1Compress::LZ4(3) User Contributed Perl Documentation Compress::LZ4(3)
2
6 Compress::LZ4 - Perl interface to the LZ4 (de)compressor
7
9 use Compress::LZ4;
10 my $compressed = compress($bytes);
12 my $decompressed = decompress($compressed);
13
15 The "Compress::LZ4" module provides an interface to the LZ4
16 (de)compressor.
17
19 compress
20 $compressed = compress($bytes [, $level])
21 Compresses the given buffer and returns the resulting bytes. The input
23 buffer can be either a scalar or a scalar reference. The default
24 acceleration level (1) can be changed, with each additional level
25 providing ~3% increase in speed; the compression level will be
26 negatively affected.
27 compress_hc
29 $compressed = compress_hc($bytes [, $level])
30 A higher-compression, but slower, version of "compress". The default
32 compression level (9) can be changed if an optional value (0-16) is
33 given.
34 decompress
36 uncompress
37 $bytes = decompress($compressed)
38 Decompresses the given buffer and returns the resulting bytes. The
40 input buffer can be either a scalar or a scalar reference.
41 On error (in case of corrupted data) undef is returned.
43
45 This library does not produce output that is compatible with the
46 official frame format. Because LZ4 did not define a container format
47 until long after it was released, many bindings, including this one,
48 prepend the original data size to the compressed data as a little-
49 endian 4-byte integer.
50 If you are dealing with raw data from an external source that does not
52 format the data this way, you need to use the following functions:
53 lz4_compress
55 lz4_compress_hc
56 Same as "compress"/"compress_hc" but does not add the length header.
57 lz4_decompress
59 lz4_uncompress
60 $bytes = decompress($compressed, $original_data_size)
61 Same as "decompress"/"uncompress" but also requires the original data
63 size to be given.
64
66 This distribution contains a benchmarking script which compares several
67 modules available on CPAN. These are the results on a MacBook 2.6GHz
68 Core i5 (64-bit) with Perl 5.24.1:
69 Compressible data (10 KiB) - compression
71 ----------------------------------------
72 Compress::LZ4::compress 8 670690/s 6550 MiB/s 1.152%
73 Compress::LZ4::compress 649176/s 6340 MiB/s 1.152%
74 Compress::Snappy::compress 367492/s 3589 MiB/s 5.332%
75 Compress::LZF::compress 127765/s 1248 MiB/s 1.865%
76 Compress::LZ4::compress_hc 84620/s 826 MiB/s 1.152%
77 Compress::Zlib::compress 15514/s 152 MiB/s 1.201%
78 Compress::Bzip2::compress 246/s 2 MiB/s 2.070%
79 Compressible data (10 KiB) - decompression
81 ------------------------------------------
82 Compress::LZF::decompress 1262620/s 12330 MiB/s
83 Compress::LZ4::decompress 819200/s 8000 MiB/s
84 Compress::Snappy::decompress 619934/s 6054 MiB/s
85 Compress::Zlib::uncompress 65163/s 636 MiB/s
86 Compress::Bzip2::decompress 12679/s 124 MiB/s
87 Uncompressible data (10 KiB) - compression
89 ------------------------------------------
90 Compress::LZ4::compress 8 2102098/s 20528 MiB/s 109.231%
91 Compress::LZ4::compress 1854792/s 18113 MiB/s 109.231%
92 Compress::Snappy::compress 1619124/s 15812 MiB/s 104.615%
93 Compress::LZF::compress 1349269/s 13176 MiB/s 101.538%
94 Compress::LZ4::compress_hc 96376/s 941 MiB/s 109.231%
95 Compress::Zlib::compress 66370/s 648 MiB/s 112.308%
96 Compress::Bzip2::compress 54098/s 528 MiB/s 201.538%
97 Uncompressible data (10 KiB) - decompression
99 --------------------------------------------
100 Compress::LZF::decompress 5004566/s 48873 MiB/s
101 Compress::LZ4::decompress 4915199/s 48000 MiB/s
102 Compress::Snappy::decompress 4906438/s 47914 MiB/s
103 Compress::Zlib::uncompress 355071/s 3467 MiB/s
104 Compress::Bzip2::decompress 175812/s 1717 MiB/s
105
107 <http://lz4.org/>
108
110 Please report any bugs or feature requests to
111 <http://rt.cpan.org/Public/Bug/Report.html?Queue=Compress-LZ4>. I will
112 be notified, and then you'll automatically be notified of progress on
113 your bug as I make changes.
114
116 You can find documentation for this module with the perldoc command.
117 perldoc Compress::LZ4
119 You can also look for information at:
121 · GitHub Source Repository
123 <https://github.com/gray/compress-lz4>
125 · AnnoCPAN: Annotated CPAN documentation
127 <http://annocpan.org/dist/Compress-LZ4>
129 · CPAN Ratings
131 <http://cpanratings.perl.org/d/Compress-LZ4>
133 · RT: CPAN's request tracker
135 <http://rt.cpan.org/Public/Dist/Display.html?Name=Compress-LZ4>
137 · Search CPAN
139 <http://search.cpan.org/dist/Compress-LZ4/>
141
143 Copyright (C) 2012-2017 gray <gray at cpan.org>, all rights reserved.
144 This library is free software; you can redistribute it and/or modify it
146 under the same terms as Perl itself.
147
149 gray, <gray at cpan.org>
150perl v5.28.1 2017-04-06 Compress::LZ4(3)