Cnfpack

Encoder and decoder for the Cnfpack format.

Converts between the text based DIMACS CNF file format and the compressed binary Cnfpack format.

Format

Cnfpack is a compressed file format for CNF formulas. Converting a DIMACS CNF formula to and from Cnfpack maintains the order of clauses as well as the order of literals within clauses. Comments, optional whitespace or leading zeros in the DIMACS input are not stored.

Example Usage

```bash

Download example instance

wget -nv https://gbd.iti.kit.edu/file/5fb0d1f02c02c6a7fb485707b637d7e4/bvsub_12973.smt2.cnf.xz

> 2021-08-23 17:55:24 URL:https://gbd.iti.kit.edu/file/5fb0d1f02c02c6a7fb485707b637d7e4/bvsub12973.smt2.cnf.xz [1559552/1559552] -> "bvsub12973.smt2.cnf.xz" [1]

Decompress xz file

xz -dk bvsub_12973.smt2.cnf.xz

Convert to cnfpack

cnfpack bvsub12973.smt2.cnf bvsub12973.smt2.cnfpack

Check file sizes

du -bh bvsub_12973.smt2.{cnf,cnf.xz,cnfpack}

> 20M bvsub_12973.smt2.cnf

> 1.5M bvsub_12973.smt2.cnf.xz

> 2.2K bvsub_12973.smt2.cnfpack

Decompress and compute GBD hash to verify the formula

cnfpack -d bvsub_12973.smt2.cnfpack | tail +2 | head -c -1 | tr '\n' ' ' | md5sum

> 5fb0d1f02c02c6a7fb485707b637d7e4 -

^ Matches the hash in the download URL

```

Install

Make sure you have a working [Rust toolchain] and then run cargo install cnfpack to download, install and build the latest version. Alternatively I also provide [binaries for some platforms].

License

This software is available under the Zero-Clause BSD license, see LICENSE for full licensing information.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this software by you shall be licensed as defined in LICENSE.