view tests/test-wireproto-caching.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

  $ . $TESTDIR/wireprotohelpers.sh
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > blackbox =
  > [blackbox]
  > track = simplecache
  > EOF
  $ hg init server
  $ enablehttpv2 server
  $ cd server
  $ cat >> .hg/hgrc << EOF
  > [extensions]
  > simplecache = $TESTDIR/wireprotosimplecache.py
  > EOF

  $ echo a0 > a
  $ echo b0 > b
  $ hg -q commit -A -m 'commit 0'
  $ echo a1 > a
  $ hg commit -m 'commit 1'
  $ echo b1 > b
  $ hg commit -m 'commit 2'
  $ echo a2 > a
  $ echo b2 > b
  $ hg commit -m 'commit 3'

  $ hg log -G -T '{rev}:{node} {desc}'
  @  3:50590a86f3ff5d1e9a1624a7a6957884565cc8e8 commit 3
  |
  o  2:4d01eda50c6ac5f7e89cbe1880143a32f559c302 commit 2
  |
  o  1:4432d83626e8a98655f062ec1f2a43b07f7fbbb0 commit 1
  |
  o  0:3390ef850073fbc2f0dfff2244342c8e9229013a commit 0
  

  $ hg --debug debugindex -m
     rev linkrev nodeid                                   p1                                       p2
       0       0 992f4779029a3df8d0666d00bb924f69634e2641 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000
       1       1 a988fb43583e871d1ed5750ee074c6d840bbbfc8 992f4779029a3df8d0666d00bb924f69634e2641 0000000000000000000000000000000000000000
       2       2 a8853dafacfca6fc807055a660d8b835141a3bb4 a988fb43583e871d1ed5750ee074c6d840bbbfc8 0000000000000000000000000000000000000000
       3       3 3fe11dfbb13645782b0addafbe75a87c210ffddc a8853dafacfca6fc807055a660d8b835141a3bb4 0000000000000000000000000000000000000000

  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
  $ cat hg.pid > $DAEMON_PIDS

Performing the same request should result in same result, with 2nd response
coming from cache.

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x99\x2f\x47\x79\x02\x9a\x3d\xf8\xd0\x66\x6d\x00\xbb\x92\x4f\x69\x63\x4e\x26\x41']
  >     tree eval:b''
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      b'parents': [
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    }
  ]

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x99\x2f\x47\x79\x02\x9a\x3d\xf8\xd0\x66\x6d\x00\xbb\x92\x4f\x69\x63\x4e\x26\x41']
  >     tree eval:b''
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      b'parents': [
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    }
  ]

Sending different request doesn't yield cache hit.

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x99\x2f\x47\x79\x02\x9a\x3d\xf8\xd0\x66\x6d\x00\xbb\x92\x4f\x69\x63\x4e\x26\x41', b'\xa9\x88\xfb\x43\x58\x3e\x87\x1d\x1e\xd5\x75\x0e\xe0\x74\xc6\xd8\x40\xbb\xbf\xc8']
  >     tree eval:b''
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'node': b'\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      b'parents': [
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    },
    {
      b'node': b'\xa9\x88\xfbCX>\x87\x1d\x1e\xd5u\x0e\xe0t\xc6\xd8@\xbb\xbf\xc8',
      b'parents': [
        b'\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    }
  ]

  $ cat .hg/blackbox.log
  *> cacher constructed for manifestdata (glob)
  *> cache miss for 47abb8efa5f01b8964d74917793ad2464db0fa2c (glob)
  *> storing cache entry for 47abb8efa5f01b8964d74917793ad2464db0fa2c (glob)
  *> cacher constructed for manifestdata (glob)
  *> cache hit for 47abb8efa5f01b8964d74917793ad2464db0fa2c (glob)
  *> cacher constructed for manifestdata (glob)
  *> cache miss for 37326a83e9843f15161fce9d1e92d06b795d5e8e (glob)
  *> storing cache entry for 37326a83e9843f15161fce9d1e92d06b795d5e8e (glob)

  $ cat error.log

  $ killdaemons.py
  $ rm .hg/blackbox.log

Try with object caching mode

  $ cat >> .hg/hgrc << EOF
  > [simplecache]
  > cacheobjects = true
  > EOF

  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
  $ cat hg.pid > $DAEMON_PIDS

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x99\x2f\x47\x79\x02\x9a\x3d\xf8\xd0\x66\x6d\x00\xbb\x92\x4f\x69\x63\x4e\x26\x41']
  >     tree eval:b''
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      b'parents': [
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    }
  ]

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x99\x2f\x47\x79\x02\x9a\x3d\xf8\xd0\x66\x6d\x00\xbb\x92\x4f\x69\x63\x4e\x26\x41']
  >     tree eval:b''
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'\x99/Gy\x02\x9a=\xf8\xd0fm\x00\xbb\x92OicN&A',
      b'parents': [
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    }
  ]

  $ cat .hg/blackbox.log
  *> cacher constructed for manifestdata (glob)
  *> cache miss for 47abb8efa5f01b8964d74917793ad2464db0fa2c (glob)
  *> storing cache entry for 47abb8efa5f01b8964d74917793ad2464db0fa2c (glob)
  *> cacher constructed for manifestdata (glob)
  *> cache hit for 47abb8efa5f01b8964d74917793ad2464db0fa2c (glob)

