From fb9ce65a91d674b1a80174c70a025aee83783388 Mon Sep 17 00:00:00 2001 From: Alexandre Vassalotti Date: Mon, 12 May 2008 01:37:10 +0000 Subject: Renamed SocketServer to 'socketserver'. Deprecated old name. --- Lib/SocketServer.py | 681 -------------------------------------------- Lib/lib-old/SocketServer.py | 8 + Lib/socketserver.py | 681 ++++++++++++++++++++++++++++++++++++++++++++ Lib/test/test_py3kwarn.py | 3 +- Misc/NEWS | 3 + 5 files changed, 694 insertions(+), 682 deletions(-) delete mode 100644 Lib/SocketServer.py create mode 100644 Lib/lib-old/SocketServer.py create mode 100644 Lib/socketserver.py diff --git a/Lib/SocketServer.py b/Lib/SocketServer.py deleted file mode 100644 index 2c41fbb..0000000 --- a/Lib/SocketServer.py +++ /dev/null @@ -1,681 +0,0 @@ -"""Generic socket server classes. - -This module tries to capture the various aspects of defining a server: - -For socket-based servers: - -- address family: - - AF_INET{,6}: IP (Internet Protocol) sockets (default) - - AF_UNIX: Unix domain sockets - - others, e.g. AF_DECNET are conceivable (see -- socket type: - - SOCK_STREAM (reliable stream, e.g. TCP) - - SOCK_DGRAM (datagrams, e.g. UDP) - -For request-based servers (including socket-based): - -- client address verification before further looking at the request - (This is actually a hook for any processing that needs to look - at the request before anything else, e.g. logging) -- how to handle multiple requests: - - synchronous (one request is handled at a time) - - forking (each request is handled by a new process) - - threading (each request is handled by a new thread) - -The classes in this module favor the server type that is simplest to -write: a synchronous TCP/IP server. This is bad class design, but -save some typing. (There's also the issue that a deep class hierarchy -slows down method lookups.) - -There are five classes in an inheritance diagram, four of which represent -synchronous servers of four types: - - +------------+ - | BaseServer | - +------------+ - | - v - +-----------+ +------------------+ - | TCPServer |------->| UnixStreamServer | - +-----------+ +------------------+ - | - v - +-----------+ +--------------------+ - | UDPServer |------->| UnixDatagramServer | - +-----------+ +--------------------+ - -Note that UnixDatagramServer derives from UDPServer, not from -UnixStreamServer -- the only difference between an IP and a Unix -stream server is the address family, which is simply repeated in both -unix server classes. - -Forking and threading versions of each type of server can be created -using the ForkingMixIn and ThreadingMixIn mix-in classes. For -instance, a threading UDP server class is created as follows: - - class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass - -The Mix-in class must come first, since it overrides a method defined -in UDPServer! Setting the various member variables also changes -the behavior of the underlying server mechanism. - -To implement a service, you must derive a class from -BaseRequestHandler and redefine its handle() method. You can then run -various versions of the service by combining one of the server classes -with your request handler class. - -The request handler class must be different for datagram or stream -services. This can be hidden by using the request handler -subclasses StreamRequestHandler or DatagramRequestHandler. - -Of course, you still have to use your head! - -For instance, it makes no sense to use a forking server if the service -contains state in memory that can be modified by requests (since the -modifications in the child process would never reach the initial state -kept in the parent process and passed to each child). In this case, -you can use a threading server, but you will probably have to use -locks to avoid two requests that come in nearly simultaneous to apply -conflicting changes to the server state. - -On the other hand, if you are building e.g. an HTTP server, where all -data is stored externally (e.g. in the file system), a synchronous -class will essentially render the service "deaf" while one request is -being handled -- which may be for a very long time if a client is slow -to reqd all the data it has requested. Here a threading or forking -server is appropriate. - -In some cases, it may be appropriate to process part of a request -synchronously, but to finish processing in a forked child depending on -the request data. This can be implemented by using a synchronous -server and doing an explicit fork in the request handler class -handle() method. - -Another approach to handling multiple simultaneous requests in an -environment that supports neither threads nor fork (or where these are -too expensive or inappropriate for the service) is to maintain an -explicit table of partially finished requests and to use select() to -decide which request to work on next (or whether to handle a new -incoming request). This is particularly important for stream services -where each client can potentially be connected for a long time (if -threads or subprocesses cannot be used). - -Future work: -- Standard classes for Sun RPC (which uses either UDP or TCP) -- Standard mix-in classes to implement various