contrib/catapipe.py

typing: make the localrepo classes known to pytype

9d4ad05bc91c and 1b17309cdaab both mentioned making `bundlerepository` and
`unionrepository` subclass `localrepository` during the type checking phase, but
that didn't apply to pytype in practice.  See bcaa5d408657 and friends for how
the zope interfaces confuse pytype, and end up converting the classes they
decorate into `Any`.

This commit is slightly more complex though, because `localrepository` has mixin
classes applied to it when it is instantiated.  Specifically, `RevlogFileStorage`
is added, which adds `def file(f)` (which isn't defined on `localrepository`).
Therefore a list of `localrepository` superclasses is provided during type
checking to account for the mixins.  Without this, the `bundlerepository` class
gets flagged when it attempts to call its superclass implementation of `file()`.
Note that pytype doesn't understand these mixin superclasses (it marks the
superclass of `localrepository` as `Any`, because they are zope interfaces it
doesn't understand), but that's enough to get it to not flag `bundlerepository`.
PyCharm also stops flagging it as a missing function, though it seems like it is
able to handle the zope interfaces.

#!/usr/bin/env python3
#
# Copyright 2018 Google LLC.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Tool read primitive events from a pipe to produce a catapult trace.

Usage:
    Terminal 1: $ catapipe.py /tmp/mypipe /tmp/trace.json
    Terminal 2: $ HGCATAPULTSERVERPIPE=/tmp/mypipe hg root
    <ctrl-c catapipe.py in Terminal 1>
    $ catapult/tracing/bin/trace2html /tmp/trace.json  # produce /tmp/trace.html
    <open trace.html in your browser of choice; the WASD keys are very useful>
    (catapult is located at https://github.com/catapult-project/catapult)

For now the event stream supports

  START $SESSIONID ...

and

  END $SESSIONID ...

events. Everything after the SESSIONID (which must not contain spaces)
is used as a label for the event. Events are timestamped as of when
they arrive in this process and are then used to produce catapult
traces that can be loaded in Chrome's about:tracing utility. It's
important that the event stream *into* this process stay simple,
because we have to emit it from the shell scripts produced by
run-tests.py.

Typically you'll want to place the path to the named pipe in the
HGCATAPULTSERVERPIPE environment variable, which both run-tests and hg
understand. To trace *only* run-tests, use HGTESTCATAPULTSERVERPIPE instead.
"""

import argparse
import json
import os
import timeit

_TYPEMAP = {
    'START': 'B',
    'END': 'E',
    'COUNTER': 'C',
}

_threadmap = {}

# Timeit already contains the whole logic about which timer to use based on
# Python version and OS
timer = timeit.default_timer


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'pipe',
        type=str,
        nargs=1,
        help='Path of named pipe to create and listen on.',
    )
    parser.add_argument(
        'output',
        default='trace.json',
        type=str,
        nargs='?',
        help='Path of json file to create where the traces ' 'will be stored.',
    )
    parser.add_argument(
        '--debug',
        default=False,
        action='store_true',
        help='Print useful debug messages',
    )
    args = parser.parse_args()
    fn = args.pipe[0]
    os.mkfifo(fn)
    try:
        with open(fn) as f, open(args.output, 'w') as out:
            out.write('[\n')
            start = timer()
            while True:
                ev = f.readline().strip()
                if not ev:
                    continue
                now = timer()
                if args.debug:
                    print(ev)
                verb, session, label = ev.split(' ', 2)
                if session not in _threadmap:
                    _threadmap[session] = len(_threadmap)
                if verb == 'COUNTER':
                    amount, label = label.split(' ', 1)
                    payload_args = {'value': int(amount)}
                else:
                    payload_args = {}
                pid = _threadmap[session]
                ts_micros = (now - start) * 1000000
                out.write(
                    json.dumps(
                        {
                            "name": label,
                            "cat": "misc",
                            "ph": _TYPEMAP[verb],
                            "ts": ts_micros,
                            "pid": pid,
                            "tid": 1,
                            "args": payload_args,
                        }
                    )
                )
                out.write(',\n')
    finally:
        os.unlink(fn)


if __name__ == '__main__':
    main()