Function validate_branch_state

atomic-core/src/crdt/apply/branch.rs:407–433

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

(
    txn: &T,
    branch_id: BranchId,
    expected_state: Option<BranchState>,
)

///
/// The branch if validation passes.
pub fn validate_branch_state<T: MutCrdtTxnT>(
    txn: &T,
    branch_id: BranchId,
    expected_state: Option<BranchState>,
) -> ApplyResult<Branch> {
    let branch = txn
        .get_branch(branch_id)
        .map_err(|e| storage_err(e, "getting branch"))?
        .ok_or_else(|| ApplyError::branch_not_found(branch_id))?;

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

        if !matches {
            return Err(ApplyError::invalid_branch_state(
                branch_id,
                branch.state().to_string(),
                format!("expected {}", expected),
            ));
        }
    }

    Ok(branch)
}

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