authentication - and encryption schemes -- Standard framework for select-based multiplexing - -XXX Open problems: -- What to do with out-of-band data? - -BaseServer: -- split generic "request" functionality out into BaseServer class. - Copyright (C) 2000 Luke Kenneth Casson Leighton - - example: read entries from a SQL database (requires overriding - get_request() to return a table entry from the database). - entry is processed by a RequestHandlerClass. - -""" - -# Author of the BaseServer patch: Luke Kenneth Casson Leighton - -# XXX Warning! -# There is a test suite for this module, but it cannot be run by the -# standard regression test. -# To run it manually, run Lib/test/test_socketserver.py. - -__version__ = "0.4" - - -import socket -import select -import sys -import os -try: - import threading -except ImportError: - import dummy_threading as threading - -__all__ = ["TCPServer","UDPServer","ForkingUDPServer","ForkingTCPServer", - "ThreadingUDPServer","ThreadingTCPServer","BaseRequestHandler", - "StreamRequestHandler","DatagramRequestHandler", - "ThreadingMixIn", "ForkingMixIn"] -if hasattr(socket, "AF_UNIX"): - __all__.extend(["UnixStreamServer","UnixDatagramServer", - "ThreadingUnixStreamServer", - "ThreadingUnixDatagramServer"]) - -class BaseServer: - - """Base class for server classes. - - Methods for the caller: - - - __init__(server_address, RequestHandlerClass) - - serve_forever(poll_interval=0.5) - - shutdown() - - handle_request() # if you do not use serve_forever() - - fileno() -> int # for select() - - Methods that may be overridden: - - - server_bind() - - server_activate() - - get_request() -> request, client_address - - handle_timeout() - - verify_request(request, client_address) - - server_close() - - process_request(request, client_address) - - close_request(request) - - handle_error() - - Methods for derived classes: - - - finish_request(request, client_address) - - Class variables that may be overridden by derived classes or - instances: - - - timeout - - address_family - - socket_type - - allow_reuse_address - - Instance variables: - - - RequestHandlerClass - - socket - - """ - - timeout = None - - def __init__(self, server_address, RequestHandlerClass): - """Constructor. May be extended, do not override.""" - self.server_address = server_address - self.RequestHandlerClass = RequestHandlerClass - self.__is_shut_down = threading.Event() - self.__serving = False - - def server_activate(self): - """Called by constructor to activate the server. - - May be overridden. - - """ - pass - - def serve_forever(self, poll_interval=0.5): - """Handle one request at a time until shutdown. - - Polls for shutdown every poll_interval seconds. Ignores - self.timeout. If you need to do periodic tasks, do them in - another thread. - """ - self.__serving = True - self.__is_shut_down.clear() - while self.__serving: - # XXX: Consider using another file descriptor or - # connecting to the socket to wake this up instead of - # polling. Polling reduces our responsiveness to a - # shutdown request and wastes cpu at all other times. - r, w, e = select.select([self], [], [], poll_interval) - if r: - self._handle_request_noblock() - self.__is_shut_down.set() - - def shutdown(self): - """Stops the serve_forever loop. - - Blocks until the loop has finished. This must be called while - serve_forever() is running in another thread, or it will - deadlock. - """ - self.__serving = False - self.__is_shut_down.wait() - - # The distinction between handling, getting, processing and - # finishing a request is fairly arbitrary. Remember: - # - # - handle_request() is the top-level call. It calls - # select, get_request(), verify_request() and process_request() - # - get_request() is different for stream or datagram sockets - # - process_request() is the place that may fork a new process - # or create a new thread to finish the request - # - finish_request() instantiates the request handler class; - # this constructor will handle the request all by itself - - def handle_request(self): - """Handle one request, possibly blocking. - - Respects self.timeout. - """ - # Support people who used socket.settimeout() to escape - # handle_request before self.timeout was available. - timeout = self.socket.gettimeout() - if timeout is None: - timeout = self.timeout - elif self.timeout is not None: - timeout = min(timeout, self.timeout) - fd_sets = select.select([self], [], [], timeout) - if not fd_sets[0]: - self.handle_timeout() - return - self._handle_request_noblock() - - def _handle_request_noblock(self): - """Handle one request, without blocking. - - I assume that select.select has returned that the socket is - readable before this function was called, so there should be - no risk of blocking in get_request(). - """ - try: - request, client_address = self.get_request() - except socket.error: - return - if self.verify_request(request, client_address): - try: - self.process_request(request, client_address) - except: - self.handle_error(request, client_address) - self.close_request(request) - - def handle_timeout(self): - """Called if no new request arrives within self.timeout. - - Overridden by ForkingMixIn. - """ - pass - - def