Hi,

I talked with the xz developer in IRC and he helped me to reduce memory usage.

The problem was, that compressing with lzma with 9 uncompressing needs about 
65MB of RAM. The needed memory is in fact dependend of used compression level. 
Using level 3 reduced the memory usage to about 1,5MB, that it works now on 
the NanoNote. There is a additional flag LZMA_PRESET_EXTREME, which makes 
compressing slower but compression ratio better. Using 3 + extreme results in 
a file, which works on Nanonote while the size is almost identical with 9 or 
bzip2.

Uncompressing bzip2 chunks take about 2 seconds while lzma needs 0,5 seconds 
on the nanonote. So we keep the size while improving speed with the factor 
4!!!

Have a good Year.

Tommi
_______________________________________________
dev-l mailing list
[email protected]
https://intern.openzim.org/mailman/listinfo/dev-l

Reply via email to