def sendData(sock, data):
"""
Send some data over a socket.
Some systems have problems with ``sendall()`` when the socket is in non-blocking mode.
For instance, Mac OS X seems to be happy to throw EAGAIN errors too often.
This function falls back to using a regular send loop if needed.
"""
if sock.gettimeout() is None:
# socket is in blocking mode, we can use sendall normally.
try:
sock.sendall(data)
return
except socket.timeout:
raise TimeoutError("sending: timeout")
except socket.error as x:
raise ConnectionClosedError("sending: connection lost: " + str(x))
else:
# Socket is in non-blocking mode, use regular send loop.
retrydelay = 0.0
while data:
try:
sent = sock.send(data)
data = data[sent:]
except socket.timeout:
raise TimeoutError("sending: timeout")
except socket.error as x:
err = getattr(x, "errno", x.args[0])
if err not in ERRNO_RETRIES:
raise ConnectionClosedError("sending: connection lost: " +
str(x))
time.sleep(
0.00001 +
retrydelay) # a slight delay to wait before retrying
retrydelay = __nextRetrydelay(retrydelay)
def receiveData(sock, size):
"""Retrieve a given number of bytes from a socket.
It is expected the socket is able to supply that number of bytes.
If it isn't, an exception is raised (you will not get a zero length result
or a result that is smaller than what you asked for). The partial data that
has been received however is stored in the 'partialData' attribute of
the exception object."""
try:
retrydelay = 0.0
msglen = 0
chunks = []
if config.USE_MSG_WAITALL and not hasattr(sock, "getpeercert"):
# waitall is very convenient and if a socket error occurs,
# we can assume the receive has failed. No need for a loop,
# unless it is a retryable error.
# Some systems have an erratic MSG_WAITALL and sometimes still return
# less bytes than asked. In that case, we drop down into the normal
# receive loop to finish the task.
# Also note that on SSL sockets, you cannot use MSG_WAITALL (or any other flag)
while True:
try:
data = sock.recv(size, socket.MSG_WAITALL)
if len(data) == size:
return data
# less data than asked, drop down into normal receive loop to finish
msglen = len(data)
chunks = [data]
break
except socket.timeout:
raise TimeoutError("receiving: timeout")
except socket.error as x:
err = getattr(x, "errno", x.args[0])
if err not in ERRNO_RETRIES:
raise ConnectionClosedError(
"receiving: connection lost: " + str(x))
time.sleep(
0.00001 +
retrydelay) # a slight delay to wait before retrying
retrydelay = __nextRetrydelay(retrydelay)
# old fashioned recv loop, we gather chunks until the message is complete
while True:
try:
while msglen < size:
# 60k buffer limit avoids problems on certain OSes like VMS, Windows
chunk = sock.recv(min(60000, size - msglen))
if not chunk:
break
chunks.append(chunk)
msglen += len(chunk)
data = b"".join(chunks)
del chunks
if len(data) != size:
err = ConnectionClosedError("receiving: not enough data")
err.partialData = data # store the message that was received until now
raise err
return data # yay, complete
except socket.timeout:
raise TimeoutError("receiving: timeout")
except socket.error:
x = sys.exc_info()[1]
err = getattr(x, "errno", x.args[0])
if err not in ERRNO_RETRIES:
raise ConnectionClosedError(
"receiving: connection lost: " + str(x))
time.sleep(
0.00001 +
retrydelay) # a slight delay to wait before retrying
retrydelay = __nextRetrydelay(retrydelay)
except socket.timeout:
raise TimeoutError("receiving: timeout")
