python3/ashd-wsgi3

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