mirror of https://github.com/python/cpython
315 lines
11 KiB
Python
315 lines
11 KiB
Python
# TODO: This module was deprecated and removed from CPython 3.12
|
|
# Now it is a test-only helper. Any attempts to rewrite existing tests that
|
|
# are using this module and remove it completely are appreciated!
|
|
# See: https://github.com/python/cpython/issues/72719
|
|
|
|
# -*- Mode: Python; tab-width: 4 -*-
|
|
# Id: asynchat.py,v 2.26 2000/09/07 22:29:26 rushing 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.
|
|
# ======================================================================
|
|
|
|
r"""A class supporting chat-style (command/response) protocols.
|
|
|
|
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.
|
|
"""
|
|
|
|
from collections import deque
|
|
|
|
from test.support import asyncore
|
|
|
|
|
|
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 = 65536
|
|
ac_out_buffer_size = 65536
|
|
|
|
# we don't want to enable the use of encoding by default, because that is a
|
|
# sign of an application bug that we don't want to pass silently
|
|
|
|
use_encoding = 0
|
|
encoding = 'latin-1'
|
|
|
|
def __init__(self, sock=None, map=None):
|
|
# for string terminator matching
|
|
self.ac_in_buffer = b''
|
|
|
|
# we use a list here rather than io.BytesIO for a few reasons...
|
|
# del lst[:] is faster than bio.truncate(0)
|
|
# lst = [] is faster than bio.truncate(0)
|
|
self.incoming = []
|
|
|
|
# we toss the use of the "simple producer" and replace it with
|
|
# a pure deque, which the original fifo was a wrapping of
|
|
self.producer_fifo = deque()
|
|
asyncore.dispatcher.__init__(self, sock, map)
|
|
|
|
def collect_incoming_data(self, data):
|
|
raise NotImplementedError("must be implemented in subclass")
|
|
|
|
def _collect_incoming_data(self, data):
|
|
self.incoming.append(data)
|
|
|
|
def _get_data(self):
|
|
d = b''.join(self.incoming)
|
|
del self.incoming[:]
|
|
return d
|
|
|
|
def found_terminator(self):
|
|
raise NotImplementedError("must be implemented in subclass")
|
|
|
|
def set_terminator(self, term):
|
|
"""Set the input delimiter.
|
|
|
|
Can be a fixed string of any length, an integer, or None.
|
|
"""
|
|
if isinstance(term, str) and self.use_encoding:
|
|
term = bytes(term, self.encoding)
|
|
elif isinstance(term, int) and term < 0:
|
|
raise ValueError('the number of received bytes must be positive')
|
|
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 BlockingIOError:
|
|
return
|
|
except OSError:
|
|
self.handle_error()
|
|
return
|
|
|
|
if isinstance(data, str) and self.use_encoding:
|
|
data = bytes(str, self.encoding)
|
|
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(4096).
|
|
|
|
while self.ac_in_buffer:
|
|
lb = len(self.ac_in_buffer)
|
|
terminator = self.get_terminator()
|
|
if not terminator:
|
|
# no terminator, collect it all
|
|
self.collect_incoming_data(self.ac_in_buffer)
|
|
self.ac_in_buffer = b''
|
|
elif isinstance(terminator, int):
|
|
# numeric terminator
|
|
n = terminator
|
|
if lb < n:
|
|
self.collect_incoming_data(self.ac_in_buffer)
|
|
self.ac_in_buffer = b''
|
|
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 = self.ac_in_buffer.find(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 = b''
|
|
|
|
def handle_write(self):
|
|
self.initiate_send()
|
|
|
|
def handle_close(self):
|
|
self.close()
|
|
|
|
def push(self, data):
|
|
if not isinstance(data, (bytes, bytearray, memoryview)):
|
|
raise TypeError('data argument must be byte-ish (%r)',
|
|
type(data))
|
|
sabs = self.ac_out_buffer_size
|
|
if len(data) > sabs:
|
|
for i in range(0, len(data), sabs):
|
|
self.producer_fifo.append(data[i:i+sabs])
|
|
else:
|
|
self.producer_fifo.append(data)
|
|
self.initiate_send()
|
|
|
|
def push_with_producer(self, producer):
|
|
self.producer_fifo.append(producer)
|
|
self.initiate_send()
|
|
|
|
def readable(self):
|
|
"predicate for inclusion in the readable for select()"
|
|
# cannot use the old predicate, it violates the claim of the
|
|
# set_terminator method.
|
|
|
|
# return (len(self.ac_in_buffer) <= self.ac_in_buffer_size)
|
|
return 1
|
|
|
|
def writable(self):
|
|
"predicate for inclusion in the writable for select()"
|
|
return self.producer_fifo or (not self.connected)
|
|
|
|
def close_when_done(self):
|
|
"automatically close this channel once the outgoing queue is empty"
|
|
self.producer_fifo.append(None)
|
|
|
|
def initiate_send(self):
|
|
while self.producer_fifo and self.connected:
|
|
first = self.producer_fifo[0]
|
|
# handle empty string/buffer or None entry
|
|
if not first:
|
|
del self.producer_fifo[0]
|
|
if first is None:
|
|
self.handle_close()
|
|
return
|
|
|
|
# handle classic producer behavior
|
|
obs = self.ac_out_buffer_size
|
|
try:
|
|
data = first[:obs]
|
|
except TypeError:
|
|
data = first.more()
|
|
if data:
|
|
self.producer_fifo.appendleft(data)
|
|
else:
|
|
del self.producer_fifo[0]
|
|
continue
|
|
|
|
if isinstance(data, str) and self.use_encoding:
|
|
data = bytes(data, self.encoding)
|
|
|
|
# send the data
|
|
try:
|
|
num_sent = self.send(data)
|
|
except OSError:
|
|
self.handle_error()
|
|
return
|
|
|
|
if num_sent:
|
|
if num_sent < len(data) or obs < len(first):
|
|
self.producer_fifo[0] = first[num_sent:]
|
|
else:
|
|
del self.producer_fifo[0]
|
|
# we tried to send some actual data
|
|
return
|
|
|
|
def discard_buffers(self):
|
|
# Emergencies only!
|
|
self.ac_in_buffer = b''
|
|
del self.incoming[:]
|
|
self.producer_fifo.clear()
|
|
|
|
|
|
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 = b''
|
|
return result
|
|
|
|
|
|
# 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("qwertydkjf", "\r\n") => 0
|
|
# f_p_a_e("qwerty\r\n", "\r\n") => <undefined>
|
|
|
|
# this could maybe be made faster with a computed regex?
|
|
# [answer: no; circa Python-2.0, Jan 2001]
|
|
# new python: 28961/s
|
|
# old python: 18307/s
|
|
# re: 12820/s
|
|
# regex: 14035/s
|
|
|
|
def find_prefix_at_end(haystack, needle):
|
|
l = len(needle) - 1
|
|
while l and not haystack.endswith(needle[:l]):
|
|
l -= 1
|
|
return l
|