hdrhist is a small footprint hdr histogram in rust. It collects u64 samples in the full u64 value range with precision of 5 most significant bits. You can add new samples in O(1) time (a handful of cycles), and it will never reallocate.
Add the following to your [dependecies] in Cargo.toml.
hdrhist = "^<version>"
where <version> is the desired version of the library. The latest version is
The reference documentation is at docs.rs/hdrhist.