Module aggregate 

Available on crate feature aggregate only.

flowscope::aggregate — distribution / quantile primitives.

Two small types every observability example reinvents:

• Histogram — explicit-bucket counter with record / quantile / merge. For “distribution of X” reports (flow durations, packet sizes, response times).
• Percentile — t-digest-style streaming quantile estimator for unbounded streams. Wraps the tdigest crate.

Use Histogram when you know the buckets up front and want exact counts per bucket. Use Percentile for unbounded streams where memorising every sample isn’t feasible and you only need quantile reads at the tail (p95, p99, p999).

use flowscope::aggregate::Histogram;

// Flow-duration buckets in seconds, log-spaced 100 ms → 1 h.
let mut h = Histogram::log_spaced(0.1, 3600.0, 6);
for d in [0.5, 1.2, 8.0, 45.0, 200.0] {
    h.record(d);
}
assert_eq!(h.samples(), 5);
let _p95 = h.quantile(0.95);

New in 0.10.0 (plan 102 sub-B).

Structs

Histogram

Explicit-bucket histogram for f64 samples.

Percentile

Streaming quantile estimator.

Enums

HistogramError

Histogram error type.