NAME Compress::LZV1 - extremely leight-weight Lev-Zimpel-Vogt compression SYNOPSIS use Compress::LZV1; $probably_compressed = compress $uncompressed_data; $original_data = uncompress $probably_compressed; DESCRIPTION LZV1 is an extremely fast (not that much slower than a pure memcpy) compression algorithm. It is ideal for applications where you want to save *some* space but not at the cost of speed. It is ideal for repetitive data as well. The module is self-contained and very small (no large library to be pulled in). I have no idea wether any patents in any countries apply to this algorithm, but at the moment it is believed that it is free from any patents. FUNCTIONS $compressed = compress $uncompressed Try to compress the given string as quickly and as much as possible. In the worst case, the string can enlarge by at most a single byte. Empty strings yield empty strings. The uncompressed data string must be smaller than 16MB (1<<24). The compressed is (currently) in one of two forms: * a literal 'U', followed by the original, uncompressed data * a literal 'L', followed by three bytes (big-endian) uncompressed length, followed by the actual LZV1 data $decompressed = decompress $compressed Uncompress the string (compressed by `compress') and return the original data. Decompression errors can result in either broken data (there is no checksum kept) or a runtime error. SEE ALSO Other Compress::* modules, especially Compress::LZO (for speed) and Compress::Zlib. AUTHOR This perl extension was written by Marc Lehmann <pcg@goof.com> (See also http://www.goof.com/pcg/marc/). The original lzv1 code was written by Hermann Vogt and put under the GPL. (There is also a i386 assembler version that is not used in this module). The lzv1 code was accompanied by the following comment: The method presented here is faster and compresses better than lzrw1 and lzrw1-a. I named it lzv for "Lev-Zimpel-Vogt". It uses ideas introduced by Ross Williams in his algorithm lzrw1 [R. N. Williams (1991): "An Extremly Fast ZIV-Lempel Data Compression Algorithm", Proceedings IEEE Data Compression Conference, Snowbird, Utah, 362-371] and by Fiala and Green in their algorithm a1 [E. R. Fiala, D. H. Greene (1989): "Data Compression with Finite Windows", Communications of the ACM, 4, 490-505]. Because lzv differs strongly from both, I hope there will be no patent problems. The hashing-method has been stolen from Jean-loup Gailly's (patent free) gzip. BUGS It seems that the c-code has _big_ alignment problems :(