69 

    70 

    71 class _blockingreader(object):

    72     def __init__(self, wrapped):

    73         self._wrapped = wrapped

    74 

    75     # Do NOT implement readinto() by making it delegate to

    76     # _wrapped.readinto(), since that is unbuffered. The unpickler is fine

    77     # with just read() and readline(), so we don't need to implement it.

    78 

    79     if (3, 8, 0) <= sys.version_info[:3] < (3, 8, 2):

    80 

    81         # This is required for python 3.8, prior to 3.8.2.  See issue6444.

    82         def readinto(self, b):

    83             pos = 0

    84             size = len(b)

    85 

    86             while pos < size:

    87                 ret = self._wrapped.readinto(b[pos:])

    88                 if not ret:

    89                     break

    90                 pos += ret

    91 

    92             return pos

    93 

    94     def readline(self):

    95         return self._wrapped.readline()

    96 

    97     # issue multiple reads until size is fulfilled

    98     def read(self, size=-1):

    99         if size < 0:

   100             return self._wrapped.readall()

   101 

   102         buf = bytearray(size)

   103         view = memoryview(buf)

   104         pos = 0

   105 

   106         while pos < size:

   107             ret = self._wrapped.readinto(view[pos:])

   108             if not ret:

   109                 break

   110             pos += ret

   111 

   112         del view

   113         del buf[pos:]

   114         return bytes(buf)