python/ashd-wsgi

   1 #!/usr/bin/python
   2
   3 import sys, os, getopt, threading, logging, time
   4 import ashd.proto, ashd.util, ashd.perf
   5 try:
   6     import pdm.srv
   7 except:
   8     pdm = None
   9
  10 def usage(out):
  11     out.write("usage: ashd-wsgi [-hAL] [-m PDM-SPEC] [-p MODPATH] [-l REQLIMIT] HANDLER-MODULE [ARGS...]\n")
  12
  13 reqlimit = 0
  14 modwsgi_compat = False
  15 setlog = True
  16 opts, args = getopt.getopt(sys.argv[1:], "+hAp:l:m:")
  17 for o, a in opts:
  18     if o == "-h":
  19         usage(sys.stdout)
  20         sys.exit(0)
  21     elif o == "-p":
  22         sys.path.insert(0, a)
  23     elif o == "-L":
  24         setlog = False
  25     elif o == "-A":
  26         modwsgi_compat = True
  27     elif o == "-l":
  28         reqlimit = int(a)
  29     elif o == "-m":
  30         if pdm is not None:
  31             pdm.srv.listen(a)
  32 if len(args) < 1:
  33     usage(sys.stderr)
  34     sys.exit(1)
  35 if setlog:
  36     logging.basicConfig(format="ashd-wsgi(%(name)s): %(levelname)s: %(message)s")
  37
  38 try:
  39     handlermod = __import__(args[0], fromlist = ["dummy"])
  40 except ImportError, exc:
  41     sys.stderr.write("ashd-wsgi: handler %s not found: %s\n" % (args[0], exc.message))
  42     sys.exit(1)
  43 if not modwsgi_compat:
  44     if not hasattr(handlermod, "wmain"):
  45         sys.stderr.write("ashd-wsgi: handler %s has no `wmain' function\n" % args[0])
  46         sys.exit(1)
  47     handler = handlermod.wmain(*args[1:])
  48 else:
  49     if not hasattr(handlermod, "application"):
  50         sys.stderr.write("ashd-wsgi: handler %s has no `application' object\n" % args[0])
  51         sys.exit(1)
  52     handler = handlermod.application
  53
  54 class closed(IOError):
  55     def __init__(self):
  56         super(closed, self).__init__("The client has closed the connection.")
  57
  58 cwd = os.getcwd()
  59 def absolutify(path):
  60     if path[0] != '/':
  61         return os.path.join(cwd, path)
  62     return path
  63
  64 def unquoteurl(url):
  65     buf = ""
  66     i = 0
  67     while i < len(url):
  68         c = url[i]
  69         i += 1
  70         if c == '%':
  71             if len(url) >= i + 2:
  72                 c = 0
  73                 if '0' <= url[i] <= '9':
  74                     c |= (ord(url[i]) - ord('0')) << 4
  75                 elif 'a' <= url[i] <= 'f':
  76                     c |= (ord(url[i]) - ord('a') + 10) << 4
  77                 elif 'A' <= url[i] <= 'F':
  78                     c |= (ord(url[i]) - ord('A') + 10) << 4
  79                 else:
  80                     raise ValueError("Illegal URL escape character")
  81                 if '0' <= url[i + 1] <= '9':
  82                     c |= ord(url[i + 1]) - ord('0')
  83                 elif 'a' <= url[i + 1] <= 'f':
  84                     c |= ord(url[i + 1]) - ord('a') + 10
  85                 elif 'A' <= url[i + 1] <= 'F':
  86                     c |= ord(url[i + 1]) - ord('A') + 10
  87                 else:
  88                     raise ValueError("Illegal URL escape character")
  89                 buf += chr(c)
  90                 i += 2
  91             else:
  92                 raise ValueError("Incomplete URL escape character")
  93         else:
  94             buf += c
  95     return buf
  96
  97 def dowsgi(req):
  98     env = {}
  99     env["wsgi.version"] = 1, 0
 100     for key, val in req.headers:
 101         env["HTTP_" + key.upper().replace("-", "_")] = val
 102     env["SERVER_SOFTWARE"] = "ashd-wsgi/1"
 103     env["GATEWAY_INTERFACE"] = "CGI/1.1"
 104     env["SERVER_PROTOCOL"] = req.ver
 105     env["REQUEST_METHOD"] = req.method
 106     env["REQUEST_URI"] = req.url
 107     name = req.url
 108     p = name.find('?')
