# Rustics
A minimal statistics library for performance monitoring
Rustics implements 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.
At this time, statistics can be gathered for i64 values, time periods (also of
type i64), and f64 samples. They can be kept as a running total of all
samples recorded, or as a window covering the last N samples. The library also
supports creating sets of structs.
Most modules have sample code in their documentation, and many testing modules
contain example functions called "sample_usage". The "main.rs" program
contains a small example of using running integer and time statistics structs
in a set. You can run it by invoking "cargo run".
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 users to keep 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. This module
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 invocation,
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 default title
printed for that instance will be "Network Statistics ==\> Packet Latency".