]> granicus.if.org Git - python/commitdiff
A gift from Sam Rushing - modules asyncore and asynchat for the
authorGuido van Rossum <guido@python.org>
Tue, 12 Jan 1999 20:19:27 +0000 (20:19 +0000)
committerGuido van Rossum <guido@python.org>
Tue, 12 Jan 1999 20:19:27 +0000 (20:19 +0000)
standard Python library.  (Async socket support.)

Lib/asynchat.py [new file with mode: 0644]
Lib/asyncore.py [new file with mode: 0644]

diff --git a/Lib/asynchat.py b/Lib/asynchat.py
new file mode 100644 (file)
index 0000000..5486419
--- /dev/null
@@ -0,0 +1,290 @@
+# -*- Mode: Python; tab-width: 4 -*-
+#      $Id$
+#      Author: Sam Rushing <rushing@nightmare.com>
+
+# ======================================================================
+# Copyright 1996 by Sam Rushing
+# 
+#                         All Rights Reserved
+# 
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose and without fee is hereby
+# granted, provided that the above copyright notice appear in all
+# copies and that both that copyright notice and this permission
+# notice appear in supporting documentation, and that the name of Sam
+# Rushing not be used in advertising or publicity pertaining to
+# distribution of the software without specific, written prior
+# permission.
+# 
+# SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+# INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
+# NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+# ======================================================================
+
+import socket
+import asyncore
+import string
+
+# This class adds support for 'chat' style protocols - where one side
+# sends a 'command', and the other sends a response (examples would be
+# the common internet protocols - smtp, nntp, ftp, etc..).
+
+# The handle_read() method looks at the input stream for the current
+# 'terminator' (usually '\r\n' for single-line responses, '\r\n.\r\n'
+# for multi-line output), calling self.found_terminator() on its
+# receipt.
+
+# for example:
+# Say you build an async nntp client using this class.  At the start
+# of the connection, you'll have self.terminator set to '\r\n', in
+# order to process the single-line greeting.  Just before issuing a
+# 'LIST' command you'll set it to '\r\n.\r\n'.  The output of the LIST
+# command will be accumulated (using your own 'collect_incoming_data'
+# method) up to the terminator, and then control will be returned to
+# you - by calling your self.found_terminator() method
+
+class async_chat (asyncore.dispatcher):
+       """This is an abstract class.  You must derive from this class, and add
+       the two methods collect_incoming_data() and found_terminator()"""
+
+       # these are overridable defaults
+
+       ac_in_buffer_size       = 4096
+       ac_out_buffer_size      = 4096
+
+       def __init__ (self, conn=None):
+               self.ac_in_buffer = ''
+               self.ac_out_buffer = ''
+               self.producer_fifo = fifo()
+               asyncore.dispatcher.__init__ (self, conn)
+
+       def set_terminator (self, term):
+               "Set the input delimiter.  Can be a fixed string of any length, or None"
+               if term is None:
+                       self.terminator = ''
+               else:
+                       self.terminator = term
+
+       def get_terminator (self):
+               return self.terminator
+
+       # grab some more data from the socket,
+       # throw it to the collector method,
+       # check for the terminator,
+       # if found, transition to the next state.
+
+       def handle_read (self):
+
+               try:
+                       data = self.recv (self.ac_in_buffer_size)
+               except socket.error, why:
+                       import sys
+                       self.handle_error (sys.exc_type, sys.exc_value, sys.exc_traceback)
+                       return
+
+               self.ac_in_buffer = self.ac_in_buffer + data
+
+               # Continue to search for self.terminator in self.ac_in_buffer,
+               # while calling self.collect_incoming_data.  The while loop
+               # is necessary because we might read several data+terminator
+               # combos with a single recv(1024).
+
+               while self.ac_in_buffer:
+                       terminator = self.get_terminator()
+                       terminator_len = len(terminator)
+                       # 4 cases:
+                       # 1) end of buffer matches terminator exactly:
+                       #    collect data, transition
+                       # 2) end of buffer matches some prefix:
+                       #    collect data to the prefix
+                       # 3) end of buffer does not match any prefix:
+                       #    collect data
+                       # 4) no terminator, just collect the data
+                       if terminator:
+                               index = string.find (self.ac_in_buffer, terminator)
+                               if index != -1:
+                                       # we found the terminator
+                                       self.collect_incoming_data (self.ac_in_buffer[:index])
+                                       self.ac_in_buffer = self.ac_in_buffer[index+terminator_len:]
+                                       # This does the Right Thing if the terminator is changed here.
