python3/ashd/serve.py

   1 import sys, os, threading, time, logging, select, queue, collections
   2 from . import perf
   3
   4 log = logging.getLogger("ashd.serve")
   5 seq = 1
   6 seqlk = threading.Lock()
   7
   8 def reqseq():
   9     global seq
  10     with seqlk:
  11         s = seq
  12         seq += 1
  13         return s
  14
  15 class closed(IOError):
  16     def __init__(self):
  17         super().__init__("The client has closed the connection.")
  18
  19 class reqthread(threading.Thread):
  20     def __init__(self, *, name=None, **kw):
  21         if name is None:
  22             name = "Request handler %i" % reqseq()
  23         super().__init__(name=name, **kw)
  24
  25 class wsgirequest(object):
  26     def __init__(self, *, handler):
  27         self.status = None
  28         self.headers = []
  29         self.respsent = False
  30         self.handler = handler
  31         self.buffer = bytearray()
  32
  33     def handlewsgi(self):
  34         raise Exception()
  35     def fileno(self):
  36         raise Exception()
  37     def writehead(self, status, headers):
  38         raise Exception()
  39     def flush(self):
  40         raise Exception()
  41     def close(self):
  42         pass
  43     def writedata(self, data):
  44         self.buffer.extend(data)
  45
  46     def flushreq(self):
  47         if not self.respsent:
  48             if not self.status:
  49                 raise Exception("Cannot send response body before starting response.")
  50             self.respsent = True
  51             self.writehead(self.status, self.headers)
  52
  53     def write(self, data):
  54         if not data:
  55             return
  56         self.flushreq()
  57         self.writedata(data)
  58         self.handler.ckflush(self)
  59
  60     def startreq(self, status, headers, exc_info=None):
  61         if self.status:
  62             if exc_info:
  63                 try:
  64                     if self.respsent:
  65                         raise exc_info[1]
  66                 finally:
  67                     exc_info = None
  68             else:
  69                 raise Exception("Can only start responding once.")
  70         self.status = status
  71         self.headers = headers
  72         return self.write
  73
  74 class handler(object):
  75     def handle(self, request):
  76         raise Exception()
  77     def ckflush(self, req):
  78         while len(req.buffer) > 0:
  79             rls, wls, els = select.select([], [req], [req])
  80             req.flush()
  81     def close(self):
  82         pass
  83
  84     @classmethod
  85     def parseargs(cls, **args):
  86         if len(args) > 0:
  87             raise ValueError("unknown handler argument: " + next(iter(args)))
  88         return {}
  89
  90 class single(handler):
  91     cname = "single"
  92
  93     def handle(self, req):
  94         try:
  95             env = req.mkenv()
  96             with perf.request(env) as reqevent:
  97                 respiter = req.handlewsgi(env, req.startreq)
  98                 for data in respiter:
  99                     req.write(data)
 100                 if req.status:
 101                     reqevent.response([req.status, req.headers])
 102                     req.flushreq()
 103                 self.ckflush(req)
 104         except closed:
 105             pass
 106         except:
 107             log.error("exception occurred when handling request", exc_info=True)
 108         finally:
 109             req.close()
 110
 111 def dbg(*a):
 112     f = True
 113     for o in a:
 114         if not f:
 115             sys.stderr.write(" ")
 116         sys.stderr.write(str(a))
 117         f = False
 118     sys.stderr.write("\n")
 119     sys.stderr.flush()
 120
 121 class freethread(handler):
 122     cname = "free"
 123
 124     def __init__(self, *, max=None, timeout=None, **kw):
 125         super().__init__(**kw)
 126         self.current = set()
 127         self.lk = threading.Lock()
 128         self.tcond = threading.Condition(self.lk)
 129         self.max = max
 130         self.timeout = timeout
 131
 132     @classmethod
 133     def parseargs(cls, *, max=None, abort=None, **args):
 134         ret = super().parseargs(**args)
 135         if max:
 136             ret["max"] = int(max)
 137         if abort:
 138             ret["timeout"] = int(abort)
 139         return ret
 140
 141     def handle(self, req):
 142         with self.lk:
 143             if self.max is not None:
 144                 if self.timeout is not None:
 145                     now = start = time.time()
 146                     while len(self.current) >= self.max:
 147                         self.tcond.wait(start + self.timeout - now)
 148                         now = time.time()
 149                         if now - start > self.timeout:
 150                             os.abort()
 151                 else:
 152                     while len(self.current) >= self.max:
 153                         self.tcond.wait()
 154             th = reqthread(target=self.run, args=[req])
 155             th.registered = False
 156             th.start()
 157             while not th.registered:
 158                 self.tcond.wait()
 159
 160     def run(self, req):
 161         try:
 162             th = threading.current_thread()
 163             with self.lk:
 164                 self.current.add(th)
 165                 th.registered = True
 166                 self.tcond.notify_all()
 167             try:
 168                 env = req.mkenv()
 169                 with perf.request(env) as reqevent:
 170                     respiter = req.handlewsgi(env, req.startreq)
 171                     for data in respiter:
 172                         req.write(data)
 173                     if req.status:
 174                         reqevent.response([req.status, req.headers])
 175                         req.flushreq()
