mirror of
https://github.com/python/cpython.git
synced 2025-11-04 11:49:12 +00:00
290 lines
8.5 KiB
Python
290 lines
8.5 KiB
Python
# -*- 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
|