Function next_seq

crates/flowtrace-cli/src/reply.rs:65–76

Allocate the next seq for this run. Cache-backed: O(1) after first use.

(trace_root: &Path, run_id: &str)

/// Allocate the next seq for this run. Cache-backed: O(1) after first use.
fn next_seq(trace_root: &Path, run_id: &str) -> u32 {
    let key = (trace_root.to_path_buf(), run_id.to_string());
    let cache = SEQ_CACHE.get_or_init(|| std::sync::Mutex::new(std::collections::HashMap::new()));
    let mut guard = cache.lock().unwrap();
    let last = match guard.get(&key).copied() {
        Some(v) => v,
        None => scan_max_seq(&replies_dir(trace_root, run_id)),
    };
    let next = last + 1;
    guard.insert(key, next);
    next
}

/// Append a new reply file. Returns the assigned seq and timestamp.
///