CBOR for Ruby
This is an initial Ruby implementation of the CBOR encoding, based on the (polished) high-performance msgpack-ruby code.
Documentation will follow, but generally, if you replace MessagePack and msgpack with CBOR and cbor in the below, you will be on the right track.
CBOR is an object representation format defined by the IETF. The specification has recently been approved as an IETF Standards-Track specification and will be an RFC in a couple of months, after the RFC editor has done their work.
This is all based on wonderful work by frsyuki, and I have no idea how to acknowledge him appropriately. This gem is not intended to fork or supersede MessagePack, which has a vibrant ecosystem. It is just making use of the high-quality code that is available in this community. If MessagePack works for you, go for it. If you need CBOR, you need this.
Todos:
-
This code has not yet been fully optimized, so it is still a few percent slower than msgpack-ruby.
-
Properly document things, in particular the classes CBOR::Simple and CBOR::Tagged. If you check out the source, you can rake doc to get some documentation in the directory
doc
(seeindex.html
there). -
So far, this has been tested on MRI (1.9.3 and 2.0.0). To do:
-
Check this code out with Rubinius.
-
Publish the pure-ruby version and make it work the same way on JRuby.
-
-
Find and implement good ways to offer CBOR’s indefinite length (“streaming”) capability at the Ruby API level.
-
Rename some of the internals from msgpack to cbor. Right now, much of the code still uses the name msgpack in its identifiers, to facilitate merging upstream fixes. (The msgpack and cbor gems coexist nicely in one MRI instance due to the magic in
renamer.h
.)
Same Apache 2.0 License applies to the changes as to the original. For the changes:
- Author
-
Carsten Bormann <[email protected]>
- Copyright
-
Copyright © 2013 Carsten Bormann
- License
-
Apache License, Version 2.0
<img src=“https://travis-ci.org/cabo/cbor-ruby.png?branch=master” />
For the original, see below.
MessagePack
MessagePack is an efficient binary serialization format. It lets you exchange data among multiple languages like JSON but it’s faster and smaller. For example, small integers (like flags or error code) are encoded into a single byte, and typical short strings only require an extra byte in addition to the strings themselves.
If you ever wished to use JSON for convenience (storing an image with metadata) but could not for technical reasons (binary data, size, speed…), MessagePack is a perfect replacement.
require 'msgpack'
msg = [1,2,3].to_msgpack #=> "\x93\x01\x02\x03"
MessagePack.unpack(msg) #=> [1,2,3]
Use RubyGems to install:
gem install msgpack
or build msgpack-ruby and install:
bundle
rake
gem install --local pkg/msgpack
Use cases
-
Store objects efficiently serialized by msgpack on memcached or Redis
-
In fact Redis supports msgpack in EVAL-scripts
-
-
Upload data in efficient format from mobile devices such as smartphones
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MessagePack works on iPhone/iPad and Android. See also Objective-C and Java implementations
-
-
Design a portable protocol to communicate with embedded devices
-
Check also Fluentd which is a log collector which uses msgpack for the log format (they say it uses JSON but actually it’s msgpack, which is compatible with JSON)
-
-
Exchange objects between software components written in different languages
-
You’ll need a flexible but efficient format so that components exchange objects while keeping compatibility
-
Portability
MessagePack for Ruby should run on x86, ARM, PowerPC, SPARC and other CPU architectures.
And it works with MRI (CRuby) and Rubinius. Patches to improve portability is highly welcomed.
Serializing objects
Use MessagePack.pack or to_msgpack:
require 'msgpack'
msg = MessagePack.pack(obj) # or
msg = obj.to_msgpack
Streaming serialization
Packer provides advanced API to serialize objects in streaming style:
# serialize a 2-element array [e1, e2]
pk = MessagePack::Packer.new(io)
pk.write_array_header(2).write(e1).write(e2).flush
See API reference for details.
Deserializing objects
Use MessagePack.unpack:
require 'msgpack'
obj = MessagePack.unpack(msg)
Streaming deserialization
Unpacker provides advanced API to deserialize objects in streaming style:
# deserialize objects from an IO
u = MessagePack::Unpacker.new(io)
u.each do |obj|
# ...
end
or event-driven style which works well with EventMachine:
# event-driven deserialization
def on_read(data)
@u ||= MessagePack::Unpacker.new
@u.feed_each(data) {|obj|
# ...
}
end
See API reference for details.
Buffer API
MessagePack for Ruby provides a buffer API so that you can read or write data by hand, not via Packer or Unpacker API.
This MessagePack::Buffer is backed with a fixed-length shared memory pool which is very fast for small data (<= 4KB), and has zero-copy capability which significantly affects performance to handle large binary data.
How to build and run tests
Before building msgpack, you need to install bundler and dependencies.
gem install bundler
bundle install
Then, you can run the tasks as follows:
-
Build
bundle exec rake build
-
Run tests
bundle exec rake spec
-
Generating docs
bundle exec rake doc
Copyright
- Author
-
Sadayuki Furuhashi <[email protected]>
- Copyright
-
Copyright © 2008-2013 Sadayuki Furuhashi
- License
-
Apache License, Version 2.0