view tests/test-wireproto-command-filesdata.t @ 44363:f7459da77f23

nodemap: introduce an option to use mmap to read the nodemap mapping

The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.

This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).

Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:

Before:

 * do not use the persistent nodemap
 * use the CPython implementation of the index for nodemap
 * use mmapping of the changelog index

After:

 * use the MixedIndex Rust code, with the NodeTree object for nodemap access
   (still in review)
 * use the persistent nodemap data from disk
 * access the persistent nodemap data through mmap
 * use mmapping of the changelog index

The persistent nodemap greatly speed up  most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.

Here are some numbers (in seconds) for the reference copy of mozilla-try:

Revset            Before   After     abs-change speedup

-10000:           0.004622 0.005532   0.000910  ×   0.83
-10:              0.000050 0.000132   0.000082  ×   0.37
tip               0.000052 0.000085   0.000033  ×   0.61
0 + (-10000:)     0.028222 0.005337  -0.022885  ×   5.29
0                 0.023521 0.000084  -0.023437  × 280.01
(-10000:) + 0     0.235539 0.005308  -0.230231  ×  44.37
(-10:) + :9       0.232883 0.000180  -0.232703  ×1293.79
(-10000:) + (:99) 0.238735 0.005358  -0.233377  ×  44.55
:99 + (-10000:)   0.317942 0.005593  -0.312349  ×  56.84
:9 + (-10:)       0.313372 0.000179  -0.313193  ×1750.68
:9                0.316450 0.000143  -0.316307  ×2212.93


On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.

Here are some numbers (in seconds) for the reference copy of mercurial:

Revset            Before   After     abs-change speedup
-10:              0.000065 0.000097   0.000032  × 0.67
tip               0.000063 0.000078   0.000015  × 0.80
0                 0.000561 0.000079  -0.000482  × 7.10
-10000:           0.004609 0.003648  -0.000961  × 1.26
0 + (-10000:)     0.005023 0.003715  -0.001307  × 1.35
(-10:) + :9       0.002187 0.000108  -0.002079  ×20.25
(-10000:) + 0     0.006252 0.003716  -0.002536  × 1.68
(-10000:) + (:99) 0.006367 0.003707  -0.002660  × 1.71
:9 + (-10:)       0.003846 0.000110  -0.003736  ×34.96
:9                0.003854 0.000099  -0.003755  ×38.92
:99 + (-10000:)   0.007644 0.003778  -0.003866  × 2.02

Differential Revision: https://phab.mercurial-scm.org/D7894

  $ . $TESTDIR/wireprotohelpers.sh

  $ hg init server
  $ enablehttpv2 server
  $ cd server
  $ cat > a << EOF
  > a0
  > 00000000000000000000000000000000000000
  > 11111111111111111111111111111111111111
  > EOF
  $ cat > b << EOF
  > b0
  > aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  > bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
  > EOF
  $ 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
  $ echo g0 > g
  $ echo h0 > h
  $ hg -q commit -A -m 'commit 1'
  $ echo f1 > dir0/child1/f
  $ echo i0 > dir0/i
  $ hg -q commit -A -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 file nodefile node

  $ 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'
  @  5:47fc30580911232cb264675b402819deddf6c6f0 dupe 2
  |
  | o  4:b16cce2967c1749ef4f4e3086a806cfbad8a3af7 dupe 1
  |/
  | o  3:476fbf122cd82f6726f0191ff146f67140946abc commit 3
  |/
  | o  2:b91c03cbba3519ab149b6cd0a0afbdb5cf1b5c8a commit 2
  | |
  | o  1:5b0b1a23577e205ea240e39c9704e28d7697cbd8 commit 1
  |/
  o  0:6e875ff18c227659ad6143bb3580c65700734884 commit 0
  

  $ 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 filesdata
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  abort: missing required arguments: revisions!
  [255]

