[Zlib-devel] ABI change in zlib 1.2.4

[Mark Adler]

On Apr 3, 2010, at 3:30 AM, Enrico Weigelt wrote:
>> z_stream: the main interface to zlib (public)
>> gz_header: for passing gzip file header information when writing or reading gzip files (public)
> 
> do they have to be completely public or is it okay to publish 
> just the typedef w/o the struct decl. ?

Yes.  Their usage obviously depends on them being public.

>> z_stream->state: either the deflate or the inflate structure 
>> containing state information for compression or decompression
>> respectively (private)
>> gzFile: state for reading and writing gzip files, analogous 
>> to stdio's FILE (private)
> 
> Are these accessible from outside of zlib code ?

Yes.  But only as pointers to mysterious objects.  state is in z_stream as a contentless struct pointer, hiding the innards.  Similary, gzFile is a typedef of a void pointer, hiding the innards.

Mark