Commit ce0aad43 authored by Antoine Millet's avatar Antoine Millet

Implementation of sjRpc tunnel protocol.

parent 561c7544
from __future__ import absolute_import
import socket
from sjrpc.core.protocols import Protocol
import pyev
class TunnelProtocol(Protocol):
'''
A Tunneling protocol used to
'''
GET_SIZE = 1024 * 1024 # 1MB
DEFAULT_GET_SIZE = GET_SIZE
def __init__(self, *args, **kwargs):
endpoint = kwargs.pop('endpoint', None)
super(TunnelProtocol, self).__init__(*args, **kwargs)
if endpoint is None:
self._endpoint, self._socket = socket.socketpair()
else:
self._endpoint = endpoint
self._from_tun_to_endpoint_buf = ''
self._asked = 0 # Data asked to the peer
self._ok_to_send = 0 # Data I can send to the peer
# Set the endpoint as non-blocking socket:
self._endpoint.setblocking(False)
# Create watcher to handle data coming from the endpoint:
props = dict(fd=self._endpoint, events=pyev.EV_READ,
callback=self._handle_from_endpoint)
self._endpoint_reader = self._connection.create_watcher(pyev.Io, **props)
# Create watcher to handle data going to the endpoint:
props = dict(fd=self._endpoint, events=pyev.EV_WRITE,
callback=self._handle_from_tunnel)
self._endpoint_writer = self._connection.create_watcher(pyev.Io, **props)
# Ask some data to the peer:
self._send_get(TunnelProtocol.GET_SIZE)
def _handle_from_endpoint(self, watcher, revents):
'''
Handle data coming from the endpoint socket and push it through the
sjRpc tunnel.
'''
read = self._endpoint.recv(self._ok_to_send)
self._ok_to_send -= len(read)
self.send(read)
if not self._ok_to_send:
watcher.stop()
def _handle_from_tunnel(self, watcher, revent):
'''
Handle writing of the data already received from the tunnel and stored
into the incoming buffer. Data are writed only when the endpoint socket
is ready to write.
This method is also responsible of asking more data to the peer when
the incoming buffer is empty.
'''
sent = self._endpoint.send(self._from_tun_to_endpoint_buf)
self._from_tun_to_endpoint_buf = self._from_tun_to_endpoint_buf[sent:]
self._asked -= sent
if self._asked < TunnelProtocol.GET_SIZE * 2:
self._send_get(TunnelProtocol.GET_SIZE)
if not self._from_tun_to_endpoint_buf:
watcher.stop()
def _send_get(self, size):
self._connection.rpc.send_special('protoctl', label=self._label,
type='get', payload=dict(size=size))
self._asked += size
#
# Public methods:
#
def end_of_message(self):
'''
Handle inbound data from the :class:`RpcConnection` peer and place it
on the incoming buffer.
'''
self._from_tun_to_endpoint_buf += self._incoming_buf
self._endpoint_writer.start()
def handle_control(self, control_type, payload):
if control_type == 'get':
size = payload.get('size', TunnelProtocol.DEFAULT_GET_SIZE)
self._ok_to_send += size
self._endpoint_reader.start()
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