901 class bufferingdecoder(object):

   902     """A CBOR decoder that buffers undecoded input.

   903 

   904     This is a glorified wrapper around ``sansiodecoder`` that adds a buffering

   905     layer. All input that isn't consumed by ``sansiodecoder`` will be buffered

   906     and concatenated with any new input that arrives later.

   907 

   908     TODO consider adding limits as to the maximum amount of data that can

   909     be buffered.

   910     """

   911     def __init__(self):

   912         self._decoder = sansiodecoder()

   913         self._leftover = None

   914 

   915     def decode(self, b):

   916         """Attempt to decode bytes to CBOR values.

   917 

   918         Returns a tuple with the following fields:

   919 

   920         * Bool indicating whether new values are available for retrieval.

   921         * Integer number of bytes decoded from the new input.

   922         * Integer number of bytes wanted to decode the next value.

   923         """

   924 

   925         if self._leftover:

   926             oldlen = len(self._leftover)

   927             b = self._leftover + b

   928             self._leftover = None

   929         else:

   930             b = b

   931             oldlen = 0

   932 

   933         available, readcount, wanted = self._decoder.decode(b)

   934 

   935         if readcount < len(b):

   936             self._leftover = b[readcount:]

   937 

   938         return available, readcount - oldlen, wanted

   939 

   940     def getavailable(self):

   941         return self._decoder.getavailable()

   942