Pruning: EVM

[rakanalh]

Description

Depends on #1191

EVM has 3 storage items that we need to cleanup:

1. blocks: Implements StateVecAccessor which enables us to iter / retain blocks which would not be pruned.
2. block_hashes: Implements StateMapAccessor which lets us remove entries for blocks which should be pruned.
3. receipts: Implements StateVecAccessor. For the blocks we end up removing, each SealedBlockprovides access to the transactions which we'd want to remove. For reference:

citrea/crates/evm/src/query.rs

Lines 248 to 287 in 3fe658b

	let block = match block_number_or_hash {
	BlockId::Hash(block_hash) => {
	let block_number = match self
	.block_hashes
	.get(&block_hash.block_hash, &mut working_set.accessory_state())
	{
	Some(block_number) => block_number,
	None => return Ok(None), // if hash is unknown, return None
	};
	// if hash is known, but we don't have the block, fail
	self.blocks
	.get(block_number as usize, &mut working_set.accessory_state())
	.expect("Block must be set")
	}
	BlockId::Number(block_number) => {
	match self.get_sealed_block_by_number(Some(block_number), working_set)? {
	Some(block) => block,
	None => return Ok(None), // if block doesn't exist return null
	}
	}
	};
	let receipts = &block
	.transactions
	.clone()
	.map(|id| {
	let tx = self
	.transactions
	.get(id as usize, &mut working_set.accessory_state())
	.expect("Transaction must be set");
	let receipt = self
	.receipts
	.get(id as usize, &mut working_set.accessory_state())
	.expect("Receipt for known transaction must be set");
	build_rpc_receipt(&block, tx, id, receipt)
	})
	.collect::<Vec<_>>();

This needs to be implemented in the pruner.

Concerns

Since blocks is a vector, we should consider race conditions between the pruner which is creating a new vector by filtering pruned blocks and the sequencer which is pushing new blocks into this list.

While pruning EVM, we should somehow lock access to EVM.