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The lzma egg provides a simple wrapper around the C library lzmalib, which in turn provides access to the excellent Lempel-Ziv-Markov chain algorithm.
Two functions are provided, which simply compress or decompress a buffer represented as a Chicken blob object.
(use lzma) (blob->string (decompress (compress (string->blob "Hello, World!")))) => "Hello, World!" (blob-size (compress (string->blob "Hello, World!"))) => 32 (blob-size (compress (string->blob "Hello, World! Hello, World! Hello, World!"))) => 36
Library functions[procedure] (compress BLOB) => BLOB
Given a blob, returns a blob that's hopefully smaller, and contains all the entropy of the original blob. Returns #f in the event of failure (typically, an out-of-memory condition).[procedure] (decompress BLOB) => BLOB
Given a blob returned by compress, returns the original blob. Returns #f in the event of failure (typically, an out-of-memory condition or an invalid input).
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You'll need lzmalib installed. Source of this can be had from http://tokyocabinet.sourceforge.net/misc/lzmalib-0.0.1.tar.gz.
- 1.1: Schoolboy errors fixed
- 1.0: Initial release