 176                     self.ckflush(req)
 177             except closed:
 178                 pass
 179             except:
 180                 log.error("exception occurred when handling request", exc_info=True)
 181             finally:
 182                 with self.lk:
 183                     self.current.remove(th)
 184                     self.tcond.notify_all()
 185         finally:
 186             req.close()
 187
 188     def close(self):
 189         while True:
 190             with self.lk:
 191                 if len(self.current) > 0:
 192                     th = next(iter(self.current))
 193                 else:
 194                     return
 195             th.join()
 196
 197 class threadpool(handler):
 198     cname = "pool"
 199
 200     def __init__(self, *, max=25, qsz=100, timeout=None, **kw):
 201         super().__init__(**kw)
 202         self.current = set()
 203         self.clk = threading.Lock()
 204         self.ccond = threading.Condition(self.clk)
 205         self.queue = collections.deque()
 206         self.waiting = set()
 207         self.qlk = threading.Lock()
 208         self.qcond = threading.Condition(self.qlk)
 209         self.max = max
 210         self.qsz = qsz
 211         self.timeout = timeout
 212
 213     @classmethod
 214     def parseargs(cls, *, max=None, queue=None, abort=None, **args):
 215         ret = super().parseargs(**args)
 216         if max:
 217             ret["max"] = int(max)
 218         if queue:
 219             ret["qsz"] = int(queue)
 220         if abort:
 221             ret["timeout"] = int(abort)
 222         return ret
 223
 224     def handle(self, req):
 225         start = False
 226         with self.qlk:
 227             if self.timeout is not None:
 228                 now = start = time.time()
 229                 while len(self.queue) >= self.qsz:
 230                     self.qcond.wait(start + self.timeout - now)
 231                     now = time.time()
 232                     if now - start > self.timeout:
 233                         os.abort()
 234             else:
 235                 while len(self.current) >= self.qsz:
 236                     self.qcond.wait()
 237             self.queue.append(req)
 238             self.qcond.notify()
 239             if len(self.waiting) < 1:
 240                 start = True
 241         if start:
 242             with self.clk:
 243                 if len(self.current) < self.max:
 244                     th = reqthread(target=self.run)
 245                     th.registered = False
 246                     th.start()
 247                     while not th.registered:
 248                         self.ccond.wait()
 249
 250     def handle1(self, req):
 251         try:
 252             env = req.mkenv()
 253             with perf.request(env) as reqevent:
 254                 respiter = req.handlewsgi(env, req.startreq)
 255                 for data in respiter:
 256                     req.write(data)
 257                 if req.status:
 258                     reqevent.response([req.status, req.headers])
 259                     req.flushreq()
 260                 self.ckflush(req)
 261         except closed:
 262             pass
 263         except:
 264             log.error("exception occurred when handling request", exc_info=True)
 265
 266     def run(self):
 267         timeout = 10.0
 268         th = threading.current_thread()
 269         with self.clk:
 270             self.current.add(th)
 271             th.registered = True
 272             self.ccond.notify_all()
 273         try:
 274             while True:
 275                 start = now = time.time()
 276                 with self.qlk:
 277                     while len(self.queue) < 1:
 278                         self.waiting.add(th)
 279                         self.qcond.wait(start + timeout - now)
 280                         self.waiting.remove(th)
 281                         now = time.time()
 282                         if now - start > timeout:
 283                             return
 284                     req = self.queue.popleft()
 285                 try:
 286                     self.handle1(req)
 287                 finally:
 288                     req.close()
 289         finally:
 290             with self.clk:
 291                 self.current.remove(th)
 292
 293     def close(self):
 294         while True:
 295             with self.lk:
 296                 if len(self.current) > 0:
 297                     th = next(iter(self.current))
 298                 else:
 299                     return
 300             th.join()
 301
 302 class resplex(handler):
 303     cname = "rplex"
 304
 305     def __init__(self, *, max=None, **kw):
 306         super().__init__(**kw)
 307         self.current = set()
 308         self.lk = threading.Lock()
 309         self.tcond = threading.Condition(self.lk)
 310         self.max = max
 311         self.cqueue = queue.Queue(5)
 312         self.cnpipe = os.pipe()
 313         self.rthread = reqthread(name="Response thread", target=self.handle2)
 314         self.rthread.start()
 315
 316     @classmethod
 317     def parseargs(cls, *, max=None, **args):
 318         ret = super().parseargs(**args)
 319         if max:
 320             ret["max"] = int(max)
 321         return ret
 322
 323     def ckflush(self, req):
 324         raise Exception("resplex handler does not support the write() function")
 325
 326     def handle(self, req):
 327         with self.lk:
 328             if self.max is not None:
 329                 while len(self.current) >= self.max:
 330                     self.tcond.wait()
 331             th = reqthread(target=self.handle1, args=[req])
 332             th.registered = False
 333             th.start()
 334             while not th.registered:
 335                 self.tcond.wait()
 336
 337     def handle1(self, req):
 338         try:
