branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
Mercurial for Plan 9 from Bell Labs
===================================
This directory contains support for Mercurial on Plan 9 from Bell Labs
platforms. It is assumed that the version of Python running on these
systems supports the ANSI/POSIX Environment (APE). At the time of this
writing, the bichued/python port is the most commonly installed version
of Python on these platforms. If a native port of Python is ever made,
some minor modification will need to be made to support some of the more
esoteric requirements of the platform rather than those currently made
(cf. posix.py).
By default, installations will have the factotum extension enabled; this
extension permits factotum(4) to act as an authentication agent for
HTTP repositories. Additionally, an extdiff command named 9diff is
enabled which generates diff(1) compatible output suitable for use with
the plumber(4).
Commit messages are plumbed using E if no editor is defined; users must
update the plumbed file to continue, otherwise the hg process must be
interrupted.
Some work remains with regard to documentation. Section 5 manual page
references for hgignore and hgrc need to be re-numbered to section 6 (file
formats) and a new man page writer should be written to support the
Plan 9 man macro set. Until these issues can be resolved, manual pages
are elided from the installation.
Basic install:
% mk install # do a system-wide install
% hg debuginstall # sanity-check setup
% hg # see help
A proto(2) file is included in this directory as an example of how a
binary distribution could be packaged, ostensibly with contrib(1).
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.