[P3] Proposal: fastcodec for Hessian2

[felix021]

In the first version of codec-hessian2, we'll be using the dubbo-go-hessian2 to provide encoding and decoding of hessian2.

As the dubbo-go-hessian2 uses reflection, we realize that there's room for further optimization.

So in our implementation of dubbo protocol, we defined two interfaces Encoder and Decoder, so that we can replace it with another library.

This proposal suggests the implemention of a new Hessian2 encoder/decoder to achieve the best performance.

Take thrift as an example:

• The official (apache) way is to generate all the go code for encoding/decoding, to avoid the use of reflection.
• Kitex goes further with the fastcodec implementation, by generating the BLength() method to calculate the length of the encoded binary, we can allocate only once before encoding, thus greatly improving the performance.

This proposal suggests to implement a fastcodec library for hessian2.

[DMwangnima]

I want to take this issue.

[tiltwind]

@DMwangnima Will you implement this proposal as a separate library? Hope it can be easily integrated into other framework, not only in kitex.

[DMwangnima]

@DMwangnima Will you implement this proposal as a separate library? Hope it can be easily integrated into other framework, not only in kitex.

I will take this into consideration so that both kitex and dubbo-go can benefit from this library.