class Telemetry::Sampler

class Telemetry::Sampler { }

Note: This class is a Rakudo-specific feature and not standard Raku.

use Telemetry;
$*SAMPLER.set-instruments(<Usage ThreadPool>); # default setting 

One usually does not create any Telemetry::Sampler objects: when the Telemetry module is loaded, a Telemetry::Sampler object is automatically created in the $*SAMPLER dynamic variable.

An object of the Telemetry::Sampler class knows about which instruments to use when making a snapshot.

method new

method new(Telemetry::Sampler: @instruments --> Telemetry::Sampler:D)

The new method takes a list of instruments. If no instruments are specified, then it will look at the RAKUDO_TELEMETRY_INSTRUMENTS environment variable to find specification of instruments. If that is not available either, then Telemetry::Instrument::Usage and Telemetry::Instrument::ThreadPool will be assumed.

Instruments can be specified by either the type object of the instrument class (e.g. Telemetry::Instrument::Usage) or by a string, in which case it will be automatically prefixed with "Telemetry::Instrument::", so "Usage" would be the same as Telemetry::Instrument::Usage.

method set-instruments

method set-instruments(Telemetry::Sampler:D @instruments --> Nil)

Allows one to change the instruments on an existing Instrument::Sampler object. Generally only used by calling it on the $*SAMPLER dynamic variable. Takes the same parameters as new, except that specifying no instruments will actually remove all of the instruments, effectively blocking any snap taking.