# Usage: python3 seed.py OUTPUT_DIRECTORY
# Creates the same four-member USTAR fixtures used by measure.mjs.
import io,pathlib,sys,tarfile
p=pathlib.Path(sys.argv[1]);p.mkdir(parents=True,exist_ok=True)
for archive,size in [('mixed.tar',40*1024*1024),('control.tar',1)]:
    with tarfile.open(p/archive,'w',format=tarfile.USTAR_FORMAT) as t:
        for name,data in [('before.txt',b'before'),('large.txt',b'a'*size),('empty.txt',b''),('after.txt',b'after')]:
            entry=tarfile.TarInfo(name);entry.size=len(data);t.addfile(entry,io.BytesIO(data))