Rustics

A minimal statistics library for performance monitoring

Rustics implements a simple set of statistics structs intended primarily for measuring performance parameters. The struct implementations compute various statistical characterizations of the data, such as the mean and variance. The trait Rustics defines the common interface for all statistical types.

Most modules have sample code in their documentation, and many testing modules contain example functions called "sample_usage". The "main.rs" program contains a simple example of using RunningInteger and RunningTime instances in a set.

At this time, statistics can be gathered for i64 values, time periods (also of type i64), and f64 samples. Statistics can gathered collected as a running total of all samples recorded, or as a window covering the last N samples.

The structs for time samples require a timer implementation. See the time module for information on timers and to see some sample implementations.

In addition to the more detailed statistics types, the library supports a simple counter for which no other statistics are generated. This can be useful for counting events, for example.

This library also implements a form of hierarchical statistics. The hierarchical statistics combine sets of Rustics instances into single Rustics instances. This summation can allow keeping historical data with a lower memory footprint, and can reduce floating-point loss of precision. See the lib.rs comments for an overview.

Rustics also implements sets that contain Rustics instances. All the instances in a set can be printed via the print() method of the set, and other functions are provided, as well. Rustics provides one set type that contains Rustics instances as Arc<Mutex<dyn Rustics>> structures and another set type that uses structures of type Rc<RefCell<dyn Rustics>>. The two set modules are otherwise largely identical.

Sets are recursive: a set can have a set as a member. All the Rustics instances in a set hierarchy can be printed with a single method call, and the contained Rustics instances can be cleared with a single method, as well.

The set implementation automatically creates hierarchical titles for Rustics instances. For example, if a user has a set named "Network Statistics" and that set contains a Rustics instance named "Packet Latency", the title printed for that instance will be "Network Statistics ==> Packet Latency".