[Zope-Checkins] CVS: Zope2 - __init__.py:1.1 asynchat.py:1.1 asyncore.py:1.1

Jim Fulton jim@digicool.com
Thu, 5 Apr 2001 19:38:18 -0400 (EDT)


Update of /cvs-repository/Zope2/ZServer/async1x
In directory korak:/tmp/cvs-serv24500

Added Files:
	__init__.py asynchat.py asyncore.py 
Log Message:
Moved Python 1.x compatable asyncx to their own package that takes
care of installing them when necessary (not for Python 2.0)



--- Added File __init__.py in package Zope2 ---

# We want to use updated asynchat and asyncore if using Python1.5
import sys
if sys.version[:1] < '2':
    import asyncore, asynchat
    sys.modules['asyncore']=asyncore
    sys.modules['asynchat']=asynchat
    del asyncore
    del asynchat

del sys

--- Added File asynchat.py in package Zope2 ---
# -*- Mode: Python; tab-width: 4 -*-
#	$Id: asynchat.py,v 1.1 2001/04/05 23:38:16 jim Exp $
#	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, an integer, or None"
		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:
			self.handle_error()
			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:
			lb = len(self.ac_in_buffer)
			terminator = self.get_terminator()
			if terminator is None:
				# no terminator, collect it all
				self.collect_incoming_data (self.ac_in_buffer)
				self.ac_in_buffer = ''
			elif type(terminator) == type(0):
				# numeric terminator
				n = terminator
				if lb < n:
					self.collect_incoming_data (self.ac_in_buffer)
					self.ac_in_buffer = ''
					self.terminator = self.terminator - lb
				else:
					self.collect_incoming_data (self.ac_in_buffer[:n])
					self.ac_in_buffer = self.ac_in_buffer[n:]
					self.terminator = 0
					self.found_terminator()
			else:
				# 3 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
				terminator_len = len(terminator)
				index = string.find (self.ac_in_buffer, terminator)
				if index != -1:
					# we found the terminator
					if index > 0:
						# don't bother reporting the empty string (source of subtle bugs)
						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:
						if index != lb:
							# 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 = ''

	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):
		"predicate for inclusion in the readable for select()"
		return (len(self.ac_in_buffer) <= self.ac_in_buffer_size)

	def writable (self):
		"predicate for inclusion in the writable for select()"
		# return len(self.ac_out_buffer) or len(self.producer_fifo) or (not self.connected)
		# this is about twice as fast, though not as clear.
		return not (
			(self.ac_out_buffer is '') and
			self.producer_fifo.is_empty() and
			self.connected
			)

	def close_when_done (self):
		"automatically close this channel once the outgoing queue is empty"
		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):
		_string_type = type('')
		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
				elif type(p) is _string_type:
					self.producer_fifo.pop()
					self.ac_out_buffer = self.ac_out_buffer + p
					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 (len (self.ac_out_buffer) < obs):
			self.refill_buffer()

		if self.ac_out_buffer and self.connected:
			# try to send the buffer
			try:
				num_sent = self.send (self.ac_out_buffer[:obs])
				if num_sent:
					self.ac_out_buffer = self.ac_out_buffer[num_sent:]

			except socket.error, why:
				self.handle_error()
				return

	def discard_buffers (self):
		# Emergencies only!
		self.ac_in_buffer = ''
		self.ac_out_buffer = ''
		while self.producer_fifo:
			self.producer_fifo.pop()


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 is_empty (self):
		return 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

--- Added File asyncore.py in package Zope2 ---
# -*- Mode: Python; tab-width: 4 -*-
#   $Id: asyncore.py,v 1.1 2001/04/05 23:38:16 jim Exp $
#   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 exceptions
import select
import socket
import string
import sys

import os
if os.name == 'nt':
    EWOULDBLOCK = 10035
    EINPROGRESS = 10036
    EALREADY    = 10037
    ECONNRESET  = 10054
    ENOTCONN    = 10057
    ESHUTDOWN   = 10058
    EINTR       = 0 # what should this be?
else:
    from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET
    from errno import ENOTCONN, ESHUTDOWN, EINTR

try:
    socket_map
except NameError:
    socket_map = {}

class ExitNow (exceptions.Exception):
    pass

DEBUG = 0

def poll (timeout=0.0, map=None):
    global DEBUG
    if map is None:
        map = socket_map
    if map:
        r = []; w = []; e = []
        for fd, obj in map.items():
            if obj.readable():
                r.append (fd)
            if obj.writable():
                w.append (fd)

        while 1:
            try: r,w,e = select.select (r,w,e, timeout)
            except select.error, v:
                if v[0] != EINTR: raise
            else: break
            

