diff options
Diffstat (limited to 'wsgitools/scgi.py')
| -rw-r--r-- | wsgitools/scgi.py | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/wsgitools/scgi.py b/wsgitools/scgi.py new file mode 100644 index 0000000..e5b7dfc --- /dev/null +++ b/wsgitools/scgi.py @@ -0,0 +1,188 @@ +__all__ = [] + +import asyncore +import socket +import sys +try: + import cStringIO as StringIO +except ImportError: + import StringIO + +class SCGIConnection(asyncore.dispatcher): + """SCGI connection class used by WSGISCGIServer.""" + # maximum request size + MAX_REQUEST_SIZE = 65536 + # maximum post size + MAX_POST_SIZE = 8 << 20 + # read and write size + BLOCK_SIZE = 4096 + # connection states + NEW = 0*4 | 1 # connection established, waiting for request + HEADER = 1*4 | 1 # the request length was received, waiting for the rest + BODY = 2*4 | 1 # the request header was received, waiting for the body + REQ = 3*4 | 2 # request received, sending response + def __init__(self, server, connection, addr): + self.server = server # WSGISCGIServer instance + self.addr = addr # scgi client address + self.state = SCGIConnection.NEW # internal state + self.environ = {} # environment passed to wsgi app + self.reqlen = -1 # request length used in two different meanings + self.inbuff = "" # input buffer + self.outbuff = "" # output buffer + self.wsgihandler = None # wsgi application iterator + self.outheaders = () # headers to be sent + # () -> unset, (..,..) -> set, True -> sent + self.body = StringIO.StringIO() # request body + asyncore.dispatcher.__init__(self, connection) + + def _wsgi_headers(self): + return {"wsgi.version": (1, 0), + "wsgi.input": self.body, + "wsgi.errors": self.server.error, + "wsgi.url_scheme": "http", # TODO: this is wrong + "wsgi.multithread": False, + "wsgi.multiprocess": False, + "wsgi.run_once": False} + + def _try_send_headers(self): + if self.outheaders != True: + assert not self.outbuff + status, headers = self.outheaders + headdata = "".join(map("%s: %s\r\n".__mod__, headers)) + self.outbuff = "Status: %s\r\n%s\r\n" % (status, headdata) + self.outheaders = True + + def _wsgi_write(self, data): + assert self.state >= SCGIConnection.REQ + self._try_send_headers() + self.outbuff += data + + def readable(self): + """asyncore interface""" + return self.state & 1 == 1 + + def writable(self): + """asyncore interface""" + return self.state & 2 == 2 + + def handle_read(self): + """asyncore interface""" + data = self.recv(self.BLOCK_SIZE) + self.inbuff += data + if self.state == SCGIConnection.NEW: + if ':' in self.inbuff: + l, self.inbuff = self.inbuff.split(':', 1) + if not l.isdigit(): + self.close() + return # invalid request format + l = long(l) + if l > self.MAX_REQUEST_SIZE: + self.close() + return # request too long + self.reqlen = l + self.state = SCGIConnection.HEADER + elif len(self.inbuff) > self.MAX_REQUEST_SIZE: + self.close() + return # request too long + + if self.state == SCGIConnection.HEADER: + buff = self.inbuff[:self.reqlen] + remainder = self.inbuff[self.reqlen:] + + while buff.count('\0') >= 2: + k, v, buff = buff.split('\0', 2) + self.environ[k] = v + self.reqlen -= len(k) + len(v) + 2 + + self.inbuff = buff + remainder + + if self.reqlen == 0: + if self.inbuff.startswith(','): + self.inbuff = self.inbuff[1:] + self.reqlen = long(self.environ["CONTENT_LENGTH"]) + if self.reqlen > self.MAX_POST_SIZE: + self.close() + return + self.state = SCGIConnection.BODY + else: + self.close() + return # protocol violation + + if self.state == SCGIConnection.BODY: + if len(self.inbuff) >= self.reqlen: + self.body.write(self.inbuff[:self.reqlen]) + self.body.seek(0) + self.inbuff = "" + self.reqlen = 0 + self.environ.update(self._wsgi_headers()) + if "HTTP_CONTENT_TYPE" in self.environ: + self.environ["CONTENT_TYPE"] = \ + self.environ.pop("HTTP_CONTENT_TYPE") + if "HTTP_CONTENT_LENGTH" in self.environ: + del self.environ["HTTP_CONTENT_LENGTH"] # TODO: better way? + self.wsgihandler = iter(self.server.wsgiapp( + self.environ, self.start_response)) + self.state = SCGIConnection.REQ + else: + self.body.write(self.inbuff) + self.reqlen -= len(self.inbuff) + self.inbuff = "" + + def start_response(self, status, headers, exc_info=None): + if exc_info: + if self.outheaders == True: + try: + raise exc_info[0], exc_info[1], exc_info[2] + finally: + exc_info = None + assert self.outheaders != True # unsent + self.outheaders = (status, headers) + return self._wsgi_write + + def handle_write(self): + """asyncore interface""" + assert self.state >= SCGIConnection.REQ + if len(self.outbuff) < self.BLOCK_SIZE: + for data in self.wsgihandler: + self._try_send_headers() + self.outbuff += data + if len(self.outbuff) >= self.BLOCK_SIZE: + break + if len(self.outbuff) == 0: + if hasattr(self.wsgihandler, "close"): + self.wsgihandler.close() + self.close() + return + try: + n = self.send(self.outbuff[:self.BLOCK_SIZE]) + except socket.error: + if hasattr(self.wsgihandler, "close"): + self.wsgihandler.close() + self.close() + return + self.outbuff = self.outbuff[n:] + + def handle_close(self): + """asyncore interface""" + self.close() + +__all__.append("SCGIServer") +class SCGIServer(asyncore.dispatcher): + def __init__(self, wsgiapp, port, interface="localhost", error=sys.stderr): + asyncore.dispatcher.__init__(self) + self.wsgiapp = wsgiapp + self.error = error + self.create_socket(socket.AF_INET, socket.SOCK_STREAM) + self.set_reuse_addr() + self.bind((interface, port)) + self.listen(5) + + def handle_accept(self): + r = self.accept() + if r is not None: + conn, addr = r + SCGIConnection(self, conn, addr) + + def run(self): + asyncore.loop() + |