stratum.py

   1 import json
   2 import socket
   3 import threading
   4 import time
   5 import Queue as queue
   6
   7 class Processor(threading.Thread):
   8
   9     def __init__(self):
  10         self.shared = None
  11         self.lock = threading.Lock()
  12         self.sessions = []
  13         threading.Thread.__init__(self)
  14         self.daemon = True
  15
  16     def add_session(self, session):
  17         with self.lock:
  18             self.sessions.append(session)
  19
  20     def run(self):
  21         if self.shared is None:
  22             raise TypeError("self.shared not set in Processor")
  23         while not self.shared.stopped():
  24             # Deep copy entire sessions list and blank it
  25             # This is done to minimise lock contention
  26             with self.lock:
  27                 sessions = self.sessions[:]
  28                 self.sessions = []
  29             for session in sessions:
  30                 if not session.stopped():
  31                     # If session is still alive then re-add it back
  32                     # to our internal register
  33                     self.add_session(session)
  34                     self.process(session)
  35
  36     def process(self, session):
  37         request = session.pop_request()
  38         print "New request", request
  39         # Execute and when ready, you call
  40         # session.push_response(response)
  41
  42 class Session:
  43
  44     def __init__(self, connection, address):
  45         self._connection = connection
  46         self.address = address
  47         self._stopped = False
  48         self.lock = threading.Lock()
  49
  50         self.request_queue = queue.Queue()
  51         self.response_queue = queue.Queue()
  52
  53     def stop(self):
  54         self._connection.close()
  55         print "Terminating connection:", self.address[0]
  56         with self.lock:
  57             self._stopped = True
  58
  59     def stopped(self):
  60         with self.lock:
  61             return self._stopped
  62
  63     def connection(self):
  64         if self.stopped():
  65             raise Exception("Session was stopped")
  66         else:
  67             return self._connection
  68
  69     def push_request(self, item):
  70         self.request_queue.put(item)
  71
  72     def pop_request(self):
  73         return self.request_queue.get()
  74
  75     def push_response(self):
  76         self.response_queue.put(item)
  77
  78     def pop_response(self):
  79         return self.response_queue.get()
  80
  81 class TcpClientResponder(threading.Thread):
  82
  83     def __init__(self, shared, session):
  84         self.shared = shared
  85         self.session = session
  86         threading.Thread.__init__(self)
  87
  88     def run(self):
  89         while not self.shared.stopped() or self.session.stopped():
  90             response = self.session.pop_response()
  91             # Possible race condition here by having session
  92             # close connection?
  93             # I assume Python connections are thread safe interfaces
  94             connection = self.session.connection()
  95             try:
  96                 connection.send(response + "\n")
  97             except:
  98                 self.session.stop()
  99
 100 class TcpClientRequestor(threading.Thread):
 101
 102     def __init__(self, shared, session):
 103         self.shared = shared
 104         self.message = ""
 105         self.session = session
 106         threading.Thread.__init__(self)
 107
 108     def run(self):
 109         while not self.shared.stopped():
 110             if not self.update():
 111                 self.session.stop()
 112                 return
 113
 114     def update(self):
 115         data = self.receive()
 116         if data is None:
 117             # close_session
 118             self.stop()
 119             return False
 120
 121         self.message += data
 122         if not self.parse():
 123             return False
 124         return True
 125
 126     def receive(self):
 127         try:
 128             return self.session.connection().recv(1024)
 129         except socket.error:
 130             return None
 131
 132     def parse(self):
 133         while True:
 134             raw_buffer = self.message.find('\n')
 135             if raw_buffer == -1:
 136                 return True
 137
 138             command = self.message[0:raw_buffer].strip()
 139             self.message = self.message[raw_buffer + 1:]
 140             if command == 'quit':
 141                 return False
 142
 143             try:
 144                 command = json.loads(command)
 145             except:
 146                 print "json error", repr(command)
 147                 continue
 148
 149             try:
 150                 message_id = command.get('id')
 151                 method = command.get('method')
 152                 params = command.get('params')
 153             except:
 154                 print "syntax error", repr(command), self.session.address[0]
 155                 continue
 156
 157             self.session.push_request((message_id, method, params))
 158             print message_id, method, params
 159
 160 class TcpServer(threading.Thread):
 161
 162     def __init__(self, shared, processor):
 163         self.shared = shared
 164         self.processor = processor
 165         self.clients = []
 166         threading.Thread.__init__(self)
 167         self.daemon = True
 168
 169     def run(self):
 170         print "TCP server started."
 171         sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 172         sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 173         sock.bind(("localhost", 50001))
 174         sock.listen(1)
 175         while not self.shared.stopped():
 176             session = Session(*sock.accept())
 177             client_req = TcpClientRequestor(self.shared, session)
 178             client_req.start()
 179             client_res = TcpClientResponder(self.shared, session)
 180             client_res.start()
 181             self.processor.add_session(session)
 182
 183 class Shared:
 184
 185     def __init__(self):
 186         self.lock = threading.Lock()
 187         self._stopped = False
 188
 189     def stop(self):
 190         print "Stopping Stratum"
 191         with self.lock:
 192             self._stopped = True
 193
 194     def stopped(self):
 195         with self.lock:
 196             return self._stopped
 197
 198 class Stratum:
 199
 200     def start(self, processor):
 201         shared = Shared()
 202         # Bind shared to processor since constructor is user defined
 203         processor.shared = shared
 204         processor.start()
 205         # Create various transports we need
 206         transports = TcpServer(shared, processor),
 207         for server in transports:
 208             server.start()
 209         while not shared.stopped():
 210             if raw_input() == "quit":
 211                 shared.stop()
 212             time.sleep(1)
 213
 214 if __name__ == "__main__":
 215     processor = Processor()
 216     app = Stratum()
 217     app.start(processor)
 218