 339             th = threading.current_thread()
 340             with self.lk:
 341                 self.current.add(th)
 342                 th.registered = True
 343                 self.tcond.notify_all()
 344             try:
 345                 env = req.mkenv()
 346                 respobj = req.handlewsgi(env, req.startreq)
 347                 respiter = iter(respobj)
 348                 if not req.status:
 349                     log.error("request handler returned without calling start_request")
 350                     if hasattr(respiter, "close"):
 351                         respiter.close()
 352                     return
 353                 else:
 354                     self.cqueue.put((req, respiter))
 355                     os.write(self.cnpipe[1], b" ")
 356                     req = None
 357             finally:
 358                 with self.lk:
 359                     self.current.remove(th)
 360                     self.tcond.notify_all()
 361         except closed:
 362             pass
 363         except:
 364             log.error("exception occurred when handling request", exc_info=True)
 365         finally:
 366             if req is not None:
 367                 req.close()
 368
 369     def handle2(self):
 370         try:
 371             rp = self.cnpipe[0]
 372             current = {}
 373
 374             def closereq(req):
 375                 respiter = current[req]
 376                 try:
 377                     if respiter is not None and hasattr(respiter, "close"):
 378                         respiter.close()
 379                 except:
 380                     log.error("exception occurred when closing iterator", exc_info=True)
 381                 try:
 382                     req.close()
 383                 except:
 384                     log.error("exception occurred when closing request", exc_info=True)
 385                 del current[req]
 386             def ckiter(req):
 387                 respiter = current[req]
 388                 if respiter is not None:
 389                     rem = False
 390                     try:
 391                         data = next(respiter)
 392                     except StopIteration:
 393                         rem = True
 394                         try:
 395                             req.flushreq()
 396                         except:
 397                             log.error("exception occurred when handling response data", exc_info=True)
 398                     except:
 399                         rem = True
 400                         log.error("exception occurred when iterating response", exc_info=True)
 401                     if not rem:
 402                         if data:
 403                             try:
 404                                 req.flushreq()
 405                                 req.writedata(data)
 406                             except:
 407                                 log.error("exception occurred when handling response data", exc_info=True)
 408                                 rem = True
 409                     if rem:
 410                         current[req] = None
 411                         try:
 412                             if hasattr(respiter, "close"):
 413                                 respiter.close()
 414                         except:
 415                             log.error("exception occurred when closing iterator", exc_info=True)
 416                         respiter = None
 417                 if respiter is None and not req.buffer:
 418                     closereq(req)
 419
 420             while True:
 421                 bufl = list(req for req in current.keys() if req.buffer)
 422                 rls, wls, els = select.select([rp], bufl, [rp] + bufl)
 423                 if rp in rls:
 424                     ret = os.read(rp, 1024)
 425                     if not ret:
 426                         os.close(rp)
 427                         return
 428                     try:
 429                         while True:
 430                             req, respiter = self.cqueue.get(False)
 431                             current[req] = respiter
 432                             ckiter(req)
 433                     except queue.Empty:
 434                         pass
 435                 for req in wls:
 436                     try:
 437                         req.flush()
 438                     except closed:
 439                         closereq(req)
 440                     except:
 441                         log.error("exception occurred when writing response", exc_info=True)
 442                         closereq(req)
 443                     else:
 444                         if len(req.buffer) < 65536:
 445                             ckiter(req)
 446         except:
 447             log.critical("unexpected exception occurred in response handler thread", exc_info=True)
 448             os.abort()
 449
 450     def close(self):
 451         while True:
 452             with self.lk:
 453                 if len(self.current) > 0:
 454                     th = next(iter(self.current))
 455                 else:
 456                     break
 457             th.join()
 458         os.close(self.cnpipe[1])
 459         self.rthread.join()
 460
 461 names = {cls.cname: cls for cls in globals().values() if
 462          isinstance(cls, type) and
 463          issubclass(cls, handler) and
 464          hasattr(cls, "cname")}
 465
 466 def parsehspec(spec):
 467     if ":" not in spec:
 468         return spec, {}
 469     nm, spec = spec.split(":", 1)
 470     args = {}
 471     while spec:
 472         if "," in spec:
 473             part, spec = spec.split(",", 1)
 474         else:
 475             part, spec = spec, None
 476         if "=" in part:
 477             key, val = part.split("=", 1)
 478         else:
 479             key, val = part, ""
 480         args[key] = val
 481     return nm, args