Re: *****POSSIBLE SPAM***** Re: [pdf-devel] Crypt module

[jemarch]

   > Currently it is not possible for a filter to know how much information
   > has been written by a writing stream. I don't see how that information
   > would be useful for a filter: the filter can record how much data was
   > filtered at the moment.

   I mean it could be required due to some filters, since the number of
   written bytes by a filter could not to be known a priori. For example,
   the number of bytes written by AESV2 filter is the lowest multiple of 16
   which is greater than the input. In this case, it can be computed
   easily. But it could not to be always like this.

In that case the number of bytes to write is a function of the number
of processed bytes. The filter can count how many bytes it processed
after the last reset, in a local way.

Consider:

   
    -> filter1 -> aesv2 -> filter2 ->


Both filter1 and filter2 may be implementing quite different filtering
algorithms. How would aesv2 benefit with the knowledge of the number
of bytes already written by filter2, for example?