cl-zstd

1Description

cl-zstd is a Common Lisp library for Zstandard compression/decompression using bindings to the libzstd C library.

2License

cl-zstd is released under the GPL-3 license or later. See the LICENSE file for details.

3Dependencies

cl-zstd requires:

• cffi
• cl-octet-streams
• libzstd
• trivial-gray-streams

There should be a package providing libzstd in almost every GNU/Linux or *BSD distribution. For example it is called libzstd1 on Debian, zstd on Gentoo, and zstd:lib on Guix.

4API

The library can be loaded with the usual:

(asdf:load-system "zstd")

or

(quicklisp:quickload "zstd")

The functions will then be available in the zstd package.

4.1Compression

(compress-stream input output &key level) => t

Read the data from the input octet stream, compress it, and write the result to the output octet stream.

(compress-file input output &key level) => t

Read the data from the input file, compress it, and write the result to the output file.

(compress-buffer buffer &key start end level) => bytes

Read the data between the start and end offsets in the buffer, compress it, and return the resulting octet vector.

(make-compressing-stream output-stream &key level) => stream

Return a stream that will compress the bytes written to it at the given compression level and write them to the output-stream.

(with-compressing-stream (stream output-stream &key level) &body body)

Within body, stream is bound to a compressing stream for the given compression level and output-stream. The result of the last form of body is returned.

4.2Decompression

(decompress-stream input output) => t

Read the data from the input octet stream, decompress it, and write the result to the output octet stream.

(decompress-file input output) => t

Read the data from the input file, decompress it, and write the result to the output file.

(decompress-buffer buffer &key start end) => bytes

Read the data between the start and end offsets in the buffer, decompress it, and return the resulting octet vector.

(make-decompressing-stream input-stream) => stream

Return a stream that will supply the bytes resulting from the decompression of the data read from the input-stream.

(with-decompressing-stream (stream input-stream) &body body)

Within body, stream is bound to a decompressing stream for the given input-stream. The result of the last form of body is returned.

5Tests

The tests require the fiveam package. They can be run with:

(asdf:test-system "zstd")