1 # -----------------------------------------------------------------------
2 # Copyright (C) 2007 Georgia Public Library Service
3 # Bill Erickson <billserickson@gmail.com>
5 # This program is free software; you can redistribute it and/or
6 # modify it under the terms of the GNU General Public License
7 # as published by the Free Software Foundation; either version 2
8 # of the License, or (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
14 # -----------------------------------------------------------------------
21 from osrf.const import OSRF_APP_SESSION_CONNECTED, \
22 OSRF_APP_SESSION_CONNECTING, OSRF_APP_SESSION_DISCONNECTED, \
23 OSRF_MESSAGE_TYPE_CONNECT, OSRF_MESSAGE_TYPE_DISCONNECT, \
24 OSRF_MESSAGE_TYPE_REQUEST
26 import random, os, time, threading
29 # -----------------------------------------------------------------------
30 # Go ahead and register the common network objects
31 # -----------------------------------------------------------------------
32 osrf.net_obj.NetworkRegisterHint('osrfMessage', ['threadTrace', 'type', 'payload'], 'hash')
33 osrf.net_obj.NetworkRegisterHint('osrfMethod', ['method', 'params'], 'hash')
34 osrf.net_obj.NetworkRegisterHint('osrfResult', ['status', 'statusCode', 'content'], 'hash')
35 osrf.net_obj.NetworkRegisterHint('osrfConnectStatus', ['status', 'statusCode'], 'hash')
36 osrf.net_obj.NetworkRegisterHint('osrfMethodException', ['status', 'statusCode'], 'hash')
39 class Session(object):
40 """Abstract session superclass."""
42 ''' Global cache of in-service sessions '''
46 # by default, we're connected to no one
47 self.state = OSRF_APP_SESSION_DISCONNECTED
50 def find_session(threadTrace):
51 return Session.session_cache.get(threadTrace)
52 find_session = staticmethod(find_session)
54 def wait(self, timeout=120):
55 """Wait up to <timeout> seconds for data to arrive on the network"""
56 osrf.log.osrfLogInternal("Session.wait(%d)" % timeout)
57 handle = osrf.net.get_network_handle()
60 def send(self, omessage):
61 """Sends an OpenSRF message"""
62 net_msg = osrf.net.NetworkMessage(
63 recipient = self.remote_id,
64 body = osrf.json.to_json([omessage]),
65 thread = self.thread )
67 handle = osrf.net.get_network_handle()
71 """Removes the session from the global session cache."""
72 del Session.session_cache[self.thread]
74 class ClientSession(Session):
75 """Client session object. Use this to make server requests."""
77 def __init__(self, service):
79 # call superclass constructor
80 Session.__init__(self)
82 # the remote service we want to make requests of
83 self.service = service
85 # find the remote service handle <router>@<domain>/<service>
86 domain = osrf.conf.get('domains.domain', 0)
87 router = osrf.conf.get('router_name')
88 self.remote_id = "%s@%s/%s" % (router, domain, service)
89 self.orig_remote_id = self.remote_id
91 # generate a random message thread
92 self.thread = "%s%s%s%s" % (os.getpid(),
93 str(random.randint(100,100000)), str(time.time()),threading.currentThread().getName().lower())
95 # how many requests this session has taken part in
98 # cache of request objects
101 # cache this session in the global session cache
102 Session.session_cache[self.thread] = self
104 def reset_request_timeout(self, rid):
105 req = self.find_request(rid)
107 req.reset_timeout = True
110 def request2(self, method, arr):
111 """Creates a new request and sends the request to the server using a python array as the params."""
112 return self.__request(method, arr)
114 def request(self, method, *args):
115 """Creates a new request and sends the request to the server using a variable argument list as params"""
117 return self.__request(method, arr)
119 def __request(self, method, arr):
120 """Builds the request object and sends it."""
