tests/test-batching.py

tests: add tests of pathcopies()

I'm working on support for storing copy metadata in the changeset
instead of in the filelog. When storing it in the changeset, it will
obviously be efficient to get the copy metadata for all files in a
single changeset, but it will be more expensive to get the copy
metadata all revisions of a single file. Some algorithms will then
need to be optimized differently. The first method I'm going to
rewrite is pathcopies().

This commit adds many tests for pathcopies(), so we can run the tests
with both old and new versions of the code, as well as with metadata
stored in filelog or in changeset (later). They use the
debugpathcopies command I recently added (with no tests when it was
added). They show a few bugs and few cases of slightly weird
behavior. I'll fix the bugs in the next few commits.

Differential Revision: https://phab.mercurial-scm.org/D5986

# test-batching.py - tests for transparent command batching
#
# Copyright 2011 Peter Arrenbrecht <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import, print_function

import contextlib

from mercurial import (
    localrepo,
    pycompat,
    wireprotov1peer,
)

def bprint(*bs):
    print(*[pycompat.sysstr(b) for b in bs])

# equivalent of repo.repository
class thing(object):
    def hello(self):
        return b"Ready."

# equivalent of localrepo.localrepository
class localthing(thing):
    def foo(self, one, two=None):
        if one:
            return b"%s and %s" % (one, two,)
        return b"Nope"
    def bar(self, b, a):
        return b"%s und %s" % (b, a,)
    def greet(self, name=None):
        return b"Hello, %s" % name

    @contextlib.contextmanager
    def commandexecutor(self):
        e = localrepo.localcommandexecutor(self)
        try:
            yield e
        finally:
            e.close()

# usage of "thing" interface
def use(it):

    # Direct call to base method shared between client and server.
    bprint(it.hello())

    # Direct calls to proxied methods. They cause individual roundtrips.
    bprint(it.foo(b"Un", two=b"Deux"))
    bprint(it.bar(b"Eins", b"Zwei"))

    # Batched call to a couple of proxied methods.

    with it.commandexecutor() as e:
        ffoo = e.callcommand(b'foo', {b'one': b'One', b'two': b'Two'})
        fbar = e.callcommand(b'bar', {b'b': b'Eins', b'a': b'Zwei'})
        fbar2 = e.callcommand(b'bar', {b'b': b'Uno', b'a': b'Due'})

    bprint(ffoo.result())
    bprint(fbar.result())
    bprint(fbar2.result())

# local usage
mylocal = localthing()
print()
bprint(b"== Local")
use(mylocal)

# demo remoting; mimicks what wireproto and HTTP/SSH do

# shared

def escapearg(plain):
    return (plain
            .replace(b':', b'::')
            .replace(b',', b':,')
            .replace(b';', b':;')
            .replace(b'=', b':='))
def unescapearg(escaped):
    return (escaped
            .replace(b':=', b'=')
            .replace(b':;', b';')
            .replace(b':,', b',')
            .replace(b'::', b':'))

# server side

# equivalent of wireproto's global functions
class server(object):
    def __init__(self, local):
        self.local = local
    def _call(self, name, args):
        args = dict(arg.split(b'=', 1) for arg in args)
        return getattr(self, name)(**args)
    def perform(self, req):
        bprint(b"REQ:", req)
        name, args = req.split(b'?', 1)
        args = args.split(b'&')
        vals = dict(arg.split(b'=', 1) for arg in args)
        res = getattr(self, pycompat.sysstr(name))(**pycompat.strkwargs(vals))
        bprint(b"  ->", res)
        return res
    def batch(self, cmds):
        res = []
        for pair in cmds.split(b';'):
            name, args = pair.split(b':', 1)
            vals = {}
            for a in args.split(b','):
                if a:
                    n, v = a.split(b'=')
                    vals[n] = unescapearg(v)
            res.append(escapearg(getattr(self, pycompat.sysstr(name))(
                **pycompat.strkwargs(vals))))
        return b';'.join(res)
    def foo(self, one, two):
        return mangle(self.local.foo(unmangle(one), unmangle(two)))
    def bar(self, b, a):
        return mangle(self.local.bar(unmangle(b), unmangle(a)))
    def greet(self, name):
        return mangle(self.local.greet(unmangle(name)))
myserver = server(mylocal)

# local side

# equivalent of wireproto.encode/decodelist, that is, type-specific marshalling
# here we just transform the strings a bit to check we're properly en-/decoding
def mangle(s):
    return b''.join(pycompat.bytechr(ord(c) + 1) for c in pycompat.bytestr(s))
def unmangle(s):
    return b''.join(pycompat.bytechr(ord(c) - 1) for c in pycompat.bytestr(s))

# equivalent of wireproto.wirerepository and something like http's wire format
class remotething(thing):
    def __init__(self, server):
        self.server = server
    def _submitone(self, name, args):
        req = name + b'?' + b'&'.join([b'%s=%s' % (n, v) for n, v in args])
        return self.server.perform(req)
    def _submitbatch(self, cmds):
        req = []
        for name, args in cmds:
            args = b','.join(n + b'=' + escapearg(v) for n, v in args)
            req.append(name + b':' + args)
        req = b';'.join(req)
        res = self._submitone(b'batch', [(b'cmds', req,)])
        for r in res.split(b';'):
            yield r

    @contextlib.contextmanager
    def commandexecutor(self):
        e = wireprotov1peer.peerexecutor(self)
        try:
            yield e
        finally:
            e.close()

    @wireprotov1peer.batchable
    def foo(self, one, two=None):
        encargs = [(b'one', mangle(one),), (b'two', mangle(two),)]
        encresref = wireprotov1peer.future()
        yield encargs, encresref
        yield unmangle(encresref.value)

    @wireprotov1peer.batchable
    def bar(self, b, a):
        encresref = wireprotov1peer.future()
        yield [(b'b', mangle(b),), (b'a', mangle(a),)], encresref
        yield unmangle(encresref.value)

    # greet is coded directly. It therefore does not support batching. If it
    # does appear in a batch, the batch is split around greet, and the call to
    # greet is done in its own roundtrip.
    def greet(self, name=None):
        return unmangle(self._submitone(b'greet', [(b'name', mangle(name),)]))

# demo remote usage

myproxy = remotething(myserver)
print()
bprint(b"== Remote")
use(myproxy)