+                                       self.found_terminator()
+                               else:
+                                       # check for a prefix of the terminator
+                                       index = find_prefix_at_end (self.ac_in_buffer, terminator)
+                                       if index:
+                                               # we found a prefix, collect up to the prefix
+                                               self.collect_incoming_data (self.ac_in_buffer[:-index])
+                                               self.ac_in_buffer = self.ac_in_buffer[-index:]
+                                               break
+                                       else:
+                                               # no prefix, collect it all
+                                               self.collect_incoming_data (self.ac_in_buffer)
+                                               self.ac_in_buffer = ''
+                       else:
+                               # no terminator, collect it all
+                               self.collect_incoming_data (self.ac_in_buffer)
+                               self.ac_in_buffer = ''
+
+       def handle_write (self):
+               self.initiate_send ()
+               
+       def handle_close (self):
+               self.close()
+
+       def push (self, data):
+               self.producer_fifo.push (simple_producer (data))
+               self.initiate_send()
+
+       def push_with_producer (self, producer):
+               self.producer_fifo.push (producer)
+               self.initiate_send()
+
+       def readable (self):
+               return (len(self.ac_in_buffer) <= self.ac_in_buffer_size)
+
+       def writable (self):
+               return len(self.ac_out_buffer) or len(self.producer_fifo) or (not self.connected)
+
+       def close_when_done (self):
+               self.producer_fifo.push (None)
+
+       # refill the outgoing buffer by calling the more() method
+       # of the first producer in the queue
+       def refill_buffer (self):
+               while 1:
+                       if len(self.producer_fifo):
+                               p = self.producer_fifo.first()
+                               # a 'None' in the producer fifo is a sentinel,
+                               # telling us to close the channel.
+                               if p is None:
+                                       if not self.ac_out_buffer:
+                                               self.producer_fifo.pop()
+                                               self.close()
+                                       return
+                               data = p.more()
+                               if data:
+                                       self.ac_out_buffer = self.ac_out_buffer + data
+                                       return
+                               else:
+                                       self.producer_fifo.pop()
+                       else:
+                               return
+
+       def initiate_send (self):
+               obs = self.ac_out_buffer_size
+               # try to refill the buffer
+               if (not self._push_mode) and (len (self.ac_out_buffer) < obs):
+                       self.refill_buffer()
+
+               if self.ac_out_buffer and self.connected:
+                       # try to send the buffer
+                       num_sent = self.send (self.ac_out_buffer[:obs])
+                       if num_sent:
+                               self.ac_out_buffer = self.ac_out_buffer[num_sent:]
+
+       def discard_buffers (self):
+               # Emergencies only!
+               self.ac_in_buffer = ''
+               self.ac_out_buffer == ''
+               while self.producer_fifo:
+                       self.producer_fifo.pop()
+
+       # ==================================================
+       # support for push mode.
+       # ==================================================
+       _push_mode = 0
+       def push_mode (self, boolean):
+               self._push_mode = boolean
+
+       def writable_push (self):
+               return self.connected and len(self.ac_out_buffer)
+
+class simple_producer:
+       def __init__ (self, data, buffer_size=512):
+               self.data = data
+               self.buffer_size = buffer_size
+
+       def more (self):
+               if len (self.data) > self.buffer_size:
+                       result = self.data[:self.buffer_size]
+                       self.data = self.data[self.buffer_size:]
+                       return result
+               else:
+                       result = self.data
+                       self.data = ''
+                       return result
+
+class fifo:
+       def __init__ (self, list=None):
+               if not list:
+                       self.list = []
+               else:
+                       self.list = list
+               
+       def __len__ (self):
+               return len(self.list)
+
+       def first (self):
+               return self.list[0]
+
+       def push (self, data):
+               self.list.append (data)
+
+       def pop (self):
+               if self.list:
+                       result = self.list[0]
+                       del self.list[0]
+                       return (1, result)
+               else:
+                       return (0, None)
+
+# Given 'haystack', see if any prefix of 'needle' is at its end.  This
+# assumes an exact match has already been checked.  Return the number of
+# characters matched.
+# for example:
+# f_p_a_e ("qwerty\r", "\r\n") => 1
+# f_p_a_e ("qwerty\r\n", "\r\n") => 2
+# f_p_a_e ("qwertydkjf", "\r\n") => 0
+
+# this could maybe be made faster with a computed regex?
+
+##def find_prefix_at_end (haystack, needle):
+##     nl = len(needle)
+##     result = 0
+##     for i in range (1,nl):
+##             if haystack[-(nl-i):] == needle[:(nl-i)]:
+##                     result = nl-i
+##                     break
+##     return result
+
+# yes, this is about twice as fast, but still seems
+# to be neglible CPU.  The previous could do about 290
+# searches/sec. the new one about 555/sec.
