tests/test-clone-uncompressed.t

exchange: send bundle2 stream clones uncompressed

Stream clones don't compress well. And compression undermines
a point of stream clones which is to trade significant CPU
reductions by increasing size.

Building upon our introduction of metadata to communicate bundle
information back to callers of exchange.getbundlechunks(), we add
an attribute to the bundler that communicates whether the bundle is
best left uncompressed. We return this attribute as part of the bundle
metadata. And the wire protocol honors it when determining whether
to compress the wire protocol response.

The added test demonstrates that the raw result from the wire
protocol is not compressed. It also demonstrates that the server
will serve stream responses when the feature isn't enabled. We'll
address that in another commit.

The effect of this change is that server-side CPU usage for bundle2
stream clones is significantly reduced by removing zstd compression.
For the mozilla-unified repository:

before: 37.69 user 8.01 system
after:  27.38 user 7.34 system

Assuming things are CPU bound, that ~10s reduction would translate to
faster clones on the client. zstd can decompress at >1 GB/s. So the
overhead from decompression on the client is small in the grand scheme
of things. But if zlib compression were being used, the overhead would
be much greater.

Differential Revision: https://phab.mercurial-scm.org/D1926

#require serve

#testcases stream-legacy stream-bundle2

#if stream-bundle2
  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > bundle2.stream = yes
  > EOF
#endif

Initialize repository
the status call is to check for issue5130

  $ hg init server
  $ cd server
  $ touch foo
  $ hg -q commit -A -m initial
  >>> for i in range(1024):
  ...     with open(str(i), 'wb') as fh:
  ...         fh.write(str(i))
  $ hg -q commit -A -m 'add a lot of files'
  $ hg st
  $ hg serve -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..

Basic clone

#if stream-legacy
  $ hg clone --stream -U http://localhost:$HGPORT clone1
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*/sec) (glob)
  searching for changes
  no changes found
#endif
#if stream-bundle2
  $ hg clone --stream -U http://localhost:$HGPORT clone1
  streaming all changes
  1030 files to transfer, 96.4 KB of data
  transferred 96.4 KB in * seconds (* */sec) (glob)

  $ ls -1 clone1/.hg/cache
  branch2-served
  rbc-names-v1
  rbc-revs-v1
#endif

getbundle requests with stream=1 are uncompressed

  $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=getbundle' content-type --bodyfile body --hgproto '0.1 0.2 comp=zlib,none' --requestheader "x-hgarg-1=bundlecaps=HG20%2Cbundle2%3DHG20%250Abookmarks%250Achangegroup%253D01%252C02%250Adigests%253Dmd5%252Csha1%252Csha512%250Aerror%253Dabort%252Cunsupportedcontent%252Cpushraced%252Cpushkey%250Ahgtagsfnodes%250Alistkeys%250Aphases%253Dheads%250Apushkey%250Aremote-changegroup%253Dhttp%252Chttps&cg=0&common=0000000000000000000000000000000000000000&heads=c17445101a72edac06facd130d14808dfbd5c7c2&stream=1"
  200 Script output follows
  content-type: application/mercurial-0.2
  

  $ f --size --hex --bytes 256 body
  body: size=112328
  0000: 04 6e 6f 6e 65 48 47 32 30 00 00 00 00 00 00 00 |.noneHG20.......|
  0010: 72 06 53 54 52 45 41 4d 00 00 00 00 04 00 09 05 |r.STREAM........|
  0020: 09 04 0c 2d 07 02 62 79 74 65 63 6f 75 6e 74 39 |...-..bytecount9|
  0030: 38 37 35 38 66 69 6c 65 63 6f 75 6e 74 31 30 33 |8758filecount103|
  0040: 30 72 65 71 75 69 72 65 6d 65 6e 74 73 64 6f 74 |0requirementsdot|
  0050: 65 6e 63 6f 64 65 20 66 6e 63 61 63 68 65 20 67 |encode fncache g|
  0060: 65 6e 65 72 61 6c 64 65 6c 74 61 20 72 65 76 6c |eneraldelta revl|
  0070: 6f 67 76 31 20 73 74 6f 72 65 76 65 72 73 69 6f |ogv1 storeversio|
  0080: 6e 76 32 00 00 10 00 73 08 42 64 61 74 61 2f 30 |nv2....s.Bdata/0|
  0090: 2e 69 00 03 00 01 00 00 00 00 00 00 00 02 00 00 |.i..............|
  00a0: 00 01 00 00 00 00 00 00 00 01 ff ff ff ff ff ff |................|
  00b0: ff ff 80 29 63 a0 49 d3 23 87 bf ce fe 56 67 92 |...)c.I.#....Vg.|
  00c0: 67 2c 69 d1 ec 39 00 00 00 00 00 00 00 00 00 00 |g,i..9..........|
  00d0: 00 00 75 30 73 08 42 64 61 74 61 2f 31 2e 69 00 |..u0s.Bdata/1.i.|
  00e0: 03 00 01 00 00 00 00 00 00 00 02 00 00 00 01 00 |................|
  00f0: 00 00 00 00 00 00 01 ff ff ff ff ff ff ff ff f9 |................|

