Mercurial > hg
view tests/test-mq-qdelete.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 | 143b52fce68e |
| children | 95c4cca641f6 |
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$ echo "[extensions]" >> $HGRCPATH $ echo "mq=" >> $HGRCPATH $ hg init a $ cd a $ echo 'base' > base $ hg ci -Ambase -d '1 0' adding base $ hg qnew -d '1 0' pa $ hg qnew -d '1 0' pb $ hg qnew -d '1 0' pc $ hg qdel abort: qdelete requires at least one revision or patch name [255] $ hg qdel pc abort: cannot delete applied patch pc [255] $ hg qpop popping pc now at: pb Delete the same patch twice in one command (issue2427) $ hg qdel pc pc $ hg qseries pa pb $ ls .hg/patches pa pb series status $ hg qpop popping pb now at: pa $ hg qdel -k 1 $ ls .hg/patches pa pb series status $ hg qdel -r pa patch pa finalized without changeset message $ hg qapplied $ hg log --template '{rev} {desc}\n' 1 [mq]: pa 0 base $ hg qnew pd $ hg qnew pe $ hg qnew pf $ hg qdel -r pe abort: cannot delete revision 3 above applied patches [255] $ hg qdel -r qbase:pe patch pd finalized without changeset message patch pe finalized without changeset message $ hg qapplied pf $ hg log --template '{rev} {desc}\n' 4 [mq]: pf 3 [mq]: pe 2 [mq]: pd 1 [mq]: pa 0 base $ cd .. $ hg init b $ cd b $ echo 'base' > base $ hg ci -Ambase -d '1 0' adding base $ hg qfinish abort: no revisions specified [255] $ hg qfinish -a no patches applied $ hg qnew -d '1 0' pa $ hg qnew -d '1 0' pb $ hg qnew pc # XXX fails to apply by /usr/bin/patch if we put a date $ hg qfinish 0 abort: revision 0 is not managed [255] $ hg qfinish pb abort: cannot delete revision 2 above applied patches [255] $ hg qpop popping pc now at: pb $ hg qfinish -a pc abort: unknown revision 'pc'! [255] $ hg qpush applying pc patch pc is empty now at: pc $ hg qfinish qbase:pb patch pa finalized without changeset message patch pb finalized without changeset message $ hg qapplied pc $ hg log --template '{rev} {desc}\n' 3 imported patch pc 2 [mq]: pb 1 [mq]: pa 0 base $ hg qfinish -a pc patch pc finalized without changeset message $ hg qapplied $ hg log --template '{rev} {desc}\n' 3 imported patch pc 2 [mq]: pb 1 [mq]: pa 0 base $ ls .hg/patches series status qdel -k X && hg qimp -e X used to trigger spurious output with versioned queues $ hg init --mq $ hg qimport -r 3 $ hg qpop popping imported_patch_pc patch queue now empty $ hg qdel -k imported_patch_pc $ hg qimp -e imported_patch_pc adding imported_patch_pc to series file $ hg qfinish -a no patches applied resilience to inconsistency: qfinish -a with applied patches not in series $ hg qser imported_patch_pc $ hg qapplied $ hg qpush applying imported_patch_pc patch imported_patch_pc is empty now at: imported_patch_pc $ echo next >> base $ hg qrefresh -d '1 0' $ echo > .hg/patches/series # remove 3.diff from series to confuse mq $ hg qfinish -a revision 47dfa8501675 refers to unknown patches: imported_patch_pc more complex state 'both known and unknown patches $ echo hip >> base $ hg qnew -f -d '1 0' -m 4 4.diff $ echo hop >> base $ hg qnew -f -d '1 0' -m 5 5.diff $ echo > .hg/patches/series # remove 4.diff and 5.diff from series to confuse mq $ echo hup >> base $ hg qnew -f -d '1 0' -m 6 6.diff $ echo pup > base $ hg qfinish -a warning: uncommitted changes in the working directory revision 2b1c98802260 refers to unknown patches: 5.diff revision 33a6861311c0 refers to unknown patches: 4.diff $ cd ..