  $ cat error.log

  $ killdaemons.py
  $ rm .hg/blackbox.log

A non-cacheable command does not instantiate cacher

  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
  $ cat hg.pid > $DAEMON_PIDS
  $ sendhttpv2peer << EOF
  > command capabilities
  > EOF
  creating http peer for wire protocol version 2
  sending capabilities command
  response: gen[
    {
      b'commands': {
        b'branchmap': {
          b'args': {},
          b'permissions': [
            b'pull'
          ]
        },
        b'capabilities': {
          b'args': {},
          b'permissions': [
            b'pull'
          ]
        },
        b'changesetdata': {
          b'args': {
            b'fields': {
              b'default': set([]),
              b'required': False,
              b'type': b'set',
              b'validvalues': set([
                b'bookmarks',
                b'parents',
                b'phase',
                b'revision'
              ])
            },
            b'revisions': {
              b'required': True,
              b'type': b'list'
            }
          },
          b'permissions': [
            b'pull'
          ]
        },
        b'filedata': {
          b'args': {
            b'fields': {
              b'default': set([]),
              b'required': False,
              b'type': b'set',
              b'validvalues': set([
                b'linknode',
                b'parents',
                b'revision'
              ])
            },
            b'haveparents': {
              b'default': False,
              b'required': False,
              b'type': b'bool'
            },
            b'nodes': {
              b'required': True,
              b'type': b'list'
            },
            b'path': {
              b'required': True,
              b'type': b'bytes'
            }
          },
          b'permissions': [
            b'pull'
          ]
        },
        b'filesdata': {
          b'args': {
            b'fields': {
              b'default': set([]),
              b'required': False,
              b'type': b'set',
              b'validvalues': set([
                b'firstchangeset',
                b'linknode',
                b'parents',
                b'revision'
              ])
            },
            b'haveparents': {
              b'default': False,
              b'required': False,
              b'type': b'bool'
            },
            b'pathfilter': {
              b'default': None,
              b'required': False,
              b'type': b'dict'
            },
            b'revisions': {
              b'required': True,
              b'type': b'list'
            }
          },
          b'permissions': [
            b'pull'
          ],
          b'recommendedbatchsize': 50000
        },
        b'heads': {
          b'args': {
            b'publiconly': {
              b'default': False,
              b'required': False,
              b'type': b'bool'
            }
          },
          b'permissions': [
            b'pull'
          ]
        },
        b'known': {
          b'args': {
            b'nodes': {
              b'default': [],
              b'required': False,
              b'type': b'list'
            }
          },
          b'permissions': [
            b'pull'
          ]
        },
        b'listkeys': {
          b'args': {
            b'namespace': {
              b'required': True,
              b'type': b'bytes'
            }
          },
          b'permissions': [
            b'pull'
          ]
        },
        b'lookup': {
          b'args': {
            b'key': {
              b'required': True,
              b'type': b'bytes'
            }
          },
          b'permissions': [
            b'pull'
          ]
        },
        b'manifestdata': {
          b'args': {
            b'fields': {
              b'default': set([]),
              b'required': False,
              b'type': b'set',
              b'validvalues': set([
                b'parents',
                b'revision'
              ])
            },
            b'haveparents': {
              b'default': False,
              b'required': False,
              b'type': b'bool'
            },
            b'nodes': {
              b'required': True,
              b'type': b'list'
            },
            b'tree': {
              b'required': True,
              b'type': b'bytes'
            }
          },
          b'permissions': [
            b'pull'
          ],
          b'recommendedbatchsize': 100000
        },
        b'pushkey': {
          b'args': {
            b'key': {
              b'required': True,
              b'type': b'bytes'
            },
            b'namespace': {
              b'required': True,
              b'type': b'bytes'
            },
            b'new': {
              b'required': True,
              b'type': b'bytes'
            },
            b'old': {
              b'required': True,
              b'type': b'bytes'
            }
          },
          b'permissions': [
            b'push'
          ]
        },
        b'rawstorefiledata': {
          b'args': {
            b'files': {
              b'required': True,
              b'type': b'list'
            },
            b'pathfilter': {
              b'default': None,
              b'required': False,
              b'type': b'list'
            }
          },
          b'permissions': [
            b'pull'
          ]
        }
      },
      b'framingmediatypes': [
        b'application/mercurial-exp-framing-0006'
      ],
      b'pathfilterprefixes': set([
        b'path:',
        b'rootfilesin:'
      ]),
      b'rawrepoformats': [
        b'generaldelta',
        b'revlogv1',
        b'sparserevlog'
      ]
    }
  ]

  $ test -f .hg/blackbox.log
  [1]

An error is not cached

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa']
  >     tree eval:b''
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  abort: unknown node: \xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa! (esc)
  [255]

  $ cat .hg/blackbox.log
  *> cacher constructed for manifestdata (glob)
  *> cache miss for 2cba2a7d0d1575fea2fe68f597e97a7c2ac2f705 (glob)
  *> cacher exiting due to error (glob)

  $ killdaemons.py
  $ rm .hg/blackbox.log