Ecosyste.ms: Packages

proxy.golang.org : modernc.org/zappy

Package zappy implements the zappy block-based compression format. It aims for a combination of good speed and reasonable compression. Zappy is a format incompatible, API compatible fork of snappy[1]. The C++ snappy implementation is at [2]. The snappy compression is pretty good. Yet it has one problem built into its format definition[3] - the maximum length of a copy "instruction" is 64 bytes. For some specific usage patterns with long runs of repeated data, it turns out the compression is suboptimal. For example a 1:1000 "sparseness" 64kB bit index with only few set bits is compressed to about 3kB (about 1000 of 64B copy, 3 byte "instructions"). Zappy uses much less complicated format than snappy. Each encoded block begins with the uvarint-encoded[4] length of the decoded data, followed by a sequence of chunks. Chunks begin and end on byte boundaries. The chunk starts with a varint encoded number N: Compression rate is roughly the same as of snappy for the reference data set: Zappy has better RLE handling (1/1000+1 non zero bytes in each index): When compiled with CGO_ENABLED=1, zappy is now faster than Go snappy. Old=Go snappy, new=zappy: The package builds with CGO_ENABLED=0 as well, but the performance is worse. If a constraint 'purego' appears in the build constraints [5] then a pure Go version is built regardless of the $CGO_ENABLED value. ... referenced from the above documentation.

Registry - Source - Documentation - JSON
purl: pkg:golang/modernc.org/zappy
License: BSD-3-Clause
Latest release: 9 months ago
First release: over 5 years ago
Namespace: modernc.org
Dependent packages: 256
Dependent repositories: 2,731
Stars: 1 on GitLab.com
Forks: 1 on GitLab.com
Docker dependents: 30
Docker downloads: 9,623,378
See more repository details: repos.ecosyste.ms
Last synced: 23 days ago

• Readme
• Versions 11
• Dependent Packages 256
• Maintainers 0
• Related Packages 1