Bad pattern to pathfilter is rejected

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >          b'type': b'changesetexplicit',
  >          b'nodes': [
  >              b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >          ]}]
  >     pathfilter eval:{b'include': [b'bad:foo']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  abort: include pattern must begin with `path:` or `rootfilesin:`; got bad:foo!
  [255]

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     pathfilter eval:{b'exclude': [b'glob:foo']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  abort: exclude pattern must begin with `path:` or `rootfilesin:`; got glob:foo!
  [255]

Fetching a single changeset without parents fetches all files

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 8,
      b'totalpaths': 8
    },
    {
      b'path': b'a',
      b'totalitems': 1
    },
    {
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2'
    },
    {
      b'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01'
    },
    {
      b'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\xe4'
    },
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 1
    },
    {
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4'
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    }
  ]

Fetching a single changeset saying parents data is available fetches just new files

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     haveparents eval:True
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 4,
      b'totalpaths': 4
    },
    {
      b'path': b'a',
      b'totalitems': 1
    },
    {
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    }
  ]

A path filter for a sub-directory is honored

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     haveparents eval:True
  >     pathfilter eval:{b'include': [b'path:dir0']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 1,
      b'totalpaths': 1
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    }
  ]

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     haveparents eval:True
  >     pathfilter eval:{b'exclude': [b'path:a', b'path:g']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 2,
      b'totalpaths': 2
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    }
  ]

Requesting multiple changeset nodes without haveparents sends all data for both

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >             b'\xb9\x1c\x03\xcb\xba\x35\x19\xab\x14\x9b\x6c\xd0\xa0\xaf\xbd\xb5\xcf\x1b\x5c\x8a',
  >         ]}]
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 10,
      b'totalpaths': 9
    },
    {
      b'path': b'a',
      b'totalitems': 1
    },
    {
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2'
    },
    {
      b'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01'
    },
    {
      b'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\xe4'
    },
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 2
    },
    {
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4'
    },
    {
      b'node': b'(\xc7v\xae\x08\xd0\xd5^\xb4\x06H\xb4\x01\xb9\x0f\xf5DH4\x8e'
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    {
      b'path': b'dir0/i',
      b'totalitems': 1
    },
    {
      b'node': b'\xd7t\xb5\x80Jq\xfd1\xe1\xae\x05\xea\x8e2\xdd\x9b\xa3\xd8S\xd7'
    },
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    }
  ]

Requesting multiple changeset nodes with haveparents sends incremental data for both

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >             b'\xb9\x1c\x03\xcb\xba\x35\x19\xab\x14\x9b\x6c\xd0\xa0\xaf\xbd\xb5\xcf\x1b\x5c\x8a',
  >         ]}]
  >     haveparents eval:True
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 6,
      b'totalpaths': 6
    },
    {
      b'path': b'a',
      b'totalitems': 1
    },
    {
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 1
    },
    {
      b'node': b'(\xc7v\xae\x08\xd0\xd5^\xb4\x06H\xb4\x01\xb9\x0f\xf5DH4\x8e'
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    {
      b'path': b'dir0/i',
      b'totalitems': 1
    },
    {
      b'node': b'\xd7t\xb5\x80Jq\xfd1\xe1\xae\x05\xea\x8e2\xdd\x9b\xa3\xd8S\xd7'
    },
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    }
  ]

Requesting parents works

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     fields eval:[b'parents']
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 8,
      b'totalpaths': 8
    },
    {
      b'path': b'a',
      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'
      ]
    },
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2',
      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'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01',
      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'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\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'path': b'dir0/child1/f',
      b'totalitems': 1
    },
    {
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4',
      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'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G',
      b'parents': [
        b'S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4&',
        b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
      ]
    },
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c',
      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'path': b'h',
      b'totalitems': 1
    },
    {
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K',
      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'
      ]
    }
  ]

