view tests/test-wireproto-exchangev2-shallow.t @ 42743:8c9a6adec67a

rust-discovery: using the children cache in add_missing

The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.

The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.

This is a case where staying on the same side of the interface
between the two languages has clear benefits.

On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.

For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:

Rust version with simple iteration
  addcommons: 57.287us
  first undecided computation: 184.278334ms
  first children cache computation: 131.056us
  addmissings iteration: 42.766us
  first addinfo total: 185.24 ms

Python + C version
  first addcommons: 0.29 ms
  addcommons 0.21 ms
  first undecided computation 191.35 ms
  addmissings 45.75 ms
  first addinfo total: 237.77 ms

On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:

Rust version:
  first undecided computation: 293.842629ms
  first children cache computation: 407.911297ms
  addmissings iteration: 34.312869ms
  first addinfo total: 776.02 ms
  taking initial sample
  query 2: sampling time: 1318.38 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings: 143.062us

Python + C version:
  first undecided computation 298.13 ms
  addmissings 80.13 ms
  first addinfo total: 399.62 ms
  taking initial sample
  query 2: sampling time: 3957.23 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings 52.88 ms

Differential Revision: https://phab.mercurial-scm.org/D6428

#require sqlite

Tests for wire protocol version 2 exchange.
Tests in this file should be folded into existing tests once protocol
v2 has enough features that it can be enabled via #testcase in existing
tests.

  $ . $TESTDIR/wireprotohelpers.sh
  $ enablehttpv2client
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > sqlitestore =
  > pullext = $TESTDIR/pullext.py
  > [storage]
  > new-repo-backend=sqlite
  > EOF

Configure a server

  $ hg init server-basic
  $ enablehttpv2 server-basic
  $ cd server-basic
  $ mkdir dir0 dir1
  $ echo a0 > a
  $ echo b0 > b
  $ hg -q commit -A -m 'commit 0'
  $ echo c0 > dir0/c
  $ echo d0 > dir0/d
  $ hg -q commit -A -m 'commit 1'
  $ echo e0 > dir1/e
  $ echo f0 > dir1/f
  $ hg -q commit -A -m 'commit 2'
  $ echo c1 > dir0/c
  $ echo e1 > dir1/e
  $ hg commit -m 'commit 3'
  $ echo c2 > dir0/c
  $ echo e2 > dir1/e
  $ echo f1 > dir1/f
  $ hg commit -m 'commit 4'
  $ echo a1 > a
  $ echo b1 > b
  $ hg commit -m 'commit 5'

  $ hg log -G -T '{node} {desc}'
  @  93a8bd067ed2840d9aa810ad598168383a3a2c3a commit 5
  |
  o  dc666cf9ecf3d94e6b830f30e5f1272e2a9164d9 commit 4
  |
  o  97765fc3cd624fd1fa0176932c21ffd16adf432e commit 3
  |
  o  47fe012ab237a8c7fc0c78f9f26d5866eef3f825 commit 2
  |
  o  b709380892b193c1091d3a817f706052e346821b commit 1
  |
  o  3390ef850073fbc2f0dfff2244342c8e9229013a commit 0
  
  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
  $ cat hg.pid > $DAEMON_PIDS

  $ cd ..

