perf: in_memory

[malik672]

Describe the feature

might be wrong but in_memory file is it not better to remove block below persisted height than to clear then re-insert in the for loop

        numbers.retain(|&block_num, _| block_num > persisted_height);

            // drain all blocks and only keep the ones that are not persisted (below the persisted
            // height)
            let mut old_blocks = blocks
                .drain()
                .filter(|(_, b)| b.block_ref().block().number > persisted_height)
                .map(|(_, b)| b.block.clone())
                .collect::<Vec<_>>();

            // sort the blocks by number so we can insert them back in natural order (low -> high)
            old_blocks.sort_unstable_by_key(|block| block.block().number);

            // re-insert the blocks in natural order and connect them to their parent blocks
            for block in old_blocks {
                let parent = blocks.get(&block.block().parent_hash).cloned();
                let block_state = BlockState::with_parent(block, parent);
                let hash = block_state.hash();
                // append new blocks
                blocks.insert(hash, Arc::new(block_state));
            }

Additional context

No response

[mattsse]

we need to re-insert because of this

let parent = blocks.get(&block.block().parent_hash).cloned();
let block_state = BlockState::with_parent(block, parent);