Function compute_block_trie_changesets 

pub fn compute_block_trie_changesets<Provider>(
    provider: &Provider,
    block_number: u64,
) -> Result<TrieUpdatesSorted, ProviderError>
where
    Provider: DBProvider + StageCheckpointReader + ChangeSetReader + StorageChangeSetReader + BlockNumReader,

Available on crate features trie and trie-db only.

Computes trie changesets for a block.

Algorithm

For block N:

1. Query cumulative HashedPostState revert for block N-1 (from db tip to after N-1)
2. Use that to calculate cumulative TrieUpdates revert for block N-1
3. Query per-block HashedPostState revert for block N
4. Create prefix sets from the per-block revert (step 3)
5. Create overlay with cumulative trie updates and cumulative state revert for N-1
6. Calculate trie updates for block N using the overlay and per-block HashedPostState.
7. Compute changesets using the N-1 overlay and the newly calculated trie updates for N

Arguments

• provider - Database provider with changeset access
• block_number - Block number to compute changesets for

Returns

Changesets (old trie node values) for the specified block

Errors

Returns error if:

• Block number exceeds database tip (based on Finish stage checkpoint)
• Database access fails
• State root computation fails