From db9d4aa502f88fa39de69142517b4ab5f1a0d5ab Mon Sep 17 00:00:00 2001 From: Helmut Grohne Date: Tue, 17 Apr 2007 18:38:13 +0200 Subject: added wsgitools.scgi.forkpool wsgitools.scgi is now known as wsgitools.scgi.asynchronous --- wsgitools/scgi/forkpool.py | 225 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 225 insertions(+) create mode 100644 wsgitools/scgi/forkpool.py (limited to 'wsgitools/scgi/forkpool.py') diff --git a/wsgitools/scgi/forkpool.py b/wsgitools/scgi/forkpool.py new file mode 100644 index 0000000..1ff2bee --- /dev/null +++ b/wsgitools/scgi/forkpool.py @@ -0,0 +1,225 @@ +import socket +import os +import select +import sys + +class SocketFileWrapper: + """Wraps a socket to a wsgi-compliant file-like object.""" + def __init__(self, sock): + """@param sock is a socket.socket()""" + self.sock = sock + self.buff = "" + def read(self, size=None): + """see pep333""" + if size is None: + try: + return self.buff + self.sock.recv() + except: raise # Yes, this is necessary. + else: + self.buff = "" + if size >= len(self.buff): + ret, self.buff = self.buff[:size], self.buff[size:] + return ret + try: + return self.buff + self.sock.recv(size) + except: raise # Yes, this is necessary. + else: + self.buff = "" + def readline(self): + """see pep333""" + while True: + try: + split = self.buff.index('\n') + 1 + ret, self.buff = self.buff[:split], self.buff[split:] + return ret + except ValueError: + data = self.sock.recv(4096) + if not data: + ret, self.buff = self.buff, "" + return ret + self.buff += data + def readlines(self): + """see pep333""" + data = self.readline() + while data: + yield data + data = self.readline() + def __iter__(self): + """see pep333""" + return self + def next(self): + """see pep333""" + data = self.read(4096) + if not data: + raise StopIteration + return data + def flush(self): + """see pep333""" + pass + def write(self, data): + """see pep333""" + self.sock.send(data) + def writelines(self, lines): + """see pep333""" + map(self.write, lines) + +class SCGIServer: + """Usage: create an SCGIServer object and invoke the run method which will + then turn this process into an scgi server.""" + class WorkerState: + """state: 0 means idle and 1 means working. + These values are also sent as strings '0' and '1' over the socket.""" + def __init__(self, pid, sock, state): + self.pid = pid + self.sock = sock + self.state = state + + def __init__(self, wsgiapp, port, interface="localhost", error=sys.stderr, + minworkers=2, maxworkers=32, maxrequests=1000): + """Parameters: + wsgiapp is the WSGI application to be run. + port is the tcp port to listen on + interface is the interface to bind to (default: "localhost") + error is a filelike object beeing passed as wsgi.error in environ + minworkers is the number of worker processes to spawn + maxworkers is the maximum number of workers that can be spawned on demand + maxrequests is the number of requests a worker processes before dying + """ + self.wsgiapp = wsgiapp + self.port = port + self.interface = interface + self.minworkers = minworkers + self.maxworkers = maxworkers + self.maxrequests = maxrequests + self.error = error + self.server = None # becomes a socket + # maps filedescriptors to WorkerStates + self.workers = {} + + def run(self): + """ + Serve the wsgi application. + """ + self.server = socket.socket() + self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) + self.server.bind((self.interface, self.port)) + self.server.listen(5) + while True: + while (len(self.workers) < self.minworkers or # less than min + (len(self.workers) < self.maxworkers and # less than max + not len([w for w in # no inctive + self.workers.values() if w.state == 0]))): + self.spawnworker() + rs, _, _ = select.select(self.workers.keys(), [], []) + for s in rs: + data = self.workers[s].sock.recv(1) + if data == '': + self.workers[s].sock.close() + del self.workers[s] + elif data in ('0', '1'): + self.workers[s].state = int(data) + else: + raise RuntimeError, "unexpected data from worker" + try: + pid = 1 + while pid > 0: + pid, _ = os.waitpid(0, os.WNOHANG) + except OSError: + pass + + def spawnworker(self): + """ + internal! spawns a single worker + """ + srvsock, worksock = socket.socketpair() + + pid = os.fork() + if pid == 0: + # close unneeded sockets + srvsock.close() + for worker in self.workers.values(): + worker.sock.close() + del self.workers + + self.work(worksock) + + sys.exit() + elif pid > 0: + # close unneeded sockets + worksock.close() + + self.workers[srvsock.fileno()] = SCGIServer.\ + WorkerState(pid, srvsock, 0) + else: + raise RuntimeError, "fork failed" + + def work(self, worksock): + """ + internal! serves maxrequests times + """ + for _ in range(self.maxrequests): + (con, addr) = self.server.accept() + worksock.send('1') # tell server we're working + self.process(con) + worksock.send('0') # tell server we've finished + + def process(self, con): + """ + internal! processes a single request on the connection con. + """ + # This is a little bit ugly: + # The server has to send the length of the request followed by a colon. + # We assume that 1. the colon is within the first seven bytes. + # 2. the packet isn't fragmented. + # Furthermore 1 implies that the request isn't longer than 999999 bytes. + # This method however works. :-) + data = con.recv(7) + if not ':' in data: + con.close() + return + length, data = data.split(':', 1) + if not length.isdigit(): # clear protocol violation + con.close() + return + length = long(length) + + while len(data) != length + 1: # read one byte beyond + t = con.recv(length + 1 - len(data)) + if not t: # request too short + con.close() + return + data += t + + # netstrings! + data = data.split('\0') + # the byte beyond has to be a ','. + # and the number of netstrings excluding the final ',' has to be even + if data.pop() != ',' or len(data) % 2 != 0: + con.close() + return + + environ = {} + while data: + key = data.pop(0) + value = data.pop(0) + environ[key] = value + + def start_response(status, headers): + con.send('Status: %s\r\n%s\r\n\r\n' % (status, + '\r\n'.join(map("%s: %s".__mod__, headers)))) + return con.send + + environ.update({ + "wsgi.version": (1, 0), + "wsgi.input": SocketFileWrapper(con), + "wsgi.errors": self.error, + "wsgi.url_scheme": "http", # TODO: this is wrong + "wsgi.multithread": False, + "wsgi.multiprocess": True, + "wsgi.run_once": False}) + result = self.wsgiapp(environ, start_response) + for data in result: + con.send(data) + if hasattr(result, "close"): + result.close() + con.close() -- cgit v1.2.3