On 23/1/20 2:03 am, Anatol Pomozov wrote:
Hello
On Wed, Jan 22, 2020 at 2:23 AM Allan McRae <allan@archlinux.org> wrote:
On 22/1/20 6:54 pm, Anatol Pomozov wrote:
The first experiment is to parse db tarfile using the script and then write it back to a file: uncompressed size is 17757184 that is equal to original sample 'zstd -19' compressed size is 4366994 that is 1.0084540990896713 times better than original sample
Tar *entries* content is identical to the original file. Uncompressed size is exactly the same. Compressed (zstd -19) size is 0.8% better. It comes from the fact that my script does not set entries user/group value and neither sets tar entries modification time. I am not sure if this information is actually used by pacman. Modification time contains a lot of entropy that compressor does not like.
tl;dr
"original" 4366994 no md5 4188019 no pgp 1160912 np md5+pgp 1021667
But do any of these numbers stand if you keep the tar file?
I do not fully understand your question here. plainXXX+uncomressed is a TAR file that matches current db format.
Oops... Did not look down far enough your supplied files. I downloaded db.original from your link, which is not original, and thought your numbers were based off that. A