NAME

       "Net::Prometheus::Metric" - the base class for observed metrics

DESCRIPTION

       This class provides the basic methods shared by the concrete subclasses,

       • Net::Prometheus::Gauge - a snapshot value-reporting metric

       • Net::Prometheus::Counter - a monotonically-increasing counter metric

       • Net::Prometheus::Summary - summarise individual numeric observations

       • Net::Prometheus::Histogram - count the distribution of numeric observations

CONSTRUCTOR

   new
          $metric = Net::Prometheus::Metric->new(
             name => $name,
             help => $help,
          )

       The constructor is not normally used directly by instrumented code. Instead it is more
       common to use one of the "new_*" methods on the containing Net::Prometheus client instance
       so that the new metric is automatically registered as a collector, and gets exported by
       the render method.

          $metric = $prometheus->new_counter(
             name => $name,
             help => $help,
          )

       In either case, it returns a newly-constructed metric.

       Takes the following named arguments:

       namespace => STR
       subsystem => STR
           Optional strings giving the namespace and subsystem name parts of the variable name.

       name => STR
           The basename of the exported variable.

       help => STR
           Descriptive help text for the variable.

       labels => ARRAY of STR
           Optional ARRAY reference giving the names of labels for the metric.

METHODS

   fullname
          $fullname = $metric->fullname

       Returns the full name for the metric. This is formed by joining any of the defined values
       for "namespace", "subsystem" and "name" with '_'.

   labelcount
          $labels = $metric->labelcount

       Returns the number of labels defined for this metric.

   labels
          $child = $metric->labels( @values )

          $child = $metric->labels( { name => $value, name => $value, ... } )

       Returns a child metric to represent the general one with the given set of labels. The
       label values may be provided either in a list corresponding to the list of label names
       given at construction time, or by name in a single HASH reference.

       The child instance supports the same methods to control the value of the reported metric
       as the parent metric object, except that any label values are already provided.

       This object may be cached for efficiency.

   make_sample
          $sample = $metric->make_sample( $suffix, $labelkey, $value, $extralabels )

       Returns a new "Sample" in Net::Prometheus::Types structure to represent the given value,
       by expanding the opaque $labelkey value into its actual label names and values and
       appending the given suffix (which may be an empty string) to the metric's fullname. If
       provided, the suffix will be separated by an underscore '_'. If provided, $extralabels
       provides more label names and values to be added to the sample.

   samples
          @samples = $metric->samples

       An abstract method in this class, this method is intended to be overridden by subclasses.

       Called during the value collection process, this method should return a list of "Sample"
       in Net::Prometheus::Types instances containing the values to report from this metric.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>