BridgeTask Trait Draft

[hackfisher]

Continue with the refactor of #177 , we also need to do framework level refactor. There will be several key components for bridger.

1. Bridger Client, including general shared key sub components for all bridge tasks, including

   • Config Manager and Storage Persistency(Cache, task storage etc.)
   • Cli
   • Service Manager, mpsc/channel, micro service etc.
   • Chain Client/Definition Manager
   • Secret/private_key Manager
   • Error
   • Bridge task loader/executor

2. BridgeTask, common trait for specific BridgeTask to implement

   • ID(name)
   • Config Definition
   • Storage Definition
   • Source chain and target chain/Client definitions, (Ethereum web3, Substrate client, e.g. substrate-subxt, substrate-api-client etc, chain/runtime definition)
   • Key/Account Definition
   • Tasks definition, loops for bridger to execute
   • Event handle

We do not need dynamic load, to keep simple, we do not need to incorporate web assembly to define BridgeTask, we only need a well abstracted trait, and one struct for specific bridge, e.g. the bridge from bsc to darwinia, and implement this trait.