source: titan/mediathek/localhoster/lib/python2.7/asyncore.py @ 40114

Last change on this file since 40114 was 40094, checked in by obi, 5 years ago

tithek add yoztube-dl support

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1# -*- Mode: Python -*-
2#   Id: asyncore.py,v 2.51 2000/09/07 22:29:26 rushing Exp
3#   Author: Sam Rushing <rushing@nightmare.com>
4
5# ======================================================================
6# Copyright 1996 by Sam Rushing
7#
8#                         All Rights Reserved
9#
10# Permission to use, copy, modify, and distribute this software and
11# its documentation for any purpose and without fee is hereby
12# granted, provided that the above copyright notice appear in all
13# copies and that both that copyright notice and this permission
14# notice appear in supporting documentation, and that the name of Sam
15# Rushing not be used in advertising or publicity pertaining to
16# distribution of the software without specific, written prior
17# permission.
18#
19# SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
20# INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
21# NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
22# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
23# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
24# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
25# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
26# ======================================================================
27
28"""Basic infrastructure for asynchronous socket service clients and servers.
29
30There are only two ways to have a program on a single processor do "more
31than one thing at a time".  Multi-threaded programming is the simplest and
32most popular way to do it, but there is another very different technique,
33that lets you have nearly all the advantages of multi-threading, without
34actually using multiple threads. it's really only practical if your program
35is largely I/O bound. If your program is CPU bound, then pre-emptive
36scheduled threads are probably what you really need. Network servers are
37rarely CPU-bound, however.
38
39If your operating system supports the select() system call in its I/O
40library (and nearly all do), then you can use it to juggle multiple
41communication channels at once; doing other work while your I/O is taking
42place in the "background."  Although this strategy can seem strange and
43complex, especially at first, it is in many ways easier to understand and
44control than multi-threaded programming. The module documented here solves
45many of the difficult problems for you, making the task of building
46sophisticated high-performance network servers and clients a snap.
47"""
48
49import select
50import socket
51import sys
52import time
53import warnings
54
55import os
56from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, EINVAL, \
57     ENOTCONN, ESHUTDOWN, EINTR, EISCONN, EBADF, ECONNABORTED, EPIPE, EAGAIN, \
58     errorcode
59
60_DISCONNECTED = frozenset((ECONNRESET, ENOTCONN, ESHUTDOWN, ECONNABORTED, EPIPE,
61                           EBADF))
62
63try:
64    socket_map
65except NameError:
66    socket_map = {}
67
68def _strerror(err):
69    try:
70        return os.strerror(err)
71    except (ValueError, OverflowError, NameError):
72        if err in errorcode:
73            return errorcode[err]
74        return "Unknown error %s" %err
75
76class ExitNow(Exception):
77    pass
78
79_reraised_exceptions = (ExitNow, KeyboardInterrupt, SystemExit)
80
81def read(obj):
82    try:
83        obj.handle_read_event()
84    except _reraised_exceptions:
85        raise
86    except:
87        obj.handle_error()
88
89def write(obj):
90    try:
91        obj.handle_write_event()
92    except _reraised_exceptions:
93        raise
94    except:
95        obj.handle_error()
96
97def _exception(obj):
98    try:
99        obj.handle_expt_event()
100    except _reraised_exceptions:
101        raise
102    except:
103        obj.handle_error()
104
105def readwrite(obj, flags):
106    try:
107        if flags & select.POLLIN:
108            obj.handle_read_event()
109        if flags & select.POLLOUT:
110            obj.handle_write_event()
111        if flags & select.POLLPRI:
112            obj.handle_expt_event()
113        if flags & (select.POLLHUP | select.POLLERR | select.POLLNVAL):
114            obj.handle_close()
115    except socket.error, e:
116        if e.args[0] not in _DISCONNECTED:
117            obj.handle_error()
118        else:
119            obj.handle_close()
120    except _reraised_exceptions:
121        raise
122    except:
123        obj.handle_error()
124
125def poll(timeout=0.0, map=None):
126    if map is None:
127        map = socket_map
128    if map:
129        r = []; w = []; e = []
130        for fd, obj in map.items():
131            is_r = obj.readable()
132            is_w = obj.writable()
133            if is_r:
134                r.append(fd)
135            # accepting sockets should not be writable
136            if is_w and not obj.accepting:
137                w.append(fd)
138            if is_r or is_w:
139                e.append(fd)
140        if [] == r == w == e:
141            time.sleep(timeout)
142            return
143
144        try:
145            r, w, e = select.select(r, w, e, timeout)
146        except select.error, err:
147            if err.args[0] != EINTR:
148                raise
149            else:
150                return
151
152        for fd in r:
153            obj = map.get(fd)
154            if obj is None:
155                continue
156            read(obj)
157
158        for fd in w:
159            obj = map.get(fd)
160            if obj is None:
161                continue
162            write(obj)
163
164        for fd in e:
165            obj = map.get(fd)
166            if obj is None:
167                continue
168            _exception(obj)
169
170def poll2(timeout=0.0, map=None):
171    # Use the poll() support added to the select module in Python 2.0
172    if map is None:
173        map = socket_map
174    if timeout is not None:
175        # timeout is in milliseconds
176        timeout = int(timeout*1000)
177    pollster = select.poll()
178    if map:
179        for fd, obj in map.items():
180            flags = 0
181            if obj.readable():
182                flags |= select.POLLIN | select.POLLPRI
183            # accepting sockets should not be writable
184            if obj.writable() and not obj.accepting:
185                flags |= select.POLLOUT
186            if flags:
187                # Only check for exceptions if object was either readable
188                # or writable.
