Mercurial > hg
view tests/tinyproxy.py @ 14007:d764463b433e
atomictempfile: avoid infinite recursion in __del__().
The problem is that a programmer using atomictempfile directly can
make an innocent everyday mistake -- not enough args to the
constructor -- which escalates badly. You would expect a simple
TypeError crash in that case, but you actually get an infinite
recursion that is surprisingly difficult to kill: it happens between
__del__() and __getattr__(), and Python does not handle infinite
recursion from __del__() well.
The fix is to not implement __getattr__(), but instead assign instance
attributes for the methods we wish to delegate to the builtin file
type: write() and fileno(). I've audited mercurial.* and hgext.* and
found no users of atomictempfile using methods other than write() and
rename(). I audited third-party extensions and found one (snap)
passing an atomictempfile to util.fstat(), so I also threw in
fileno().
The last time I submitted a similar patch, Matt proposed that we make
atomictempfile a subclass of file instead of wrapping it. Rejected on
grounds of unnecessary complexity: for one thing, it would make the
Windows implementation of posixfile quite a bit more complex. It would
have to become a subclass of file rather than a simple function -- but
since it's written in C, this is non-obvious and non-trivial.
Furthermore, there's nothing wrong with wrapping objects and
delegating methods: it's a well-established pattern that works just
fine in many cases. Subclassing is not the answer to all of life's
problems.
author | Greg Ward <greg@gerg.ca> |
---|---|
date | Sun, 24 Apr 2011 19:25:10 -0400 |
parents | 08a0f04b56bd |
children | ce99d887585f |
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#!/usr/bin/env python __doc__ = """Tiny HTTP Proxy. This module implements GET, HEAD, POST, PUT and DELETE methods on BaseHTTPServer, and behaves as an HTTP proxy. The CONNECT method is also implemented experimentally, but has not been tested yet. Any help will be greatly appreciated. SUZUKI Hisao """ __version__ = "0.2.1" import BaseHTTPServer, select, socket, SocketServer, urlparse class ProxyHandler (BaseHTTPServer.BaseHTTPRequestHandler): __base = BaseHTTPServer.BaseHTTPRequestHandler __base_handle = __base.handle server_version = "TinyHTTPProxy/" + __version__ rbufsize = 0 # self.rfile Be unbuffered def handle(self): (ip, port) = self.client_address if hasattr(self, 'allowed_clients') and ip not in self.allowed_clients: self.raw_requestline = self.rfile.readline() if self.parse_request(): self.send_error(403) else: self.__base_handle() def _connect_to(self, netloc, soc): i = netloc.find(':') if i >= 0: host_port = netloc[:i], int(netloc[i + 1:]) else: host_port = netloc, 80 print "\t" "connect to %s:%d" % host_port try: soc.connect(host_port) except socket.error, arg: try: msg = arg[1] except: msg = arg self.send_error(404, msg) return 0 return 1 def do_CONNECT(self): soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: if self._connect_to(self.path, soc): self.log_request(200) self.wfile.write(self.protocol_version + " 200 Connection established\r\n") self.wfile.write("Proxy-agent: %s\r\n" % self.version_string()) self.wfile.write("\r\n") self._read_write(soc, 300) finally: print "\t" "bye" soc.close() self.connection.close() def do_GET(self): (scm, netloc, path, params, query, fragment) = urlparse.urlparse( self.path, 'http') if scm != 'http' or fragment or not netloc: self.send_error(400, "bad url %s" % self.path) return soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM) try: if self._connect_to(netloc, soc): self.log_request() soc.send("%s %s %s\r\n" % ( self.command, urlparse.urlunparse(('', '', path, params, query, '')), self.request_version)) self.headers['Connection'] = 'close' del self.headers['Proxy-Connection'] for key_val in self.headers.items(): soc.send("%s: %s\r\n" % key_val) soc.send("\r\n") self._read_write(soc) finally: print "\t" "bye" soc.close() self.connection.close() def _read_write(self, soc, max_idling=20): iw = [self.connection, soc] ow = [] count = 0 while 1: count += 1 (ins, _, exs) = select.select(iw, ow, iw, 3) if exs: break if ins: for i in ins: if i is soc: out = self.connection else: out = soc data = i.recv(8192) if data: out.send(data) count = 0 else: print "\t" "idle", count if count == max_idling: break do_HEAD = do_GET do_POST = do_GET do_PUT = do_GET do_DELETE = do_GET class ThreadingHTTPServer (SocketServer.ThreadingMixIn, BaseHTTPServer.HTTPServer): pass if __name__ == '__main__': from sys import argv if argv[1:] and argv[1] in ('-h', '--help'): print argv[0], "[port [allowed_client_name ...]]" else: if argv[2:]: allowed = [] for name in argv[2:]: client = socket.gethostbyname(name) allowed.append(client) print "Accept: %s (%s)" % (client, name) ProxyHandler.allowed_clients = allowed del argv[2:] else: print "Any clients will be served..." BaseHTTPServer.test(ProxyHandler, ThreadingHTTPServer)