Re: [pdf-devel] Crypt module

[jemarch]

   > 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?

   Sorry, I think I don't explain enough well.

   I mean that due to some filters, _we_ could require know the output
   size. Consider we create a new memory writing stream. It is possible
   stream doesn't fill the buffer. Then, how I know how many bytes it
   wrote?

   I hope it is clear now :-)

To know how many bytes a filter wrote in a memory backend you can use
the 'pdf_stm_tell' function, that will tell you the current read/write
position.