561 lines
18 KiB
Python
561 lines
18 KiB
Python
"""RPC Implemention, originally written for the Python Idle IDE
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For security reasons, GvR requested that Idle's Python execution server process
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connect to the Idle process, which listens for the connection. Since Idle has
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has only one client per server, this was not a limitation.
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+---------------------------------+ +-------------+
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| SocketServer.BaseRequestHandler | | SocketIO |
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+---------------------------------+ +-------------+
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^ | register() |
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| | unregister()|
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| +-------------+
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| ^ ^
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| | |
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| + -------------------+ |
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| | |
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+-------------------------+ +-----------------+
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| RPCHandler | | RPCClient |
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| [attribute of RPCServer]| | |
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+-------------------------+ +-----------------+
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The RPCServer handler class is expected to provide register/unregister methods.
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RPCHandler inherits the mix-in class SocketIO, which provides these methods.
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See the Idle run.main() docstring for further information on how this was
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accomplished in Idle.
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"""
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import sys
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import socket
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import select
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import SocketServer
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import struct
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import cPickle as pickle
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import threading
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import traceback
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import copy_reg
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import types
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import marshal
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def unpickle_code(ms):
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co = marshal.loads(ms)
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assert isinstance(co, types.CodeType)
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return co
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def pickle_code(co):
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assert isinstance(co, types.CodeType)
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ms = marshal.dumps(co)
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return unpickle_code, (ms,)
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# XXX KBK 24Aug02 function pickling capability not used in Idle
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# def unpickle_function(ms):
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# return ms
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# def pickle_function(fn):
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# assert isinstance(fn, type.FunctionType)
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# return `fn`
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copy_reg.pickle(types.CodeType, pickle_code, unpickle_code)
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# copy_reg.pickle(types.FunctionType, pickle_function, unpickle_function)
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BUFSIZE = 8*1024
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class RPCServer(SocketServer.TCPServer):
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def __init__(self, addr, handlerclass=None):
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if handlerclass is None:
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handlerclass = RPCHandler
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SocketServer.TCPServer.__init__(self, addr, handlerclass)
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def server_bind(self):
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"Override TCPServer method, no bind() phase for connecting entity"
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pass
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def server_activate(self):
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"""Override TCPServer method, connect() instead of listen()
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Due to the reversed connection, self.server_address is actually the
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address of the Idle Client to which we are connecting.
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"""
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self.socket.connect(self.server_address)
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def get_request(self):
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"Override TCPServer method, return already connected socket"
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return self.socket, self.server_address
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def handle_error(self, request, client_address):
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"""Override TCPServer method, no error message if exiting"""
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try:
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raise
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except SystemExit:
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raise
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else:
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TCPServer.handle_error(request, client_address)
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objecttable = {}
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class SocketIO:
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nextseq = 0
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def __init__(self, sock, objtable=None, debugging=None):
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self.mainthread = threading.currentThread()
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if debugging is not None:
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self.debugging = debugging
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self.sock = sock
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if objtable is None:
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objtable = objecttable
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self.objtable = objtable
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self.cvar = threading.Condition()
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self.responses = {}
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self.cvars = {}
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self.interrupted = False
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def close(self):
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sock = self.sock
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self.sock = None
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if sock is not None:
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sock.close()
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def debug(self, *args):
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if not self.debugging:
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return
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s = self.location + " " + str(threading.currentThread().getName())
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for a in args:
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s = s + " " + str(a)
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print>>sys.__stderr__, s
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def register(self, oid, object):
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self.objtable[oid] = object
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def unregister(self, oid):
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try:
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del self.objtable[oid]
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except KeyError:
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pass
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def localcall(self, request):
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self.debug("localcall:", request)
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try:
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how, (oid, methodname, args, kwargs) = request
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except TypeError:
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return ("ERROR", "Bad request format")
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assert how == "call"
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if not self.objtable.has_key(oid):
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return ("ERROR", "Unknown object id: %s" % `oid`)
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obj = self.objtable[oid]
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if methodname == "__methods__":
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methods = {}
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_getmethods(obj, methods)
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return ("OK", methods)
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if methodname == "__attributes__":
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attributes = {}
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_getattributes(obj, attributes)
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return ("OK", attributes)
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if not hasattr(obj, methodname):
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return ("ERROR", "Unsupported method name: %s" % `methodname`)
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method = getattr(obj, methodname)
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try:
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ret = method(*args, **kwargs)
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if isinstance(ret, RemoteObject):
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ret = remoteref(ret)
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return ("OK", ret)
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except SystemExit:
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raise
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except:
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self.debug("localcall:EXCEPTION")
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traceback.print_exc(file=sys.__stderr__)
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return ("EXCEPTION", None)
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def remotecall(self, oid, methodname, args, kwargs):
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self.debug("remotecall:asynccall: ", oid, methodname)
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# XXX KBK 06Feb03 self.interrupted logic may not be necessary if
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# subprocess is threaded.
