Implement prestateTracer

[mattsse]

Describe the feature

See https://geth.ethereum.org/docs/developers/evm-tracing/built-in-tracers

This is similar to #2110 but for the missing

reth/crates/rpc/rpc/src/debug.rs

Lines 378 to 380 in abcadd9

	GethDebugBuiltInTracerType::PreStateTracer => {
	todo!()
	}

variant

TODO

• add conversions for the inspector for pre state frame, See feat: implement call tracer #2349 for CallTrace ref

Additional context

No response

[jerusan]

I am working on this.

[mattsse]

lmk if you have any questions,
I think we need to look closely at the geth reference impl.

[jerusan]

@mattsse I'm not sure if my method of obtaining the prestate is correct. I am thinking of making a copy of state_db before passing it to inspect(). In that way, db values can be accessed after passing it to inspect(). When inspect() returns post_state, I can iterate the post_state to get the addresses affected by the transaction then I will be able to use the db_copy to get the old account state.

[0x366]

Any updates on prestate tracer? It's must-have to simulate a bundle

[mattsse]

I can bump prio for this,

[PlamenHristov]

@mattsse, mind I give it a try?

[0x366]

The prestateTracer is currently missing the "diffMode" option: nothing happens when

"tracerConfig": { "diffMode": true }

, that returns the differences between the transaction's pre and post-state (i.e. what changed because the transaction happened).
https://github.com/ethereum/go-ethereum/blob/8f2ae29b8f7743a14760e6f2b458ecddc8bb7d8f/eth/tracers/native/prestate.go#L254

[PlamenHristov]

@0x366, there is a small bug, in how the config is parsed. Will push a fix EOD.

[PlamenHristov]

@0x366 here is the PR. Apologies for the bug. Otherwise, I tested the functionality on a live node and looks good.