 109     if p >= 0:
 110         env["QUERY_STRING"] = name[p + 1:]
 111         name = name[:p]
 112     else:
 113         env["QUERY_STRING"] = ""
 114     if name[-len(req.rest):] == req.rest:
 115         # This is the same hack used in call*cgi.
 116         name = name[:-len(req.rest)]
 117     try:
 118         pi = unquoteurl(req.rest)
 119     except:
 120         pi = req.rest
 121     if name == '/':
 122         # This seems to be normal CGI behavior, but see callcgi.c for
 123         # details.
 124         pi = "/" + pi
 125         name = ""
 126     env["SCRIPT_NAME"] = name
 127     env["PATH_INFO"] = pi
 128     if "Host" in req: env["SERVER_NAME"] = req["Host"]
 129     if "X-Ash-Server-Port" in req: env["SERVER_PORT"] = req["X-Ash-Server-Port"]
 130     if "X-Ash-Protocol" in req and req["X-Ash-Protocol"] == "https": env["HTTPS"] = "on"
 131     if "X-Ash-Address" in req: env["REMOTE_ADDR"] = req["X-Ash-Address"]
 132     if "Content-Type" in req: env["CONTENT_TYPE"] = req["Content-Type"]
 133     if "Content-Length" in req: env["CONTENT_LENGTH"] = req["Content-Length"]
 134     if "X-Ash-File" in req: env["SCRIPT_FILENAME"] = absolutify(req["X-Ash-File"])
 135     if "X-Ash-Protocol" in req: env["wsgi.url_scheme"] = req["X-Ash-Protocol"]
 136     env["wsgi.input"] = req.sk
 137     env["wsgi.errors"] = sys.stderr
 138     env["wsgi.multithread"] = True
 139     env["wsgi.multiprocess"] = False
 140     env["wsgi.run_once"] = False
 141
 142     resp = []
 143     respsent = []
 144
 145     def flushreq():
 146         if not respsent:
 147             if not resp:
 148                 raise Exception, "Trying to write data before starting response."
 149             status, headers = resp
 150             respsent[:] = [True]
 151             try:
 152                 req.sk.write("HTTP/1.1 %s\n" % status)
 153                 for nm, val in headers:
 154                     req.sk.write("%s: %s\n" % (nm, val))
 155                 req.sk.write("\n")
 156             except IOError:
 157                 raise closed()
 158
 159     def write(data):
 160         if not data:
 161             return
 162         flushreq()
 163         try:
 164             req.sk.write(data)
 165             req.sk.flush()
 166         except IOError:
 167             raise closed()
 168
 169     def startreq(status, headers, exc_info = None):
 170         if resp:
 171             if exc_info:                # Interesting, this...
 172                 try:
 173                     if respsent:
 174                         raise exc_info[0], exc_info[1], exc_info[2]
 175                 finally:
 176                     exc_info = None     # CPython GC bug?
 177             else:
 178                 raise Exception, "Can only start responding once."
 179         resp[:] = status, headers
 180         return write
 181
 182     reqevent = ashd.perf.request(env)
 183     exc = (None, None, None)
 184     try:
 185         respiter = handler(env, startreq)
 186         try:
 187             try:
 188                 for data in respiter:
 189                     write(data)
 190                 if resp:
 191                     flushreq()
 192             except closed:
 193                 pass
 194         finally:
 195             if hasattr(respiter, "close"):
 196                 respiter.close()
 197         if resp:
 198             reqevent.response(resp)
 199     except:
 200         exc = sys.exc_info()
 201         raise
 202     finally:
 203         reqevent.__exit__(*exc)
 204
 205 flightlock = threading.Condition()
 206 inflight = 0
 207
 208 class reqthread(threading.Thread):
 209     def __init__(self, req):
 210         super(reqthread, self).__init__(name = "Request handler")
 211         self.req = req.dup()
 212
 213     def run(self):
 214         global inflight
 215         try:
 216             flightlock.acquire()
 217             try:
 218                 if reqlimit != 0:
 219                     start = time.time()
 220                     while inflight >= reqlimit:
 221                         flightlock.wait(10)
 222                         if time.time() - start > 10:
 223                             os.abort()
 224                 inflight += 1
 225             finally:
 226                 flightlock.release()
 227             try:
 228                 dowsgi(self.req)
 229             finally:
 230                 flightlock.acquire()
 231                 try:
 232                     inflight -= 1
 233                     flightlock.notify()
 234                 finally:
 235                     flightlock.release()
 236         finally:
 237             self.req.close()
 238
 239 def handle(req):
 240     reqthread(req).start()
 241
 242 ashd.util.serveloop(handle)