        if DEBUG:
            print r,w,e

        for fd in r:
            try:
                obj = map[fd]
                try:
                    obj.handle_read_event()
                except ExitNow:
                    raise ExitNow
                except:
                    obj.handle_error()
            except KeyError:
                pass

        for fd in w:
            try:
                obj = map[fd]
                try:
                    obj.handle_write_event()
                except ExitNow:
                    raise ExitNow
                except:
                    obj.handle_error()
            except KeyError:
                pass

def poll2 (timeout=0.0, map=None):
    import poll
    if map is None:
        map=socket_map
    # timeout is in milliseconds
    timeout = int(timeout*1000)
    if map:
        l = []
        for fd, obj in map.items():
            flags = 0
            if obj.readable():
                flags = poll.POLLIN
            if obj.writable():
                flags = flags | poll.POLLOUT
            if flags:
                l.append ((fd, flags))
        r = poll.poll (l, timeout)
        for fd, flags in r:
            try:
                obj = map[fd]
                try:
                    if (flags  & poll.POLLIN):
                        obj.handle_read_event()
                    if (flags & poll.POLLOUT):
                        obj.handle_write_event()
                except ExitNow:
                    raise ExitNow
                except:
                    obj.handle_error()
            except KeyError:
                pass

def loop (timeout=30.0, use_poll=0, map=None):

    if use_poll:
        poll_fun = poll2
    else:
        poll_fun = poll

        if map is None:
            map=socket_map

    while map:
        poll_fun (timeout, map)

class dispatcher:
    debug = 0
    connected = 0
    accepting = 0
    closing = 0
    addr = None

    def __init__ (self, sock=None, map=None):
        if sock:
            self.set_socket (sock, map)
            # 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, map=None):
        #self.log_info ('adding channel %s' % self)
        if map is None:
            map=socket_map
        map [self._fileno] = self

    def del_channel (self, map=None):
        fd = self._fileno
        if map is None:
            map=socket_map
        if map.has_key (fd):
            #self.log_info ('closing channel %d:%s' % (fd, self))
            del map [fd]

    def create_socket (self, family, type):
        self.family_and_type = family, type
        self.socket = socket.socket (family, type)
        self.socket.setblocking(0)
        self._fileno = self.socket.fileno()
        self.add_channel()

    def set_socket (self, sock, map=None):
        self.__dict__['socket'] = sock
        self._fileno = sock.fileno()
        self.add_channel (map)

    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):
        self.connected = 0
        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, ESHUTDOWN]:
                self.handle_close()
                return ''
            else:
                raise socket.error, why

    def close (self):
        self.del_channel()
        self.socket.close()

    # cheap inheritance, used to pass all other attribute
    # references to the underlying socket object.
    def __getattr__ (self, attr):
        return getattr (self.socket, attr)

    # log and log_info maybe overriden to provide more sophisitcated
    # logging and warning methods. In general, log is for 'hit' logging
    # and 'log_info' is for informational, warning and error logging. 

    def log (self, message):
        sys.stderr.write ('log: %s\n' % str(message))

    def log_info (self, message, type='info'):
        if __debug__ or type != 'info':
            print '%s: %s' % (type, 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):
        (file,fun,line), t, v, tbinfo = compact_traceback()

        # sometimes a user repr method will crash.
        try:
            self_repr = repr (self)
        except:
            self_repr = '<__repr__ (self) failed for object at %0x>' % id(self)

        self.log_info (
            'uncaptured python exception, closing channel %s (%s:%s %s)' % (
                self_repr,
                t,
                v,
                tbinfo
                ),
            'error'
            )
        self.close()

    def handle_expt (self):
        self.log_info ('unhandled exception', 'warning')

    def handle_read (self):
        self.log_info ('unhandled read event', 'warning')

    def handle_write (self):
        self.log_info ('unhandled write event', 'warning')

    def handle_connect (self):
        self.log_info ('unhandled connect event', 'warning')

    def handle_accept (self):
        self.log_info ('unhandled accept event', 'warning')

    def handle_close (self):
        self.log_info ('unhandled close event', 'warning')
        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_info ('sending %s' % repr(data))
        self.out_buffer = self.out_buffer + data
        self.initiate_send()

# ---------------------------------------------------------------------------
# used for debugging.
# ---------------------------------------------------------------------------

def compact_traceback ():
    t,v,tb = sys.exc_info()
    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

    # just to be safe
    del tb

    file, function, line = tbinfo[-1]
    info = '[' + string.join (
        map (
            lambda x: string.join (x, '|'),
            tbinfo
            ),
        '] ['
        ) + ']'
    return (file, function, line), t, v, info

def close_all (map=None):
    if map is None:
        map=socket_map
    for x in map.values():
        x.socket.close()
    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._fileno = fd
            self.socket = file_wrapper (fd)
            self.add_channel()