Shallow clone pulls down latest revision of every file

  $ hg --debug clone --depth 1 http://localhost:$HGPORT client-shallow-1
  using http://localhost:$HGPORT/
  sending capabilities command
  query 1; heads
  sending 2 commands
  sending command heads: {}
  sending command known: {
    'nodes': []
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=22; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  received frame(size=11; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=3; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command changesetdata: {
    'fields': set([
      'bookmarks',
      'parents',
      'phase',
      'revision'
    ]),
    'revisions': [
      {
        'heads': [
          '\x93\xa8\xbd\x06~\xd2\x84\r\x9a\xa8\x10\xadY\x81h8::,:'
        ],
        'roots': [],
        'type': 'changesetdagrange'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1170; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  add changeset 3390ef850073
  add changeset b709380892b1
  add changeset 47fe012ab237
  add changeset 97765fc3cd62
  add changeset dc666cf9ecf3
  add changeset 93a8bd067ed2
  checking for updated bookmarks
  sending 1 commands
  sending command manifestdata: {
    'fields': set([
      'parents',
      'revision'
    ]),
    'haveparents': True,
    'nodes': [
      '\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      '|2 \x1a\xa3\xa1R\xa9\xe6\xa9"+?\xa8\xd0\xe3\x0f\xc2V\xe8',
      '\x8d\xd0W<\x7f\xaf\xe2\x04F\xcc\xea\xac\x05N\xea\xa4x\x91M\xdb',
      '113\x85\xf2!\x8b\x08^\xb2Z\x821\x1e*\xdd\x0e\xeb\x8c3',
      'H]O\xc2`\xef\\\xb9\xc0p6\x88K\x00k\x11\x0ej\xdby',
      '\xd9;\xc4\x0b\x0e*GMp\xee\xf7}^\x91/f\x7fSd\x83'
    ],
    'tree': ''
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1515; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command filesdata: {
    'fields': set([
      'linknode',
      'parents',
      'revision'
    ]),
    'haveparents': False,
    'revisions': [
      {
        'nodes': [
          '\x93\xa8\xbd\x06~\xd2\x84\r\x9a\xa8\x10\xadY\x81h8::,:'
        ],
        'type': 'changesetexplicit'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1005; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  updating the branch cache
  new changesets 3390ef850073:93a8bd067ed2
  updating to branch default
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 000000000000, local: 000000000000+, remote: 93a8bd067ed2
   a: remote created -> g
  getting a
   b: remote created -> g
  getting b
   dir0/c: remote created -> g
  getting dir0/c
   dir0/d: remote created -> g
  getting dir0/d
   dir1/e: remote created -> g
  getting dir1/e
   dir1/f: remote created -> g
  getting dir1/f
  6 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (sent 5 HTTP requests and * bytes; received * bytes in responses) (glob)

  $ sqlite3 -line client-shallow-1/.hg/store/db.sqlite << EOF
  > SELECT id, path, revnum, node, p1rev, p2rev, linkrev, flags FROM filedata ORDER BY id ASC;
  > EOF
       id = 1
     path = a
   revnum = 0
     node = \x9a8\x12)\x97\xb3\xac\x97\xbe*\x9a\xa2\xe5V\x83\x83A\xfd\xf2\xcc (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 2
  
       id = 2
     path = b
   revnum = 0
     node = \xb1zk\xd3g=\x9a\xb8\xce\xd5\x81\xa2	\xf6/=\xa5\xccEx (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 2
  
       id = 3
     path = dir0/c
   revnum = 0
     node = I\x1d\xa1\xbb\x89\xeax\xc0\xc0\xa2s[\x16\xce}\x93\x1d\xc8\xe2\r (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 2
  
       id = 4
     path = dir0/d
   revnum = 0
     node = S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4& (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 0
  
       id = 5
     path = dir1/e
   revnum = 0
     node = ]\xf3\xac\xd8\xd0\xc7\xfaP\x98\xd0'\x9a\x044\xc3\x02\x9e+x\xe1 (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 2
  
       id = 6
     path = dir1/f
   revnum = 0
     node = (\xc7v\xae\x08\xd0\xd5^\xb4\x06H\xb4\x01\xb9\x0f\xf5DH4\x8e (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 2

