view tests/dummysmtpd.py @ 40132:e67522413ca8

wireprotov2: define and use stream encoders

Now that we have basic support for defining stream encoding, it is
time to start doing something with it.

We define various classes implementing stream encoders/decoders for
the defined encoding profiles. This is relatively straightforward.

We teach the inputstream and outputstream classes how to encode,
decode, and flush data.

We then teach the clientreactor how to filter received data through
the inputstream decoder.

One of the features of the framing format is that streams can span
requests. This is a differentiating feature from say HTTP/2, which
associates streams with requests. By allowing streams to span requests,
we can reuse compression context data across requests/responses. But
in order to do this, we need a mechanism to "flush" the encoder at
logical boundaries so that receivers receive all data where it is
expected. And a "flush" event is distinct from a "finish" event from
the perspective of certain compressors because a "flush" will retain
compression context state whereas a "finish" operation will not. This
is why encoders have both a flush() and a finish() and each uses
specific flushing semantics on the underlying compressor.

The added tests verify various behavior of decoders via clientreactor.
These tests do test some compression behavior via use of outputstream.
But for all intents and purposes, server reactor support for encoding
is not yet implemented.

Differential Revision: https://phab.mercurial-scm.org/D4921

#!/usr/bin/env python

"""dummy SMTP server for use in tests"""

from __future__ import absolute_import

import asyncore
import optparse
import smtpd
import ssl
import sys
import traceback

from mercurial import (
    pycompat,
    server,
    sslutil,
    ui as uimod,
)

def log(msg):
    sys.stdout.write(msg)
    sys.stdout.flush()

class dummysmtpserver(smtpd.SMTPServer):
    def __init__(self, localaddr):
        smtpd.SMTPServer.__init__(self, localaddr, remoteaddr=None)

    def process_message(self, peer, mailfrom, rcpttos, data, **kwargs):
        log('%s from=%s to=%s\n' % (peer[0], mailfrom, ', '.join(rcpttos)))

    def handle_error(self):
        # On Windows, a bad SSL connection sometimes generates a WSAECONNRESET.
        # The default handler will shutdown this server, and then both the
        # current connection and subsequent ones fail on the client side with
        # "No connection could be made because the target machine actively
        # refused it".  If we eat the error, then the client properly aborts in
        # the expected way, and the server is available for subsequent requests.
        traceback.print_exc()

class dummysmtpsecureserver(dummysmtpserver):
    def __init__(self, localaddr, certfile):
        dummysmtpserver.__init__(self, localaddr)
        self._certfile = certfile

    def handle_accept(self):
        pair = self.accept()
        if not pair:
            return
        conn, addr = pair
        ui = uimod.ui.load()
        try:
            # wrap_socket() would block, but we don't care
            conn = sslutil.wrapserversocket(conn, ui, certfile=self._certfile)
        except ssl.SSLError:
            log('%s ssl error\n' % addr[0])
            conn.close()
            return
        smtpd.SMTPChannel(self, conn, addr)

def run():
    try:
        asyncore.loop()
    except KeyboardInterrupt:
        pass

def _encodestrsonly(v):
    if isinstance(v, type(u'')):
        return v.encode('ascii')
    return v

def bytesvars(obj):
    unidict = vars(obj)
    bd = {k.encode('ascii'): _encodestrsonly(v) for k, v in unidict.items()}
    if bd[b'daemon_postexec'] is not None:
        bd[b'daemon_postexec'] = [
            _encodestrsonly(v) for v in bd[b'daemon_postexec']]
    return bd

def main():
    op = optparse.OptionParser()
    op.add_option('-d', '--daemon', action='store_true')
    op.add_option('--daemon-postexec', action='append')
    op.add_option('-p', '--port', type=int, default=8025)
    op.add_option('-a', '--address', default='localhost')
    op.add_option('--pid-file', metavar='FILE')
    op.add_option('--tls', choices=['none', 'smtps'], default='none')
    op.add_option('--certificate', metavar='FILE')

    opts, args = op.parse_args()
    if opts.tls == 'smtps' and not opts.certificate:
        op.error('--certificate must be specified')

    addr = (opts.address, opts.port)
    def init():
        if opts.tls == 'none':
            dummysmtpserver(addr)
        else:
            dummysmtpsecureserver(addr, opts.certificate)
        log('listening at %s:%d\n' % addr)

    server.runservice(
        bytesvars(opts), initfn=init, runfn=run,
        runargs=[pycompat.sysexecutable,
                 pycompat.fsencode(__file__)] + pycompat.sysargv[1:])

if __name__ == '__main__':
    main()