tests/test-clone-uncompressed.t

bundle2: increase payload part chunk size to 32kb

Bundle2 payload parts are framed chunks. Esentially, we obtain
data in equal size chunks of size `preferedchunksize` and emit those
to a generator. That generator is fed into a compressor (which can
be the no-op compressor, which just re-emits the generator). And
the output from the compressor likely goes to a file descriptor
or socket.

What this means is that small chunk sizes create more Python objects
and Python function calls than larger chunk sizes. And as we know,
Python object and function call overhead in performance sensitive
code matters (at least with CPython).

This commit increases the bundle2 part payload chunk size from 4k
to 32k. Practically speaking, this means that the chunks we feed
into a compressor (implemented in C code) or feed directly into a
file handle or socket write() are larger. It's possible the chunks
might be larger than what the receiver can handle in one logical
operation. But at that point, we're in C code, which is much more
efficient at dealing with splitting up the chunk and making multiple
function calls than Python is.

A downside to larger chunks is that the receiver has to wait for that
much data to arrive (either raw or from a decompressor) before it
can process the chunk. But 32kb still feels like a small buffer to
have to wait for. And in many cases, the client will convert from
8 read(4096) to 1 read(32768). That's happening in Python land. So
we cut down on the number of Python objects and function calls,
making the client faster as well. I don't think there are any
significant concerns to increasing the payload chunk size to 32kb.

The impact of this change on performance significant. Using `curl`
to obtain a stream clone bundle2 payload from a server on localhost
serving the mozilla-unified repository:

before: 20.78 user; 7.71 system;  80.5 MB/s
after:  13.90 user; 3.51 system; 132 MB/s
legacy:  9.72 user; 8.16 system; 132 MB/s

bundle2 stream clone generation is still more resource intensive than
legacy stream clone (that's likely because of the use of a
util.chunkbuffer). But the throughput is the same. We might
be in territory we're this is effectively a benchmark of the
networking stack or Python's syscall throughput.

From the client perspective, `hg clone -U --stream`:

before: 33.50 user; 7.95 system; 53.3 MB/s
after:  22.82 user; 7.33 system; 72.7 MB/s
legacy: 29.96 user; 7.94 system; 58.0 MB/s

And for `hg clone --stream` with a working directory update of
~230k files:

after:  119.55 user; 26.47 system; 0:57.08 wall
legacy: 126.98 user; 26.94 system; 1:05.56 wall

So, it appears that bundle2's stream clone is now definitively faster
than legacy stream clone!

Differential Revision: https://phab.mercurial-scm.org/D1932

#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 --config server.uncompressed=false serve -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid > $DAEMON_PIDS
  $ cd ..

Cannot stream clone when server.uncompressed is set

  $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=stream_out'
  200 Script output follows
  
  1

#if stream-legacy
  $ hg debugcapabilities http://localhost:$HGPORT
  Main capabilities:
    batch
    branchmap
    $USUAL_BUNDLE2_CAPS_SERVER$
    changegroupsubset
    compression=zstd,zlib
    getbundle
    httpheader=1024
    httpmediatype=0.1rx,0.1tx,0.2tx
    known
    lookup
    pushkey
    unbundle=HG10GZ,HG10BZ,HG10UN
    unbundlehash
  Bundle2 capabilities:
    HG20
    bookmarks
    changegroup
      01
      02
    digests
      md5
      sha1
      sha512
    error
      abort
      unsupportedcontent
      pushraced
      pushkey
    hgtagsfnodes
    listkeys
    phases
      heads
    pushkey
    remote-changegroup
      http
      https

  $ hg clone --stream -U http://localhost:$HGPORT server-disabled
  warning: stream clone requested but server has them disabled
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1025 changes to 1025 files
  new changesets 96ee1d7354c4:c17445101a72

  $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=getbundle' content-type --bodyfile body --hgproto 0.2 --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 body --hexdump --bytes 100
  body: size=232
  0000: 04 6e 6f 6e 65 48 47 32 30 00 00 00 00 00 00 00 |.noneHG20.......|
  0010: cf 0b 45 52 52 4f 52 3a 41 42 4f 52 54 00 00 00 |..ERROR:ABORT...|
  0020: 00 01 01 07 3c 04 72 6d 65 73 73 61 67 65 73 74 |....<.rmessagest|
  0030: 72 65 61 6d 20 64 61 74 61 20 72 65 71 75 65 73 |ream data reques|
  0040: 74 65 64 20 62 75 74 20 73 65 72 76 65 72 20 64 |ted but server d|
  0050: 6f 65 73 20 6e 6f 74 20 61 6c 6c 6f 77 20 74 68 |oes not allow th|
  0060: 69 73 20 66                                     |is f|

