class SocketTransport(object):
"""Provides network I/O for a Proton Transport via a socket.
"""
def __init__(self, socket, name=None):
"""socket - Python socket. Expected to be configured and connected.
name - optional name for this SocketTransport
"""
self._name = name
self._socket = socket
self._transport = Transport()
self._read_done = False
self._write_done = False
self._next_tick = 0
def fileno(self):
"""Allows use of a SocketTransport by the select module.
"""
return self._socket.fileno()
@property
def transport(self):
return self._transport
@property
def socket(self):
return self._socket
@property
def name(self):
return self._name
def tick(self, now):
"""Invoke the transport's tick method. 'now' is seconds since Epoch.
Returns the timestamp for the next tick, or zero if no next tick.
"""
self._next_tick = self._transport.tick(now)
return self._next_tick
@property
def next_tick(self):
"""Timestamp for next call to tick()
"""
return self._next_tick
@property
def need_read(self):
"""True when the Transport requires data from the network layer.
"""
return (not self._read_done) and self._transport.capacity() > 0
@property
def need_write(self):
"""True when the Transport has data to write to the network layer.
"""
return (not self._write_done) and self._transport.pending() > 0
def read_input(self):
"""Read from the network layer and processes all data read. Can
support both blocking and non-blocking sockets.
"""
if self._read_done:
return None
c = self._transport.capacity()
if c < 0:
try:
self._socket.shutdown(socket.SHUT_RD)
except:
pass
self._read_done = True
return None
if c > 0:
try:
buf = self._socket.recv(c)
if buf:
self._transport.push(buf)
return len(buf)
# else socket closed
self._transport.close_tail()
self._read_done = True
return None
except socket.timeout, e:
raise # let the caller handle this
except socket.error, e:
err = e.args[0]
if err != errno.EAGAIN and err != errno.EWOULDBLOCK and err != errno.EINTR:
# otherwise, unrecoverable:
self._transport.close_tail()
self._read_done = True
raise
except: # beats me...