verify_request(self, request, client_address): - """Verify the request. May be overridden. - - Return True if we should proceed with this request. - - """ - return True - - def process_request(self, request, client_address): - """Call finish_request. - - Overridden by ForkingMixIn and ThreadingMixIn. - - """ - self.finish_request(request, client_address) - self.close_request(request) - - def server_close(self): - """Called to clean-up the server. - - May be overridden. - - """ - pass - - def finish_request(self, request, client_address): - """Finish one request by instantiating RequestHandlerClass.""" - self.RequestHandlerClass(request, client_address, self) - - def close_request(self, request): - """Called to clean up an individual request.""" - pass - - def handle_error(self, request, client_address): - """Handle an error gracefully. May be overridden. - - The default is to print a traceback and continue. - - """ - print '-'*40 - print 'Exception happened during processing of request from', - print client_address - import traceback - traceback.print_exc() # XXX But this goes to stderr! - print '-'*40 - - -class TCPServer(BaseServer): - - """Base class for various socket-based server classes. - - Defaults to synchronous IP stream (i.e., TCP). - - Methods for the caller: - - - __init__(server_address, RequestHandlerClass, bind_and_activate=True) - - serve_forever(poll_interval=0.5) - - shutdown() - - handle_request() # if you don't use serve_forever() - - fileno() -> int # for select() - - Methods that may be overridden: - - - server_bind() - - server_activate() - - get_request() -> request, client_address - - handle_timeout() - - verify_request(request, client_address) - - process_request(request, client_address) - - close_request(request) - - handle_error() - - Methods for derived classes: - - - finish_request(request, client_address) - - Class variables that may be overridden by derived classes or - instances: - - - timeout - - address_family - - socket_type - - request_queue_size (only for stream sockets) - - allow_reuse_address - - Instance variables: - - - server_address - - RequestHandlerClass - - socket - - """ - - address_family = socket.AF_INET - - socket_type = socket.SOCK_STREAM - - request_queue_size = 5 - - allow_reuse_address = False - - def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True): - """Constructor. May be extended, do not override.""" - BaseServer.__init__(self, server_address, RequestHandlerClass) - self.socket = socket.socket(self.address_family, - self.socket_type) - if bind_and_activate: - self.server_bind() - self.server_activate() - - def server_bind(self): - """Called by constructor to bind the socket. - - May be overridden. - - """ - if self.allow_reuse_address: - self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) - self.socket.bind(self.server_address) - self.server_address = self.socket.getsockname() - - def server_activate(self): - """Called by constructor to activate the server. - - May be overridden. - - """ - self.socket.listen(self.request_queue_size) - - def server_close(self): - """Called to clean-up the server. - - May be overridden. - - """ - self.socket.close() - - def fileno(self): - """Return socket file number. - - Interface required by select(). - - """ - return self.socket.fileno() - - def get_request(self): - """Get the request and client address from the socket. - - May be overridden. - - """ - return self.socket.accept() - - def close_request(self, request): - """Called to clean up an individual request.""" - request.close() - - -class UDPServer(TCPServer): - - """UDP server class.""" - - allow_reuse_address = False - - socket_type = socket.SOCK_DGRAM - - max_packet_size = 8192 - - def get_request(self): - data, client_addr = self.socket.recvfrom(self.max_packet_size) - return (data, self.socket), client_addr - - def server_activate(self): - # No need to call listen() for UDP. - pass - - def close_request(self, request): - # No need to close anything. - pass - -class ForkingMixIn: - - """Mix-in class to handle each request in a new process.""" - - timeout = 300 - active_children = None - max_children = 40 - - def collect_children(self): - """Internal routine to wait for children that have exited.""" - if self.active_children is None: return - while len(self.active_children) >= self.max_children: - # XXX: This will wait for any child process, not just ones - # spawned by this library. This could confuse other - # libraries that expect to be able to wait for their own - # children. - try: - pid, status = os.waitpid(0, options=0) - except os.error: - pid = None - if pid not in self.active_children: continue - self.active_children.remove(pid) - - # XXX: This loop runs more system calls than it ought - # to. There should be a way to put the active_children into a - # process group and then use os.waitpid(-pgid) to wait for any - # of that set, but I couldn't find a way to allocate pgids - # that couldn't collide. - for child in self.active_children: - try: - pid, status = os.waitpid(child, os.WNOHANG) - except os.error: - pid = None - if not pid: continue - try: - self.active_children.remove(pid) - except ValueError, e: - raise ValueError('%s. x=%d and