python/ashd-wsgi

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