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.waitlimit = 5
 208         self.wlstart = 0.0
 209         self.qlk = threading.Lock()
 210         self.qcond = threading.Condition(self.qlk)
 211         self.max = max
 212         self.qsz = qsz
 213         self.timeout = timeout
 214
 215     @classmethod
 216     def parseargs(cls, *, max=None, queue=None, abort=None, **args):
 217         ret = super().parseargs(**args)
 218         if max:
 219             ret["max"] = int(max)
 220         if queue:
 221             ret["qsz"] = int(queue)
 222         if abort:
 223             ret["timeout"] = int(abort)
 224         return ret
 225
 226     def handle(self, req):
 227         spawn = False
 228         with self.qlk:
 229             if self.timeout is not None:
 230                 now = start = time.time()
 231                 while len(self.queue) >= self.qsz:
 232                     self.qcond.wait(start + self.timeout - now)
 233                     now = time.time()
 234                     if now - start > self.timeout:
 235                         os.abort()
 236             else:
 237                 while len(self.current) >= self.qsz:
 238                     self.qcond.wait()
 239             self.queue.append(req)
 240             self.qcond.notify()
 241             if len(self.waiting) < 1:
 242                 spawn = True
 243         if spawn:
 244             with self.clk:
 245                 if len(self.current) < self.max:
 246                     th = reqthread(target=self.run)
 247                     th.registered = False
 248                     th.start()
 249                     while not th.registered:
 250                         self.ccond.wait()
 251
 252     def handle1(self, req):
 253         try:
 254             env = req.mkenv()
 255             with perf.request(env) as reqevent:
 256                 respiter = req.handlewsgi(env, req.startreq)
 257                 for data in respiter:
 258                     req.write(data)
 259                 if req.status:
 260                     reqevent.response([req.status, req.headers])
 261                     req.flushreq()
 262                 self.ckflush(req)
 263         except closed:
 264             pass
 265         except:
 266             log.error("exception occurred when handling request", exc_info=True)
 267
 268     def run(self):
 269         timeout = 10.0
 270         th = threading.current_thread()
 271         with self.clk:
 272             self.current.add(th)
 273             th.registered = True
 274             self.ccond.notify_all()
 275         try:
 276             while True:
 277                 start = now = time.time()
 278                 with self.qlk:
 279                     while len(self.queue) < 1:
 280                         if len(self.waiting) >= self.waitlimit and now - self.wlstart >= timeout:
 281                             return
 282                         self.waiting.add(th)
 283                         try:
 284                             if len(self.waiting) == self.waitlimit:
 285                                 self.wlstart = now
 286                             self.qcond.wait(start + timeout - now)
 287                         finally:
 288                             self.waiting.remove(th)
 289                         now = time.time()
 290                         if now - start > timeout:
 291                             return
 292                     req = self.queue.popleft()
 293                 try:
 294                     self.handle1(req)
 295                 finally:
 296                     req.close()
 297         finally:
 298             with self.clk:
 299                 self.current.remove(th)
 300
 301     def close(self):
 302         while True:
 303             with self.clk:
 304                 if len(self.current) > 0:
 305                     th = next(iter(self.current))
 306                 else:
 307                     return
 308             th.join()
 309
 310 class resplex(handler):
 311     cname = "rplex"
 312
 313     def __init__(self, *, max=None, **kw):
 314         super().__init__(**kw)
 315         self.current = set()
 316         self.lk = threading.Lock()
 317         self.tcond = threading.Condition(self.lk)
 318         self.max = max
 319         self.cqueue = queue.Queue(5)
 320         self.cnpipe = os.pipe()
 321         self.rthread = reqthread(name="Response thread", target=self.handle2)
 322         self.rthread.start()
 323
 324     @classmethod
 325     def parseargs(cls, *, max=None, **args):
 326         ret = super().parseargs(**args)
 327         if max:
 328             ret["max"] = int(max)
 329         return ret
 330
 331     def ckflush(self, req):
 332         raise Exception("resplex handler does not support the write() function")
 333
 334     def handle(self, req):
 335         with self.lk:
 336             if self.max is not None:
 337                 while len(self.current) >= self.max:
 338                     self.tcond.wait()
 339             th = reqthread(target=self.handle1, args=[req])
 340             th.registered = False
 341             th.start()
 342             while not th.registered:
 343                 self.tcond.wait()
 344
 345     def handle1(self, req):
 346         try:
 347             th = threading.current_thread()
 348             with self.lk:
 349                 self.current.add(th)
 350                 th.registered = True
 351                 self.tcond.notify_all()
 352             try:
 353                 env = req.mkenv()
 354                 respobj = req.handlewsgi(env, req.startreq)
