wrw/dispatch.py

   1 __all__ = ["restart"]
   2
   3 class restart(Exception):
   4     def handle(self, req):
   5         pass
   6
   7 def mangle(result):
   8     try:
   9         iter(result)
  10     except TypeError:
  11         pass
  12     else:
  13         return result
  14     return [str(result)]
  15
  16 class iterproxy(object):
  17     # Makes sure iter(real).next() is called immediately, in order to
  18     # let generator code run.
  19     def __init__(self, real):
  20         self.bk = real
  21         self.bki = iter(real)
  22         self._next = [None]
  23         self.__next__()
  24
  25     def __iter__(self):
  26         return self
  27
  28     def __next__(self):
  29         if self._next is None:
  30             raise StopIteration()
  31         ret = self._next[0]
  32         try:
  33             self._next[:] = [self.bki.__next__()]
  34         except StopIteration:
  35             self._next = None
  36         return ret
  37
  38     def close(self):
  39         if hasattr(self.bk, "close"):
  40             self.bk.close()
  41
  42 def handle(req, startreq, handler):
  43     try:
  44         resp = [""]
  45         while True:
  46             try:
  47                 resp = iterproxy(handler(req))
  48                 break
  49             except restart as i:
  50                 handler = i.handle
  51         req.commit(startreq)
  52         return resp
  53     finally:
  54         req.cleanup()