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

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 8,
      b'totalpaths': 8
    },
    {
      b'path': b'a',
      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',
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          81
        ]
      ],
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2'
    },
    b'b0\naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\n',
    {
      b'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01'
    },
    b'c0\n',
    {
      b'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\xe4'
    },
    b'e0\n',
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4'
    },
    b'f0\n',
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    b'd1\n',
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    b'g0\n',
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    },
    b'h0\n'
  ]

haveparents=False should be same as above

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     fields eval:[b'revision']
  >     haveparents eval:False
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 8,
      b'totalpaths': 8
    },
    {
      b'path': b'a',
      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',
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          81
        ]
      ],
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2'
    },
    b'b0\naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\n',
    {
      b'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01'
    },
    b'c0\n',
    {
      b'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\xe4'
    },
    b'e0\n',
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4'
    },
    b'f0\n',
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    b'd1\n',
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    b'g0\n',
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    },
    b'h0\n'
  ]

haveparents=True should emit a delta

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >         ]}]
  >     fields eval:[b'revision']
  >     haveparents eval:True
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 4,
      b'totalpaths': 4
    },
    {
      b'path': b'a',
      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',
    {
      b'path': b'dir0/d',
      b'totalitems': 1
    },
    {
      b'deltabasenode': b'S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4&',
      b'fieldsfollowing': [
        [
          b'delta',
          15
        ]
      ],
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    b'\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x03d1\n',
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    b'g0\n',
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    },
    b'h0\n'
  ]

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

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x6e\x87\x5f\xf1\x8c\x22\x76\x59\xad\x61\x43\xbb\x35\x80\xc6\x57\x00\x73\x48\x84',
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >             b'\xb9\x1c\x03\xcb\xba\x35\x19\xab\x14\x9b\x6c\xd0\xa0\xaf\xbd\xb5\xcf\x1b\x5c\x8a',
  >         ]}]
  >     fields eval:[b'revision']
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 12,
      b'totalpaths': 9
    },
    {
      b'path': b'a',
      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',
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          81
        ]
      ],
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2'
    },
    b'b0\naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\nbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\n',
    {
      b'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01'
    },
    b'c0\n',
    {
      b'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\xe4'
    },
    b'e0\n',
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4'
    },
    b'f0\n',
    {
      b'deltabasenode': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4',
      b'fieldsfollowing': [
        [
          b'delta',
          15
        ]
      ],
      b'node': b'(\xc7v\xae\x08\xd0\xd5^\xb4\x06H\xb4\x01\xb9\x0f\xf5DH4\x8e'
    },
    b'\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x03f1\n',
    {
      b'path': b'dir0/d',
      b'totalitems': 2
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4&'
    },
    b'd0\n',
    {
      b'deltabasenode': b'S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4&',
      b'fieldsfollowing': [
        [
          b'delta',
          15
        ]
      ],
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    b'\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x03d1\n',
    {
      b'path': b'dir0/i',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xd7t\xb5\x80Jq\xfd1\xe1\xae\x05\xea\x8e2\xdd\x9b\xa3\xd8S\xd7'
    },
    b'i0\n',
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    b'g0\n',
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'fieldsfollowing': [
        [
          b'revision',
          3
        ]
      ],
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    },
    b'h0\n'
  ]

