Ruby binding for zstd(Zstandard - Fast real-time compression algorithm)
See https://github.com/facebook/zstd
Fork from https://github.com/jarredholman/ruby-zstd.
Starting from v2.0.0, this gem follows Semantic Versioning.
- Major version (X.0.0): Breaking changes to the API
- Minor version (X.Y.0): New features, including Zstd library version updates
- Patch version (X.Y.Z): Bug fixes and other backward-compatible changes
Updates to the underlying Zstd library version will be released as minor version updates, as they may introduce new features or performance improvements while maintaining backward compatibility.
Note: Versions prior to v2.0.0 followed the Zstd library versioning scheme with an additional patch number (e.g., 1.5.6.2). This approach has been replaced with semantic versioning to provide clearer expectations for API stability.
Add this line to your application's Gemfile:
gem 'zstd-ruby'And then execute:
$ bundle
Or install it yourself as:
$ gem install zstd-ruby
require 'zstd-ruby'compressed_data = Zstd.compress(data) # default: 3
compressed_data = Zstd.compress(data, level: 6)For better performance with multiple operations, use reusable contexts:
# Unified context (recommended)
ctx = Zstd::Context.new(level: 6)
compressed = ctx.compress(data)
original = ctx.decompress(compressed)
# Specialized contexts for memory optimization
cctx = Zstd::CContext.new(level: 6) # Compression-only
dctx = Zstd::DContext.new # Decompression-onlyDictionaries provide better compression for similar data:
dictionary = File.read('dictionary_file')
# Using module methods
compressed = Zstd.compress(data, level: 3, dict: dictionary)
original = Zstd.decompress(compressed, dict: dictionary)
# Using contexts for better performance
ctx = Zstd::Context.new(level: 6, dict: dictionary)
compressed = ctx.compress(data)
original = ctx.decompress(compressed)If you use the same dictionary repeatedly, you can speed up the setup by creating CDict in advance:
cdict = Zstd::CDict.new(File.read('dictionary_file'))
compressed_using_dict = Zstd.compress("", dict: cdict)The compression_level can be specified on creating CDict.
cdict = Zstd::CDict.new(File.read('dictionary_file'), 5)
compressed_using_dict = Zstd.compress("", dict: cdict)stream = Zstd::StreamingCompress.new
stream << "abc" << "def"
res = stream.flush
stream << "ghi"
res << stream.finishor
stream = Zstd::StreamingCompress.new
res = stream.compress("abc")
res << stream.flush
res << stream.compress("def")
res << stream.finishstream = Zstd::StreamingCompress.new(dict: File.read('dictionary_file'))
stream << "abc" << "def"
res = stream.flush
stream << "ghi"
res << stream.finishstream = Zstd::StreamingCompress.new(level: 5, dict: File.read('dictionary_file'))
stream << "abc" << "def"
res = stream.flush
stream << "ghi"
res << stream.finishcdict = Zstd::CDict.new(File.read('dictionary_file', 5)
stream = Zstd::StreamingCompress.new(dict: cdict)
stream << "abc" << "def"
res = stream.flush
stream << "ghi"
res << stream.finishdata = Zstd.decompress(compressed_data)
data = Zstd.decompress(compressed_data, dict: dictionary)If you use the same dictionary repeatedly, you can speed up the setup by creating DDict in advance:
ddict = Zstd::Ddict.new(File.read('dictionary_file'))
data = Zstd.compress(compressed_using_dict, ddict)cstr = "" # Compressed data
stream = Zstd::StreamingDecompress.new
result = ''
result << stream.decompress(cstr[0, 10])
result << stream.decompress(cstr[10..-1])Unified context for both compression and decompression.
ctx = Zstd::Context.new # Default settings
ctx = Zstd::Context.new(level: 6) # With compression level
ctx = Zstd::Context.new(level: 6, dict: dictionary) # With dictionarycompress(data)→ Stringdecompress(compressed_data)→ String
Compression-only context for memory optimization.
cctx = Zstd::CContext.new(level: 6) # With compression level
cctx = Zstd::CContext.new(level: 6, dict: dictionary) # With dictionarycompress(data)→ String
Decompression-only context for memory optimization.
dctx = Zstd::DContext.new # Default settings
dctx = Zstd::DContext.new(dict: dictionary) # With dictionarydecompress(compressed_data)→ String
Zstd.compress(data)→ String (default level 3)Zstd.compress(data, dict: dictionary)→ String
Zstd.decompress(compressed_data)→ StringZstd.decompress(compressed_data, dict: dictionary)→ String
Zstd.zstd_version→ Integer
| Use Case | Recommended API | Benefits |
|---|---|---|
| Single operations | Zstd.compress/decompress |
Simple, no setup |
| Multiple operations | Zstd::Context |
2-3x faster, convenient |
| Specialized needs | Zstd::CContext/DContext |
Direct API access |
Compression Levels: 1-3 (fast, 3 is default), 9-19 (better compression)
To test performance on your system:
cd benchmarks
ruby quick_benchmark.rb # Fast overview of all APIs (recommended)This gem does not support JRuby.
Please consider using https://github.com/luben/zstd-jni.
Sample code is below.
require 'java'
require_relative './zstd-jni-1.5.2-3.jar'
str = "testtest"
compressed = com.github.luben.zstd.Zstd.compress(str.to_java_bytes)
puts com.github.luben.zstd.Zstd.decompress(compressed, str.length)
% ls
test.rb zstd-jni-1.5.2-3.jar
% ruby -v
jruby 9.3.2.0 (2.6.8) 2021-12-01 0b8223f905 OpenJDK 64-Bit Server VM 11.0.12+0 on 11.0.12+0 +jit [darwin-x86_64]
% ruby test.rb
testtest
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/SpringMT/zstd-ruby. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
The gem is available as open source under the terms of the BSD-3-Clause License.