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if self.interrupted:
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self.interrupted = False
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raise KeyboardInterrupt
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seq = self.asynccall(oid, methodname, args, kwargs)
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return self.asyncreturn(seq)
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def asynccall(self, oid, methodname, args, kwargs):
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request = ("call", (oid, methodname, args, kwargs))
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seq = self.newseq()
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self.debug(("asynccall:%d:" % seq), oid, methodname, args, kwargs)
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self.putmessage((seq, request))
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return seq
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def asyncreturn(self, seq):
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self.debug("asyncreturn:%d:call getresponse(): " % seq)
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response = self.getresponse(seq)
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self.debug(("asyncreturn:%d:response: " % seq), response)
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return self.decoderesponse(response)
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def decoderesponse(self, response):
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how, what = response
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if how == "OK":
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return what
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if how == "EXCEPTION":
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self.debug("decoderesponse: EXCEPTION")
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return None
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if how == "ERROR":
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self.debug("decoderesponse: Internal ERROR:", what)
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raise RuntimeError, what
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raise SystemError, (how, what)
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def mainloop(self):
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"""Listen on socket until I/O not ready or EOF
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pollpacket() will loop looking for seq number None, which never
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comes. The loop will exit when self.ioready() returns 0.
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"""
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try:
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self.getresponse(None)
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except EOFError:
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pass
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def getresponse(self, myseq):
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response = self._getresponse(myseq)
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if response is not None:
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how, what = response
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if how == "OK":
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response = how, self._proxify(what)
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return response
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def _proxify(self, obj):
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if isinstance(obj, RemoteProxy):
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return RPCProxy(self, obj.oid)
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if isinstance(obj, types.ListType):
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return map(self._proxify, obj)
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# XXX Check for other types -- not currently needed
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return obj
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def _getresponse(self, myseq):
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self.debug("_getresponse:myseq:", myseq)
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if threading.currentThread() is self.mainthread:
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# Main thread: does all reading of requests or responses
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# Loop here until there is message traffic on the socket
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while 1:
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response = self.pollresponse(myseq, None)
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if response is not None:
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return response
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else:
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# Auxiliary thread: wait for notification from main thread
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self.cvar.acquire()
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self.cvars[myseq] = self.cvar
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while not self.responses.has_key(myseq):
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self.cvar.wait()
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response = self.responses[myseq]
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del self.responses[myseq]
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del self.cvars[myseq]
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self.cvar.release()
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return response
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def newseq(self):
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self.nextseq = seq = self.nextseq + 2
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return seq
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def putmessage(self, message):
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self.debug("putmessage:%d:" % message[0])
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try:
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s = pickle.dumps(message)
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except:
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print >>sys.__stderr__, "Cannot pickle:", `message`
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raise
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s = struct.pack("<i", len(s)) + s
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while len(s) > 0:
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try:
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n = self.sock.send(s)
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except AttributeError:
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# socket was closed
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raise IOError
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else:
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s = s[n:]
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def ioready(self, wait=0.0):
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r, w, x = select.select([self.sock.fileno()], [], [], wait)
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return len(r)
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buffer = ""
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bufneed = 4
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bufstate = 0 # meaning: 0 => reading count; 1 => reading data
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def pollpacket(self, wait=0.0):
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self._stage0()
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if len(self.buffer) < self.bufneed:
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if not self.ioready(wait):
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return None
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try:
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s = self.sock.recv(BUFSIZE)
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except socket.error:
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raise EOFError
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if len(s) == 0:
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raise EOFError
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self.buffer += s
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self._stage0()
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return self._stage1()
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def _stage0(self):
