Source Code for Module joy.scratch

  1  import struct 
  2  import socket 
  3  import time 
  4  import sys 
  5  import select 
  6  import re 
  7  from warnings import warn 
  8   
  9 -class FramedSock( object ): 
 10 -  def __init__(self, host="127.0.0.1", port=42001): 
 11      self.addr = (host,port) 
 12      self.iterLimit = 32 
 13      self.sock = None 
 14     
 15 -  def isConnected( self ): 
 16      return self.sock is not None 
 17       
 18 -  def connect( self ): 
 19      if self.sock != None: 
 20        raise ValueError("Socket is already open") 
 21      self.sock = socket.socket(socket.AF_INET,socket.SOCK_STREAM) 
 22      self.sock.connect(self.addr) 
 23     
 24 -  def close( self ): 
 25      if self.sock is not None: 
 26        self.sock.close() 
 27        self.sock = None 
 28       
 29 -  def recv( self ): 
 30      hdr = self.sock.recv(4) 
 31      if len(hdr) != 4: 
 32        raise IOError("Failed to read header from socket") 
 33      H = struct.unpack(">L",hdr)[0] 
 34      N = 0 
 35      msg = [] 
 36      while N<H: 
 37        msg.append( self.sock.recv(H-N) ) 
 38        N += len(msg[-1]) 
 39      return "".join(msg) 
 40     
 41 -  def send( self, msg ): 
 42      hdr = struct.pack(">L",len(msg)) 
 43      self.sock.send( hdr+msg ) 
 44     
 45 -  def recv_async( self, timeout=0.01 ): 
 46      if self.sock: 
 47        r,_,_ = select.select( [self.sock],[],[],timeout ) 
 48        if r: 
 49          return self.recv() 
 50      return None 
 51   
 52 -  def __iter__(self): 
 53      for k in xrange(self.iterLimit): 
 54        msg = self.recv_async() 
 55        if msg is None: 
 56          break 
 57        yield msg 
 58       
 59 -class Board( object ): 
 60 -  def __init__(self, host="127.0.0.1", port=42001 ): 
 61      self._fsk = FramedSock( host, port ) 
 62       
 63    REX_STR = re.compile('\s*(?:"(([^"]|"")*)")\s*') 
 64    REX_VAL = re.compile('\s*((?:-?\d*(.\d+)?)|(?:\w[-A-Za-z0-9_]*))\s*') 
 65    REX_CMD = re.compile('\s*((?:sensor-update)|(?:broadcast))\s*')   
 66    @classmethod 
 67 -  def _tokenize( cls, msg ): 
 68      tok = [] 
 69      # Tokenize the command portion 
 70      m = cls.REX_CMD.match(msg) 
 71      if not m: return tok 
 72      tok.append( m.group(1) ) 
 73      msg = msg[len(m.group(0)):] 
 74      # Tokenize the remainder 
 75      while msg: 
 76        m = cls.REX_STR.match(msg) 
 77        if m: 
 78          tok.append( m.group(1).replace('""','"') ) 
 79          msg = msg[len(m.group(0)):] 
 80          continue 
 81        m = cls.REX_VAL.match(msg) 
 82        if m: 
 83          tok.append( m.group(1) ) 
 84          msg = msg[len(m.group(0)):] 
 85          continue 
 86        raise SyntaxError("Cannot parse '%s'" % msg) 
 87      return tok 
 88     
 89 -  def _doSensorUpdate( self, tok, upd ): 
 90      if len(tok) & 1: 
 91        warn('Sensor-update with odd number of tokens; skipping last') 
 92        tok.pop() 
 93      while tok: 
 94        nm = tok.pop(0) 
 95        val = tok.pop(0) 
 96        if val=="true": val = True 
 97        elif val=="false": val = False 
 98        elif val[0] in "-0123456789": val = float(val) 
 99        upd[nm] = val 
100     
101 -  def close( self ): 
102      self._fsk.close() 
103     
104 -  def _autoConnect( self ): 
105      if self._fsk.isConnected(): return True 
106      try: 
107        self._fsk.connect() 
108        return True 
109      except IOError, ioe: 
110        sys.stderr.write( "Failed to connect: %s\n" % ioe ) 
111        self._fsk.close() 
112      return False 
113       
114 -  def poll( self ): 
115      if not self._autoConnect(): return None,None 
116      # Poll for messages on socket 
117      upds = {} 
118      evts = set() 
119      for msg in self._fsk: 
120        tok = self._tokenize(msg) 
121        if tok is None: 
122          warn("Failed to parse Scratch message '%s'" % msg) 
123          continue 
124        # If 'sensor-update' message 
125        if tok[0][0]=='s': 
126          self._doSensorUpdate(tok[1:],upds)     
127        elif tok[0][0]=='b': 
128          for nm in tok[1:]: 
129            evts.add(nm) 
130      return upds, evts 
131     
132 -  def sensorUpdate(self, **kw): 
133      if not self._autoConnect(): return 
134      msg = ['sensor-update'] 
135      for k,v in kw.iteritems(): 
136        msg.append('"%s"' % k) 
137        msg.append(str(v)) 
138      self._fsk.send( " ".join(msg) ) 
139     
140 -  def broadcast(self,*arg): 
141      if not self._autoConnect(): return 
142      for txt in arg: 
143        txt = txt.replace('"','""') 
144        self._fsk.send( 'broadcast "%s"' % txt ) 
145       
146       
147  if __name__=="__main__": 
148    print "Connecting to Scratch at default host:port" 
149    try: 
150      sk = FramedSock() 
151      sk.connect() 
152      t0 = time.time() 
153      while True: 
154        msg = sk.recv() 
155        sys.stdout.write("%6.2f %s\n" % (time.time()-t0,msg)) 
156        sys.stdout.flush() 
157    finally: 
158      sk.close() 
159