121 if self.state != OSRF_APP_SESSION_CONNECTED:
122 self.reset_remote_id()
124 osrf.log.logDebug("Sending request %s -> %s " % (self.service, method))
125 req = Request(self, self.next_id, method, arr)
126 self.requests[str(self.next_id)] = req
132 def connect(self, timeout=10):
133 """Connects to a remote service"""
135 if self.state == OSRF_APP_SESSION_CONNECTED:
137 self.state == OSRF_APP_SESSION_CONNECTING
139 # construct and send a CONNECT message
141 osrf.net_obj.NetworkObject.osrfMessage(
143 'type' : OSRF_MESSAGE_TYPE_CONNECT
148 while timeout >= 0 and not self.state == OSRF_APP_SESSION_CONNECTED:
151 timeout -= time.time() - start
153 if self.state != OSRF_APP_SESSION_CONNECTED:
154 raise osrf.ex.OSRFServiceException("Unable to connect to " + self.service)
158 def disconnect(self):
159 """Disconnects from a remote service"""
161 if self.state == OSRF_APP_SESSION_DISCONNECTED:
165 osrf.net_obj.NetworkObject.osrfMessage(
167 'type' : OSRF_MESSAGE_TYPE_DISCONNECT
172 self.state = OSRF_APP_SESSION_DISCONNECTED
175 def set_remote_id(self, remoteid):
176 self.remote_id = remoteid
177 osrf.log.osrfLogInternal("Setting request remote ID to %s" % self.remote_id)
179 def reset_remote_id(self):
180 """Recovers the original remote id"""
181 self.remote_id = self.orig_remote_id
182 osrf.log.osrfLogInternal("Resetting remote ID to %s" % self.remote_id)
184 def push_response_queue(self, message):
185 """Pushes the message payload onto the response queue
186 for the request associated with the message's ID."""
187 osrf.log.logDebug("pushing %s" % message.payload())
189 self.find_request(message.threadTrace()).pushResponse(message.payload())
191 osrf.log.osrfLogWarn("pushing respond to non-existent request %s : %s" % (message.threadTrace(), e))
193 def find_request(self, rid):
194 """Returns the original request matching this message's threadTrace."""
196 return self.requests[str(rid)]
198 osrf.log.logDebug('find_request(): non-existent request %s' % str(rid))
203 class Request(object):
204 """Represents a single OpenSRF request.
205 A request is made and any resulting respones are
206 collected for the client."""
208 def __init__(self, session, rid, method=None, params=[]):
210 self.session = session # my session handle
211 self.rid = rid # my unique request ID
212 self.method = method # method name
213 self.params = params # my method params
214 self.queue = [] # response queue
215 self.reset_timeout = False # resets the recv timeout?
216 self.complete = False # has the server told us this request is done?
217 self.send_time = 0 # local time the request was put on the wire
218 self.complete_time = 0 # time the server told us the request was completed
219 self.first_response_time = 0 # time it took for our first reponse to be received
222 """Sends a request message"""
224 # construct the method object message with params and method name
225 method = osrf.net_obj.NetworkObject.osrfMethod( {
226 'method' : self.method,
227 'params' : self.params
230 # construct the osrf message with our method message embedded
231 message = osrf.net_obj.NetworkObject.osrfMessage( {
232 'threadTrace' : self.rid,
233 'type' : OSRF_MESSAGE_TYPE_REQUEST,
237 self.send_time = time.time()
238 self.session.send(message)
240 def recv(self, timeout=120):
241 """Waits up to <timeout> seconds for a response to this request.
243 If a message is received in time, the response message is returned.
244 Returns None otherwise."""
248 orig_timeout = timeout
249 while not self.complete and timeout >= 0 and len(self.queue) == 0:
251 self.session.wait(timeout)
252 timeout -= time.time() - s
253 if self.reset_timeout:
254 self.reset_timeout = False
255 timeout = orig_timeout
259 # -----------------------------------------------------------------
260 # log some statistics
261 if len(self.queue) > 0:
262 if not self.first_response_time:
263 self.first_response_time = now
264 osrf.log.logDebug("time elapsed before first response: %f" \
265 % (self.first_response_time - self.send_time))
268 if not self.complete_time:
269 self.complete_time = now
270 osrf.log.logDebug("time elapsed before complete: %f" \
271 % (self.complete_time - self.send_time))
272 # -----------------------------------------------------------------
275 if len(self.queue) > 0:
276 # we have a reponse, return it
277 return self.queue.pop(0)
281 def pushResponse(self, content):
282 """Pushes a method response onto this requests response queue."""
283 self.queue.append(content)
286 """Cleans up request data from the cache.
288 Do this when you are done with a request to prevent "leaked" cache memory."""
289 del self.session.requests[str(self.rid)]
291 def set_complete(self):
292 """Sets me as complete. This means the server has sent a 'request complete' message"""
296 class ServerSession(Session):
297 """Implements a server-side session"""
301 def AtomicRequest(service, method, *args):
302 ses = ClientSession(service)
303 req = ses.request2(method, list(args))
305 data = resp.content()