list=%r' % (e.message, pid, - self.active_children)) - - def handle_timeout(self): - """Wait for zombies after self.timeout seconds of inactivity. - - May be extended, do not override. - """ - self.collect_children() - - def process_request(self, request, client_address): - """Fork a new subprocess to process the request.""" - self.collect_children() - pid = os.fork() - if pid: - # Parent process - if self.active_children is None: - self.active_children = [] - self.active_children.append(pid) - self.close_request(request) - return - else: - # Child process. - # This must never return, hence os._exit()! - try: - self.finish_request(request, client_address) - os._exit(0) - except: - try: - self.handle_error(request, client_address) - finally: - os._exit(1) - - -class ThreadingMixIn: - """Mix-in class to handle each request in a new thread.""" - - # Decides how threads will act upon termination of the - # main process - daemon_threads = False - - def process_request_thread(self, request, client_address): - """Same as in BaseServer but as a thread. - - In addition, exception handling is done here. - - """ - try: - self.finish_request(request, client_address) - self.close_request(request) - except: - self.handle_error(request, client_address) - self.close_request(request) - - def process_request(self, request, client_address): - """Start a new thread to process the request.""" - t = threading.Thread(target = self.process_request_thread, - args = (request, client_address)) - if self.daemon_threads: - t.setDaemon (1) - t.start() - - -class ForkingUDPServer(ForkingMixIn, UDPServer): pass -class ForkingTCPServer(ForkingMixIn, TCPServer): pass - -class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass -class ThreadingTCPServer(ThreadingMixIn, TCPServer): pass - -if hasattr(socket, 'AF_UNIX'): - - class UnixStreamServer(TCPServer): - address_family = socket.AF_UNIX - - class UnixDatagramServer(UDPServer): - address_family = socket.AF_UNIX - - class ThreadingUnixStreamServer(ThreadingMixIn, UnixStreamServer): pass - - class ThreadingUnixDatagramServer(ThreadingMixIn, UnixDatagramServer): pass - -class BaseRequestHandler: - - """Base class for request handler classes. - - This class is instantiated for each request to be handled. The - constructor sets the instance variables request, client_address - and server, and then calls the handle() method. To implement a - specific service, all you need to do is to derive a class which - defines a handle() method. - - The handle() method can find the request as self.request, the - client address as self.client_address, and the server (in case it - needs access to per-server information) as self.server. Since a - separate instance is created for each request, the handle() method - can define arbitrary other instance variariables. - - """ - - def __init__(self, request, client_address, server): - self.request = request - self.client_address = client_address - self.server = server - try: - self.setup() - self.handle() - self.finish() - finally: - sys.exc_traceback = None # Help garbage collection - - def setup(self): - pass - - def handle(self): - pass - - def finish(self): - pass - - -# The following two classes make it possible to use the same service -# class for stream or datagram servers. -# Each class sets up these instance variables: -# - rfile: a file object from which receives the request is read -# - wfile: a file object to which the reply is written -# When the handle() method returns, wfile is flushed properly - - -class StreamRequestHandler(BaseRequestHandler): - - """Define self.rfile and self.wfile for stream sockets.""" - - # Default buffer sizes for rfile, wfile. - # We default rfile to buffered because otherwise it could be - # really slow for large data (a getc() call per byte); we make - # wfile unbuffered because (a) often after a write() we want to - # read and we need to flush the line; (b) big writes to unbuffered - # files are typically optimized by stdio even when big reads - # aren't. - rbufsize = -1 - wbufsize = 0 - - def setup(self): - self.connection = self.request - self.rfile = self.connection.makefile('rb', self.rbufsize) - self.wfile = self.connection.makefile('wb', self.wbufsize) - - def finish(self): - if not self.wfile.closed: - self.wfile.flush() - self.wfile.close() - self.rfile.close() - - -class DatagramRequestHandler(BaseRequestHandler): - - # XXX Regrettably, I cannot get this working on Linux; - # s.recvfrom() doesn't return a meaningful client address. - - """Define self.rfile and self.wfile for datagram sockets.""" - - def setup(self): - try: - from cStringIO import StringIO - except ImportError: - from StringIO import StringIO - self.packet, self.socket = self.request - self.rfile = StringIO(self.packet) - self.wfile = StringIO() - - def finish(self): - self.socket.sendto(self.wfile.getvalue(), self.client_address) diff --git a/Lib/lib-old/SocketServer.py b/Lib/lib-old/SocketServer.py new file mode 100644 index 0000000..9875894 --- /dev/null +++ b/Lib/lib-old/SocketServer.py @@ -0,0 +1,8 @@ +import sys +from warnings import warnpy3k + +warnpy3k("the SocketServer module has been renamed " + "to 'socketserver' in Python 3.0", stacklevel=2) + +import