Class: OpenTelemetry::Propagator::B3::Single::TextMapPropagator

Inherits:
Object
  • Object
show all
Includes:
TextMapExtractor
Defined in:
lib/opentelemetry/propagator/b3/single/text_map_propagator.rb

Overview

Propagates trace context using the b3 single header format

Instance Method Summary collapse

Methods included from TextMapExtractor

#extract

Instance Method Details

#fields ⇒ Array<String>

Returns the predefined propagation fields. If your carrier is reused, you should delete the fields returned by this method before calling inject.

Returns:

  • (Array<String>) —

    a list of fields that will be used by this propagator.



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# File 'lib/opentelemetry/propagator/b3/single/text_map_propagator.rb', line 57

def fields
  FIELDS
end

#inject(carrier, context: Context.current, setter: Context::Propagation.text_map_setter) ⇒ Object

Inject trace context into the supplied carrier.

Parameters:

  • carrier (Carrier) —

    The mutable carrier to inject trace context into

  • context (Context) (defaults to: Context.current) —

    The context to read trace context from

  • setter (optional Setter) (defaults to: Context::Propagation.text_map_setter) —

    If the optional setter is provided, it will be used to write context into the carrier, otherwise the default text map setter will be used.



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# File 'lib/opentelemetry/propagator/b3/single/text_map_propagator.rb', line 35

def inject(carrier, context: Context.current, setter: Context::Propagation.text_map_setter)
  span_context = Trace.current_span(context).context
  return unless span_context.valid?

  sampling_state = if B3.debug?(context)
                     'd'
                   elsif span_context.trace_flags.sampled?
                     '1'
                   else
                     '0'
                   end

  b3_value = "#{span_context.hex_trace_id}-#{span_context.hex_span_id}-#{sampling_state}"

  setter.set(carrier, B3_CONTEXT_KEY, b3_value)
  nil
end