Package: dpkg Version: 1.19.7 Severity: wishlist I've been thinking about parallel decompression for dpkg/xz. Is there any interest in doing this? I hacked parallel-unxz [0] in the meantime to see what is missing from the API point of view (query block offsets is missing). My idea of accomplishing this is roughly the following: During archive creation the output of tar is also analysed (like via libarchive) in order to gain the start position of the files within the uncompressed archive (which is something pixz does). Once we have those, we can reduce the list to the files which spread accross a block within the stream and those which are the first files within a block. Then on the decompression side, each thread could focus on an independent block. It starts decompressing the block and throws away data until it reaches the start of a file. Then it continues to decompress as many files as it can until it reaches the end of the block and finishes the file crossing the block boudary.
So is this something that sounds worth doing or does it sound too complex / hacky in general? [0] git://git.breakpoint.cc/bigeasy/punxz.git Sebastian
