python3/ashd-wsgi3

   1 #!/usr/bin/python3
   2
   3 import sys, os, getopt, threading, logging, time, locale, collections
   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-wsgi3 [-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:], "+hALp: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-wsgi3(%(name)s): %(levelname)s: %(message)s")
  37
  38 try:
  39     handlermod = __import__(args[0], fromlist = ["dummy"])
  40 except ImportError as exc:
  41     sys.stderr.write("ashd-wsgi3: handler %s not found: %s\n" % (args[0], exc.args[0]))
  42     sys.exit(1)
  43 if not modwsgi_compat:
  44     if not hasattr(handlermod, "wmain"):
  45         sys.stderr.write("ashd-wsgi3: 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-wsgi3: 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().__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 = bytearray()
  66     i = 0
  67     while i < len(url):
  68         c = url[i]
  69         i += 1
  70         if c == ord(b'%'):
  71             if len(url) >= i + 2:
  72                 c = 0
  73                 if ord(b'0') <= url[i] <= ord(b'9'):
  74                     c |= (url[i] - ord(b'0')) << 4
  75                 elif ord(b'a') <= url[i] <= ord(b'f'):
  76                     c |= (url[i] - ord(b'a') + 10) << 4
  77                 elif ord(b'A') <= url[i] <= ord(b'F'):
  78                     c |= (url[i] - ord(b'A') + 10) << 4
  79                 else:
  80                     raise ValueError("Illegal URL escape character")
  81                 if ord(b'0') <= url[i + 1] <= ord(b'9'):
  82                     c |= url[i + 1] - ord('0')
  83                 elif ord(b'a') <= url[i + 1] <= ord(b'f'):
  84                     c |= url[i + 1] - ord(b'a') + 10
  85                 elif ord(b'A') <= url[i + 1] <= ord(b'F'):
  86                     c |= url[i + 1] - ord(b'A') + 10
  87                 else:
  88                     raise ValueError("Illegal URL escape character")
  89                 buf.append(c)
  90                 i += 2
  91             else:
  92                 raise ValueError("Incomplete URL escape character")
  93         else:
  94             buf.append(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(b"-", b"_").decode("latin-1")] = val.decode("latin-1")
 102     env["SERVER_SOFTWARE"] = "ashd-wsgi/1"
 103     env["GATEWAY_INTERFACE"] = "CGI/1.1"
 104     env["SERVER_PROTOCOL"] = req.ver.decode("latin-1")
 105     env["REQUEST_METHOD"] = req.method.decode("latin-1")
 106     try:
 107         rawpi = unquoteurl(req.rest)
 108     except:
 109         rawpi = req.rest
 110     try:
 111         name, rest, pi = (v.decode("utf-8") for v in (req.url, req.rest, rawpi))
 112         env["wsgi.uri_encoding"] = "utf-8"
 113     except UnicodeError as exc:
 114         name, rest, pi = (v.decode("latin-1") for v in (req.url, req.rest, rawpi))
 115         env["wsgi.uri_encoding"] = "latin-1"
 116     env["REQUEST_URI"] = name
 117     p = name.find('?')
 118     if p >= 0:
 119         env["QUERY_STRING"] = name[p + 1:]
 120         name = name[:p]
 121     else:
 122         env["QUERY_STRING"] = ""
 123     if name[-len(rest):] == rest:
 124         # This is the same hack used in call*cgi.
 125         name = name[:-len(rest)]
 126     if name == "/":
 127         # This seems to be normal CGI behavior, but see callcgi.c for
 128         # details.
 129         pi = "/" + pi
 130         name = ""
 131     env["SCRIPT_NAME"] = name
 132     env["PATH_INFO"] = pi
 133     for src, tgt in [("HTTP_HOST", "SERVER_NAME"), ("HTTP_X_ASH_SERVER_PORT", "SERVER_PORT"),
 134                      ("HTTP_X_ASH_ADDRESS", "REMOTE_ADDR"), ("HTTP_CONTENT_TYPE", "CONTENT_TYPE"),
 135                      ("HTTP_CONTENT_LENGTH", "CONTENT_LENGTH"), ("HTTP_X_ASH_PROTOCOL", "wsgi.url_scheme")]:
 136         if src in env: env[tgt] = env[src]
 137     if "X-Ash-Protocol" in req and req["X-Ash-Protocol"] == b"https": env["HTTPS"] = "on"
 138     if "X-Ash-File" in req: env["SCRIPT_FILENAME"] = absolutify(req["X-Ash-File"].decode(locale.getpreferredencoding()))
 139     env["wsgi.input"] = req.sk
 140     env["wsgi.errors"] = sys.stderr
 141     env["wsgi.multithread"] = True
 142     env["wsgi.multiprocess"] = False
 143     env["wsgi.run_once"] = False
 144
 145     resp = []
 146     respsent = []
 147
 148     def recode(thing):
 149         if isinstance(thing, collections.ByteString):
 150             return thing
 151         else:
 152             return str(thing).encode("latin-1")
 153
 154     def flushreq():
 155         if not respsent:
 156             if not resp:
 157                 raise Exception("Trying to write data before starting response.")
 158             status, headers = resp
 159             respsent[:] = [True]
 160             buf = bytearray()
 161             buf += b"HTTP/1.1 " + recode(status) + b"\n"
 162             for nm, val in headers:
 163                 buf += recode(nm) + b": " + recode(val) + b"\n"
 164             buf += b"\n"
 165             try:
 166                 req.sk.write(buf)
 167             except IOError:
 168                 raise closed()
 169
 170     def write(data):
 171         if not data:
 172             return
 173         flushreq()
 174         try:
 175             req.sk.write(data)
 176             req.sk.flush()
 177         except IOError:
 178             raise closed()
 179
 180     def startreq(status, headers, exc_info = None):
 181         if resp:
 182             if exc_info:                # Interesting, this...
 183                 try:
 184                     if respsent:
 185                         raise exc_info[1]
 186                 finally:
 187                     exc_info = None     # CPython GC bug?
 188             else:
 189                 raise Exception("Can only start responding once.")
 190         resp[:] = status, headers
 191         return write
 192
 193     with ashd.perf.request(env) as reqevent:
 194         respiter = handler(env, startreq)
 195         try:
 196             try:
 197                 for data in respiter:
 198                     write(data)
 199                 if resp:
 200                     flushreq()
 201             except closed:
 202                 pass
 203         finally:
 204             if hasattr(respiter, "close"):
 205                 respiter.close()
 206         if resp:
 207             reqevent.response(resp)
 208
 209 flightlock = threading.Condition()
 210 inflight = 0
 211
 212 class reqthread(threading.Thread):
 213     def __init__(self, req):
 214         super().__init__(name = "Request handler")
 215         self.req = req.dup()
 216
 217     def run(self):
 218         global inflight
 219         try:
 220             with flightlock:
 221                 if reqlimit != 0:
 222                     start = time.time()
 223                     while inflight >= reqlimit:
 224                         flightlock.wait(10)
 225                         if time.time() - start > 10:
 226                             os.abort()
 227                 inflight += 1
 228             try:
 229                 dowsgi(self.req)
 230             finally:
 231                 with flightlock:
 232                     inflight -= 1
 233                     flightlock.notify()
 234         finally:
 235             self.req.close()
 236             sys.stderr.flush()
 237
 238 def handle(req):
 239     reqthread(req).start()
 240
 241 ashd.util.serveloop(handle)