Mercurial > hg
view tests/test-contrib.t @ 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.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 24 Dec 2016 15:29:32 -0700 |
parents | c3e9269d9602 |
children | 8e6f4939a69a |
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Set vars: $ CONTRIBDIR="$TESTDIR/../contrib" Prepare repo-a: $ hg init repo-a $ cd repo-a $ echo this is file a > a $ hg add a $ hg commit -m first $ echo adding to file a >> a $ hg commit -m second $ echo adding more to file a >> a $ hg commit -m third $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 3 changesets, 3 total revisions Dumping revlog of file a to stdout: $ python "$CONTRIBDIR/dumprevlog" .hg/store/data/a.i file: .hg/store/data/a.i node: 183d2312b35066fb6b3b449b84efc370d50993d0 linkrev: 0 parents: 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 length: 15 -start- this is file a -end- node: b1047953b6e6b633c0d8197eaa5116fbdfd3095b linkrev: 1 parents: 183d2312b35066fb6b3b449b84efc370d50993d0 0000000000000000000000000000000000000000 length: 32 -start- this is file a adding to file a -end- node: 8c4fd1f7129b8cdec6c7f58bf48fb5237a4030c1 linkrev: 2 parents: b1047953b6e6b633c0d8197eaa5116fbdfd3095b 0000000000000000000000000000000000000000 length: 54 -start- this is file a adding to file a adding more to file a -end- Dump all revlogs to file repo.dump: $ find .hg/store -name "*.i" | sort | xargs python "$CONTRIBDIR/dumprevlog" > ../repo.dump $ cd .. Undumping into repo-b: $ hg init repo-b $ cd repo-b $ python "$CONTRIBDIR/undumprevlog" < ../repo.dump .hg/store/00changelog.i .hg/store/00manifest.i .hg/store/data/a.i $ cd .. Rebuild fncache with clone --pull: $ hg clone --pull -U repo-b repo-c requesting all changes adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 1 files Verify: $ hg -R repo-c verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 3 changesets, 3 total revisions Compare repos: $ hg -R repo-c incoming repo-a comparing with repo-a searching for changes no changes found [1] $ hg -R repo-a incoming repo-c comparing with repo-c searching for changes no changes found [1] Test simplemerge command: $ cp "$CONTRIBDIR/simplemerge" . $ echo base > base $ echo local > local $ cat base >> local $ cp local orig $ cat base > other $ echo other >> other changing local directly $ python simplemerge local base other && echo "merge succeeded" merge succeeded $ cat local local base other $ cp orig local printing to stdout $ python simplemerge -p local base other local base other local: $ cat local local base conflicts $ cp base conflict-local $ cp other conflict-other $ echo not other >> conflict-local $ echo end >> conflict-local $ echo end >> conflict-other $ python simplemerge -p conflict-local base conflict-other base <<<<<<< conflict-local not other ======= other >>>>>>> conflict-other end [1] 1 label $ python simplemerge -p -L foo conflict-local base conflict-other base <<<<<<< foo not other ======= other >>>>>>> conflict-other end [1] 2 labels $ python simplemerge -p -L foo -L bar conflict-local base conflict-other base <<<<<<< foo not other ======= other >>>>>>> bar end [1] 3 labels $ python simplemerge -p -L foo -L bar -L base conflict-local base conflict-other base <<<<<<< foo not other end ||||||| base ======= other end >>>>>>> bar [1] too many labels $ python simplemerge -p -L foo -L bar -L baz -L buz conflict-local base conflict-other abort: can only specify three labels. [255] binary file $ $PYTHON -c "f = file('binary-local', 'w'); f.write('\x00'); f.close()" $ cat orig >> binary-local $ python simplemerge -p binary-local base other warning: binary-local looks like a binary file. [1] binary file --text $ python simplemerge -a -p binary-local base other 2>&1 warning: binary-local looks like a binary file. \x00local (esc) base other help $ python simplemerge --help simplemerge [OPTS] LOCAL BASE OTHER Simple three-way file merge utility with a minimal feature set. Apply to LOCAL the changes necessary to go from BASE to OTHER. By default, LOCAL is overwritten with the results of this operation. options: -L --label labels to use on conflict markers -a --text treat all files as text -p --print print results instead of overwriting LOCAL --no-minimal no effect (DEPRECATED) -h --help display help and exit -q --quiet suppress output wrong number of arguments $ python simplemerge simplemerge: wrong number of arguments simplemerge [OPTS] LOCAL BASE OTHER Simple three-way file merge utility with a minimal feature set. Apply to LOCAL the changes necessary to go from BASE to OTHER. By default, LOCAL is overwritten with the results of this operation. options: -L --label labels to use on conflict markers -a --text treat all files as text -p --print print results instead of overwriting LOCAL --no-minimal no effect (DEPRECATED) -h --help display help and exit -q --quiet suppress output [1] bad option $ python simplemerge --foo -p local base other simplemerge: option --foo not recognized simplemerge [OPTS] LOCAL BASE OTHER Simple three-way file merge utility with a minimal feature set. Apply to LOCAL the changes necessary to go from BASE to OTHER. By default, LOCAL is overwritten with the results of this operation. options: -L --label labels to use on conflict markers -a --text treat all files as text -p --print print results instead of overwriting LOCAL --no-minimal no effect (DEPRECATED) -h --help display help and exit -q --quiet suppress output [1]