python/ashd-wsgi

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