Properly write up download backends GSoC task

Replace the placeholder with a proper task description, and uncomment it
in the main list.

2 files changed, 35 insertions, 54 deletions

diff --git a/community/gsoc/project_ideas.mdwn b/community/gsoc/project_ideas.mdwn
index 43f966ad..503dc417 100644
--- a/community/gsoc/project_ideas.mdwn
+++ b/community/gsoc/project_ideas.mdwn
@@ -94,6 +94,4 @@ will assist you as well as we can.
 [[inline pages="community/gsoc/project_ideas/secure_chroot" show=0 feeds=no actions=yes]]
 [[inline pages="community/gsoc/project_ideas/package_manager" show=0 feeds=no actions=yes]]
 [[inline pages="community/gsoc/project_ideas/debian_installer" show=0 feeds=no actions=yes]]
-<!--
 [[inline pages="community/gsoc/project_ideas/apt_ftpfs" show=0 feeds=no actions=yes]]
--->
diff --git a/community/gsoc/project_ideas/apt_ftpfs.mdwn b/community/gsoc/project_ideas/apt_ftpfs.mdwn
index 8c862360..aa4823de 100644
--- a/community/gsoc/project_ideas/apt_ftpfs.mdwn
+++ b/community/gsoc/project_ideas/apt_ftpfs.mdwn
@@ -8,57 +8,40 @@ Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
 is included in the section entitled
 [[GNU_Free_Documentation_License|/fdl]]."]]"""]]
 
-[[meta title="Have Debian's apt use ftpfs"]]
+[[meta title="Use Internet Protocol Translators (ftpfs etc.) as Backends for Other Programs"]]
 
-\#hurd [[IRC]] channel, 2009-03-13.
+The Hurd design faciliates splitting up large applications into independent,
+generic components, which can be easily combined in different contexts, by
+moving common functionality into separate Hurd servers (translators),
+accessible trough filesystem interfaces and/or specialized RPC interfaces.
 
-    <tschwinge> By the way: I had another GSoC idea:
-    <tschwinge> (a) make ftpfs / httpfs unsable enough for...
-    <tschwinge> (b) have Debian's apt / whetever not use a direct ftp / http
-      connection, but instead use /ftp/ftp.debian.org/whatever etc.
-    <tschwinge> (c) Make unionfs unsable enough, so that it can be used
-      together with nfs (or whatever) to sarve as a cache for /ftp/.
-    <antrik> uhm... you mean all of this as a single GSoC project?
-    <antrik> indeed I have the intention of turning ftpfs/httpfs into something
-      that can be used by other tools instead of a library
-    <antrik> but that requires them to grow completely new interfaces, making
-      them suitable for interactive use
-    <antrik> you are right though that this would be a nice GSoC project... no
-      idea why I never thought of it in this context
-    <tschwinge> I think I proposed this idea already some months ago on some
-      mailing list.
-    <tschwinge> I don't think it's too much work.
-    <tschwinge> Or why do you think?
-    <antrik> it is considerable work
-    <antrik> it requires implementing a non-trivial, directory based FS
-      interface
-    <tschwinge> (c), OK, but why (a) and (b)?
-    <antrik> also, I'd probably reimplement them on top of libcurl... no need
-      to maintain our own wheels :-)
-    <tschwinge> That for sure, yes.  But for starterst, we can just take ftpfs
-      as it is.
-    <antrik> I think I explained the issues in some past discussion, though I
-      don't remember where it was
-    <tschwinge> And just teach apt to open /ftp/... instead of calling whatever
-      function to retrieve a ftp file.
-    <antrik> you want progress tracking for one
-    <antrik> you want the client to see redirects
-    <antrik> (OK, that might not be necessary for apt-get... it would be
-      necessary for other use cases like a web browser, though)
-    <antrik> you want proper error handlin
-    <tschwinge> http://thread.gmane.org/gmane.os.hurd.bugs/16575/focus=16795
-    <antrik> none of this can be expressed by opening a single virtual file
-    <antrik> it would require adding a completely new interface, either using
-      custom RPCs, or a directory with several virtual files for various
-      aspects of the interaction
-    <antrik> (I prefer the latter variant, though I guess some people would
-      argue in favour of the former :-) )
-    <antrik> anyways, I'll add it to the list
-    <tschwinge> OK, I see.  Nevertheless, don't you think that a more simple
-      implementation of my idea (also leaving out (c) for now) wouldn't be a
-      suitable GSoC project?
-    <antrik> apt-get is probably quite a good example use case for this, so you
-      are probably right that it would be useful to develop this together
-    <antrik> (I'll leave out (c) though -- I would consider it a distinct
-      project. we can place a followup task once (a)+(b) is done :-) )
-    <tschwinge> Yes, sure.
+Download protocols like FTP, HTTP, BitTorrent etc. are very good candidates for
+this kind of modularization: a program could simply use the download
+functionality by accessing FTP, HTTP etc. translators.
+
+There is already an ftpfs traslator in the Hurd tree, as well as a [httpfs
+translator on hurdextras](http://www.nongnu.org/hurdextras/#httpfs); however,
+these are only suitable for very simple use cases: they just provide the actual
+file contents downloaded from the URL, but no additional status information
+that are necessary for interactive use. (Progress indication, error codes, HTTP
+redirects etc.)
+
+A new interface providing all this additional information (either as an
+extension to the existing translators, or as distinct translators) is required
+to make such translators usable as backends for programs like apt-get for
+example.
+
+The goal of this project is to design a suitable interface, implement it for at
+least one download protocol, and adapt apt-get (or some other program) to use
+this as a backend.
+
+This task requires some design skills and some knowlegde of internet protocols,
+to create a suitable interface. Translator programming knowledge will have to
+be obtained while implementing it.
+
+It is not an easy task, but it shouldn't pose any really hard problems either.
+
+Possible mentors: Olaf Buddenhagen (antrik)
+
+Exercise: Make some improvement to one of the existing download translators --
+httpfs in particular is known to be buggy.