Source Code for Module rhn.nonblocking

 1  # 
 2  # 
 3  # 
 4   
 5  import select 
 6  import fcntl 
 7  import os 
 8   
 9 -class NonBlockingFile: 
10 -    def __init__(self, fd): 
11          # Keep a copy of the file descriptor 
12          self.fd = fd 
13          fcntl.fcntl(self.fd.fileno(), fcntl.F_SETFL, os.O_NDELAY) 
14          # Set the callback-related stuff 
15          self.read_fd_set = [] 
16          self.write_fd_set = [] 
17          self.exc_fd_set = [] 
18          self.user_data = None 
19          self.callback = None 
20   
21 -    def set_callback(self, read_fd_set, write_fd_set, exc_fd_set, 
22              user_data, callback): 
23          self.read_fd_set = read_fd_set 
24          # Make the objects non-blocking 
25          for f in self.read_fd_set: 
26              fcntl.fcntl(f.fileno(), fcntl.F_SETFL, os.O_NDELAY) 
27   
28          self.write_fd_set = write_fd_set 
29          self.exc_fd_set = exc_fd_set 
30          self.user_data = user_data 
31          self.callback = callback 
32   
33 -    def read(self, amt=0): 
34          while 1: 
35              status_changed = 0 
36              readfds = self.read_fd_set + [self.fd] 
37              writefds = self.write_fd_set 
38              excfds = self.exc_fd_set 
39              print("Calling select", readfds) 
40              readfds, writefds, excfds = select.select(readfds, writefds, excfds) 
41              print("Select returned", readfds, writefds, excfds) 
42              if self.fd in readfds: 
43                  # Our own file descriptor has changed status 
44                  # Mark this, but also try to call the callback with the rest 
45                  # of the file descriptors that changed status 
46                  status_changed = 1 
47                  readfds.remove(self.fd) 
48              if self.callback and (readfds or writefds or excfds): 
49                  self.callback(readfds, writefds, excfds, self.user_data) 
50              if status_changed: 
51                  break 
52          print("Returning") 
53          return self.fd.read(amt) 
54   
55 -    def write(self, data): 
56          return self.fd.write(data) 
57   
58 -    def __getattr__(self, name): 
59          return getattr(self.fd, name) 
60   
61 -def callback(r, w, e, user_data): 
62      print("Callback called", r, w, e) 
63      print(r[0].read()) 
64   
65  if __name__ == '__main__': 
66      import socket 
67   
68      s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
69      s.connect(("localhost", 5555)) 
70      f = s.makefile() 
71      ss = NonBlockingFile(f) 
72   
73      s2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
74      s2.connect(("localhost", 5556)) 
75      f = s2.makefile() 
76      ss.set_callback([f], [], [], None, callback) 
77   
78      xx = ss.read() 
79      print(len(xx)) 
80