Ruby bindings for brotli library

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See brotli library.

Other bindings: lzw, zstd, bzip2.

Installation

Operating systems: GNU/Linux, FreeBSD, OSX.

Dependencies: brotli 1.0.0+ version.

Popular OS	Dependencies
Ubuntu	libbrotli-dev
CentOS	brotli-devel
ArchLinux	brotli
OSX	brotli

gem install ruby-brs

You can build it from source.

rake gem
gem install pkg/ruby-brs-*.gem

You can also use overlay for gentoo.

Installation in macOS on Apple Silicon

On M1 Macs, Homebrew installs to /opt/homebrew, so you'll need to specify its include and lib paths when building the native extension for brotli.

brew install brotli
gem install ruby-brs -- --with-opt-include=/opt/homebrew/include --with-opt-lib=/opt/homebrew/lib

You can also configure Bundler to use those options when installing:

bundle config set build.ruby-brs "--with-opt-include=/opt/homebrew/include --with-opt-lib=/opt/homebrew/lib"

Usage

There are simple APIs: String and File. Also you can use generic streaming API: Stream::Writer and Stream::Reader.

require "brs"

data = BRS::String.compress "sample string"
puts BRS::String.decompress(data)

BRS::File.compress "file.txt", "file.txt.br"
BRS::File.decompress "file.txt.br", "file.txt"

BRS::Stream::Writer.open("file.txt.br") { |writer| writer << "sample string" }
puts BRS::Stream::Reader.open("file.txt.br") { |reader| reader.read }

writer = BRS::Stream::Writer.new output_socket
begin
  bytes_written = writer.write_nonblock "sample string"
  # handle "bytes_written"
rescue IO::WaitWritable
  # handle wait
ensure
  writer.close
end

reader = BRS::Stream::Reader.new input_socket
begin
  puts reader.read_nonblock(512)
rescue IO::WaitReadable
  # handle wait
rescue ::EOFError
  # handle eof
ensure
  reader.close
end

You can create and read tar.br archives with minitar.

require "brs"
require "minitar"

BRS::Stream::Writer.open "file.tar.br" do |writer|
  Minitar::Writer.open writer do |tar|
    tar.add_file_simple "file", :data => "sample string"
  end
end

BRS::Stream::Reader.open "file.tar.br" do |reader|
  Minitar::Reader.open reader do |tar|
    tar.each_entry do |entry|
      puts entry.name
      puts entry.read
    end
  end
end

You can also use Content-Encoding: br with sinatra:

require "brs"
require "sinatra"

get "/" do
  headers["Content-Encoding"] = "br"
  BRS::String.compress "sample string"
end

All functionality (including streaming) can be used inside multiple threads with parallel. This code will provide heavy load for your CPU.

require "brs"
require "parallel"

Parallel.each large_datas do |large_data|
  BRS::String.compress large_data
end

Docs

Please review rdoc generated docs.

Options

Option	Values	Default	Description
source_buffer_length	0 - inf	0 (auto)	internal buffer length for source data
destination_buffer_length	0 - inf	0 (auto)	internal buffer length for description data
gvl	true/false	false	enables global VM lock where possible
mode	MODES	:generic	compressor mode
quality	0 - 11	11	compression level
lgwin	10 - 24	22	compressor window size
lgblock	16 - 24	nil (auto)	compressor input block size
npostfix	0 - 3	nil (auto)	recommended number of postfix bits
ndirect	0 - 120	nil (auto)	recommended number of direct distance codes (step 1 << npostfix, max 15 << npostfix)
disable_literal_context_modeling	true/false	false	disables literal context modeling format
disable_ring_buffer_reallocation	true/false	false	disables ring buffer reallocation
size_hint	0 - inf	0 (auto)	size of input (if known)
large_window	true/false	false	enables large window

There are internal buffers for compressed and decompressed data. For example you want to use 1 KB as source_buffer_length for compressor - please use 256 B as destination_buffer_length. You want to use 256 B as source_buffer_length for decompressor - please use 1 KB as destination_buffer_length.

gvl is disabled by default, this mode allows running multiple compressors/decompressors in different threads simultaneously. Please consider enabling gvl if you don't want to launch processors in separate threads. If gvl is enabled ruby won't waste time on acquiring/releasing VM lock.

String and File will set :size_hint automaticaly.

You can also read brotli docs for more info about options.