Requesting linknode field works

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x6e\x87\x5f\xf1\x8c\x22\x76\x59\xad\x61\x43\xbb\x35\x80\xc6\x57\x00\x73\x48\x84',
  >             b'\x5b\x0b\x1a\x23\x57\x7e\x20\x5e\xa2\x40\xe3\x9c\x97\x04\xe2\x8d\x76\x97\xcb\xd8',
  >             b'\xb9\x1c\x03\xcb\xba\x35\x19\xab\x14\x9b\x6c\xd0\xa0\xaf\xbd\xb5\xcf\x1b\x5c\x8a',
  >         ]}]
  >     fields eval:[b'linknode']
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 12,
      b'totalpaths': 9
    },
    {
      b'path': b'a',
      b'totalitems': 2
    },
    {
      b'linknode': b'n\x87_\xf1\x8c"vY\xadaC\xbb5\x80\xc6W\x00sH\x84',
      b'node': b'd\x9d\x14\x9d\xf4=\x83\x88%#\xb7\xfb\x1ej:\xf6\xf1\x90{9'
    },
    {
      b'linknode': b'[\x0b\x1a#W~ ^\xa2@\xe3\x9c\x97\x04\xe2\x8dv\x97\xcb\xd8',
      b'node': b'\n\x862\x1f\x13y\xd1\xa9\xec\xd0W\x9a"\x97z\xf7\xa5\xac\xaf\x11'
    },
    {
      b'path': b'b',
      b'totalitems': 1
    },
    {
      b'linknode': b'n\x87_\xf1\x8c"vY\xadaC\xbb5\x80\xc6W\x00sH\x84',
      b'node': b'\x88\xbac\xb8\xd8\xc6 :\xc6z\xc9\x98\xac\xd9\x17K\xf7\x05!\xb2'
    },
    {
      b'path': b'dir0/c',
      b'totalitems': 1
    },
    {
      b'linknode': b'n\x87_\xf1\x8c"vY\xadaC\xbb5\x80\xc6W\x00sH\x84',
      b'node': b'\x91DE4j\x0c\xa0b\x9b\xd4|\xeb]\xfe\x07\xe4\xd4\xcf%\x01'
    },
    {
      b'path': b'dir0/child0/e',
      b'totalitems': 1
    },
    {
      b'linknode': b'n\x87_\xf1\x8c"vY\xadaC\xbb5\x80\xc6W\x00sH\x84',
      b'node': b'\xbb\xbal\x06\xb3\x0fD=4\xff\x84\x1b\xc9\x85\xc4\xd0\x82|k\xe4'
    },
    {
      b'path': b'dir0/child1/f',
      b'totalitems': 2
    },
    {
      b'linknode': b'n\x87_\xf1\x8c"vY\xadaC\xbb5\x80\xc6W\x00sH\x84',
      b'node': b'\x12\xfc}\xcdw;Z\n\x92\x9c\xe1\x95"\x80\x83\xc6\xdd\xc9\xce\xc4'
    },
    {
      b'linknode': b'\xb9\x1c\x03\xcb\xba5\x19\xab\x14\x9bl\xd0\xa0\xaf\xbd\xb5\xcf\x1b\\\x8a',
      b'node': b'(\xc7v\xae\x08\xd0\xd5^\xb4\x06H\xb4\x01\xb9\x0f\xf5DH4\x8e'
    },
    {
      b'path': b'dir0/d',
      b'totalitems': 2
    },
    {
      b'linknode': b'n\x87_\xf1\x8c"vY\xadaC\xbb5\x80\xc6W\x00sH\x84',
      b'node': b'S\x82\x06\xdc\x97\x1eR\x15@\xd6\x84:\xbf\xe6\xd1`2\xf6\xd4&'
    },
    {
      b'linknode': b'[\x0b\x1a#W~ ^\xa2@\xe3\x9c\x97\x04\xe2\x8dv\x97\xcb\xd8',
      b'node': b'\x93\x88)\xad\x01R}2\xba\x06_\x81#6\xfe\xc7\x9d\xdd9G'
    },
    {
      b'path': b'dir0/i',
      b'totalitems': 1
    },
    {
      b'linknode': b'\xb9\x1c\x03\xcb\xba5\x19\xab\x14\x9bl\xd0\xa0\xaf\xbd\xb5\xcf\x1b\\\x8a',
      b'node': b'\xd7t\xb5\x80Jq\xfd1\xe1\xae\x05\xea\x8e2\xdd\x9b\xa3\xd8S\xd7'
    },
    {
      b'path': b'g',
      b'totalitems': 1
    },
    {
      b'linknode': b'[\x0b\x1a#W~ ^\xa2@\xe3\x9c\x97\x04\xe2\x8dv\x97\xcb\xd8',
      b'node': b'\xde\xca\xba5DFjI\x95r\xe9\x0f\xac\xe6\xfa\x0c!k\xba\x8c'
    },
    {
      b'path': b'h',
      b'totalitems': 1
    },
    {
      b'linknode': b'[\x0b\x1a#W~ ^\xa2@\xe3\x9c\x97\x04\xe2\x8dv\x97\xcb\xd8',
      b'node': b'\x03A\xfc\x84\x1b\xb5\xb4\xba\x93\xb2mM\xdaa\xf7y6]\xb3K'
    }
  ]

