Function validate_leaf_state

atomic-core/src/crdt/apply/leaf.rs:356–382

Validates that a leaf exists and is in the expected state. # Arguments `txn` - The transaction `leaf_id` - The leaf to validate `expected_state` - The expected state, or `None` for any state # Returns The leaf if validation passes.

(
    txn: &T,
    leaf_id: LeafId,
    expected_state: Option<LeafState>,
)

///
/// The leaf if validation passes.
pub fn validate_leaf_state<T: MutCrdtTxnT>(
    txn: &T,
    leaf_id: LeafId,
    expected_state: Option<LeafState>,
) -> ApplyResult<Leaf> {
    let leaf = txn
        .get_leaf(leaf_id)
        .map_err(|e| storage_err(e, "getting leaf"))?
        .ok_or_else(|| ApplyError::leaf_not_found(leaf_id))?;

    if let Some(expected) = expected_state {
        let matches = match expected {
            LeafState::Alive => leaf.state().is_alive(),
            LeafState::Deleted => leaf.state().is_deleted(),
        };

        if !matches {
            return Err(ApplyError::invalid_leaf_state(
                leaf_id,
                leaf.state().to_string(),
                format!("expected {}", expected),
            ));
        }
    }

    Ok(leaf)
}

/// Validates that a leaf belongs to the specified branch.
///