view tests/test-wireproto-command-filedata.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
  $ cat > a << EOF
  > a0
  > 00000000000000000000000000000000000000
  > 11111111111111111111111111111111111111
  > EOF
  $ 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 f1 > dir0/child1/f
  $ hg commit -m 'commit 2'

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

Create multiple heads introducing the same changeset

  $ hg -q up -r 0
  $ echo foo > dupe-file
  $ hg commit -Am 'dupe 1'
  adding dupe-file
  created new head
  $ hg -q up -r 0
  $ echo foo > dupe-file
  $ hg commit -Am 'dupe 2'
  adding dupe-file
  created new head

  $ hg log -G -T '{rev}:{node} {desc}\n'
  @  5:732c3dd7bee94242de656000e5f458e7ccfe2828 dupe 2
  |
  | o  4:4334f10897d13c3e8beb4b636f7272b4ec2d0322 dupe 1
  |/
  | o  3:5ce944d7fece1252dae06c34422b573c191b9489 commit 3
  |/
  | o  2:b3c27db01410dae01e5485d425b1440078df540c commit 2
  | |
  | o  1:3ef5e551f219ba505481d34d6b0316b017fa3f00 commit 1
  |/
  o  0:91b232a2253ce0638496f67bdfd7a4933fb51b25 commit 0
  

  $ hg --debug debugindex a
     rev linkrev nodeid                                   p1                                       p2
       0       0 649d149df43d83882523b7fb1e6a3af6f1907b39 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000
       1       1 0a86321f1379d1a9ecd0579a22977af7a5acaf11 649d149df43d83882523b7fb1e6a3af6f1907b39 0000000000000000000000000000000000000000
       2       3 7e5801b6d5f03a5a54f3c47b583f7567aad43e5b 649d149df43d83882523b7fb1e6a3af6f1907b39 0000000000000000000000000000000000000000

  $ hg --debug debugindex dir0/child0/e
     rev linkrev nodeid                                   p1                                       p2
       0       0 bbba6c06b30f443d34ff841bc985c4d0827c6be4 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000

  $ hg --debug debugindex dupe-file
     rev linkrev nodeid                                   p1                                       p2
       0       4 2ed2a3912a0b24502043eae84ee4b279c18b90dd 0000000000000000000000000000000000000000 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 filedata
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  abort: missing required arguments: nodes, path!
  [255]

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

Unknown node is an error

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa\xaa']
  >     path eval:b'a'
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  abort: unknown file node: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!
  [255]

Fetching a single revision returns just metadata by default

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11']
  >     path eval:b'a'
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    }
  ]

Requesting parents works

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11']
  >     path eval:b'a'
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11',
      b'parents': [
        b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9',
        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 filedata
  >     nodes eval:[b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11']
  >     path eval:b'a'
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          84
        ]
      ],
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    b'a0\n00000000000000000000000000000000000000\n11111111111111111111111111111111111111\na1\n'
  ]

haveparents=False should be same as above

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11']
  >     path eval:b'a'
  >     fields eval:[b'revision']
  >     haveparents eval:False
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          84
        ]
      ],
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    b'a0\n00000000000000000000000000000000000000\n11111111111111111111111111111111111111\na1\n'
  ]

haveparents=True should emit a delta

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11']
  >     path eval:b'a'
  >     fields eval:[b'revision']
  >     haveparents eval:True
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'deltabasenode': b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9',
      b'fieldsfollowing': [
        [
          b'delta',
          15
        ]
      ],
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    b'\x00\x00\x00Q\x00\x00\x00Q\x00\x00\x00\x03a1\n'
  ]

Requesting multiple revisions works
(first revision is a fulltext since haveparents=False by default)

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x64\x9d\x14\x9d\xf4\x3d\x83\x88\x25\x23\xb7\xfb\x1e\x6a\x3a\xf6\xf1\x90\x7b\x39', b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11']
  >     path eval:b'a'
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          81
        ]
      ],
      b'node': b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9'
    },
    b'a0\n00000000000000000000000000000000000000\n11111111111111111111111111111111111111\n',
    {
      b'deltabasenode': b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9',
      b'fieldsfollowing': [
        [
          b'delta',
          15
        ]
      ],
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    b'\x00\x00\x00Q\x00\x00\x00Q\x00\x00\x00\x03a1\n'
  ]

Revisions are sorted by DAG order, parents first

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x0a\x86\x32\x1f\x13\x79\xd1\xa9\xec\xd0\x57\x9a\x22\x97\x7a\xf7\xa5\xac\xaf\x11', b'\x64\x9d\x14\x9d\xf4\x3d\x83\x88\x25\x23\xb7\xfb\x1e\x6a\x3a\xf6\xf1\x90\x7b\x39']
  >     path eval:b'a'
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          81
        ]
      ],
      b'node': b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9'
    },
    b'a0\n00000000000000000000000000000000000000\n11111111111111111111111111111111111111\n',
    {
      b'deltabasenode': b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9',
      b'fieldsfollowing': [
        [
          b'delta',
          15
        ]
      ],
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    b'\x00\x00\x00Q\x00\x00\x00Q\x00\x00\x00\x03a1\n'
  ]

Requesting parents and revision data works

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x7e\x58\x01\xb6\xd5\xf0\x3a\x5a\x54\xf3\xc4\x7b\x58\x3f\x75\x67\xaa\xd4\x3e\x5b']
  >     path eval:b'a'
  >     fields eval:[b'parents', b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          84
        ]
      ],
      b'node': b'~X\x01\xb6\xd5\xf0:ZT\xf3\xc4{X?ug\xaa\xd4>[',
      b'parents': [
        b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    },
    b'a0\n00000000000000000000000000000000000000\n11111111111111111111111111111111111111\na2\n'
  ]

Linknode for duplicate revision is the initial revision

  $ sendhttpv2peer << EOF
  > command filedata
  >     nodes eval:[b'\x2e\xd2\xa3\x91\x2a\x0b\x24\x50\x20\x43\xea\xe8\x4e\xe4\xb2\x79\xc1\x8b\x90\xdd']
  >     path eval:b'dupe-file'
  >     fields eval:[b'linknode', b'parents', b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filedata command
  response: gen[
    {
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          4
        ]
      ],
      b'linknode': b'C4\xf1\x08\x97\xd1<>\x8b\xebKcorr\xb4\xec-\x03"',
      b'node': b'.\xd2\xa3\x91*\x0b$P C\xea\xe8N\xe4\xb2y\xc1\x8b\x90\xdd',
      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'foo\n'
  ]

  $ cat error.log