#endif
#if stream-bundle2
  $ hg debugcapabilities http://localhost:$HGPORT
  Main capabilities:
    batch
    branchmap
    $USUAL_BUNDLE2_CAPS_SERVER$
    changegroupsubset
    compression=zstd,zlib
    getbundle
    httpheader=1024
    httpmediatype=0.1rx,0.1tx,0.2tx
    known
    lookup
    pushkey
    unbundle=HG10GZ,HG10BZ,HG10UN
    unbundlehash
  Bundle2 capabilities:
    HG20
    bookmarks
    changegroup
      01
      02
    digests
      md5
      sha1
      sha512
    error
      abort
      unsupportedcontent
      pushraced
      pushkey
    hgtagsfnodes
    listkeys
    phases
      heads
    pushkey
    remote-changegroup
      http
      https

  $ hg clone --stream -U http://localhost:$HGPORT server-disabled
  warning: stream clone requested but server has them disabled
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1025 changes to 1025 files
  new changesets 96ee1d7354c4:c17445101a72

  $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=getbundle' content-type --bodyfile body --hgproto 0.2 --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 body --hexdump --bytes 100
  body: size=232
  0000: 04 6e 6f 6e 65 48 47 32 30 00 00 00 00 00 00 00 |.noneHG20.......|
  0010: cf 0b 45 52 52 4f 52 3a 41 42 4f 52 54 00 00 00 |..ERROR:ABORT...|
  0020: 00 01 01 07 3c 04 72 6d 65 73 73 61 67 65 73 74 |....<.rmessagest|
  0030: 72 65 61 6d 20 64 61 74 61 20 72 65 71 75 65 73 |ream data reques|
  0040: 74 65 64 20 62 75 74 20 73 65 72 76 65 72 20 64 |ted but server d|
  0050: 6f 65 73 20 6e 6f 74 20 61 6c 6c 6f 77 20 74 68 |oes not allow th|
  0060: 69 73 20 66                                     |is f|

#endif

  $ killdaemons.py
  $ cd server
  $ 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=112222
  0000: 04 6e 6f 6e 65 48 47 32 30 00 00 00 00 00 00 00 |.noneHG20.......|
  0010: 68 07 53 54 52 45 41 4d 32 00 00 00 00 03 00 09 |h.STREAM2.......|
  0020: 05 09 04 0c 2d 62 79 74 65 63 6f 75 6e 74 39 38 |....-bytecount98|
  0030: 37 35 38 66 69 6c 65 63 6f 75 6e 74 31 30 33 30 |758filecount1030|
  0040: 72 65 71 75 69 72 65 6d 65 6e 74 73 64 6f 74 65 |requirementsdote|
  0050: 6e 63 6f 64 65 20 66 6e 63 61 63 68 65 20 67 65 |ncode fncache ge|
  0060: 6e 65 72 61 6c 64 65 6c 74 61 20 72 65 76 6c 6f |neraldelta revlo|
  0070: 67 76 31 20 73 74 6f 72 65 00 00 80 00 73 08 42 |gv1 store....s.B|
  0080: 64 61 74 61 2f 30 2e 69 00 03 00 01 00 00 00 00 |data/0.i........|
  0090: 00 00 00 02 00 00 00 01 00 00 00 00 00 00 00 01 |................|
  00a0: ff ff ff ff ff ff ff ff 80 29 63 a0 49 d3 23 87 |.........)c.I.#.|
  00b0: bf ce fe 56 67 92 67 2c 69 d1 ec 39 00 00 00 00 |...Vg.g,i..9....|
  00c0: 00 00 00 00 00 00 00 00 75 30 73 08 42 64 61 74 |........u0s.Bdat|
  00d0: 61 2f 31 2e 69 00 03 00 01 00 00 00 00 00 00 00 |a/1.i...........|
  00e0: 02 00 00 00 01 00 00 00 00 00 00 00 01 ff ff ff |................|
  00f0: ff ff ff ff ff f9 76 da 1d 0d f2 25 6c de 08 db |......v....%l...|

--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: "stream2" (params: 3 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