Test a shallow clone with only some files

  $ hg --debug clone --depth 1 --include dir0/ http://localhost:$HGPORT client-shallow-narrow-1
  using http://localhost:$HGPORT/
  sending capabilities command
  query 1; heads
  sending 2 commands
  sending command heads: {}
  sending command known: {
    'nodes': []
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=22; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  received frame(size=11; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=3; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command changesetdata: {
    'fields': set([
      'bookmarks',
      'parents',
      'phase',
      'revision'
    ]),
    'revisions': [
      {
        'heads': [
          '\x93\xa8\xbd\x06~\xd2\x84\r\x9a\xa8\x10\xadY\x81h8::,:'
        ],
        'roots': [],
        'type': 'changesetdagrange'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1170; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  add changeset 3390ef850073
  add changeset b709380892b1
  add changeset 47fe012ab237
  add changeset 97765fc3cd62
  add changeset dc666cf9ecf3
  add changeset 93a8bd067ed2
  checking for updated bookmarks
  sending 1 commands
  sending command manifestdata: {
    'fields': set([
      'parents',
      'revision'
    ]),
    'haveparents': True,
    'nodes': [
      '\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      '|2 \x1a\xa3\xa1R\xa9\xe6\xa9"+?\xa8\xd0\xe3\x0f\xc2V\xe8',
      '\x8d\xd0W<\x7f\xaf\xe2\x04F\xcc\xea\xac\x05N\xea\xa4x\x91M\xdb',
      '113\x85\xf2!\x8b\x08^\xb2Z\x821\x1e*\xdd\x0e\xeb\x8c3',
      'H]O\xc2`\xef\\\xb9\xc0p6\x88K\x00k\x11\x0ej\xdby',
      '\xd9;\xc4\x0b\x0e*GMp\xee\xf7}^\x91/f\x7fSd\x83'
    ],
    'tree': ''
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1515; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command filesdata: {
    'fields': set([
      'linknode',
      'parents',
      'revision'
    ]),
    'haveparents': False,
    'pathfilter': {
      'include': [
        'path:dir0'
      ]
    },
    'revisions': [
      {
        'nodes': [
          '\x93\xa8\xbd\x06~\xd2\x84\r\x9a\xa8\x10\xadY\x81h8::,:'
        ],
        'type': 'changesetexplicit'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=355; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  updating the branch cache
  new changesets 3390ef850073:93a8bd067ed2
  updating to branch default
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 000000000000, local: 000000000000+, remote: 93a8bd067ed2
   dir0/c: remote created -> g
  getting dir0/c
   dir0/d: remote created -> g
  getting dir0/d
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (sent 5 HTTP requests and * bytes; received * bytes in responses) (glob)

  $ sqlite3 -line client-shallow-narrow-1/.hg/store/db.sqlite << EOF
  > SELECT id, path, revnum, node, p1rev, p2rev, linkrev, flags FROM filedata ORDER BY id ASC;
  > EOF
       id = 1
     path = dir0/c
   revnum = 0
     node = I\x1d\xa1\xbb\x89\xeax\xc0\xc0\xa2s[\x16\xce}\x93\x1d\xc8\xe2\r (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 2
  
       id = 2
     path = dir0/d
   revnum = 0
     node = S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4& (esc)
    p1rev = -1
    p2rev = -1
  linkrev = 5
    flags = 0

Cloning an old revision with depth=1 works

  $ hg --debug clone --depth 1 -r 97765fc3cd624fd1fa0176932c21ffd16adf432e http://localhost:$HGPORT client-shallow-2
  using http://localhost:$HGPORT/
  sending capabilities command
  sending 1 commands
  sending command lookup: {
    'key': '97765fc3cd624fd1fa0176932c21ffd16adf432e'
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=21; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  query 1; heads
  sending 2 commands
  sending command heads: {}
  sending command known: {
    'nodes': []
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=22; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  received frame(size=11; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=3; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command changesetdata: {
    'fields': set([
      'bookmarks',
      'parents',
      'phase',
      'revision'
    ]),
    'revisions': [
      {
        'heads': [
          '\x97v_\xc3\xcdbO\xd1\xfa\x01v\x93,!\xff\xd1j\xdfC.'
        ],
        'roots': [],
        'type': 'changesetdagrange'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=783; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  add changeset 3390ef850073
  add changeset b709380892b1
  add changeset 47fe012ab237
  add changeset 97765fc3cd62
  checking for updated bookmarks
  sending 1 commands
  sending command manifestdata: {
    'fields': set([
      'parents',
      'revision'
    ]),
    'haveparents': True,
    'nodes': [
      '\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      '|2 \x1a\xa3\xa1R\xa9\xe6\xa9"+?\xa8\xd0\xe3\x0f\xc2V\xe8',
      '\x8d\xd0W<\x7f\xaf\xe2\x04F\xcc\xea\xac\x05N\xea\xa4x\x91M\xdb',
      '113\x85\xf2!\x8b\x08^\xb2Z\x821\x1e*\xdd\x0e\xeb\x8c3'
    ],
    'tree': ''
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=967; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command filesdata: {
    'fields': set([
      'linknode',
      'parents',
      'revision'
    ]),
    'haveparents': False,
    'revisions': [
      {
        'nodes': [
          '\x97v_\xc3\xcdbO\xd1\xfa\x01v\x93,!\xff\xd1j\xdfC.'
        ],
        'type': 'changesetexplicit'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1005; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  updating the branch cache
  new changesets 3390ef850073:97765fc3cd62
  updating to branch default
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 000000000000, local: 000000000000+, remote: 97765fc3cd62
   a: remote created -> g
  getting a
   b: remote created -> g
  getting b
   dir0/c: remote created -> g
  getting dir0/c
   dir0/d: remote created -> g
  getting dir0/d
   dir1/e: remote created -> g
  getting dir1/e
   dir1/f: remote created -> g
  getting dir1/f
  6 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (sent 6 HTTP requests and * bytes; received * bytes in responses) (glob)