189                flags |= select.POLLERR | select.POLLHUP | select.POLLNVAL
190                pollster.register(fd, flags)
191        try:
192            r = pollster.poll(timeout)
193        except select.error, err:
194            if err.args[0] != EINTR:
195                raise
196            r = []
197        for fd, flags in r:
198            obj = map.get(fd)
199            if obj is None:
200                continue
201            readwrite(obj, flags)
202
203poll3 = poll2                           # Alias for backward compatibility
204
205def loop(timeout=30.0, use_poll=False, map=None, count=None):
206    if map is None:
207        map = socket_map
208
209    if use_poll and hasattr(select, 'poll'):
210        poll_fun = poll2
211    else:
212        poll_fun = poll
213
214    if count is None:
215        while map:
216            poll_fun(timeout, map)
217
218    else:
219        while map and count > 0:
220            poll_fun(timeout, map)
221            count = count - 1
222
223class dispatcher:
224
225    debug = False
226    connected = False
227    accepting = False
228    connecting = False
229    closing = False
230    addr = None
231    ignore_log_types = frozenset(['warning'])
232
233    def __init__(self, sock=None, map=None):
234        if map is None:
235            self._map = socket_map
236        else:
237            self._map = map
238
239        self._fileno = None
240
241        if sock:
242            # Set to nonblocking just to make sure for cases where we
243            # get a socket from a blocking source.
244            sock.setblocking(0)
245            self.set_socket(sock, map)
246            self.connected = True
247            # The constructor no longer requires that the socket
248            # passed be connected.
249            try:
250                self.addr = sock.getpeername()
251            except socket.error, err:
252                if err.args[0] in (ENOTCONN, EINVAL):
253                    # To handle the case where we got an unconnected
254                    # socket.
255                    self.connected = False
256                else:
257                    # The socket is broken in some unknown way, alert
258                    # the user and remove it from the map (to prevent
259                    # polling of broken sockets).
260                    self.del_channel(map)
261                    raise
262        else:
263            self.socket = None
264
265    def __repr__(self):
266        status = [self.__class__.__module__+"."+self.__class__.__name__]
267        if self.accepting and self.addr:
268            status.append('listening')
269        elif self.connected:
270            status.append('connected')
271        if self.addr is not None:
272            try:
273                status.append('%s:%d' % self.addr)
274            except TypeError:
275                status.append(repr(self.addr))
276        return '<%s at %#x>' % (' '.join(status), id(self))
277
278    __str__ = __repr__
279
280    def add_channel(self, map=None):
281        #self.log_info('adding channel %s' % self)
282        if map is None:
283            map = self._map
284        map[self._fileno] = self
285
286    def del_channel(self, map=None):
287        fd = self._fileno
288        if map is None:
289            map = self._map
290        if fd in map:
291            #self.log_info('closing channel %d:%s' % (fd, self))
292            del map[fd]
293        self._fileno = None
294
295    def create_socket(self, family, type):
296        self.family_and_type = family, type
297        sock = socket.socket(family, type)
298        sock.setblocking(0)
299        self.set_socket(sock)
300
301    def set_socket(self, sock, map=None):
302        self.socket = sock
303##        self.__dict__['socket'] = sock
304        self._fileno = sock.fileno()
305        self.add_channel(map)
306
307    def set_reuse_addr(self):
308        # try to re-use a server port if possible
309        try:
310            self.socket.setsockopt(
311                socket.SOL_SOCKET, socket.SO_REUSEADDR,
312                self.socket.getsockopt(socket.SOL_SOCKET,
313                                       socket.SO_REUSEADDR) | 1
314                )
315        except socket.error:
316            pass
317
318    # ==================================================
319    # predicates for select()
320    # these are used as filters for the lists of sockets
321    # to pass to select().
322    # ==================================================
323
324    def readable(self):
325        return True
326
327    def writable(self):
328        return True
329
330    # ==================================================
331    # socket object methods.
