view contrib/mercurial.spec @ 30764:e75463e3179f

protocol: send application/mercurial-0.2 responses to capable clients

With this commit, the HTTP transport now parses the X-HgProto-<N>
header to determine what media type and compression engine to use for
responses. So far, we only compress responses that are already being
compressed with zlib today (stream response types to specific
commands). We can expand things to cover additional response types
later.

The practical side-effect of this commit is that non-zlib compression
engines will be used if both ends support them. This means if both
ends have zstd support, zstd - not zlib - will be used to compress
data!

When cloning the mozilla-unified repository between a local HTTP
server and client, the benefits of non-zlib compression are quite
noticeable:

  engine     server CPU (s)   client CPU (s)    bundle size
zlib (l=6)      174.1            283.2         1,148,547,026
zstd (l=1)       99.2            267.3         1,127,513,841
zstd (l=3)      103.1            266.9         1,018,861,363
zstd (l=7)      128.3            269.7           919,190,278
zstd (l=10)     162.0               -            894,547,179
none             95.3            277.2         4,097,566,064

The default zstd compression level is 3. So if you deploy zstd
capable Mercurial to your clients and servers and CPU time on
your server is dominated by "getbundle" requests (clients cloning
and pulling) - and my experience at Mozilla tells me this is often
the case - this commit could drastically reduce your server-side
CPU usage *and* save on bandwidth costs!

Another benefit of this change is that server operators can install
*any* compression engine. While it isn't enabled by default, the
"none" compression engine can now be used to disable wire protocol
compression completely. Previously, commands like "getbundle" always
zlib compressed output, adding considerable overhead to generating
responses. If you are on a high speed network and your server is under
high load, it might be advantageous to trade bandwidth for CPU.
Although, zstd at level 1 doesn't use that much CPU, so I'm not
convinced that disabling compression wholesale is worthwhile. And, my
data seems to indicate a slow down on the client without compression.
I suspect this is due to a lack of buffering resulting in an increase
in socket read() calls and/or the fact we're transferring an extra 3 GB
of data (parsing HTTP chunked transfer and processing extra TCP packets
can add up). This is definitely worth investigating and optimizing. But
since the "none" compressor isn't enabled by default, I'm inclined to
punt on this issue.

This commit introduces tons of tests. Some of these should arguably
have been implemented on previous commits. But it was difficult to
test without the server functionality in place.

%global emacs_lispdir %{_datadir}/emacs/site-lisp

%define withpython %{nil}

%if "%{?withpython}"

%global pythonver %{withpython}
%global pythonname Python-%{withpython}
%global docutilsname docutils-0.12
%global docutilsmd5 4622263b62c5c771c03502afa3157768
%global pythonhg python-hg
%global hgpyprefix /opt/%{pythonhg}
# byte compilation will fail on some some Python /test/ files
%global _python_bytecompile_errors_terminate_build 0

%else

%global pythonver %(python -c 'import sys;print ".".join(map(str, sys.version_info[:2]))')

%endif

Summary: A fast, lightweight Source Control Management system
Name: mercurial
Version: snapshot
Release: 0
License: GPLv2+
Group: Development/Tools
URL: https://mercurial-scm.org/
Source0: %{name}-%{version}-%{release}.tar.gz
%if "%{?withpython}"
Source1: %{pythonname}.tgz
Source2: %{docutilsname}.tar.gz
%endif
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root

BuildRequires: make, gcc, gettext
%if "%{?withpython}"
BuildRequires: readline-devel, openssl-devel, ncurses-devel, zlib-devel, bzip2-devel
%else
BuildRequires: python >= 2.6, python-devel, python-docutils >= 0.5
Requires: python >= 2.6
%endif
# The hgk extension uses the wish tcl interpreter, but we don't enforce it
#Requires: tk

%description
Mercurial is a fast, lightweight source control management system designed
for efficient handling of very large distributed projects.

