##// END OF EJS Templates
util: implement zstd compression engine...
util: implement zstd compression engine Now that zstd is vendored and being built (in some configurations), we can implement a compression engine for zstd! The zstd engine is a little different from existing engines. Because it may not always be present, we have to defer load the module in case importing it fails. We facilitate this via a cached property that holds a reference to the module or None. The "available" method is implemented to reflect reality. The zstd engine declares its ability to handle bundles using the "zstd" human name and the "ZS" internal name. The latter was chosen because internal names are 2 characters (by only convention I think) and "ZS" seems reasonable. The engine, like others, supports specifying the compression level. However, there are no consumers of this API that yet pass in that argument. I have plans to change that, so stay tuned. Since all we need to do to support bundle generation with a new compression engine is implement and register the compression engine, bundle generation with zstd "just works!" Tests demonstrating this have been added. How does performance of zstd for bundle generation compare? On the mozilla-unified repo, `hg bundle --all -t <engine>-v2` yields the following on my i7-6700K on Linux: engine CPU time bundle size vs orig size throughput none 97.0s 4,054,405,584 100.0% 41.8 MB/s bzip2 (l=9) 393.6s 975,343,098 24.0% 10.3 MB/s gzip (l=6) 184.0s 1,140,533,074 28.1% 22.0 MB/s zstd (l=1) 108.2s 1,119,434,718 27.6% 37.5 MB/s zstd (l=2) 111.3s 1,078,328,002 26.6% 36.4 MB/s zstd (l=3) 113.7s 1,011,823,727 25.0% 35.7 MB/s zstd (l=4) 116.0s 1,008,965,888 24.9% 35.0 MB/s zstd (l=5) 121.0s 977,203,148 24.1% 33.5 MB/s zstd (l=6) 131.7s 927,360,198 22.9% 30.8 MB/s zstd (l=7) 139.0s 912,808,505 22.5% 29.2 MB/s zstd (l=12) 198.1s 854,527,714 21.1% 20.5 MB/s zstd (l=18) 681.6s 789,750,690 19.5% 5.9 MB/s On compression, zstd for bundle generation delivers: * better compression than gzip with significantly less CPU utilization * better than bzip2 compression ratios while still being significantly faster than gzip * ability to aggressively tune compression level to achieve significantly smaller bundles That last point is important. With clone bundles, a server can pre-generate a bundle file, upload it to a static file server, and redirect clients to transparently download it during clone. The server could choose to produce a zstd bundle with the highest compression settings possible. This would take a very long time - a magnitude longer than a typical zstd bundle generation - but the result would be hundreds of megabytes smaller! For the clone volume we do at Mozilla, this could translate to petabytes of bandwidth savings per year and faster clones (due to smaller transfer size). I don't have detailed numbers to report on decompression. However, zstd decompression is fast: >1 GB/s output throughput on this machine, even through the Python bindings. And it can do that regardless of the compression level of the input. By the time you have enough data to worry about overhead of decompression, you have plenty of other things to worry about performance wise. zstd is wins all around. I can't wait to implement support for it on the wire protocol and in revlogs.

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mercurial.spec
162 lines | 4.6 KiB | text/x-rpm-spec | RPMSpecLexer
%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