1,今天在hacknews上看到很多人对messagepack的争论。首先了解什么是MessagePack:MessagePack is a binary-based efficient object serialization library. It enables to exchange structured objects between many languages like JSON. But unlike JSON, it is very fast and small.
2,MessagePack的主要用途,作者解释说有两大用途:一是Space-efficient storage for Memcache entries (Pinterest),节省空间类型的mamcache应用;另一个是用于RPC传输, This use case is fairly close to my original intent. When one is designing an RPC system, one of the first tasks is to specify and implement a communication protocol. This process can get pretty hairy as you need to worry about a lot of low-level issues like Endian-ness. By using MessagePack, one can skip designing and implementing a communication protocol entirely and accelerate development.
3,争议的地方是MessagePack的benchmark说,他比protocolBuffer,Json快很多倍。但是有人不相信,做个javasript下的测试(json与messagePack)。发现MessagePack仅是压缩后的数据比json少10%左右,而压缩和解压时间则和json的解析器比起来要费时很多。
4,“MsgPack vs. JSON: Cut your client-server exchange traffic by 50% with one line of code”这篇文章使用了messagePack做服务器的优化,降低服务器的数据量,更加合理的利用带宽。作者强调了他们宁愿浪费客户端的0.5ms—1ms,但是服务器使用ruby的MessagePack解析器,效率能够比JSON快5倍。
The difference to JSONis, that MsgPack is binary-based - this gives the possibility to make the exchanged data a) smaller and use less bytes, I guess we all know the advantages of that, however there is an even bigger advantage: b) It is faster to parse and encode, having a parser parse 40 bytes takes about twice as long as parsing 20 bytes.
myJSONString = JSON.stringify(myObject);myObject = JSON.parse(myJSONString);var myByteArray = msgpack.pack(myObject);myObject = msgpack.unpack(myByteArray);
MessagePack作者也认为MessagePack may not be the best choice for client-side serialization as described by the blog author.引用2的作者有点小悲剧。
5,BSon是Json的二进制形式,但是与JSon有语法不兼容的地方。但是MessagePack保证语义上能够做到一致。
6,场景需求不同,导致技术的应用有所差异。
引用:
1,MessagePack官方网站
2,MsgPack vs. JSON: Cut your client-server exchange traffic by 50% with one line of code
HN评论地址:http://news.ycombinator.com/item?id=4090831