José Mejuto wrote:
El 27/03/2013 19:22, Michalis Kamburelis escribió:Google found an old thread on lazarus mailing list about this ("FPC, gzip and stream") but without any solution, everything mentioned there has either the limitations of TCompressionStream/TDecompressionStream (no gzip format) or TGZFileStream (not able to work wit ObjectPascal streams).Hello, .gz is a quite simple format, but it can not be implemented as a TStream (only) descendant because in a single .gz file many files could be added so something like the class to handle .zip files should be used.
The existing TGZFileStream in ZStream unit already shows that it can be implemented, i.e. TGZFileStream reads gzip data and is a TStream descendant. I assume that TGZFileStream simply returns the first file inside a multi-file gzip (otherwise it would need to call gzopen multiple times, as far as I understand).
This is also my use case: I know that my .gz files should contain only one file (X3D standard guarantees it for me), I want to ignore the remaining files (if any).
Parsing the .gz header is easy, and calling TCompressionStream and TDecompressionstream over the payload should be easy, but only for the first file in the .gz
I will probably have to implement it then. I was hoping to have something available ready, since ZStream contains things that are *so* close (but not quite) to what I want :)
Thanks, Michalis _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
