view tests/test-wireproto-command-manifestdata.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

  $ hg init server
  $ enablehttpv2 server
  $ cd server
  $ echo a0 > a
  $ echo b0 > b
  $ mkdir -p dir0/child0 dir0/child1 dir1
  $ echo c0 > dir0/c
  $ echo d0 > dir0/d
  $ echo e0 > dir0/child0/e
  $ echo f0 > dir0/child1/f
  $ hg -q commit -A -m 'commit 0'

  $ echo a1 > a
  $ echo d1 > dir0/d
  $ hg commit -m 'commit 1'
  $ echo f0 > dir0/child1/f
  $ hg commit -m 'commit 2'
  nothing changed
  [1]

  $ hg -q up -r 0
  $ echo a2 > a
  $ hg commit -m 'commit 3'
  created new head

  $ hg log -G -T '{rev}:{node} {desc}\n'
  @  2:c8757a2ffe552850d1e0dfe60d295ebf64c196d9 commit 3
  |
  | o  1:650165e803375748a94df471e5b58d85763e0b29 commit 1
  |/
  o  0:6d85ca1270b377d320098556ba5bfad34a9ee12d commit 0
  

  $ hg --debug debugindex -m
     rev linkrev nodeid                                   p1                                       p2
       0       0 1b175b595f022cfab5b809cc0ed551bd0b3ff5e4 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000
       1       1 91e0bdbfb0dde0023fa063edc1445f207a22eac7 1b175b595f022cfab5b809cc0ed551bd0b3ff5e4 0000000000000000000000000000000000000000
       2       2 46a6721b5edaf0ea04b79a5cb3218854a4d2aba0 1b175b595f022cfab5b809cc0ed551bd0b3ff5e4 0000000000000000000000000000000000000000

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

Missing arguments is an error

  $ sendhttpv2peer << EOF
  > command manifestdata
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  abort: missing required arguments: nodes, tree!
  [255]

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[]
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  abort: missing required arguments: tree!
  [255]

Unknown node is an error

  $ 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''
  > 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]

Fetching a single revision returns just metadata by default

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    }
  ]

Requesting parents works

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     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'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0',
      b'parents': [
        b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    }
  ]

Requesting revision data works
(haveparents defaults to false, so fulltext is emitted)

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          292
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    },
    b'a\x000879345e39377229634b420c639454156726c6b6\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n'
  ]

haveparents=False yields same output

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  >     fields eval:[b'revision']
  >     haveparents eval:False
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          292
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    },
    b'a\x000879345e39377229634b420c639454156726c6b6\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n'
  ]

haveparents=True will emit delta

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  >     fields eval:[b'revision']
  >     haveparents eval:True
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
      b'fieldsfollowing': [
        [
          b'delta',
          55
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    },
    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
  ]

Requesting multiple revisions works
(haveparents defaults to false, so fulltext is emitted unless a parent
has been emitted)

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4', b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          292
        ]
      ],
      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4'
    },
    b'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
    {
      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
      b'fieldsfollowing': [
        [
          b'delta',
          55
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    },
    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
  ]

With haveparents=True, first revision is a delta instead of fulltext

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4', b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  >     fields eval:[b'revision']
  >     haveparents eval:True
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          292
        ]
      ],
      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4'
    },
    b'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
    {
      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
      b'fieldsfollowing': [
        [
          b'delta',
          55
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    },
    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
  ]

Revisions are sorted by DAG order, parents first

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0', b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4']
  >     tree eval:b''
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          292
        ]
      ],
      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4'
    },
    b'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
    {
      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
      b'fieldsfollowing': [
        [
          b'delta',
          55
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0'
    },
    b'\x00\x00\x00\x00\x00\x00\x00+\x00\x00\x00+a\x000879345e39377229634b420c639454156726c6b6\n'
  ]

Requesting parents and revision data works

  $ sendhttpv2peer << EOF
  > command manifestdata
  >     nodes eval:[b'\x1b\x17\x5b\x59\x5f\x02\x2c\xfa\xb5\xb8\x09\xcc\x0e\xd5\x51\xbd\x0b\x3f\xf5\xe4', b'\x46\xa6\x72\x1b\x5e\xda\xf0\xea\x04\xb7\x9a\x5c\xb3\x21\x88\x54\xa4\xd2\xab\xa0']
  >     tree eval:b''
  >     fields eval:[b'parents', b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending manifestdata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          292
        ]
      ],
      b'node': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
      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'a\x002b4eb07319bfa077a40a2f04913659aef0da42da\nb\x00819e258d31a5e1606629f365bb902a1b21ee4216\ndir0/c\x00914445346a0ca0629bd47ceb5dfe07e4d4cf2501\ndir0/child0/e\x00bbba6c06b30f443d34ff841bc985c4d0827c6be4\ndir0/child1/f\x0012fc7dcd773b5a0a929ce195228083c6ddc9cec4\ndir0/d\x00538206dc971e521540d6843abfe6d16032f6d426\n',
    {
      b'deltabasenode': b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
      b'fieldsfollowing': [
        [
          b'delta',
          55
        ]
      ],
      b'node': b'F\xa6r\x1b^\xda\xf0\xea\x04\xb7\x9a\\\xb3!\x88T\xa4\xd2\xab\xa0',
      b'parents': [
        b'\x1b\x17[Y_\x02,\xfa\xb5\xb8\t\xcc\x0e\xd5Q\xbd\x0b?\xf5\xe4',
        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+a\x000879345e39377229634b420c639454156726c6b6\n'
  ]

  $ cat error.log