not working with memcached

[pegler]

HTTPretty causes requests to memcached to hang indefinitely when using Django.

Implementing the change here: https://github.com/nicolas-DH/HTTPretty/commit/dc622c8027a778ea4a385bf08af9ee751a189765 fixes the hanging problem, but then interaction with memcached is broken. Requests to insert keys do not succeed. I assume this is due to how _true_sendall works, but I am not sure.

Let me know how I can debug further.

[pegler]

Like I said earlier, with an unmodified version of HTTPretty, it hangs in the _true_sendall method. By modifying it to be as follows, the method returns:

        def _true_sendall(self, data, *args, **kw):
            self.truesock.connect(self._address)
            self.truesock.sendall(data, *args, **kw)
            _d = self.truesock.recv(16)
            self.fd.seek(0)
            self.fd.write(_d)
            while _d:
                if len(_d) < 16:
                    break
                _d = self.truesock.recv(16)
                self.fd.write(_d)

            self.fd.seek(0)
            self.truesock.close()

After disabling cached sessions in my django settings, I received this trace from the HTTPretty debug method when trying to access memcached while HTTPretty is enabled. memcache.py is http://pypi.python.org/pypi/python-memcached/

...
  File "/home/pegler/environments/site/local/lib/python2.7/site-packages/django/core/cache/backends/memcached.py", line 53, in add
    return self._cache.add(key, value, self._get_memcache_timeout(timeout))
  File "/home/pegler/environments/site/local/lib/python2.7/site-packages/memcache.py", line 506, in add
    return self._set("add", key, val, time, min_compress_len)
  File "/home/pegler/environments/site/local/lib/python2.7/site-packages/memcache.py", line 802, in _set
    return _unsafe_set()
  File "/home/pegler/environments/site/local/lib/python2.7/site-packages/memcache.py", line 795, in _unsafe_set
    return(server.expect("STORED") == "STORED")
  File "/home/pegler/environments/site/local/lib/python2.7/site-packages/memcache.py", line 1136, in expect
    line = self.readline()
  File "/home/pegler/environments/site/local/lib/python2.7/site-packages/memcache.py", line 1125, in readline
    data = recv(4096)
  File "/home/pegler/environments/site/src/httpretty/httpretty/__init__.py", line 319, in debug
    lines = map(utf8, traceback.format_stack(frame))

[stephenemslie]

I'm seeing the same behaviour with pymongo. In my case it's blocking on _d = self.truesock.recv(16) inside the while loop. Presumably this is down to the Mongo wire protocol not returning anything at that point, and there doesn't appear to be a timeout on the socket.

ipdb> print self.truesock.gettimeout()
None

A workaround is to set a timeout on self.truesock.

ipdb> self.truesock.settimeout(1)
ipdb> self.truesock.recv(16)
*** timeout: timed out

Or globally in your tests:

import socket
socket.setdefaulttimeout(1)