socketserver +sys.modules[__name__] = socketserver diff --git a/Lib/socketserver.py b/Lib/socketserver.py new file mode 100644 index 0000000..2c41fbb --- /dev/null +++ b/Lib/socketserver.py @@ -0,0 +1,681 @@ +"""Generic socket server classes. + +This module tries to capture the various aspects of defining a server: + +For socket-based servers: + +- address family: + - AF_INET{,6}: IP (Internet Protocol) sockets (default) + - AF_UNIX: Unix domain sockets + - others, e.g. AF_DECNET are conceivable (see +- socket type: + - SOCK_STREAM (reliable stream, e.g. TCP) + - SOCK_DGRAM (datagrams, e.g. UDP) + +For request-based servers (including socket-based): + +- client address verification before further looking at the request + (This is actually a hook for any processing that needs to look + at the request before anything else, e.g. logging) +- how to handle multiple requests: + - synchronous (one request is handled at a time) + - forking (each request is handled by a new process) + - threading (each request is handled by a new thread) + +The classes in this module favor the server type that is simplest to +write: a synchronous TCP/IP server. This is bad class design, but +save some typing. (There's also the issue that a deep class hierarchy +slows down method lookups.) + +There are five classes in an inheritance diagram, four of which represent +synchronous servers of four types: + + +------------+ + | BaseServer | + +------------+ + | + v + +-----------+ +------------------+ + | TCPServer |------->| UnixStreamServer | + +-----------+ +------------------+ + | + v + +-----------+ +--------------------+ + | UDPServer |------->| UnixDatagramServer | + +-----------+ +--------------------+ + +Note that UnixDatagramServer derives from UDPServer, not from +UnixStreamServer -- the only difference between an IP and a Unix +stream server is the address family, which is simply repeated in both +unix server classes. + +Forking and threading versions of each type of server can be created +using the ForkingMixIn and ThreadingMixIn mix-in classes. For +instance, a threading UDP server class is created as follows: + + class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass + +The Mix-in class must come first, since it overrides a method defined +in UDPServer! Setting the various member variables also changes +the behavior of the underlying server mechanism. + +To implement a service, you must derive a class from +BaseRequestHandler and redefine its handle() method. You can then run +various versions of the service by combining one of the server classes +with your request handler class. + +The request handler class must be different for datagram or stream +services. This can be hidden by using the request handler +subclasses StreamRequestHandler or DatagramRequestHandler. + +Of course, you still have to use your head! + +For instance, it makes no sense to use a forking server if the service +contains state in memory that can be modified by requests (since the +modifications in the child process would never reach the initial state +kept in the parent process and passed to each child). In this case, +you can use a threading server, but you will probably have to use +locks to avoid two requests that come in nearly simultaneous to apply +conflicting changes to the server state. + +On the other hand, if you are building e.g. an HTTP server, where all +data is stored externally (e.g. in the file system), a synchronous +class will essentially render the service "deaf" while one request is +being handled -- which may be for a very long time if a client is slow +to reqd all the data it has requested. Here a threading or forking +server is appropriate. + +In some cases, it may be appropriate to process part of a request +synchronously, but to finish processing in a forked child depending on +the request data. This can be implemented by using a synchronous +server and doing an explicit fork in the request handler class +handle() method. + +Another approach to handling multiple simultaneous requests in an +environment that supports neither threads nor fork (or where these are +too expensive or inappropriate for the service) is to maintain an +explicit table of partially finished requests and to use select() to +decide which request to work on next (or whether to handle a new +incoming request). This is particularly important for stream services +where each client can potentially be connected for a long time (if +threads or subprocesses cannot be used). + +Future work: +- Standard classes for Sun RPC (which uses either UDP or TCP) +- Standard mix-in classes to implement various authentication + and encryption schemes +- Standard framework for select-based multiplexing + +XXX Open problems: +- What to do with out-of-band data? + +BaseServer: +- split generic "request" functionality out into BaseServer class. + Copyright (C) 2000 Luke Kenneth Casson Leighton + + example: read entries from a SQL database (requires overriding + get_request() to return a table entry from the database). + entry is processed by a RequestHandlerClass. + +""" + +# Author of the BaseServer patch: Luke Kenneth Casson Leighton + +# XXX Warning! +# There is a test