lib/bup/io.py

   1
   2 import mmap as py_mmap
   3
   4 from bup.compat import pending_raise
   5
   6
   7 def byte_stream(file):
   8     return file.buffer
   9
  10 def path_msg(x):
  11     """Return a string representation of a path."""
  12     # FIXME: configurability (might git-config quotePath be involved?)
  13     return x.decode(errors='backslashreplace')
  14
  15
  16 assert not hasattr(py_mmap.mmap, '__del__')
  17 if hasattr(py_mmap.mmap, '__enter__'):
  18     assert hasattr(py_mmap.mmap, '__exit__')
  19
  20 class mmap(py_mmap.mmap):
  21     '''mmap.mmap wrapper that detects and complains about any instances
  22     that aren't explicitly closed.
  23
  24     '''
  25     def __new__(cls, *args, **kwargs):
  26         result = super().__new__(cls, *args, **kwargs)
  27         result._bup_closed = True  # supports __del__
  28         return result
  29
  30     def __init__(self, *args, **kwargs):
  31         # Silence deprecation warnings.  mmap's current parent is
  32         # object, which accepts no params and as of at least 2.7
  33         # warns about them.
  34         if py_mmap.mmap.__init__ is not object.__init__:
  35             super().__init__(self, *args, **kwargs)
  36         self._bup_closed = False
  37
  38     def close(self):
  39         self._bup_closed = True
  40         super(mmap, self).close()
  41
  42     if hasattr(py_mmap.mmap, '__enter__'):
  43         def __enter__(self):
  44             super(mmap, self).__enter__()
  45             return self
  46         def __exit__(self, type, value, traceback):
  47             # Don't call self.close() when the parent has its own __exit__;
  48             # defer to it.
  49             self._bup_closed = True
  50             result = super(mmap, self).__exit__(type, value, traceback)
  51             return result
  52     else:
  53         def __enter__(self):
  54             return self
  55         def __exit__(self, type, value, traceback):
  56             with pending_raise(value, rethrow=False):
  57                 self.close()
  58
  59     def __del__(self):
  60         assert self._bup_closed