Ann: Zip-Ada v.51

Ann: Zip-Ada v.51

[gautier_niouzes]

URL: https://sf.net/projects/unzip-ada/

* Changes in '51', 27-Aug-2016:
  - LZMA.Encoding has been added; it is a standalone compressor,
      see lzma_enc.adb for an example of use.
  - Zip.Compress provides now LZMA_1, LZMA_2 methods. In other words, you
      can use the LZMA compression with Zip.Create.
  - Zip.Compress has also a "Preselection" method that selects
      a compression method depending on hints like the uncompressed size.
  - Zip.Compress.Deflate: Deflate_1 .. Deflate_3 compression is
      slightly better.

The LZMA format, new in Zip-Ada, is especially good for compressing database data - be it in binary or text forms. Don't be surprised if the resulting archive represent only a few percents of the original data...

Enjoy!
_________________________ 
Gautier's Ada programming 
http://gautiersblog.blogspot.com/search/label/Ada 
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Re: Ann: Zip-Ada v.51

[gautier_niouzes]

Forgot to mention that the new piece, LZMA.Encoding, has been written from scratch. The current version, fully functional, holds in only 399 lines (after going through J-P. Rosen's Normalize tool). It can be interesting for those who are curious about how the "MA" part of that compression algorithm is working.

The code can be browsed here:
http://unzip-ada.sf.net/za_html/lzma-encoding__adb.htm

I've put a few notes about range encoding used in LZMA, here:
http://gautiersblog.blogspot.ch/2016/08/lzma-compression.html

Have fun
Gautier