+
+import regex
+
+prefix_cache = {}
+
+def prefix_regex (needle):
+       if prefix_cache.has_key (needle):
+               return prefix_cache[needle]
+       else:
+               reg = needle[-1]
+               for i in range(1,len(needle)):
+                       reg = '%c\(%s\)?' % (needle[-(i+1)], reg)
+               reg = regex.compile (reg+'$')
+               prefix_cache[needle] = reg, len(needle)
+               return reg, len(needle)
+
+def find_prefix_at_end (haystack, needle):
+       reg, length = prefix_regex (needle)
+       lh = len(haystack)
+       result = reg.search (haystack, max(0,lh-length))
+       if result >= 0:
+               return (lh - result)
+       else:
+               return 0
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
new file mode 100644 (file)
index 0000000..c9b39a3
--- /dev/null
@@ -0,0 +1,453 @@
+# -*- Mode: Python; tab-width: 4 -*-
+#      $Id$
+#      Author: Sam Rushing <rushing@nightmare.com>
+
+# ======================================================================
+# Copyright 1996 by Sam Rushing
+# 
+#                         All Rights Reserved
+# 
+# Permission to use, copy, modify, and distribute this software and
+# its documentation for any purpose and without fee is hereby
+# granted, provided that the above copyright notice appear in all
+# copies and that both that copyright notice and this permission
+# notice appear in supporting documentation, and that the name of Sam
+# Rushing not be used in advertising or publicity pertaining to
+# distribution of the software without specific, written prior
+# permission.
+# 
+# SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+# INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
+# NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+# ======================================================================
+
+import select
+import socket
+import string
+import sys
+
+import os
+if os.name == 'nt':
+       EWOULDBLOCK     = 10035
+       EINPROGRESS     = 10036
+       EALREADY        = 10037
+       ECONNRESET  = 10054
+       ENOTCONN        = 10057
+else:
+       from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, ENOTCONN
+
+socket_map = {}
+
+def poll (timeout=0.0, ignore_expt=1):
+       if socket_map:
+               sockets = socket_map.keys()
+               r = filter (lambda x: x.readable(), sockets)
+               w = filter (lambda x: x.writable(), sockets)
+               if ignore_expt:
+                       e = []
+               else:
+                       e = sockets[:]
+
+               (r,w,e) = select.select (r,w,e, timeout)
+
+               for x in e:
+                       try:
+                               x.handle_expt_event()
+                       except:
+                               x.handle_error (sys.exc_type, sys.exc_value, sys.exc_traceback)
+               for x in r:
+                       try:
+                               x.handle_read_event()
+                       except:
+                               x.handle_error (sys.exc_type, sys.exc_value, sys.exc_traceback)
+               for x in w:
+                       try:
+                               x.handle_write_event()
+                       except:
+                               x.handle_error (sys.exc_type, sys.exc_value, sys.exc_traceback)
+
+def poll2 (timeout=0.0):
+       import poll
+       # timeout is in milliseconds
+       timeout = int(timeout*1000)
+       if socket_map:
+               fd_map = {}
+               for s in socket_map.keys():
+                       fd_map[s.fileno()] = s
+               l = []
+               for fd, s in fd_map.items():
+                       flags = 0
+                       if s.readable():
+                               flags = poll.POLLIN
+                       if s.writable():
+                               flags = flags | poll.POLLOUT
+                       if flags:
+                               l.append (fd, flags)
+               r = poll.poll (l, timeout)
+               print r
+               for fd, flags in r:
+                       s = fd_map[fd]
+                       try:
+                               if (flags & poll.POLLIN):
+                                               s.handle_read_event()
+                               if (flags & poll.POLLOUT):
+                                               s.handle_write_event()
+                               if (flags & poll.POLLERR):
+                                               s.handle_expt_event()
+                       except:
+                               apply (s.handle_error, sys.exc_info())
+
+
+def loop (timeout=30.0, use_poll=0):
+
+       if use_poll:
+               poll_fun = poll2
+       else:
+               poll_fun = poll
+
+       while socket_map:
+               poll_fun (timeout)
+
+class dispatcher:
+       debug = 0
+       connected = 0
+       accepting = 0
+       closing = 0
+       addr = None
+
+       def __init__ (self, sock=None):
+               if sock:
+                       self.set_socket (sock)
+                       # I think it should inherit this anyway
+                       self.socket.setblocking (0)
+                       self.connected = 1
+
+       def __repr__ (self):
+               try:
+                       status = []
+                       if self.accepting and self.addr:
+                               status.append ('listening')
+                       elif self.connected:
+                               status.append ('connected')
+                       if self.addr:
+                               status.append ('%s:%d' % self.addr)
+                       return '<%s %s at %x>' % (
+                               self.__class__.__name__,
+                               string.join (status, ' '),
+                               id(self)
+                               )
+               except:
+                       try:
+                               ar = repr(self.addr)
+                       except:
+                               ar = 'no self.addr!'