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if self.bufstate == 0 and len(self.buffer) >= 4:
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s = self.buffer[:4]
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self.buffer = self.buffer[4:]
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self.bufneed = struct.unpack("<i", s)[0]
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self.bufstate = 1
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def _stage1(self):
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if self.bufstate == 1 and len(self.buffer) >= self.bufneed:
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packet = self.buffer[:self.bufneed]
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self.buffer = self.buffer[self.bufneed:]
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self.bufneed = 4
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self.bufstate = 0
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return packet
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def pollmessage(self, wait=0.0):
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packet = self.pollpacket(wait)
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if packet is None:
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return None
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try:
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message = pickle.loads(packet)
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except:
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print >>sys.__stderr__, "-----------------------"
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print >>sys.__stderr__, "cannot unpickle packet:", `packet`
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traceback.print_stack(file=sys.__stderr__)
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print >>sys.__stderr__, "-----------------------"
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raise
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return message
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def pollresponse(self, myseq, wait=0.0):
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"""Handle messages received on the socket.
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Some messages received may be asynchronous 'call' commands, and
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some may be responses intended for other threads.
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Loop until message with myseq sequence number is received. Save others
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in self.responses and notify the owning thread, except that 'call'
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commands are handed off to localcall() and the response sent back
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across the link with the appropriate sequence number.
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"""
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while 1:
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message = self.pollmessage(wait)
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if message is None: # socket not ready
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return None
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wait = 0.0
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seq, resq = message
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self.debug("pollresponse:%d:myseq:%s" % (seq, myseq))
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if resq[0] == "call":
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self.debug("pollresponse:%d:localcall:call:" % seq)
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response = self.localcall(resq)
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self.debug("pollresponse:%d:localcall:response:%s"
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% (seq, response))
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self.putmessage((seq, response))
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continue
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elif seq == myseq:
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return resq
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else:
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self.cvar.acquire()
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cv = self.cvars.get(seq)
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# response involving unknown sequence number is discarded,
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# probably intended for prior incarnation
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if cv is not None:
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self.responses[seq] = resq
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cv.notify()
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self.cvar.release()
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continue
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#----------------- end class SocketIO --------------------
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class RemoteObject:
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# Token mix-in class
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pass
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def remoteref(obj):
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oid = id(obj)
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objecttable[oid] = obj
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return RemoteProxy(oid)
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class RemoteProxy:
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def __init__(self, oid):
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self.oid = oid
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class RPCHandler(SocketServer.BaseRequestHandler, SocketIO):
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debugging = False
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location = "#S" # Server
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def __init__(self, sock, addr, svr):
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svr.current_handler = self ## cgt xxx
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SocketIO.__init__(self, sock)
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SocketServer.BaseRequestHandler.__init__(self, sock, addr, svr)
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def handle(self):
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"handle() method required by SocketServer"
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self.mainloop()
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def get_remote_proxy(self, oid):
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return RPCProxy(self, oid)
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class RPCClient(SocketIO):
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debugging = False
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location = "#C" # Client
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nextseq = 1 # Requests coming from the client are odd numbered
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def __init__(self, address, family=socket.AF_INET, type=socket.SOCK_STREAM):
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self.listening_sock = socket.socket(family, type)
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self.listening_sock.setsockopt(socket.SOL_SOCKET,
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socket.SO_REUSEADDR, 1)
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self.listening_sock.bind(address)
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self.listening_sock.listen(1)
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def accept(self):
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working_sock, address = self.listening_sock.accept()
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if self.debugging:
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print>>sys.__stderr__, "****** Connection request from ", address
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if address[0] == '127.0.0.1':
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SocketIO.__init__(self, working_sock)
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else:
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print>>sys.__stderr__, "** Invalid host: ", address
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raise socket.error
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def get_remote_proxy(self, oid):
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return RPCProxy(self, oid)
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class RPCProxy:
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__methods = None
