Theo van Hoesel
and 1 contributors

NAME

OpenTracing::Interface::ScopeManager - A role that defines the ScopeManager

SYNOPSIS

    package OpenTracing::Implementation::MyBackendService::ScopeManager;
        
    sub activate_span {
        ...
    }
    
    sub get_active_scope {
        ...
    }
    
    BEGIN {
        use Role::Tiny::With;
        with 'OpenTracing::Interface::ScopeManager'
            if $ENV{OPENTRACING_INTERFACE};
    } # check at compile time, perl -c will work
    
    1;

DESCRIPTION

This 'role' describes the interface for any OpenTracing ScopeManager implementation.

The ScopeManager interface abstracts both the activation of Span instances via activate_Span and access to an active Scope via get_active_scope.

INSTANCE METHODS

activate_span( $span, %options )

Set the specified Span as the active instance for the current context (usually a thread).

    my $span = $tracer->start_span( 'some operation'
        ignore_active_span => 1
    );
    
    my $manager = $tracer->get_scope_manager;
    
    my $scope = $manager->activate_span( $span,
        finish_span_on_close => 0
    );

The returned Scope represents the active state for the span. Once its active period is due, $scope->close() ought to be called. Observe the span will be automatically finished when $scope->close() is called.

Required Positional Parameters

Span

An object that does the Span interface.

Named Options

finish_span_on_close

A Bool when set to false, the Span will not be automatically finished when the Scope has been closed. This is 'true' by default.

Returns

An object that implements the Scope interface.

get_active_scope

Return the currently active Scope which can be used to access the currently active Span, using $scope->get_span.

    my $manager = $tracer->get_scope_manager;
    
    my $scope = $manager->get_activate_scope;

Parameters

none

Returns

The Scope that is currently active.

SEE ALSO

OpenTracing::Interface

Describes the API definition for OpenTransport implementations written in the Perl5 language.

OpenTracing::Types

A library of Type::Tiny type constraints that provides Duck Type checks for all common elements that conform OpenTracing::Interface

CAVEATS

This description is using around method modifiers that basically wraps them around the real implementation. These method modifiers provide a 'readable' and reusable interface, describing the inputs and outputs, using type constraints.

Consumers of this role, or implementors of the interface are MUST implement each method mentioned below. Not doing so will result in compilation errors.

Since this role does nothing else than checking input and output, it is useful during development. Most likely it can be switched off safely in production environments.