python: Implement virStreamSend/Recv

The return values for the python version are different that the C version
of virStreamSend: on success we return a string, an error raises an exception,
and if the stream would block we return int(-2). We need to do this
since strings aren't passed by reference in python.

python/libvirt-override-virStream.py

@@ -24,3 +24,38 @@
         cbData = {"stream": self, "cb" : cb, "opaque" : opaque}
         ret = libvirtmod.virStreamEventAddCallback(self._o, events, cbData)
         if ret == -1: raise libvirtError ('virStreamEventAddCallback() failed')
+
+    def recv(self, nbytes):
+        """Write a series of bytes to the stream. This method may
+        block the calling application for an arbitrary amount
+        of time.
+
+        Errors are not guaranteed to be reported synchronously
+        with the call, but may instead be delayed until a
+        subsequent call.
+
+        On success, the received data is returned. On failure, an
+        exception is raised. If the stream is a NONBLOCK stream and
+        the request would block, integer -2 is returned.
+        """
+        ret = libvirtmod.virStreamRecv(self._o, nbytes)
+        if ret == None: raise libvirtError ('virStreamRecv() failed')
+        return ret
+
+    def send(self, data):
+        """Write a series of bytes to the stream. This method may
+        block the calling application for an arbitrary amount
+        of time. Once an application has finished sending data
+        it should call virStreamFinish to wait for successful
+        confirmation from the driver, or detect any error
+
+        This method may not be used if a stream source has been
+        registered
+
+        Errors are not guaranteed to be reported synchronously
+        with the call, but may instead be delayed until a
+        subsequent call.
+        """
+        ret = libvirtmod.virStreamSend(self._o, data, len(data))
+        if ret == -1: raise libvirtError ('virStreamSend() failed')
+        return ret