--uncompressed is an alias to --stream

#if stream-legacy
  $ hg clone --uncompressed -U http://localhost:$HGPORT clone1-uncompressed
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*/sec) (glob)
  searching for changes
  no changes found
#endif
#if stream-bundle2
  $ hg clone --uncompressed -U http://localhost:$HGPORT clone1-uncompressed
  streaming all changes
  1030 files to transfer, 96.4 KB of data
  transferred 96.4 KB in * seconds (* */sec) (glob)
#endif

Clone with background file closing enabled

#if stream-legacy
  $ hg --debug --config worker.backgroundclose=true --config worker.backgroundcloseminfilecount=1 clone --stream -U http://localhost:$HGPORT clone-background | grep -v adding
  using http://localhost:$HGPORT/
  sending capabilities command
  sending branchmap command
  streaming all changes
  sending stream_out command
  1027 files to transfer, 96.3 KB of data
  starting 4 threads for background file closing
  transferred 96.3 KB in * seconds (*/sec) (glob)
  query 1; heads
  sending batch command
  searching for changes
  all remote heads known locally
  no changes found
  sending getbundle command
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-part: "phase-heads" supported
  bundle2-input-part: total payload size 24
  bundle2-input-bundle: 1 parts total
  checking for updated bookmarks
#endif
#if stream-bundle2
  $ hg --debug --config worker.backgroundclose=true --config worker.backgroundcloseminfilecount=1 clone --stream -U http://localhost:$HGPORT clone-background | grep -v adding
  using http://localhost:$HGPORT/
  sending capabilities command
  query 1; heads
  sending batch command
  streaming all changes
  sending getbundle command
  bundle2-input-bundle: with-transaction
  bundle2-input-part: "stream" (params: 4 mandatory) supported
  applying stream bundle
  1030 files to transfer, 96.4 KB of data
  starting 4 threads for background file closing
  starting 4 threads for background file closing
  transferred 96.4 KB in * seconds (* */sec) (glob)
  bundle2-input-part: total payload size 112077
  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
  bundle2-input-bundle: 1 parts total
  checking for updated bookmarks
#endif

Cannot stream clone when there are secret changesets

  $ hg -R server phase --force --secret -r tip
  $ hg clone --stream -U http://localhost:$HGPORT secret-denied
  warning: stream clone requested but server has them disabled
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 96ee1d7354c4

  $ killdaemons.py

Streaming of secrets can be overridden by server config

  $ cd server
  $ hg serve --config server.uncompressedallowsecret=true -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid > $DAEMON_PIDS
  $ cd ..

#if stream-legacy
  $ hg clone --stream -U http://localhost:$HGPORT secret-allowed
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*/sec) (glob)
  searching for changes
  no changes found
#endif
#if stream-bundle2
  $ hg clone --stream -U http://localhost:$HGPORT secret-allowed
  streaming all changes
  1030 files to transfer, 96.4 KB of data
  transferred 96.4 KB in * seconds (* */sec) (glob)
#endif

  $ killdaemons.py

Verify interaction between preferuncompressed and secret presence

  $ cd server
  $ hg serve --config server.preferuncompressed=true -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid > $DAEMON_PIDS
  $ cd ..

  $ hg clone -U http://localhost:$HGPORT preferuncompressed-secret
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 96ee1d7354c4

  $ killdaemons.py

Clone not allowed when full bundles disabled and can't serve secrets

  $ cd server
  $ hg serve --config server.disablefullbundle=true -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid > $DAEMON_PIDS
  $ cd ..