suite for this module, but it cannot be run by the +# standard regression test. +# To run it manually, run Lib/test/test_socketserver.py. + +__version__ = "0.4" + + +import socket +import select +import sys +import os +try: + import threading +except ImportError: + import dummy_threading as threading + +__all__ = ["TCPServer","UDPServer","ForkingUDPServer","ForkingTCPServer", + "ThreadingUDPServer","ThreadingTCPServer","BaseRequestHandler", + "StreamRequestHandler","DatagramRequestHandler", + "ThreadingMixIn", "ForkingMixIn"] +if hasattr(socket, "AF_UNIX"): + __all__.extend(["UnixStreamServer","UnixDatagramServer", + "ThreadingUnixStreamServer", + "ThreadingUnixDatagramServer"]) + +class BaseServer: + + """Base class for server classes. + + Methods for the caller: + + - __init__(server_address, RequestHandlerClass) + - serve_forever(poll_interval=0.5) + - shutdown() + - handle_request() # if you do not use serve_forever() + - fileno() -> int # for select() + + Methods that may be overridden: + + - server_bind() + - server_activate() + - get_request() -> request, client_address + - handle_timeout() + - verify_request(request, client_address) + - server_close() + - process_request(request, client_address) + - close_request(request) + - handle_error() + + Methods for derived classes: + + - finish_request(request, client_address) + + Class variables that may be overridden by derived classes or + instances: + + - timeout + - address_family + - socket_type + - allow_reuse_address + + Instance variables: + + - RequestHandlerClass + - socket + + """ + + timeout = None + + def __init__(self, server_address, RequestHandlerClass): + """Constructor. May be extended, do not override.""" + self.server_address = server_address + self.RequestHandlerClass = RequestHandlerClass + self.__is_shut_down = threading.Event() + self.__serving = False + + def server_activate(self): + """Called by constructor to activate the server. + + May be overridden. + + """ + pass + + def serve_forever(self, poll_interval=0.5): + """Handle one request at a time until shutdown. + + Polls for shutdown every poll_interval seconds. Ignores + self.timeout. If you need to do periodic tasks, do them in + another thread. + """ + self.__serving = True + self.__is_shut_down.clear() + while self.__serving: + # XXX: Consider using another file descriptor or + # connecting to the socket to wake this up instead of + # polling. Polling reduces our responsiveness to a + # shutdown request and wastes cpu at all other times. + r, w, e = select.select([self], [], [], poll_interval) + if r: + self._handle_request_noblock() + self.__is_shut_down.set() + + def shutdown(self): + """Stops the serve_forever loop. + + Blocks until the loop has finished. This must be called while + serve_forever() is running in another thread, or it will + deadlock. + """ + self.__serving = False + self.__is_shut_down.wait() + + # The distinction between handling, getting, processing and + # finishing a request is fairly arbitrary. Remember: + # + # - handle_request() is the top-level call. It calls + # select, get_request(), verify_request() and process_request() + # - get_request() is different for stream or datagram sockets + # - process_request() is the place that may fork a new process + # or create a new thread to finish the request + # - finish_request() instantiates the request handler class; + # this constructor will handle the request all by itself + + def handle_request(self): + """Handle one request, possibly blocking. + + Respects self.timeout. + """ + # Support people who used socket.settimeout() to escape + # handle_request before self.timeout was available. + timeout = self.socket.gettimeout() + if timeout is None: + timeout = self.timeout + elif self.timeout is not None: + timeout = min(timeout, self.timeout) + fd_sets = select.select([self], [], [], timeout) + if not fd_sets[0]: + self.handle_timeout() + return + self._handle_request_noblock() + + def _handle_request_noblock(self): + """Handle one request, without blocking. + + I assume that select.select has returned that the socket is + readable before this function was called, so there should be + no risk of blocking in get_request(). + """ + try: + request, client_address = self.get_request() + except socket.error: + return + if self.verify_request(request, client_address): + try: + self.process_request(request, client_address) + except: + self.handle_error(request, client_address) + self.close_request(request) + + def handle_timeout(self): + """Called if no new request arrives within self.timeout. + + Overridden by ForkingMixIn. + """ + pass + + def verify_request(self, request, client_address): + """Verify the request. May be overridden. + + Return True if we should proceed with this request. + + """ + return True + + def process_request(self, request, client_address): + """Call finish_request. + + Overridden by ForkingMixIn and ThreadingMixIn. + + """ + self.finish_request(request, client_address) + self.close_request(request) + + def server_close(self): + """Called to clean-up the server. + + May be overridden. + + """ + pass + + def finish_request(self, request, client_address): + """Finish one request by