 355                 respiter = iter(respobj)
 356                 if not req.status:
 357                     log.error("request handler returned without calling start_request")
 358                     if hasattr(respiter, "close"):
 359                         respiter.close()
 360                     return
 361                 else:
 362                     self.cqueue.put((req, respiter))
 363                     os.write(self.cnpipe[1], b" ")
 364                     req = None
 365             finally:
 366                 with self.lk:
 367                     self.current.remove(th)
 368                     self.tcond.notify_all()
 369         except closed:
 370             pass
 371         except:
 372             log.error("exception occurred when handling request", exc_info=True)
 373         finally:
 374             if req is not None:
 375                 req.close()
 376
 377     def handle2(self):
 378         try:
 379             rp = self.cnpipe[0]
 380             current = {}
 381
 382             def closereq(req):
 383                 respiter = current[req]
 384                 try:
 385                     if respiter is not None and hasattr(respiter, "close"):
 386                         respiter.close()
 387                 except:
 388                     log.error("exception occurred when closing iterator", exc_info=True)
 389                 try:
 390                     req.close()
 391                 except:
 392                     log.error("exception occurred when closing request", exc_info=True)
 393                 del current[req]
 394             def ckiter(req):
 395                 respiter = current[req]
 396                 if respiter is not None:
 397                     rem = False
 398                     try:
 399                         data = next(respiter)
 400                     except StopIteration:
 401                         rem = True
 402                         try:
 403                             req.flushreq()
 404                         except:
 405                             log.error("exception occurred when handling response data", exc_info=True)
 406                     except:
 407                         rem = True
 408                         log.error("exception occurred when iterating response", exc_info=True)
 409                     if not rem:
 410                         if data:
 411                             try:
 412                                 req.flushreq()
 413                                 req.writedata(data)
 414                             except:
 415                                 log.error("exception occurred when handling response data", exc_info=True)
 416                                 rem = True
 417                     if rem:
 418                         current[req] = None
 419                         try:
 420                             if hasattr(respiter, "close"):
 421                                 respiter.close()
 422                         except:
 423                             log.error("exception occurred when closing iterator", exc_info=True)
 424                         respiter = None
 425                 if respiter is None and not req.buffer:
 426                     closereq(req)
 427
 428             while True:
 429                 bufl = list(req for req in current.keys() if req.buffer)
 430                 rls, wls, els = select.select([rp], bufl, [rp] + bufl)
 431                 if rp in rls:
 432                     ret = os.read(rp, 1024)
 433                     if not ret:
 434                         os.close(rp)
 435                         return
 436                     try:
 437                         while True:
 438                             req, respiter = self.cqueue.get(False)
 439                             current[req] = respiter
 440                             ckiter(req)
 441                     except queue.Empty:
 442                         pass
 443                 for req in wls:
 444                     try:
 445                         req.flush()
 446                     except closed:
 447                         closereq(req)
 448                     except:
 449                         log.error("exception occurred when writing response", exc_info=True)
 450                         closereq(req)
 451                     else:
 452                         if len(req.buffer) < 65536:
 453                             ckiter(req)
 454         except:
 455             log.critical("unexpected exception occurred in response handler thread", exc_info=True)
 456             os.abort()
 457
 458     def close(self):
 459         while True:
 460             with self.lk:
 461                 if len(self.current) > 0:
 462                     th = next(iter(self.current))
 463                 else:
 464                     break
 465             th.join()
 466         os.close(self.cnpipe[1])
 467         self.rthread.join()
 468
 469 names = {cls.cname: cls for cls in globals().values() if
 470          isinstance(cls, type) and
 471          issubclass(cls, handler) and
 472          hasattr(cls, "cname")}
 473
 474 def parsehspec(spec):
 475     if ":" not in spec:
 476         return spec, {}
 477     nm, spec = spec.split(":", 1)
 478     args = {}
 479     while spec:
 480         if "," in spec:
 481             part, spec = spec.split(",", 1)
 482         else:
 483             part, spec = spec, None
 484         if "=" in part:
 485             key, val = part.split("=", 1)
 486         else:
 487             key, val = part, ""
 488         args[key] = val
 489     return nm, args