%prep

%if "%{?withpython}"
%setup -q -n mercurial-%{version}-%{release} -a1 -a2
# despite the comments in cgi.py, we do this to prevent rpmdeps from picking /usr/local/bin/python up
sed -i '1c#! /usr/bin/env python' %{pythonname}/Lib/cgi.py
%else
%setup -q -n mercurial-%{version}-%{release}
%endif

%build

%if "%{?withpython}"

PYPATH=$PWD/%{pythonname}
cd $PYPATH
./configure --prefix=%{hgpyprefix}
make all %{?_smp_mflags}
cd -

cd %{docutilsname}
LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py build
cd -

# verify Python environment
LD_LIBRARY_PATH=$PYPATH PYTHONPATH=$PWD/%{docutilsname} $PYPATH/python -c 'import sys, zlib, bz2, ssl, curses, readline'

# set environment for make
export PATH=$PYPATH:$PATH
export LD_LIBRARY_PATH=$PYPATH
export CFLAGS="-L $PYPATH"
export PYTHONPATH=$PWD/%{docutilsname}

%endif

make all

%install
rm -rf $RPM_BUILD_ROOT

%if "%{?withpython}"

PYPATH=$PWD/%{pythonname}
cd $PYPATH
make install DESTDIR=$RPM_BUILD_ROOT
# these .a are not necessary and they are readonly and strip fails - kill them!
rm -f %{buildroot}%{hgpyprefix}/lib/{,python2.*/config}/libpython2.*.a
cd -

cd %{docutilsname}
LD_LIBRARY_PATH=$PYPATH $PYPATH/python setup.py install --root="$RPM_BUILD_ROOT"
cd -

PATH=$PYPATH:$PATH LD_LIBRARY_PATH=$PYPATH make install DESTDIR=$RPM_BUILD_ROOT PREFIX=%{hgpyprefix} MANDIR=%{_mandir}
mkdir -p $RPM_BUILD_ROOT%{_bindir}
( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/hg . )
( cd $RPM_BUILD_ROOT%{_bindir}/ && ln -s ../..%{hgpyprefix}/bin/python2.? %{pythonhg} )

%else

make install DESTDIR=$RPM_BUILD_ROOT PREFIX=%{_prefix} MANDIR=%{_mandir}

%endif

install -m 755 contrib/hgk $RPM_BUILD_ROOT%{_bindir}/
install -m 755 contrib/hg-ssh $RPM_BUILD_ROOT%{_bindir}/

bash_completion_dir=$RPM_BUILD_ROOT%{_sysconfdir}/bash_completion.d
mkdir -p $bash_completion_dir
install -m 644 contrib/bash_completion $bash_completion_dir/mercurial.sh

zsh_completion_dir=$RPM_BUILD_ROOT%{_datadir}/zsh/site-functions
mkdir -p $zsh_completion_dir
install -m 644 contrib/zsh_completion $zsh_completion_dir/_mercurial

mkdir -p $RPM_BUILD_ROOT%{emacs_lispdir}
install -m 644 contrib/mercurial.el $RPM_BUILD_ROOT%{emacs_lispdir}/
install -m 644 contrib/mq.el $RPM_BUILD_ROOT%{emacs_lispdir}/

mkdir -p $RPM_BUILD_ROOT/%{_sysconfdir}/mercurial/hgrc.d

%clean
rm -rf $RPM_BUILD_ROOT

%files
%defattr(-,root,root,-)
%doc CONTRIBUTORS COPYING doc/README doc/hg*.txt doc/hg*.html *.cgi contrib/*.fcgi
%doc %attr(644,root,root) %{_mandir}/man?/hg*
%doc %attr(644,root,root) contrib/*.svg
%dir %{_datadir}/zsh/
%dir %{_datadir}/zsh/site-functions/
%{_datadir}/zsh/site-functions/_mercurial
%dir %{_datadir}/emacs/site-lisp/
%{_datadir}/emacs/site-lisp/mercurial.el
%{_datadir}/emacs/site-lisp/mq.el
%{_bindir}/hg
%{_bindir}/hgk
%{_bindir}/hg-ssh
%dir %{_sysconfdir}/bash_completion.d/
%config(noreplace) %{_sysconfdir}/bash_completion.d/mercurial.sh
%dir %{_sysconfdir}/mercurial
%dir %{_sysconfdir}/mercurial/hgrc.d
%if "%{?withpython}"
%{_bindir}/%{pythonhg}
%{hgpyprefix}
%else
%if "%{?pythonver}" != "2.4"
%{_libdir}/python%{pythonver}/site-packages/%{name}-*-py%{pythonver}.egg-info
%endif
%{_libdir}/python%{pythonver}/site-packages/%{name}
%{_libdir}/python%{pythonver}/site-packages/hgext
%{_libdir}/python%{pythonver}/site-packages/hgext3rd
%endif