processor.py

   1 import json
   2 import socket
   3 import threading
   4 import time
   5 import traceback, sys
   6 import Queue as queue
   7
   8 def random_string(N):
   9     import random, string
  10     return ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(N))
  11
  12 def timestr():
  13     return time.strftime("[%d/%m/%Y-%H:%M:%S]")
  14
  15
  16 class Shared:
  17
  18     def __init__(self):
  19         self.lock = threading.Lock()
  20         self._stopped = False
  21
  22     def stop(self):
  23         print "Stopping Stratum"
  24         with self.lock:
  25             self._stopped = True
  26
  27     def stopped(self):
  28         with self.lock:
  29             return self._stopped
  30
  31
  32 class Processor(threading.Thread):
  33
  34     def __init__(self):
  35         threading.Thread.__init__(self)
  36         self.daemon = True
  37         self.dispatcher = None
  38
  39     def process(self, request):
  40         pass
  41
  42     def push_response(self, response):
  43         #print "response", response
  44         self.dispatcher.request_dispatcher.push_response(response)
  45
  46
  47
  48 class Dispatcher:
  49
  50     def __init__(self):
  51         self.shared = Shared()
  52         self.request_dispatcher = RequestDispatcher(self.shared)
  53         self.request_dispatcher.start()
  54         self.response_dispatcher = \
  55             ResponseDispatcher(self.shared, self.request_dispatcher)
  56         self.response_dispatcher.start()
  57
  58     def register(self, prefix, processor):
  59         processor.dispatcher = self
  60         processor.shared = self.shared
  61         processor.start()
  62         self.request_dispatcher.processors[prefix] = processor
  63
  64
  65
  66 class RequestDispatcher(threading.Thread):
  67
  68     def __init__(self, shared):
  69         self.shared = shared
  70         threading.Thread.__init__(self)
  71         self.daemon = True
  72         self.request_queue = queue.Queue()
  73         self.response_queue = queue.Queue()
  74         self.internal_ids = {}
  75         self.internal_id = 1
  76         self.lock = threading.Lock()
  77         self.sessions = []
  78         self.processors = {}
  79
  80     def push_response(self, item):
  81         self.response_queue.put(item)
  82
  83     def pop_response(self):
  84         return self.response_queue.get()
  85
  86     def push_request(self, session, item):
  87         self.request_queue.put((session,item))
  88
  89     def pop_request(self):
  90         return self.request_queue.get()
  91
  92     def get_session_id(self, internal_id):
  93         with self.lock:
  94             return self.internal_ids.pop(internal_id)
  95
  96     def store_session_id(self, session, msgid):
  97         with self.lock:
  98             self.internal_ids[self.internal_id] = session, msgid
  99             r = self.internal_id
 100             self.internal_id += 1
 101             return r
 102
 103     def run(self):
 104         if self.shared is None:
 105             raise TypeError("self.shared not set in Processor")
 106         while not self.shared.stopped():
 107             session, request = self.pop_request()
 108             self.process(session, request)
 109
 110         self.stop()
 111
 112     def stop(self):
 113         pass
 114
 115     def process(self, session, request):
 116         method = request['method']
 117         params = request.get('params',[])
 118
 119         suffix = method.split('.')[-1]
 120         if suffix == 'subscribe':
 121             session.subscribe_to_service(method, params)
 122
 123         # store session and id locally
 124         request['id'] = self.store_session_id(session, request['id'])
 125
 126         # dispatch request to the relevant module..
 127         prefix = request['method'].split('.')[0]
 128         try:
 129             p = self.processors[prefix]
 130         except:
 131             print "error: no processor for", prefix
 132             return
 133         try:
 134             p.process(request)
 135         except:
 136             traceback.print_exc(file=sys.stdout)
 137
 138         if method in ['server.version']:
 139             session.version = params[0]
 140
 141
 142     def add_session(self, session):
 143         with self.lock:
 144             self.sessions.append(session)
 145
 146     def collect_garbage(self):
 147         # Deep copy entire sessions list and blank it
 148         # This is done to minimise lock contention
 149         with self.lock:
 150             sessions = self.sessions[:]
 151             self.sessions = []
 152         for session in sessions:
 153             if not session.stopped():
 154                 # If session is still alive then re-add it back
 155                 # to our internal register
 156                 self.add_session(session)
 157
 158
 159 class Session:
 160
 161     def __init__(self):
 162         self._stopped = False
 163         self.lock = threading.Lock()
 164         self.subscriptions = []
 165         self.address = ''
 166         self.name = ''
 167         threading.Timer(2, self.info).start()
 168
 169     # Debugging method. Doesn't need to be threadsafe.
 170     def info(self):
 171         for sub in self.subscriptions:
 172             #print sub
 173             method = sub[0]
 174             if method == 'blockchain.address.subscribe':
 175                 params = sub[1]
 176                 addr = params[0]
 177                 break
 178         else:
 179             addr = None
 180         print timestr(), self.name, self.address, addr,\
 181             len(self.subscriptions), self.version
 182
 183     def stopped(self):
 184         with self.lock:
 185             return self._stopped
 186
 187     def subscribe_to_service(self, method, params):
 188         subdesc = self.build_subdesc(method, params)
 189         with self.lock:
 190             if subdesc is not None:
 191                 self.subscriptions.append(subdesc)
 192
 193     # subdesc = A subscription description
 194     @staticmethod
 195     def build_subdesc(method, params):
 196         if method == "blockchain.numblocks.subscribe":
 197             return method,
 198         elif method == "blockchain.address.get_history":
 199             if not params:
 200                 return None
 201             else:
 202                 return method, params[0]
 203         else:
 204             return None
 205
 206     def contains_subscription(self, subdesc):
 207         with self.lock:
 208             return subdesc in self.subscriptions
 209
 210
 211 class ResponseDispatcher(threading.Thread):
 212
 213     def __init__(self, shared, processor):
 214         self.shared = shared
 215         self.processor = processor
 216         threading.Thread.__init__(self)
 217         self.daemon = True
 218
 219     def run(self):
 220         while not self.shared.stopped():
 221             self.update()
 222
 223     def update(self):
 224         response = self.processor.pop_response()
 225         #print "pop response", response
 226         internal_id = response.get('id')
 227         method = response.get('method')
 228         params = response.get('params')
 229
 230         # A notification
 231         if internal_id is None: # and method is not None and params is not None:
 232             self.notification(method, params, response)
 233         # A response
 234         elif internal_id is not None: # and method is None and params is None:
 235             self.send_response(internal_id, response)
 236         else:
 237             print "no method", response
 238
 239     def notification(self, method, params, response):
 240         subdesc = Session.build_subdesc(method, params)
 241         for session in self.processor.sessions:
 242             if session.stopped():
 243                 continue
 244             if session.contains_subscription(subdesc):
 245                 session.send_response(response)
 246
 247     def send_response(self, internal_id, response):
 248         session, message_id = self.processor.get_session_id(internal_id)
 249         response['id'] = message_id
 250         session.send_response(response)
 251