From ca5704936d1d57fdd11ea850608e6fa9d574d9dd Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sat, 4 Apr 2009 18:04:20 -0400 Subject: 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. --- doc/rcs/darcs.mdwn | 15 ++++++++ doc/rcs/details.mdwn | 98 ++++++---------------------------------------------- 2 files changed, 25 insertions(+), 88 deletions(-) create mode 100644 doc/rcs/darcs.mdwn (limited to 'doc/rcs') 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]] -- cgit v1.2.3