qpress-deb :: OSSO build of qpress for Debian/Ubuntu

Wondering what files with the .qz1 extension do?

Those are single stream QuickLZ level 1 compressed files.

What is qpress?

qpress, qlzip1 and qlzcat1 do QuickLZ compression/decompression. qpress works on .qp archives with multiple files. qlzip1 and qlzcat1 work on streams of QuickLZ level 1 compressed data. For those, .qz1 is the preferred extension.

The original source code is here: qpress_1.1.orig.tar.gz

A pre-built Debian/Ubuntu package with patches is here: qpress_1.1-0osso0+anydist_amd64.deb

Building

Usage:

./Dockerfile.buildmany

Builds Debian/Ubuntu packages of qpress and qlzcat1/qlunzip1/qlzip1 for a few distributions.

Includes:

• qpress-1.1 as qpress;
• the updated quicklz.h and quicklz.c, version 1.5.1 BETA 7 (October 2011);
• qlzip1, qlunzip1, qlzcat1 that behave like gzip, gunzip and zcat, but use level 1 QuickLZ compression.

Homepage: http://www.quicklz.com/

Speed/size

qpress is significantly faster than many other compression algorithms. It is however matched in speed/compression by lz4.

As an example take this non-scientific dataset with mostly (base64 encoded) attachments:

1,137,58,9591  mailbox.tar.bz2  <- 15 minutes(!), bzip2
1,534,049,770  mailbox.tar.lz4  <- 5 seconds, lz4
1,624,953,644  mailbox.tar.qp   <- 6 seconds, qpress
1,785,057,280  mailbox.tar      <- original

General recommendation: using lz4 is better or at least equally good.