# 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.

# 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 batch(self):

        '''Support for local batching.'''

        return localbatch(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 (possibly proxied) methods.

    batch = it.batch()

    # The calls return futures to eventually hold results.

    foo = batch.foo(one="One", two="Two")

    foo2 = batch.foo(None)

    bar = batch.bar("Eins", "Zwei")

    # We can call non-batchable proxy methods, but the break the current batch

    # request and cause additional roundtrips.

    greet = batch.greet(name="John Smith")

    # We can also add local methods into the mix, but they break the batch too.

    hello = batch.hello()

    bar2 = batch.bar(b="Uno", a="Due")

    # Only now are all the calls executed in sequence, with as few roundtrips

    # as possible.

    batch.submit()

    # After the call to submit, the futures actually contain values.

    print foo.value

    print foo2.value

    print bar.value

    print greet.value

    print hello.value

    print bar2.value

# 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,)])

        return res.split(';')

    def batch(self):

        return remotebatch(self)

    @batchable

    def foo(self, one, two=None):

        if not one:

            yield "Nope", None

        encargs = [('one', mangle(one),), ('two', mangle(two),)]

        encresref = future()

        yield encargs, encresref

        yield unmangle(encresref.value)

    @batchable

    def bar(self, b, a):

        encresref = 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)