Optimize ABI API to have less allocation

[LukaszRozmej]

Encoding and Decoding ABI allocates a lot, rewrite it to a version that will allocate a lot less (stream-like or spans?) and update usages.

[ssonthal]

Hi @LukaszRozmej can I work on this?

I read a bit about streams and spans. Streams are likely to work better when we have large chunk of data of variable sizes while spans work better with structured fixed-size data and the latter offers better performance enhancement, maintains concurrency in a better way.

What would you suggest is a better approach? I am currently not aware about the data that Abi encoding deals with.

[LukaszRozmej]

Hi @LukaszRozmej can I work on this?

Sure, take a look at: https://github.com/NethermindEth/nethermind/blob/master/src/Nethermind/Nethermind.Abi/AbiEncoder.cs and everything under it (AbiTypes etc). This now allocates a ton of objects when you Decode and ton of byte arrays when you Encode.

Think how can you allocate as little as possible. For inspiration you can check how our Rlp Encoding/Decoding works with NettyRlpStream that is based on pooled memory.