Option	Related constants
mode	BRS::Option::MODES = %i[text font generic]
quality	BRS::Option::MIN_QUALITY = 0, BRS::Option::MAX_QUALITY = 11
lgwin	BRS::Option::MIN_LGWIN = 10, BRS::Option::MAX_LGWIN = 24
lgblock	BRS::Option::MIN_LGBLOCK = 16, BRS::Option::MAX_LGBLOCK = 24
npostfix	BRS::Option::MIN_NPOSTFIX = 0, BRS::Option::MAX_NPOSTFIX = 3
ndirect	BRS::Option::MIN_NDIRECT = 0, BRS::Option::MAX_NDIRECT = 120, BRS::Option::NDIRECT_NPOSTFIX_STEP_BASE = 1, BRS::Option::NDIRECT_NPOSTFIX_MAX_BASE = 15

Possible compressor options:

:source_buffer_length
:destination_buffer_length
:gvl
:mode
:quality
:lgwin
:lgblock
:npostfix
:ndirect
:disable_literal_context_modeling
:size_hint
:large_window

Possible decompressor options:

:source_buffer_length
:destination_buffer_length
:gvl
:disable_ring_buffer_reallocation
:large_window

Example:

require "brs"

data = BRS::String.compress "sample string", :quality => 5
puts BRS::String.decompress(data, :disable_ring_buffer_reallocation => true)

String

String maintains destination buffer only, so it accepts destination_buffer_length option only.

::compress(source, options = {})
::decompress(source, options = {})

source is a source string.

File

File maintains both source and destination buffers, it accepts both source_buffer_length and destination_buffer_length options.

::compress(source, destination, options = {})
::decompress(source, destination, options = {})

source and destination are file pathes.

Stream::Writer

Its behaviour is similar to builtin Zlib::GzipWriter.

Writer maintains destination buffer only, so it accepts destination_buffer_length option only.

::open(file_path, options = {}, :external_encoding => nil, :transcode_options => {}, &block)

Open file path and create stream writer associated with opened file. Data will be transcoded to :external_encoding using :transcode_options before compressing.

It may be tricky to use both :size_hint and :transcode_options. You have to provide size of transcoded input.

::new(destination_io, options = {}, :external_encoding => nil, :transcode_options => {})

Create stream writer associated with destination io. Data will be transcoded to :external_encoding using :transcode_options before compressing.

It may be tricky to use both :size_hint and :transcode_options. You have to provide size of transcoded input.

#set_encoding(external_encoding, nil, transcode_options)

Set another encodings, nil is just for compatibility with IO.

#io
#to_io
#stat
#external_encoding
#transcode_options
#pos
#tell

See IO docs.

#write(*objects)
#flush
#rewind
#close
#closed?

See Zlib::GzipWriter docs.

#write_nonblock(object, *options)
#flush_nonblock(*options)
#rewind_nonblock(*options)
#close_nonblock(*options)

Special asynchronous methods missing in Zlib::GzipWriter. rewind wants to close, close wants to write something and flush, flush want to write something. So it is possible to have asynchronous variants for these synchronous methods. Behaviour is the same as IO#write_nonblock method.

#<<(object)
#print(*objects)
#printf(*args)
#putc(object, :encoding => 'ASCII-8BIT')
#puts(*objects)

Typical helpers, see Zlib::GzipWriter docs.

Stream::Reader

Its behaviour is similar to builtin Zlib::GzipReader.

Reader maintains both source and destination buffers, it accepts both source_buffer_length and destination_buffer_length options.

::open(file_path, options = {}, :external_encoding => nil, :internal_encoding => nil, :transcode_options => {}, &block)

Open file path and create stream reader associated with opened file. Data will be force encoded to :external_encoding and transcoded to :internal_encoding using :transcode_options after decompressing.

::new(source_io, options = {}, :external_encoding => nil, :internal_encoding => nil, :transcode_options => {})

Create stream reader associated with source io. Data will be force encoded to :external_encoding and transcoded to :internal_encoding using :transcode_options after decompressing.

#set_encoding(external_encoding, internal_encoding, transcode_options)

Set another encodings.

#io
#to_io
#stat
#external_encoding
#internal_encoding
#transcode_options
#pos
#tell

See IO docs.

#read(bytes_to_read = nil, out_buffer = nil)
#eof?
#rewind
#close
#closed?

See Zlib::GzipReader docs.

#readpartial(bytes_to_read = nil, out_buffer = nil)
#read_nonblock(bytes_to_read, out_buffer = nil, *options)

See IO docs.

#getbyte
#each_byte(&block)
#readbyte
#ungetbyte(byte)

#getc
#readchar
#each_char(&block)
#ungetc(char)

#lineno
#lineno=
#gets(separator = $OUTPUT_RECORD_SEPARATOR, limit = nil)
#readline
#readlines
#each(&block)
#each_line(&block)
#ungetline(line)

Typical helpers, see Zlib::GzipReader docs.

Thread safety

:gvl option is disabled by default, you can use bindings effectively in multiple threads. Please be careful: bindings are not thread safe. You should lock all shared data between threads.

For example: you should not use same compressor/decompressor inside multiple threads. Please verify that you are using each processor inside single thread at the same time.

CI

Please visit scripts/test-images. See universal test script scripts/ci_test.sh for CI.

License

MIT license, see LICENSE and AUTHORS.