3 from foolscap.tokens import Violation
5 class ServerFailure(exceptions.Exception):
6 # If the server returns a Failure instead of the normal response to a
7 # protocol, then this exception will be raised, with the Failure that the
8 # server returned as its .remote_failure attribute.
9 def __init__(self, remote_failure):
10 self.remote_failure = remote_failure
12 return repr(self.remote_failure)
14 return str(self.remote_failure)
17 if isinstance(f.value, ServerFailure):
22 return not is_remote(f)
24 def trap_remote(f, *errorTypes):
26 return f.value.remote_failure.trap(*errorTypes)
29 def trap_local(f, *errorTypes):
31 return f.trap(*errorTypes)
34 def _wrap_server_failure(f):
35 raise ServerFailure(f)
37 class WrappedRemoteReference(object):
38 """I intercept any errback from the server and wrap it in a
41 def __init__(self, original):
44 def callRemote(self, *args, **kwargs):
45 d = self.rref.callRemote(*args, **kwargs)
46 d.addErrback(_wrap_server_failure)
49 def callRemoteOnly(self, *args, **kwargs):
50 return self.rref.callRemoteOnly(*args, **kwargs)
52 def notifyOnDisconnect(self, *args, **kwargs):
53 return self.rref.notifyOnDisconnect(*args, **kwargs)
55 def dontNotifyOnDisconnect(self, *args, **kwargs):
56 return self.rref.dontNotifyOnDisconnect(*args, **kwargs)
58 class VersionedRemoteReference(WrappedRemoteReference):
59 """I wrap a RemoteReference, and add a .version attribute. I also
60 intercept any errback from the server and wrap it in a ServerFailure."""
62 def __init__(self, original, version):
63 WrappedRemoteReference.__init__(self, original)
64 self.version = version
66 def get_versioned_remote_reference(rref, default):
67 """I return a Deferred that fires with a VersionedRemoteReference"""
68 d = rref.callRemote("get_version")
69 def _no_get_version(f):
70 f.trap(Violation, AttributeError)
72 d.addErrback(_no_get_version)
73 def _got_version(version):
74 return VersionedRemoteReference(rref, version)
75 d.addCallback(_got_version)