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OpenTelemetry-0.022
River stage one • 5 direct dependents • 5 total dependents
1 ++
/ OpenTelemetry::Propagator::TraceContext::TraceState

NAME

OpenTelemetry::Propagator::TraceContext::TraceState - Represents TraceState in a W3C TraceContext

SYNOPSIS

    use OpenTelemetry::Propagator::TraceContext::TraceState;

    $state = OpenTelemetry::Propagator::TraceContext::TraceState
        ->from_string('rojo=00f067aa0ba902b7,congo=t61rcWkgMzE');

    say $state->get('rojo');    # 00f067aa0ba902b7
    say $state->get('missing'); # undef

    # Object is read-only: write operations generate clones
    $new = $state
        ->delete('congo')
        ->set( blue => 'deadbeef' );

    say $state->to_string; # rojo=00f067aa0ba902b7,congo=t61rcWkgMzE
    say $new->to_string;   # rojo=00f067aa0ba902b7,blue=deadbeef

DESCRIPTION

This class can be used to parse, manipulate, and generate the tracestate header as defined in a W3C TraceContext. Currently, this implements version 00 of that standard.

Note that, as defined in that standard, this header is only to be used to store properties that are defined by a tracing system. If you are looking to propagate other application-level properties OpenTelemetry::Propagator::Baggage might be a better fit.

METHODS

new

    $tracestate = OpenTelemetry::Propagator::TraceContext::TraceState->new;

Creates an empty OpenTelemetry::Propagator::TraceContext::TraceState object. To create an instance with initial key/value pairs, you should use "from_string".

from_string

    $tracestate = OpenTelemetry::Propagator::TraceContext::TraceState
        ->from_string($tracestate_header);

Takes the value of a tracestate header and returns a OpenTelemetry::Propagator::TraceContext::TraceState instance with the key/value pairs it contained, if any.

to_string

    $header = $tracestate->to_string;

Returns a string representation of the calling object, suitable to be used as the value of a tracestate header.

get

    $value = $tracestate->get($key);

Takes the key of a field as a string, and returns the value stored in the calling object under that key. If the key was never set, this will return an undefined value.

set

    $new = $tracestate->set( $key => $value );

Takes a key/value pair and returns a clone of the calling object with the specified key set to the specified value. If the key already existed, its value will be over-written.

delete

    $new = $tracestate->delete($key);

Takes the key of a field as a string, returns a clone of the calling object without the specified key. If the key did not exist, already existed, its value will be over-written.

SEE ALSO

OpenTelemetry::Propagator::TraceContext
W3C TraceContext format

COPYRIGHT AND LICENSE

This software is copyright (c) 2023 by José Joaquín Atria.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.