Test behavior where a file node is introduced in 2 DAG heads

Request for changeset introducing filenode returns linknode as self

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\xb1\x6c\xce\x29\x67\xc1\x74\x9e\xf4\xf4\xe3\x08\x6a\x80\x6c\xfb\xad\x8a\x3a\xf7',
  >         ]}]
  >     fields eval:[b'linknode']
  >     pathfilter eval:{b'include': [b'path:dupe-file']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 1,
      b'totalpaths': 1
    },
    {
      b'path': b'dupe-file',
      b'totalitems': 1
    },
    {
      b'linknode': b'\xb1l\xce)g\xc1t\x9e\xf4\xf4\xe3\x08j\x80l\xfb\xad\x8a:\xf7',
      b'node': b'.\xd2\xa3\x91*\x0b$P C\xea\xe8N\xe4\xb2y\xc1\x8b\x90\xdd'
    }
  ]

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\xb1\x6c\xce\x29\x67\xc1\x74\x9e\xf4\xf4\xe3\x08\x6a\x80\x6c\xfb\xad\x8a\x3a\xf7',
  >         ]}]
  >     fields eval:[b'linknode']
  >     haveparents eval:True
  >     pathfilter eval:{b'include': [b'path:dupe-file']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 1,
      b'totalpaths': 1
    },
    {
      b'path': b'dupe-file',
      b'totalitems': 1
    },
    {
      b'linknode': b'\xb1l\xce)g\xc1t\x9e\xf4\xf4\xe3\x08j\x80l\xfb\xad\x8a:\xf7',
      b'node': b'.\xd2\xa3\x91*\x0b$P C\xea\xe8N\xe4\xb2y\xc1\x8b\x90\xdd'
    }
  ]

Request for changeset where recorded linknode isn't in DAG ancestry will get
rewritten accordingly

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x47\xfc\x30\x58\x09\x11\x23\x2c\xb2\x64\x67\x5b\x40\x28\x19\xde\xdd\xf6\xc6\xf0',
  >         ]}]
  >     fields eval:[b'linknode']
  >     pathfilter eval:{b'include': [b'path:dupe-file']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 1,
      b'totalpaths': 1
    },
    {
      b'path': b'dupe-file',
      b'totalitems': 1
    },
    {
      b'linknode': b'G\xfc0X\t\x11#,\xb2dg[@(\x19\xde\xdd\xf6\xc6\xf0',
      b'node': b'.\xd2\xa3\x91*\x0b$P C\xea\xe8N\xe4\xb2y\xc1\x8b\x90\xdd'
    }
  ]

  $ sendhttpv2peer << EOF
  > command filesdata
  >     revisions eval:[{
  >         b'type': b'changesetexplicit',
  >         b'nodes': [
  >             b'\x47\xfc\x30\x58\x09\x11\x23\x2c\xb2\x64\x67\x5b\x40\x28\x19\xde\xdd\xf6\xc6\xf0',
  >         ]}]
  >     fields eval:[b'linknode']
  >     haveparents eval:True
  >     pathfilter eval:{b'include': [b'path:dupe-file']}
  > EOF
  creating http peer for wire protocol version 2
  sending filesdata command
  response: gen[
    {
      b'totalitems': 1,
      b'totalpaths': 1
    },
    {
      b'path': b'dupe-file',
      b'totalitems': 1
    },
    {
      b'linknode': b'G\xfc0X\t\x11#,\xb2dg[@(\x19\xde\xdd\xf6\xc6\xf0',
      b'node': b'.\xd2\xa3\x91*\x0b$P C\xea\xe8N\xe4\xb2y\xc1\x8b\x90\xdd'
    }
  ]

  $ cat error.log