  $ hg clone --stream http://localhost:$HGPORT secret-full-disabled
  warning: stream clone requested but server has them disabled
  requesting all changes
  remote: abort: server has pull-based clones disabled
  abort: pull failed on remote
  (remove --pull if specified or upgrade Mercurial)
  [255]

Local stream clone with secrets involved
(This is just a test over behavior: if you have access to the repo's files,
there is no security so it isn't important to prevent a clone here.)

  $ hg clone -U --stream server local-secret
  warning: stream clone requested but server has them disabled
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 96ee1d7354c4

Stream clone while repo is changing:

  $ mkdir changing
  $ cd changing

extension for delaying the server process so we reliably can modify the repo
while cloning

  $ cat > delayer.py <<EOF
  > import time
  > from mercurial import extensions, vfs
  > def __call__(orig, self, path, *args, **kwargs):
  >     if path == 'data/f1.i':
  >         time.sleep(2)
  >     return orig(self, path, *args, **kwargs)
  > extensions.wrapfunction(vfs.vfs, '__call__', __call__)
  > EOF

prepare repo with small and big file to cover both code paths in emitrevlogdata

  $ hg init repo
  $ touch repo/f1
  $ $TESTDIR/seq.py 50000 > repo/f2
  $ hg -R repo ci -Aqm "0"
  $ hg serve -R repo -p $HGPORT1 -d --pid-file=hg.pid --config extensions.delayer=delayer.py
  $ cat hg.pid >> $DAEMON_PIDS

clone while modifying the repo between stating file with write lock and
actually serving file content

  $ hg clone -q --stream -U http://localhost:$HGPORT1 clone &
  $ sleep 1
  $ echo >> repo/f1
  $ echo >> repo/f2
  $ hg -R repo ci -m "1"
  $ wait
  $ hg -R clone id
  000000000000
  $ cd ..

Stream repository with bookmarks
--------------------------------

(revert introduction of secret changeset)

  $ hg -R server phase --draft 'secret()'

add a bookmark

  $ hg -R server bookmark -r tip some-bookmark

clone it

#if stream-legacy
  $ hg clone --stream http://localhost:$HGPORT with-bookmarks
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*) (glob)
  searching for changes
  no changes found
  updating to branch default
  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
#endif
#if stream-bundle2
  $ hg clone --stream http://localhost:$HGPORT with-bookmarks
  streaming all changes
  1033 files to transfer, 96.6 KB of data
  transferred 96.6 KB in * seconds (* */sec) (glob)
  updating to branch default
  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
#endif
  $ hg -R with-bookmarks bookmarks
     some-bookmark             1:c17445101a72

Stream repository with phases
-----------------------------

Clone as publishing

  $ hg -R server phase -r 'all()'
  0: draft
  1: draft

#if stream-legacy
  $ hg clone --stream http://localhost:$HGPORT phase-publish
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*) (glob)
  searching for changes
  no changes found
  updating to branch default
  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
#endif
#if stream-bundle2
  $ hg clone --stream http://localhost:$HGPORT phase-publish
  streaming all changes
  1033 files to transfer, 96.6 KB of data
  transferred 96.6 KB in * seconds (* */sec) (glob)
  updating to branch default
  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
#endif
  $ hg -R phase-publish phase -r 'all()'
  0: public
  1: public

Clone as non publishing

  $ cat << EOF >> server/.hg/hgrc
  > [phases]
  > publish = False
  > EOF
  $ killdaemons.py
  $ hg -R server serve -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS

#if stream-legacy
  $ hg clone --stream http://localhost:$HGPORT phase-no-publish
  streaming all changes
  1027 files to transfer, 96.3 KB of data
  transferred 96.3 KB in * seconds (*) (glob)
  searching for changes
  no changes found
  updating to branch default
  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R phase-no-publish phase -r 'all()'
  0: public
  1: public
#endif
#if stream-bundle2
  $ hg clone --stream http://localhost:$HGPORT phase-no-publish
  streaming all changes
  1034 files to transfer, 96.7 KB of data
  transferred 96.7 KB in * seconds (* */sec) (glob)
  updating to branch default
  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R phase-no-publish phase -r 'all()'
  0: draft
  1: draft
#endif

  $ killdaemons.py