# test-batching.py - tests for transparent command batching

#

# Copyright 2011 Peter Arrenbrecht <peter@arrenbrecht.ch>

#

# 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)