exchange: support sorting URLs by client-side preferences
Not all bundles are appropriate for all clients. For example, someone
with a slow Internet connection may want to prefer bz2 bundles over gzip
bundles because they are smaller and don't take as long to transfer.
This is information that a server cannot know on its own. So, we invent
a mechanism for "preferring" server-advertised URLs based on their
attributes.
We could invent a negotiation between client and server where the client
sends its preferences and the sorting/filtering is done server-side.
However, this feels complex. We can avoid complicating the wire protocol
and exposing ourselves to backwards compatible concerns by performing
the sorting locally.
This patch defines a new config option for expressing preferred
attributes in server-advertised bundles.
At Mozilla, we leverage this feature so clients in fast data centers
prefer uncompressed bundles. (We advertise gzip bundles first because
that is a reasonable default.)
I consider this an advanced feature. I'm on the fence as to whether it
should be documented in `hg help config`.
#require no-msys # MSYS will translate web paths as if they were file paths
This tests if CGI files from after d0db3462d568 but
before d74fc8dec2b4 still work.
$ hg init test
$ cat >hgweb.cgi <<HGWEB
> #!/usr/bin/env python
> #
> # An example CGI script to use hgweb, edit as necessary
>
> import cgitb
> cgitb.enable()
>
> from mercurial import demandimport; demandimport.enable()
> from mercurial.hgweb import hgweb
> from mercurial.hgweb import wsgicgi
> from mercurial.hgweb.request import wsgiapplication
>
> def make_web_app():
> return hgweb("test", "Empty test repository")
>
> wsgicgi.launch(wsgiapplication(make_web_app))
> HGWEB
$ chmod 755 hgweb.cgi
$ cat >hgweb.config <<HGWEBDIRCONF
> [paths]
> test = test
> HGWEBDIRCONF
$ cat >hgwebdir.cgi <<HGWEBDIR
> #!/usr/bin/env python
> #
> # An example CGI script to export multiple hgweb repos, edit as necessary
>
> import cgitb
> cgitb.enable()
>
> from mercurial import demandimport; demandimport.enable()
> from mercurial.hgweb import hgwebdir
> from mercurial.hgweb import wsgicgi
> from mercurial.hgweb.request import wsgiapplication
>
> def make_web_app():
> return hgwebdir("hgweb.config")
>
> wsgicgi.launch(wsgiapplication(make_web_app))
> HGWEBDIR
$ chmod 755 hgwebdir.cgi
$ . "$TESTDIR/cgienv"
$ python hgweb.cgi > page1
$ python hgwebdir.cgi > page2
$ PATH_INFO="/test/"
$ PATH_TRANSLATED="/var/something/test.cgi"
$ REQUEST_URI="/test/test/"
$ SCRIPT_URI="http://hg.omnifarious.org/test/test/"
$ SCRIPT_URL="/test/test/"
$ python hgwebdir.cgi > page3
$ grep -i error page1 page2 page3
[1]