instantiating RequestHandlerClass.""" + self.RequestHandlerClass(request, client_address, self) + + def close_request(self, request): + """Called to clean up an individual request.""" + pass + + def handle_error(self, request, client_address): + """Handle an error gracefully. May be overridden. + + The default is to print a traceback and continue. + + """ + print '-'*40 + print 'Exception happened during processing of request from', + print client_address + import traceback + traceback.print_exc() # XXX But this goes to stderr! + print '-'*40 + + +class TCPServer(BaseServer): + + """Base class for various socket-based server classes. + + Defaults to synchronous IP stream (i.e., TCP). + + Methods for the caller: + + - __init__(server_address, RequestHandlerClass, bind_and_activate=True) + - serve_forever(poll_interval=0.5) + - shutdown() + - handle_request() # if you don't use serve_forever() + - fileno() -> int # for select() + + Methods that may be overridden: + + - server_bind() + - server_activate() + - get_request() -> request, client_address + - handle_timeout() + - verify_request(request, client_address) + - process_request(request, client_address) + - close_request(request) + - handle_error() + + Methods for derived classes: + + - finish_request(request, client_address) + + Class variables that may be overridden by derived classes or + instances: + + - timeout + - address_family + - socket_type + - request_queue_size (only for stream sockets) + - allow_reuse_address + + Instance variables: + + - server_address + - RequestHandlerClass + - socket + + """ + + address_family = socket.AF_INET + + socket_type = socket.SOCK_STREAM + + request_queue_size = 5 + + allow_reuse_address = False + + def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True): + """Constructor. May be extended, do not override.""" + BaseServer.__init__(self, server_address, RequestHandlerClass) + self.socket = socket.socket(self.address_family, + self.socket_type) + if bind_and_activate: + self.server_bind() + self.server_activate() + + def server_bind(self): + """Called by constructor to bind the socket. + + May be overridden. + + """ + if self.allow_reuse_address: + self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) + self.socket.bind(self.server_address) + self.server_address = self.socket.getsockname() + + def server_activate(self): + """Called by constructor to activate the server. + + May be overridden. + + """ + self.socket.listen(self.request_queue_size) + + def server_close(self): + """Called to clean-up the server. + + May be overridden. + + """ + self.socket.close() + + def fileno(self): + """Return socket file number. + + Interface required by select(). + + """ + return self.socket.fileno() + + def get_request(self): + """Get the request and client address from the socket. + + May be overridden. + + """ + return self.socket.accept() + + def close_request(self, request): + """Called to clean up an individual request.""" + request.close() + + +class UDPServer(TCPServer): + + """UDP server class.""" + + allow_reuse_address = False + + socket_type = socket.SOCK_DGRAM + + max_packet_size = 8192 + + def get_request(self): + data, client_addr = self.socket.recvfrom(self.max_packet_size) + return (data, self.socket), client_addr + + def server_activate(self): + # No need to call listen() for UDP. + pass + + def close_request(self, request): + # No need to close anything. + pass + +class ForkingMixIn: + + """Mix-in class to handle each request in a new process.""" + + timeout = 300 + active_children = None + max_children = 40 + + def collect_children(self): + """Internal routine to wait for children that have exited.""" + if self.active_children is None: return + while len(self.active_children) >= self.max_children: + # XXX: This will wait for any child process, not just ones + # spawned by this library. This could confuse other + # libraries that expect to be able to wait for their own + # children. + try: + pid, status = os.waitpid(0, options=0) + except os.error: + pid = None + if pid not in self.active_children: continue + self.active_children.remove(pid) + + # XXX: This loop runs more system calls than it ought + # to. There should be a way to put the active_children into a + # process group and then use os.waitpid(-pgid) to wait for any + # of that set, but I couldn't find a way to allocate pgids + # that couldn't collide. + for child in self.active_children: + try: + pid, status = os.waitpid(child, os.WNOHANG) + except os.error: + pid = None + if not pid: continue + try: + self.active_children.remove(pid) + except ValueError, e: + raise ValueError('%s. x=%d and list=%r' % (e.message, pid, + self.active_children)) + + def handle_timeout(self): + """Wait for zombies after self.timeout seconds of inactivity. + + May be extended, do not override. + """ + self.collect_children() + + def process_request(self, request, client_address): + """Fork a new subprocess to process the request.""" + self.collect_children() + pid = os.fork() + if pid: + # Parent process + if self.active_children is None: + self.active_children = [] + self.active_children.append(pid) + self.close_request(request) + return + else: + # Child process. + # This