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author | Gabriel SoHappy <czh.gabriel@gmail.com> | 2015-10-22 02:13:01 +0800 |
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committer | Gabriel SoHappy <czh.gabriel@gmail.com> | 2015-10-22 02:13:01 +0800 |
commit | 78693f418632a805ee7d0857a9c771615d971d88 (patch) | |
tree | 951308d576f6c211dc129f9bf3f67f08d612d193 /messagepack.html.markdown | |
parent | b354013dc9bcba5e76bd3cf720eae8af7d9eba89 (diff) |
Initial docs for messagepack using JAVA, RUBY and NODEJS
Diffstat (limited to 'messagepack.html.markdown')
-rw-r--r-- | messagepack.html.markdown | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/messagepack.html.markdown b/messagepack.html.markdown new file mode 100644 index 00000000..0ee90742 --- /dev/null +++ b/messagepack.html.markdown @@ -0,0 +1,171 @@ +--- +language: messagepack +filename: learnmessagepack.mpac +contributors: + - ["Gabriel Chuan", "https://github.com/gczh"] +--- + +MessagePack is an efficient binary serialization format. It lets you exchange data among multiple languages like JSON. The benefits over other formats is that it's faster and smaller. + +In MessagePack, small integers are encoded into a single byte, and typical short strings require only one extra byte in addition to the strings themselves. This makes MessagePack useful for efficient transmission over wire. + +``` + +# 0. Understanding The Structure ==== + +JSON, 40 Bytes UTF-8 + +---------------------------------------------- +| {“name“:”John Doe“,”age“:12} | +---------------------------------------------- +| {" | 7B 22 | +| name | 6E 61 6D 65 | +| ":" | 22 3A 22 | +| John Doe | 4A 6F 68 6E 20 44 6F 65 | +| "," | 22 2C 22 | +| age | 61 67 65 | +| ": | 22 3A 20 | +| 12 | 31 32 | +| } | 7D | +---------------------------------------------- + + +MessagePack, 27 Bytes UTF-8 + +---------------------------------------------- +| ‚¤name¨John Doe£age.12 | +---------------------------------------------- +| ‚¤ | 82 84 | +| name | 6E 61 6D 65 | +| ¨ | A8 | +| John Doe | 4A 6F 68 6E 20 44 6F 65 | +| £ | A3 | +| age | 61 67 65 | +| . | 0C | +| 12 | 31 32 | +---------------------------------------------- + +# 1. JAVA ==== + +""" Installing with Maven +""" + +<dependencies> + ... + <dependency> + <groupId>org.msgpack</groupId> + <artifactId>msgpack</artifactId> + <version>${msgpack.version}</version> + </dependency> + ... +</dependencies> + + +""" Simple Serialization/Deserialization +""" + +// Create serialize objects. +List<String> src = new ArrayList<String>(); +src.add("msgpack"); +src.add("kumofs"); + +MessagePack msgpack = new MessagePack(); +// Serialize +byte[] raw = msgpack.write(src); + +// Deserialize directly using a template +List<String> dst1 = msgpack.read(raw, Templates.tList(Templates.TString)); +System.out.println(dst1.get(0)); +System.out.println(dst1.get(1)); + +// Or, Deserialze to Value then convert type. +Value dynamic = msgpack.read(raw); +List<String> dst2 = new Converter(dynamic) + .read(Templates.tList(Templates.TString)); +System.out.println(dst2.get(0)); +System.out.println(dst2.get(1)); + + +# 2. RUBY ==== + +""" Installing the Gem +""" + +gem install msgpack + +""" Streaming API +""" + +# serialize a 2-element array [e1, e2] +pk = MessagePack::Packer.new(io) +pk.write_array_header(2).write(e1).write(e2).flush + +# deserialize objects from an IO +u = MessagePack::Unpacker.new(io) +u.each { |obj| ... } + +# event-driven deserialization +def on_read(data) + @u ||= MessagePack::Unpacker.new + @u.feed_each(data) { |obj| ... } +end + +# 3. NODE.JS ==== + +""" Installing with NPM +""" + +npm install msgpack5 --save + +""" Using in Node +""" + +var msgpack = require('msgpack5')() // namespace our extensions + , a = new MyType(2, 'a') + , encode = msgpack.encode + , decode = msgpack.decode + +msgpack.register(0x42, MyType, mytipeEncode, mytipeDecode) + +console.log(encode({ 'hello': 'world' }).toString('hex')) +// 81a568656c6c6fa5776f726c64 +console.log(decode(encode({ 'hello': 'world' }))) +// { hello: 'world' } +console.log(encode(a).toString('hex')) +// d5426161 +console.log(decode(encode(a)) instanceof MyType) +// true +console.log(decode(encode(a))) +// { value: 'a', size: 2 } + +function MyType(size, value) { + this.value = value + this.size = size +} + +function mytipeEncode(obj) { + var buf = new Buffer(obj.size) + buf.fill(obj.value) + return buf +} + +function mytipeDecode(data) { + var result = new MyType(data.length, data.toString('utf8', 0, 1)) + , i + + for (i = 0; i < data.length; i++) { + if (data.readUInt8(0) != data.readUInt8(i)) { + throw new Error('should all be the same') + } + } + + return result +} + +``` + + +# References + +- [MessagePack](http://msgpack.org/index.html) +- [MsgPack vs. JSON: Cut your client-server exchange traffic by 50% with one line of code](http://indiegamr.com/cut-your-data-exchange-traffic-by-up-to-50-with-one-line-of-code-msgpack-vs-json/)
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