view tests/test-batching.py @ 34682:7e3001b74ab3

tersestatus: re-implement the functionality to terse the status

The previous terse status implementation was hacking around os.listdir() and was
flaky. There have been a lot of instances of mercurial buildbots failing
and google's internal builds failing because of the
hacky implementation of terse status. Even though I wrote the last
implementation but it was hard for me to find the reason for the flake.

The new implementation can be slower than the old one but is clean and easy to
understand.

In this we create a node object for each directory and create a tree
like structure starting from the root of the working copy. While building the
tree like structure we store some information on the nodes which will be helpful
for deciding later whether we can terse the dir or not.
Once the whole tree is build we traverse and built the list of files for each
status with required tersing.

There is no behaviour change as the old test, test-status-terse.t passes with
the new implementation.

Differential Revision: https://phab.mercurial-scm.org/D985

# 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

from mercurial import (
    error,
    peer,
    util,
    wireproto,
)

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

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

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

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

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

    # Batched call to a couple of proxied methods.
    batch = it.batchiter()
    # The calls return futures to eventually hold results.
    foo = batch.foo(one="One", two="Two")
    bar = batch.bar("Eins", "Zwei")
    bar2 = batch.bar(b="Uno", a="Due")

    # Future shouldn't be set until we submit().
    assert isinstance(foo, peer.future)
    assert not util.safehasattr(foo, 'value')
    assert not util.safehasattr(bar, 'value')
    batch.submit()
    # Call results() to obtain results as a generator.
    results = batch.results()

    # Future results shouldn't be set until we consume a value.
    assert not util.safehasattr(foo, 'value')
    foovalue = next(results)
    assert util.safehasattr(foo, 'value')
    assert foovalue == foo.value
    print(foo.value)
    next(results)
    print(bar.value)
    next(results)
    print(bar2.value)

    # We should be at the end of the results generator.
    try:
        next(results)
    except StopIteration:
        print('proper end of results generator')
    else:
        print('extra emitted element!')

    # Attempting to call a non-batchable method inside a batch fails.
    batch = it.batchiter()
    try:
        batch.greet(name='John Smith')
    except error.ProgrammingError as e:
        print(e)

    # Attempting to call a local method inside a batch fails.
    batch = it.batchiter()
    try:
        batch.hello()
    except error.ProgrammingError as e:
        print(e)

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

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

# shared

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

# 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('=', 1) for arg in args)
        return getattr(self, name)(**args)
    def perform(self, req):
        print("REQ:", req)
        name, args = req.split('?', 1)
        args = args.split('&')
        vals = dict(arg.split('=', 1) for arg in args)
        res = getattr(self, name)(**vals)
        print("  ->", res)
        return res
    def batch(self, cmds):
        res = []
        for pair in cmds.split(';'):
            name, args = pair.split(':', 1)
            vals = {}
            for a in args.split(','):
                if a:
                    n, v = a.split('=')
                    vals[n] = unescapearg(v)
            res.append(escapearg(getattr(self, name)(**vals)))
        return ';'.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 ''.join(chr(ord(c) + 1) for c in s)
def unmangle(s):
    return ''.join(chr(ord(c) - 1) for c in 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 + '?' + '&'.join(['%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 = ','.join(n + '=' + escapearg(v) for n, v in args)
            req.append(name + ':' + args)
        req = ';'.join(req)
        res = self._submitone('batch', [('cmds', req,)])
        for r in res.split(';'):
            yield r

    def batchiter(self):
        return wireproto.remoteiterbatcher(self)

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

    @peer.batchable
    def bar(self, b, a):
        encresref = peer.future()
        yield [('b', mangle(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('greet', [('name', mangle(name),)]))

# demo remote usage

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