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     name = req.url
  96     p = name.find('?')
  97     if p >= 0:
  98         env["QUERY_STRING"] = name[p + 1:]
  99         name = name[:p]
 100     else:
 101         env["QUERY_STRING"] = ""
 102     if name[-len(req.rest):] == req.rest:
 103         # This is the same hack used in call*cgi.
 104         name = name[:-len(req.rest)]
 105     try:
 106         pi = unquoteurl(req.rest)
 107     except:
 108         pi = req.rest
 109     if name == '/':
 110         # This seems to be normal CGI behavior, but see callcgi.c for
 111         # details.
 112         pi = "/" + pi
 113         name = ""
 114     env["SCRIPT_NAME"] = name
 115     env["PATH_INFO"] = pi
 116     if "Host" in req: env["SERVER_NAME"] = req["Host"]
 117     if "X-Ash-Server-Port" in req: env["SERVER_PORT"] = req["X-Ash-Server-Port"]
 118     if "X-Ash-Protocol" in req and req["X-Ash-Protocol"] == "https": env["HTTPS"] = "on"
 119     if "X-Ash-Address" in req: env["REMOTE_ADDR"] = req["X-Ash-Address"]
 120     if "Content-Type" in req: env["CONTENT_TYPE"] = req["Content-Type"]
 121     if "Content-Length" in req: env["CONTENT_LENGTH"] = req["Content-Length"]
 122     if "X-Ash-File" in req: env["SCRIPT_FILENAME"] = absolutify(req["X-Ash-File"])
 123     if "X-Ash-Protocol" in req: env["wsgi.url_scheme"] = req["X-Ash-Protocol"]
 124     env["wsgi.input"] = req.sk
 125     env["wsgi.errors"] = sys.stderr
 126     env["wsgi.multithread"] = True
 127     env["wsgi.multiprocess"] = False
 128     env["wsgi.run_once"] = False
 129
 130     resp = []
 131     respsent = []
 132
 133     def flushreq():
 134         if not respsent:
 135             if not resp:
 136                 raise Exception, "Trying to write data before starting response."
 137             status, headers = resp
 138             respsent[:] = [True]
 139             try:
 140                 req.sk.write("HTTP/1.1 %s\n" % status)
 141                 for nm, val in headers:
 142                     req.sk.write("%s: %s\n" % (nm, val))
 143                 req.sk.write("\n")
 144             except IOError:
 145                 raise closed()
 146
 147     def write(data):
 148         if not data:
 149             return
 150         flushreq()
 151         try:
 152             req.sk.write(data)
 153             req.sk.flush()
 154         except IOError:
 155             raise closed()
 156
 157     def startreq(status, headers, exc_info = None):
 158         if resp:
 159             if exc_info:                # Interesting, this...
 160                 try:
 161                     if respsent:
 162                         raise exc_info[0], exc_info[1], exc_info[2]
 163                 finally:
 164                     exc_info = None     # CPython GC bug?
 165             else:
 166                 raise Exception, "Can only start responding once."
 167         resp[:] = status, headers
 168         return write
 169
 170     respiter = handler(env, startreq)
 171     try:
 172         try:
 173             for data in respiter:
 174                 write(data)
 175             if resp:
 176                 flushreq()
 177         except closed:
 178             pass
 179     finally:
 180         if hasattr(respiter, "close"):
 181             respiter.close()
 182
 183 flightlock = threading.Condition()
 184 inflight = 0
 185
 186 class reqthread(threading.Thread):
 187     def __init__(self, req):
 188         super(reqthread, self).__init__(name = "Request handler")
 189         self.req = req.dup()
 190
 191     def run(self):
 192         global inflight
 193         try:
 194             flightlock.acquire()
 195             try:
 196                 if reqlimit != 0:
 197                     start = time.time()
 198                     while inflight >= reqlimit:
 199                         flightlock.wait(10)
 200                         if time.time() - start > 10:
 201                             os.abort()
 202                 inflight += 1
 203             finally:
 204                 flightlock.release()
 205             try:
 206                 dowsgi(self.req)
 207             finally:
 208                 flightlock.acquire()
 209                 try:
 210                     inflight -= 1
 211                     flightlock.notify()
 212                 finally:
 213                     flightlock.release()
 214         finally:
 215             self.req.close()
 216
 217 def handle(req):
 218     reqthread(req).start()
 219
 220 ashd.util.serveloop(handle)