332    # ==================================================
333
334    def listen(self, num):
335        self.accepting = True
336        if os.name == 'nt' and num > 5:
337            num = 5
338        return self.socket.listen(num)
339
340    def bind(self, addr):
341        self.addr = addr
342        return self.socket.bind(addr)
343
344    def connect(self, address):
345        self.connected = False
346        self.connecting = True
347        err = self.socket.connect_ex(address)
348        if err in (EINPROGRESS, EALREADY, EWOULDBLOCK) \
349        or err == EINVAL and os.name in ('nt', 'ce'):
350            self.addr = address
351            return
352        if err in (0, EISCONN):
353            self.addr = address
354            self.handle_connect_event()
355        else:
356            raise socket.error(err, errorcode[err])
357
358    def accept(self):
359        # XXX can return either an address pair or None
360        try:
361            conn, addr = self.socket.accept()
362        except TypeError:
363            return None
364        except socket.error as why:
365            if why.args[0] in (EWOULDBLOCK, ECONNABORTED, EAGAIN):
366                return None
367            else:
368                raise
369        else:
370            return conn, addr
371
372    def send(self, data):
373        try:
374            result = self.socket.send(data)
375            return result
376        except socket.error, why:
377            if why.args[0] == EWOULDBLOCK:
378                return 0
379            elif why.args[0] in _DISCONNECTED:
380                self.handle_close()
381                return 0
382            else:
383                raise
384
385    def recv(self, buffer_size):
386        try:
387            data = self.socket.recv(buffer_size)
388            if not data:
389                # a closed connection is indicated by signaling
390                # a read condition, and having recv() return 0.
391                self.handle_close()
392                return ''
393            else:
394                return data
395        except socket.error, why:
396            # winsock sometimes raises ENOTCONN
397            if why.args[0] in _DISCONNECTED:
398                self.handle_close()
399                return ''
400            else:
401                raise
402
403    def close(self):
404        self.connected = False
405        self.accepting = False
406        self.connecting = False
407        self.del_channel()
408        try:
409            self.socket.close()
410        except socket.error, why:
411            if why.args[0] not in (ENOTCONN, EBADF):
412                raise
413
414    # cheap inheritance, used to pass all other attribute
415    # references to the underlying socket object.
416    def __getattr__(self, attr):
417        try:
418            retattr = getattr(self.socket, attr)
419        except AttributeError:
420            raise AttributeError("%s instance has no attribute '%s'"
421                                 %(self.__class__.__name__, attr))
422        else:
423            msg = "%(me)s.%(attr)s is deprecated. Use %(me)s.socket.%(attr)s " \
424                  "instead." % {'me': self.__class__.__name__, 'attr':attr}
425            warnings.warn(msg, DeprecationWarning, stacklevel=2)
426            return retattr
427
428    # log and log_info may be overridden to provide more sophisticated
429    # logging and warning methods. In general, log is for 'hit' logging
430    # and 'log_info' is for informational, warning and error logging.
431
432    def log(self, message):
433        sys.stderr.write('log: %s\n' % str(message))
434
435    def log_info(self, message, type='info'):
436        if type not in self.ignore_log_types:
437            print '%s: %s' % (type, message)
438
439    def handle_read_event(self):
440        if self.accepting:
441            # accepting sockets are never connected, they "spawn" new
442            # sockets that are connected
443            self.handle_accept()
444        elif not self.connected:
445            if self.connecting:
446                self.handle_connect_event()
447            self.handle_read()
448        else:
449            self.handle_read()
450
451    def handle_connect_event(self):
452        err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
453        if err != 0:
454            raise socket.error(err, _strerror(err))
455        self.handle_connect()
456        self.connected = True
457        self.connecting = False
458
459    def handle_write_event(self):
460        if self.accepting:
461            # Accepting sockets shouldn't get a write event.
462            # We will pretend it didn't happen.
463            return
464
465        if not self.connected:
466            if self.connecting:
467                self.handle_connect_event()
468        self.handle_write()
469
470    def handle_expt_event(self):
471        # handle_expt_event() is called if there might be an error on the
472        # socket, or if there is OOB data
473        # check for the error condition first
474        err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
475        if err != 0:
476            # we can get here when select.select() says that there is an
477            # exceptional condition on the socket
478            # since there is an error, we'll go ahead and close the socket
479            # like we would in a subclassed handle_read() that received no
480            # data
481            self.handle_close()
482        else:
483            self.handle_expt()
484
485    def handle_error(self):
486        nil, t, v, tbinfo = compact_traceback()
487
488        # sometimes a user repr method will crash.