+                               
+                       return '<__repr__ (self) failed for object at %x (addr=%s)>' % (id(self),ar)
+
+       def add_channel (self):
+               self.log ('adding channel %s' % self)
+               socket_map [self] = 1
+
+       def del_channel (self):
+               if socket_map.has_key (self):
+                       self.log ('closing channel %d:%s' % (self.fileno(), self))
+                       del socket_map [self]
+
+       def create_socket (self, family, type):
+               self.family_and_type = family, type
+               self.socket = socket.socket (family, type)
+               self.socket.setblocking(0)
+               self.add_channel()
+
+       def set_socket (self, socket):
+               self.socket = socket
+               self.add_channel()
+
+       def set_reuse_addr (self):
+               # try to re-use a server port if possible
+               try:
+                       self.socket.setsockopt (
+                               socket.SOL_SOCKET, socket.SO_REUSEADDR,
+                               self.socket.getsockopt (socket.SOL_SOCKET, socket.SO_REUSEADDR) | 1
+                               )
+               except:
+                       pass
+
+       # ==================================================
+       # predicates for select()
+       # these are used as filters for the lists of sockets
+       # to pass to select().
+       # ==================================================
+
+       def readable (self):
+               return 1
+
+       if os.name == 'mac':
+               # The macintosh will select a listening socket for
+               # write if you let it.  What might this mean?
+               def writable (self):
+                       return not self.accepting
+       else:
+               def writable (self):
+                       return 1
+
+       # ==================================================
+       # socket object methods.
+       # ==================================================
+
+       def listen (self, num):
+               self.accepting = 1
+               if os.name == 'nt' and num > 5:
+                       num = 1
+               return self.socket.listen (num)
+
+       def bind (self, addr):
+               self.addr = addr
+               return self.socket.bind (addr)
+
+       def connect (self, address):
+               try:
+                       self.socket.connect (address)
+               except socket.error, why:
+                       if why[0] in (EINPROGRESS, EALREADY, EWOULDBLOCK):
+                               return
+                       else:
+                               raise socket.error, why
+               self.connected = 1
+               self.handle_connect()
+
+       def accept (self):
+               try:
+                       conn, addr = self.socket.accept()
+                       return conn, addr
+               except socket.error, why:
+                       if why[0] == EWOULDBLOCK:
+                               pass
+                       else:
+                               raise socket.error, why
+
+       def send (self, data):
+               try:
+                       result = self.socket.send (data)
+                       return result
+               except socket.error, why:
+                       if why[0] == EWOULDBLOCK:
+                               return 0
+                       else:
+                               raise socket.error, why
+                       return 0
+
+       def recv (self, buffer_size):
+               try:
+                       data = self.socket.recv (buffer_size)
+                       if not data:
+                               # a closed connection is indicated by signaling
+                               # a read condition, and having recv() return 0.
+                               self.handle_close()
+                               return ''
+                       else:
+                               return data
+               except socket.error, why:
+                       # winsock sometimes throws ENOTCONN
+                       if why[0] in [ECONNRESET, ENOTCONN]:
+                               self.handle_close()
+                               return ''
+                       else:
+                               raise socket.error, why
+
+       def close (self):
+               self.del_channel()
+               self.socket.close()
+               self.connected = 0
+
+       # cheap inheritance, used to pass all other attribute
+       # references to the underlying socket object.
+       def __getattr__ (self, attr):
+               if attr != 'socket':
+                       return getattr (self.socket, attr)
+               else:
+                       raise AttributeError, attr
+
+       def log (self, message):
+               print 'log:', message
+
+       def handle_read_event (self):
+               if self.accepting:
+                       # for an accepting socket, getting a read implies
+                       # that we are connected
+                       if not self.connected:
+                               self.connected = 1
+                       self.handle_accept()
+               elif not self.connected:
+                       self.handle_connect()
+                       self.connected = 1
+                       self.handle_read()
+               else:
+                       self.handle_read()
+
+       def handle_write_event (self):
+               # getting a write implies that we are connected
+               if not self.connected:
+                       self.handle_connect()
+                       self.connected = 1
+               self.handle_write()
+
+       def handle_expt_event (self):
+               self.handle_expt()
+
+       def handle_error (self, *info):
+               (t,v,tb) = info
+               (file,fun,line), tbinfo = compact_traceback (t,v,tb)
+
+               # sometimes a user repr method will crash.