Incremental pull of shallow clone fetches new changesets

  $ hg --cwd client-shallow-2 --debug pull http://localhost:$HGPORT
  pulling from http://localhost:$HGPORT/
  using http://localhost:$HGPORT/
  sending capabilities command
  query 1; heads
  sending 2 commands
  sending command heads: {}
  sending command known: {
    'nodes': [
      '\x97v_\xc3\xcdbO\xd1\xfa\x01v\x93,!\xff\xd1j\xdfC.'
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=22; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  received frame(size=11; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=2; request=3; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=3; stream=2; streamflags=; type=command-response; flags=eos)
  searching for changes
  all local heads known remotely
  sending 1 commands
  sending command changesetdata: {
    'fields': set([
      'bookmarks',
      'parents',
      'phase',
      'revision'
    ]),
    'revisions': [
      {
        'heads': [
          '\x93\xa8\xbd\x06~\xd2\x84\r\x9a\xa8\x10\xadY\x81h8::,:'
        ],
        'roots': [
          '\x97v_\xc3\xcdbO\xd1\xfa\x01v\x93,!\xff\xd1j\xdfC.'
        ],
        'type': 'changesetdagrange'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=400; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  add changeset dc666cf9ecf3
  add changeset 93a8bd067ed2
  checking for updated bookmarks
  sending 1 commands
  sending command manifestdata: {
    'fields': set([
      'parents',
      'revision'
    ]),
    'haveparents': True,
    'nodes': [
      'H]O\xc2`\xef\\\xb9\xc0p6\x88K\x00k\x11\x0ej\xdby',
      '\xd9;\xc4\x0b\x0e*GMp\xee\xf7}^\x91/f\x7fSd\x83'
    ],
    'tree': ''
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=561; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  sending 1 commands
  sending command filesdata: {
    'fields': set([
      'linknode',
      'parents',
      'revision'
    ]),
    'haveparents': False,
    'revisions': [
      {
        'nodes': [
          '\xdcfl\xf9\xec\xf3\xd9Nk\x83\x0f0\xe5\xf1\'.*\x91d\xd9',
          '\x93\xa8\xbd\x06~\xd2\x84\r\x9a\xa8\x10\xadY\x81h8::,:'
        ],
        'type': 'changesetexplicit'
      }
    ]
  }
  received frame(size=9; request=1; stream=2; streamflags=stream-begin; type=stream-settings; flags=eos)
  received frame(size=11; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=1373; request=1; stream=2; streamflags=encoded; type=command-response; flags=continuation)
  received frame(size=0; request=1; stream=2; streamflags=; type=command-response; flags=eos)
  updating the branch cache
  new changesets dc666cf9ecf3:93a8bd067ed2
  (run 'hg update' to get a working copy)
  (sent 5 HTTP requests and * bytes; received * bytes in responses) (glob)

  $ hg --cwd client-shallow-2 up tip
  merging dir0/c
  merging dir1/e
  3 files updated, 2 files merged, 0 files removed, 0 files unresolved