489        try:
490            self_repr = repr(self)
491        except:
492            self_repr = '<__repr__(self) failed for object at %0x>' % id(self)
493
494        self.log_info(
495            'uncaptured python exception, closing channel %s (%s:%s %s)' % (
496                self_repr,
497                t,
498                v,
499                tbinfo
500                ),
501            'error'
502            )
503        self.handle_close()
504
505    def handle_expt(self):
506        self.log_info('unhandled incoming priority event', 'warning')
507
508    def handle_read(self):
509        self.log_info('unhandled read event', 'warning')
510
511    def handle_write(self):
512        self.log_info('unhandled write event', 'warning')
513
514    def handle_connect(self):
515        self.log_info('unhandled connect event', 'warning')
516
517    def handle_accept(self):
518        self.log_info('unhandled accept event', 'warning')
519
520    def handle_close(self):
521        self.log_info('unhandled close event', 'warning')
522        self.close()
523
524# ---------------------------------------------------------------------------
525# adds simple buffered output capability, useful for simple clients.
526# [for more sophisticated usage use asynchat.async_chat]
527# ---------------------------------------------------------------------------
528
529class dispatcher_with_send(dispatcher):
530
531    def __init__(self, sock=None, map=None):
532        dispatcher.__init__(self, sock, map)
533        self.out_buffer = ''
534
535    def initiate_send(self):
536        num_sent = 0
537        num_sent = dispatcher.send(self, self.out_buffer[:512])
538        self.out_buffer = self.out_buffer[num_sent:]
539
540    def handle_write(self):
541        self.initiate_send()
542
543    def writable(self):
544        return (not self.connected) or len(self.out_buffer)
545
546    def send(self, data):
547        if self.debug:
548            self.log_info('sending %s' % repr(data))
549        self.out_buffer = self.out_buffer + data
550        self.initiate_send()
551
552# ---------------------------------------------------------------------------
553# used for debugging.
554# ---------------------------------------------------------------------------
555
556def compact_traceback():
557    t, v, tb = sys.exc_info()
558    tbinfo = []
559    if not tb: # Must have a traceback
560        raise AssertionError("traceback does not exist")
561    while tb:
562        tbinfo.append((
563            tb.tb_frame.f_code.co_filename,
564            tb.tb_frame.f_code.co_name,
565            str(tb.tb_lineno)
566            ))
567        tb = tb.tb_next
568
569    # just to be safe
570    del tb
571
572    file, function, line = tbinfo[-1]
573    info = ' '.join(['[%s|%s|%s]' % x for x in tbinfo])
574    return (file, function, line), t, v, info
575
576def close_all(map=None, ignore_all=False):
577    if map is None:
578        map = socket_map
579    for x in map.values():
580        try:
581            x.close()
582        except OSError, x:
583            if x.args[0] == EBADF:
584                pass
585            elif not ignore_all:
586                raise
587        except _reraised_exceptions:
588            raise
589        except:
590            if not ignore_all:
591                raise
592    map.clear()
593
594# Asynchronous File I/O:
595#
596# After a little research (reading man pages on various unixen, and
597# digging through the linux kernel), I've determined that select()
598# isn't meant for doing asynchronous file i/o.
599# Heartening, though - reading linux/mm/filemap.c shows that linux
600# supports asynchronous read-ahead.  So _MOST_ of the time, the data
601# will be sitting in memory for us already when we go to read it.
602#
603# What other OS's (besides NT) support async file i/o?  [VMS?]
604#
605# Regardless, this is useful for pipes, and stdin/stdout...
606
607if os.name == 'posix':
608    import fcntl
609
610    class file_wrapper:
611        # Here we override just enough to make a file
612        # look like a socket for the purposes of asyncore.
613        # The passed fd is automatically os.dup()'d
614
615        def __init__(self, fd):
616            self.fd = os.dup(fd)
617
618        def recv(self, *args):
619            return os.read(self.fd, *args)
620
621        def send(self, *args):
622            return os.write(self.fd, *args)
623
624        def getsockopt(self, level, optname, buflen=None):
625            if (level == socket.SOL_SOCKET and
626                optname == socket.SO_ERROR and
627                not buflen):
628                return 0
629            raise NotImplementedError("Only asyncore specific behaviour "
630                                      "implemented.")
631
632        read = recv
633        write = send
634
635        def close(self):
636            os.close(self.fd)
637
638        def fileno(self):
639            return self.fd
640
641    class file_dispatcher(dispatcher):
642
643        def __init__(self, fd, map=None):
644            dispatcher.__init__(self, None, map)
645            self.connected = True
646            try:
647                fd = fd.fileno()
648            except AttributeError:
649                pass
650            self.set_file(fd)
651            # set it to non-blocking mode
652            flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
653            flags = flags | os.O_NONBLOCK
654            fcntl.fcntl(fd, fcntl.F_SETFL, flags)
655
656        def set_file(self, fd):
657            self.socket = file_wrapper(fd)
658            self._fileno = self.socket.fileno()
659            self.add_channel()
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