must never return, hence os._exit()! + try: + self.finish_request(request, client_address) + os._exit(0) + except: + try: + self.handle_error(request, client_address) + finally: + os._exit(1) + + +class ThreadingMixIn: + """Mix-in class to handle each request in a new thread.""" + + # Decides how threads will act upon termination of the + # main process + daemon_threads = False + + def process_request_thread(self, request, client_address): + """Same as in BaseServer but as a thread. + + In addition, exception handling is done here. + + """ + try: + self.finish_request(request, client_address) + self.close_request(request) + except: + self.handle_error(request, client_address) + self.close_request(request) + + def process_request(self, request, client_address): + """Start a new thread to process the request.""" + t = threading.Thread(target = self.process_request_thread, + args = (request, client_address)) + if self.daemon_threads: + t.setDaemon (1) + t.start() + + +class ForkingUDPServer(ForkingMixIn, UDPServer): pass +class ForkingTCPServer(ForkingMixIn, TCPServer): pass + +class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass +class ThreadingTCPServer(ThreadingMixIn, TCPServer): pass + +if hasattr(socket, 'AF_UNIX'): + + class UnixStreamServer(TCPServer): + address_family = socket.AF_UNIX + + class UnixDatagramServer(UDPServer): + address_family = socket.AF_UNIX + + class ThreadingUnixStreamServer(ThreadingMixIn, UnixStreamServer): pass + + class ThreadingUnixDatagramServer(ThreadingMixIn, UnixDatagramServer): pass + +class BaseRequestHandler: + + """Base class for request handler classes. + + This class is instantiated for each request to be handled. The + constructor sets the instance variables request, client_address + and server, and then calls the handle() method. To implement a + specific service, all you need to do is to derive a class which + defines a handle() method. + + The handle() method can find the request as self.request, the + client address as self.client_address, and the server (in case it + needs access to per-server information) as self.server. Since a + separate instance is created for each request, the handle() method + can define arbitrary other instance variariables. + + """ + + def __init__(self, request, client_address, server): + self.request = request + self.client_address = client_address + self.server = server + try: + self.setup() + self.handle() + self.finish() + finally: + sys.exc_traceback = None # Help garbage collection + + def setup(self): + pass + + def handle(self): + pass + + def finish(self): + pass + + +# The following two classes make it possible to use the same service +# class for stream or datagram servers. +# Each class sets up these instance variables: +# - rfile: a file object from which receives the request is read +# - wfile: a file object to which the reply is written +# When the handle() method returns, wfile is flushed properly + + +class StreamRequestHandler(BaseRequestHandler): + + """Define self.rfile and self.wfile for stream sockets.""" + + # Default buffer sizes for rfile, wfile. + # We default rfile to buffered because otherwise it could be + # really slow for large data (a getc() call per byte); we make + # wfile unbuffered because (a) often after a write() we want to + # read and we need to flush the line; (b) big writes to unbuffered + # files are typically optimized by stdio even when big reads + # aren't. + rbufsize = -1 + wbufsize = 0 + + def setup(self): + self.connection = self.request + self.rfile = self.connection.makefile('rb', self.rbufsize) + self.wfile = self.connection.makefile('wb', self.wbufsize) + + def finish(self): + if not self.wfile.closed: + self.wfile.flush() + self.wfile.close() + self.rfile.close() + + +class DatagramRequestHandler(BaseRequestHandler): + + # XXX Regrettably, I cannot get this working on Linux; + # s.recvfrom() doesn't return a meaningful client address. + + """Define self.rfile and self.wfile for datagram sockets.""" + + def setup(self): + try: + from cStringIO import StringIO + except ImportError: + from StringIO import StringIO + self.packet, self.socket = self.request + self.rfile = StringIO(self.packet) + self.wfile = StringIO() + + def finish(self): + self.socket.sendto(self.wfile.getvalue(), self.client_address) diff --git a/Lib/test/test_py3kwarn.py b/Lib/test/test_py3kwarn.py index a4c24d4..ef4d0b9 100644 --- a/Lib/test/test_py3kwarn.py +++ b/Lib/test/test_py3kwarn.py @@ -182,7 +182,8 @@ class TestStdlibRemovals(unittest.TestCase): class TestStdlibRenames(unittest.TestCase): - renames = {'copy_reg': 'copyreg', 'Queue': 'queue'} + renames = {'copy_reg': 'copyreg', 'Queue': 'queue', + 'SocketServer': 'socketserver'} def check_rename(self, module_name, new_module_name): """Make sure that: diff --git a/Misc/NEWS b/Misc/NEWS index 7384c9d..a15ebb4 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -26,6 +26,9 @@ Extension Modules Library ------- +- The SocketServer module has been renamed 'socketserver'. The old + name is now deprecated. + - The imageop module has been deprecated for removal in Python 3.0. - #2250: Exceptions raised during evaluation of names in rlcompleter's -- cgit v0.12