GetKey converts name+tags into a single string of the form "name|tag1=value1|...|tagN=valueN", where tag names are sorted alphabetically.

Init does the same as MustInit, but returns an error instead of panicking.

MustInit initializes the passed in metrics and initializes its fields using the passed in factory.

StartStopwatch begins recording the executing time of an event, returning a Stopwatch that should be used to stop the recording the time for that event.

NullCounter counter that does nothing.

NullFactory is a metrics factory that returns NullCounter, NullTimer, and NullGauge.

NullGauge gauge that does nothing.

NullHistogram that does nothing.

NullTimer timer that does nothing.

HistogramOptions defines the information associated with a metric.

NSOptions defines the name and tags map associated with a factory namespace.

Options defines the information associated with a metric.

A Stopwatch tracks the execution time of a specific event.

TimerOptions defines the information associated with a metric.

Counter tracks the number of times an event has occurred.

Factory creates new metrics.

Gauge returns instantaneous measurements of something as an int64 value.

Histogram that keeps track of a distribution of values.

Timer accumulates observations about how long some operation took, and also maintains a historgam of percentiles.