deoxybyte-gzip

2014-01-13

No Description

Upstream URL

github.com/keithj/deoxybyte-gzip

Author

Keith James

License

GPL v3
README
Introduction This system provides gzip and gunzip functions and a Gray-streams implementation, both built on a set of lower-level zlib functions. Functions are provided for inflating and deflating to and from Lisp octet vectors and Lisp octet streams, which may be tuned using the Zlib tuning parameters described in the Zlib C function deflateInit2. In addition, a basic implementation of the data structure described in RFC1952 is included, allowing a hybrid approach to reading gzip data, using native Lisp streams and Zlib inflate/deflate. Measuring execution times of the gz:gzip and gz:gunzip functions shows deoxybyte-gzip to be fractionally slower than gzip, but over 3x slower than gunzip. Relative execution time (SBCL 1.0.40 X86-64): gzip deoxybyte-gzip gzip-stream Compression 1.0 1.1 1.1 Decompression 1.0 3.1 3.5 Timings were taken compressing and decompressing a 1.8 Gb text file using gzip/gunzip command line programs, the gz:gzip/gz:gunzip functions (which use an internal buffer of length 2^16 -1) and the Gray streams classes using gz:stream-read-sequence/gz:stream-write-sequence methods. A zlib compression level of 6 was used. This system is named with a deoxybyte- prefix because there are several existing Common Lisp packages using the gzip name and I don't want to clash with them. Installation deoxybyte-gzip uses ASDF for system definition. Copy or symlink deoxybyte-gzip.asd (and optionally deoxybyte-gzip-test.asd) to your asdf:*central-registry* and load deoxybyte-io with the asdf:operate function: (asdf:operate 'asdf:load-op :deoxybyte-gzip) or with the equivalent deoxybyte-systems:load-system function: (dxs:load-system :deoxybyte-gzip) Tests To run the unit and regression tests you need to have LIFT installed. Run the tests with the asdf:operate function: (asdf:operate 'asdf:test-op :deoxybyte-gzip) or with the equivalent deoxybyte-systems:test-system function: (dxs:test-system :deoxybyte-gzip) Documentation See the Lisp docstrings, particularly the package docstrings for an overview. HTML documentation may be generated with the command: (dxs:document-system :deoxybyte-gzip) at the REPL, provided that CLDOC is installed. Dependencies deoxybyte-systems git://github.com/keithj/deoxybyte-systems.git deoxybyte-io git://github.com/keithj/deoxybyte-io.git Optional dependencies LIFT http://common-lisp.net/project/lift/ CLDOC http://common-lisp.net/project/cldoc/

Dependencies (4)

  • deoxybyte-io
  • deoxybyte-systems
  • deoxybyte-unix
  • lift

Dependents (1)

  • GitHub
  • Quicklisp