branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
#require no-msys # MSYS will translate web paths as if they were file paths
This tests if CGI files from before d0db3462d568 still work.
$ hg init test
$ cat >hgweb.cgi <<HGWEB
> #!"$PYTHON"
> #
> # An example CGI script to use hgweb, edit as necessary
>
> import os, sys
>
> # sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
> from mercurial import hgweb
>
> h = hgweb.hgweb(b"test", b"Empty test repository")
> h.run()
> HGWEB
$ chmod 755 hgweb.cgi
$ cat >hgweb.config <<HGWEBDIRCONF
> [paths]
> test = test
> HGWEBDIRCONF
$ cat >hgwebdir.cgi <<HGWEBDIR
> #!"$PYTHON"
> #
> # An example CGI script to export multiple hgweb repos, edit as necessary
>
> import sys
>
> # sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
> from mercurial import hgweb
>
> # The config file looks like this. You can have paths to individual
> # repos, collections of repos in a directory tree, or both.
> #
> # [paths]
> # virtual/path = /real/path
> # virtual/path = /real/path
> #
> # [collections]
> # /prefix/to/strip/off = /root/of/tree/full/of/repos
> #
> # collections example: say directory tree /foo contains repos /foo/bar,
> # /foo/quux/baz. Give this config section:
> # [collections]
> # /foo = /foo
> # Then repos will list as bar and quux/baz.
>
> # Alternatively you can pass a list of ('virtual/path', '/real/path') tuples
> # or use a dictionary with entries like 'virtual/path': '/real/path'
>
> h = hgweb.hgwebdir(b"hgweb.config")
> h.run()
> 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]