Re: Custom Lua Binary Sizes

[KHMan <keinhong@...>]

On 1/6/2018 10:48 AM, Sean Conner wrote:
> It was thus said that the Great Paige DePol once stated:
> > For embedded systems the parser/lexer could just be left out, obviously this
> > would require all necessary Lua code be pre-compiled (another good reason
> > for adding cross-platform bytecode genereration to 'luac' in my opinion). I
> > was also wondering if people who embed Lua precompile the source or not?
[snip snip snip]
>    Again, similar results, only the 64-bit compiled versions are larger than
> the 32-bit compiled versions.  The trick here is to determine if the size
> savings of compression are worth the extra cost of zlib support.  There's
> also the question of whether the reduction in Lua size of removing the
> parser is worth the larger size of pre-compiled Lua code.
>
>    -spc (Trade-offs, trade-offs)

More of a speed/size trade-off if we look at the available 
compression tools.

For a bit better size, one can use the last word in deflate 
compression, Zopfli [1].

[1] https://en.wikipedia.org/wiki/Zopfli

Also, one can merge data into a single file. This allows deflate 
to work better, since the sliding dictionary size is 32KB, and 
some savings will be due to fewer Huffman tables due to having 
fewer data blocks.

Or one can go for better size at a faster speed, use the 
new-and-hot finite state entropy methods, Zstandard [2] or LZFSE 
[3]. See the benchmark in [4].

[2] https://en.wikipedia.org/wiki/Zstandard
[3] https://en.wikipedia.org/wiki/LZFSE
[4] http://facebook.github.io/zstd/

Zlib is still good enough for a lot of use cases. Zstandard seems 
to match or is better than LZMA. One issue is some patent 
legalities that might run afoul of corporate lawyers. See this 
excellent post [5].

[5] 
https://gregoryszorc.com/blog/2017/03/07/better-compression-with-zstandard/


> [1]	Using zlib (lzlib module for Lua) with maximum compression.  I used
> 	maximum compression because I figure take the hit on time for
> 	compression on more powerful machines to save space on less powerful
> 	machines one might embed Lua in.


--
Cheers,
Kein-Hong Man (esq.)
Selangor, Malaysia