,20 @@ You browse and web-edit the wiki on W. W "belongs" to ikiwiki and should not be edited directly. -## [darcs](http://darcs.net/) (not yet included) +## [[darcs]] -Support for using darcs as a backend is being worked on by [Thomas -Schwinge](mailto:tschwinge@gnu.org), although development is on hold curretly. -There is a patch in [[todo/darcs]]. +Regarding the repository layout: There are two darcs repositories. One is the `srcdir`, the other we'll call `master`. -### How will it work internally? +* 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: -``Master'' repository R1. - -RCS commits from the outside are installed into R1. - -HTML is generated from R1. HTML is automatically generated (by using a -``post-hook'') each time a new change is installed into R1. It follows -that rcs_update() is not needed. - -There is a working copy of R1: R2. - -CGI operates on R2. rcs_commit() will push from R2 to R1. - -You browse the wiki on R1 and web-edit it on R2. This means for example -that R2 needs to be updated from R1 if you are going to web-edit a page, -as the user otherwise might be irritated otherwise... - -How do changes get from R1 to R2? Currently only internally in -rcs\_commit(). Is rcs\_prepedit() suitable? - -It follows that the HTML rendering and the CGI handling can be completely -separated parts in ikiwiki. - -What repository should [[RecentChanges]] and History work on? R1? - -#### Rationale for doing it differently than in the Subversion case - -darcs is a distributed RCS, which means that every checkout of a -repository is equal to the repository it was checked-out from. There is -no forced hierarchy. - -R1 is nevertheless called the master repository. It's used for -collecting all the changes and publishing them: on the one hand via the -rendered HTML and on the other via the standard darcs RCS interface. - -R2, the repository the CGI operates on, is just a checkout of R1 and -doesn't really differ from the other checkouts that people will branch -off from R1. - -(To be continued.) - -#### Another possible approach - -Here's what I (tuomov) think, would be a “cleaner” approach: - - 1. Upon starting to edit, Ikiwiki gets a copy of the page, and `darcs changes --context`. - This context _and_ the present version of the page are stored in as the “version” of the - page in a hidden control of the HTML. - Thus the HTML includes all that is needed to generate a patch wrt. to the state of the - repository at the time the edit was started. This is of course all that darcs needs. - 2. Once the user is done with editing, _Ikiwiki generates a patch bundle_ for darcs. - This should be easy with existing `Text::Diff` or somesuch modules, as the Web edits - only concern single files. The reason why the old version of the page is stored in - the HTML (possibly compressed) is that the diff can be generated. - 3. Now this patch bundle is applied with `darcs apply`, or sent by email for moderation… - there are many possibilities. - -This approach avoids some of the problems of concurrent edits that the previous one may have, -although there may be conflicts, which may or may not propagate to the displayed web page. -(Unfortunately there is not an option to `darcs apply` to generate some sort of ‘confliction resolution -bundle’.) Also, only one repository is needed, as it is never directly modified -by Ikiwiki. - -This approach might be applicable to other distributed VCSs as well, although they're not as oriented -towards transmitting changes with standalone patch bundles (often by email) as darcs is. - -> The mercurial plugin seems to just use one repo and edit it directly - is -> there some reason that's okay there but not for darcs? I agree with tuomov -> that having just the one repo would be preferable; the point of a dvcs is -> that there's no difference between one repo and another. I've got a -> darcs.pm based on mercurial.pm, that's almost usable... --bma - ->> IMHO it comes down to whatever works well for a given RCS. Seems like ->> the darcs approach _could_ be done with most any distributed system, but ->> it might be overkill for some (or all?) While there is the incomplete darcs ->> plugin in [[todo/darcs]], if you submit one that's complete, I will ->> probably accept it into ikiwiki.. --[[Joey]] - ->>> I'd like to help make a robust darcs (2) backend. I also think ikiwiki should use ->>> exactly one darcs repo. I think we can simplify and say conflicting web ->>> edits are not allowed, like most current wiki engines. I don't see that ->>> saving (so much) context in the html is necessary, then. ->>> bma, I would like to see your code. --[[Simon_Michael]] ->>> PS ah, there it is. Let's continue on the [[todo/darcs]] page. + apply posthook ikiwrap + apply run-posthook +* 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. ## [[Git]] 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/</) { - # 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? |