Function block_end

atomic-core/src/pristine/span_index.rs:85–104

`find_block_end` query against a loaded span set. Prefers an empty marker at exactly `target` (e.g. an inode marker `V[9:9]` over a name vertex `V[0:9]` that also ends at 9), then the non-empty span immediately left of `target` if it ends at or contains `target`, then a non-empty span starting exactly at `target`.

(set: &BTreeSet<(u64, u64)>, target: u64)

/// immediately left of `target` if it ends at or contains `target`, then a
/// non-empty span starting exactly at `target`.
fn block_end(set: &BTreeSet<(u64, u64)>, target: u64) -> Option<(u64, u64)> {
    if set.contains(&(target, target)) {
        return Some((target, target));
    }
    for &(s, e) in set.range(..(target, 0u64)).rev() {
        if s == e {
            continue;
        }
        if e == target || (s <= target && target < e) {
            return Some((s, e));
        }
        break;
    }
    for &(s, e) in set.range((target, 0u64)..=(target, u64::MAX)) {
        if s != e {
            return Some((s, e));
        }
    }
    None
}