+               try:
+                       self_repr = repr (self)
+               except:
+                       self_repr = '<__repr__ (self) failed for object at %0x>' % id(self)
+
+               print (
+                       'uncaptured python exception, closing channel %s (%s:%s %s)' % (
+                               self_repr,
+                               str(t),
+                               str(v),
+                               tbinfo
+                               )
+                       )
+               del t,v,tb
+               self.close()
+
+       def handle_expt (self):
+               self.log ('unhandled exception')
+
+       def handle_read (self):
+               self.log ('unhandled read event')
+
+       def handle_write (self):
+               self.log ('unhandled write event')
+
+       def handle_connect (self):
+               self.log ('unhandled connect event')
+
+       def handle_oob (self):
+               self.log ('unhandled out-of-band event')
+
+       def handle_accept (self):
+               self.log ('unhandled accept event')
+
+       def handle_close (self):
+               self.log ('unhandled close event')
+               self.close()
+
+# ---------------------------------------------------------------------------
+# adds simple buffered output capability, useful for simple clients.
+# [for more sophisticated usage use asynchat.async_chat]
+# ---------------------------------------------------------------------------
+
+class dispatcher_with_send (dispatcher):
+       def __init__ (self, sock=None):
+               dispatcher.__init__ (self, sock)
+               self.out_buffer = ''
+
+       def initiate_send (self):
+               num_sent = 0
+               num_sent = dispatcher.send (self, self.out_buffer[:512])
+               self.out_buffer = self.out_buffer[num_sent:]
+
+       def handle_write (self):
+               self.initiate_send()
+
+       def writable (self):
+               return (not self.connected) or len(self.out_buffer)
+
+       def send (self, data):
+               if self.debug:
+                       self.log ('sending %s' % repr(data))
+               self.out_buffer = self.out_buffer + data
+               self.initiate_send()
+
+# ---------------------------------------------------------------------------
+# used for debugging.
+# ---------------------------------------------------------------------------
+
+def compact_traceback (t,v,tb):
+       tbinfo = []
+       while 1:
+               tbinfo.append (
+                       tb.tb_frame.f_code.co_filename,
+                       tb.tb_frame.f_code.co_name,                             
+                       str(tb.tb_lineno)
+                       )
+               tb = tb.tb_next
+               if not tb:
+                       break
+
+       file, function, line = tbinfo[-1]
+       info = '[' + string.join (
+               map (
+                       lambda x: string.join (x, '|'),
+                       tbinfo
+                       ),
+               '] ['
+               ) + ']'
+       return (file, function, line), info
+
+def close_all ():
+       global socket_map
+       for x in socket_map.keys():
+               x.socket.close()
+       socket_map.clear()
+
+# Asynchronous File I/O:
+#
+# After a little research (reading man pages on various unixen, and
+# digging through the linux kernel), I've determined that select()
+# isn't meant for doing doing asynchronous file i/o.
+# Heartening, though - reading linux/mm/filemap.c shows that linux
+# supports asynchronous read-ahead.  So _MOST_ of the time, the data
+# will be sitting in memory for us already when we go to read it.
+#
+# What other OS's (besides NT) support async file i/o?  [VMS?]
+#
+# Regardless, this is useful for pipes, and stdin/stdout...
+
+import os
+if os.name == 'posix':
+       import fcntl
+       import FCNTL
+
+       class file_wrapper:
+               # here we override just enough to make a file
+               # look like a socket for the purposes of asyncore.
+               def __init__ (self, fd):
+                       self.fd = fd
+
+               def recv (self, *args):
+                       return apply (os.read, (self.fd,)+args)
+
+               def write (self, *args):
+                       return apply (os.write, (self.fd,)+args)
+
+               def close (self):
+                       return os.close (self.fd)
+
+               def fileno (self):
+                       return self.fd
+
+       class file_dispatcher (dispatcher):
+               def __init__ (self, fd):
+                       dispatcher.__init__ (self)
+                       self.connected = 1
+                       # set it to non-blocking mode
+                       flags = fcntl.fcntl (fd, FCNTL.F_GETFL, 0)
+                       flags = flags | FCNTL.O_NONBLOCK
+                       fcntl.fcntl (fd, FCNTL.F_SETFL, flags)
+                       self.set_file (fd)
+
+               def set_file (self, fd):
+                       self.socket = file_wrapper (fd)
+                       self.add_channel()
+#not really