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__attributes = None
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def __init__(self, sockio, oid):
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self.sockio = sockio
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self.oid = oid
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def __getattr__(self, name):
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if self.__methods is None:
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self.__getmethods()
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if self.__methods.get(name):
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return MethodProxy(self.sockio, self.oid, name)
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if self.__attributes is None:
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self.__getattributes()
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if not self.__attributes.has_key(name):
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raise AttributeError, name
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__getattr__.DebuggerStepThrough=1
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def __getattributes(self):
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self.__attributes = self.sockio.remotecall(self.oid,
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"__attributes__", (), {})
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def __getmethods(self):
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self.__methods = self.sockio.remotecall(self.oid,
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"__methods__", (), {})
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def _getmethods(obj, methods):
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# Helper to get a list of methods from an object
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# Adds names to dictionary argument 'methods'
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for name in dir(obj):
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attr = getattr(obj, name)
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if callable(attr):
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methods[name] = 1
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if type(obj) == types.InstanceType:
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_getmethods(obj.__class__, methods)
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if type(obj) == types.ClassType:
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for super in obj.__bases__:
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_getmethods(super, methods)
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def _getattributes(obj, attributes):
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for name in dir(obj):
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attr = getattr(obj, name)
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if not callable(attr):
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attributes[name] = 1
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class MethodProxy:
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def __init__(self, sockio, oid, name):
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self.sockio = sockio
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self.oid = oid
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self.name = name
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def __call__(self, *args, **kwargs):
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value = self.sockio.remotecall(self.oid, self.name, args, kwargs)
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return value
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#
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# Self Test
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#
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def testServer(addr):
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# XXX 25 Jul 02 KBK needs update to use rpc.py register/unregister methods
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class RemotePerson:
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def __init__(self,name):
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self.name = name
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def greet(self, name):
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print "(someone called greet)"
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print "Hello %s, I am %s." % (name, self.name)
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print
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def getName(self):
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print "(someone called getName)"
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print
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return self.name
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def greet_this_guy(self, name):
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print "(someone called greet_this_guy)"
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print "About to greet %s ..." % name
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remote_guy = self.server.current_handler.get_remote_proxy(name)
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remote_guy.greet("Thomas Edison")
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print "Done."
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print
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person = RemotePerson("Thomas Edison")
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svr = RPCServer(addr)
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svr.register('thomas', person)
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person.server = svr # only required if callbacks are used
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# svr.serve_forever()
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svr.handle_request() # process once only
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def testClient(addr):
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"demonstrates RPC Client"
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# XXX 25 Jul 02 KBK needs update to use rpc.py register/unregister methods
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import time
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clt=RPCClient(addr)
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thomas = clt.get_remote_proxy("thomas")
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print "The remote person's name is ..."
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print thomas.getName()
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# print clt.remotecall("thomas", "getName", (), {})
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print
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time.sleep(1)
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print "Getting remote thomas to say hi..."
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thomas.greet("Alexander Bell")
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#clt.remotecall("thomas","greet",("Alexander Bell",), {})
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print "Done."
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print
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time.sleep(2)
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# demonstrates remote server calling local instance
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class LocalPerson:
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def __init__(self,name):
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self.name = name
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def greet(self, name):
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print "You've greeted me!"
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def getName(self):
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return self.name
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person = LocalPerson("Alexander Bell")
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clt.register("alexander",person)
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thomas.greet_this_guy("alexander")
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# clt.remotecall("thomas","greet_this_guy",("alexander",), {})
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def test():
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addr=("localhost",8833)
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if len(sys.argv) == 2:
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if sys.argv[1]=='-server':
|
|
testServer(addr)
|
|
return
|
|
testClient(addr)
|
|
|
|
if __name__ == '__main__':
|
|
test()
|