feat: blockchain provider tree state integration

[fgimenez]

Towards #8747

Scaffolds InMemoryState trait and implements it for EngineApiTreeHandlerImpl. TreeState is updated to include pending and current_head data.

For now in BlockchainProvider there are only references to the field that will provide this state.

[Rjected]

this makes sense, I have mostly doc nits!

[mattsse]

cool, this is a very good start,
we're still missing some things but we can iterate on it.

I think from tree perspective it would be great if this state is managed separately as CanonicalState { Rwlocks } so that the tree updates only the canonical blocks in there

[mattsse]

we also need the SealedBlock + the actual state so we can perform eth_call, trace etc. on this but this is a good start

[fgimenez]

you mean, including a field with the SealedBlock? the rest of fields could be obtained from it or am I missing something?

[mattsse]

yeah, what we need to access is:
block,receipts+state at this block

[fgimenez]

ok, will propose it in a followup

[mattsse]

I think for provider access we should put all of this a separate container type that can be easily shared:

struct InMemoryState {
  blocks: HashMap<Hash, Arc<State>>
  numbers: HashMap<u64, Hash>,
  pending: Option<State>,
}

we need to share access to this with rpc etc. I think we should consider maintaining this as a separate instance in the tree that only tracks the canonical chain. because otherwise we'd need locks around all of these:

 blocks_by_hash: HashMap<B256, ExecutedBlock>,
/// Executed blocks grouped by their respective block number.    blocks_by_number: BTreeMap<BlockNumber, Vec<ExecutedBlock>>,

but maybe that's fine? at least for now

[mattsse]

yeah, what we need to access is:
block,receipts+state at this block

[fgimenez]

we need to share access to this with rpc etc. I think we should consider maintaining this as a separate instance in the tree that only tracks the canonical chain. because otherwise we'd need locks around all of these:

makes sense, will add all this in a followup