Class: Sentry::PropagationContext

Inherits:
Object
  • Object
show all
Defined in:
lib/sentry/propagation_context.rb

Constant Summary collapse

SENTRY_TRACE_REGEXP = 
Regexp.new(
  "\\A([0-9a-f]{32})?" + # trace_id
  "-?([0-9a-f]{16})?" +  # span_id
  "-?([01])?\\z"         # sampled
)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(scope, env = nil) ⇒ PropagationContext

Returns a new instance of PropagationContext.



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# File 'lib/sentry/propagation_context.rb', line 83

def initialize(scope, env = nil)
  @scope = scope
  @parent_span_id = nil
  @parent_sampled = nil
  @baggage = nil
  @incoming_trace = false
  @sample_rand = nil

  if env
    sentry_trace_header = env["HTTP_SENTRY_TRACE"] || env[SENTRY_TRACE_HEADER_NAME]
    baggage_header = env["HTTP_BAGGAGE"] || env[BAGGAGE_HEADER_NAME]

    if sentry_trace_header
      sentry_trace_data = self.class.extract_sentry_trace(sentry_trace_header)

      if sentry_trace_data
        @trace_id, @parent_span_id, @parent_sampled = sentry_trace_data

        @baggage =
          if baggage_header && !baggage_header.empty?
            Baggage.from_incoming_header(baggage_header)
          else
            # If there's an incoming sentry-trace but no incoming baggage header,
            # for instance in traces coming from older SDKs,
            # baggage will be empty and frozen and won't be populated as head SDK.
            Baggage.new({})
          end

        @sample_rand = self.class.extract_sample_rand_from_baggage(@baggage, @trace_id)

        @baggage.freeze!
        @incoming_trace = true
      end
    end
  end

  @trace_id ||= Utils.uuid
  @span_id = Utils.uuid.slice(0, 16)
  @sample_rand ||= self.class.generate_sample_rand(@baggage, @trace_id, @parent_sampled)
end

Instance Attribute Details

#baggage ⇒ Baggage? (readonly)

This is only for accessing the current baggage variable. Please use the #get_baggage method for interfacing outside this class.

Returns:



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# File 'lib/sentry/propagation_context.rb', line 34

def baggage
  @baggage
end

#incoming_trace ⇒ Boolean (readonly)

Is there an incoming trace or not?

Returns:

  • (Boolean) 


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# File 'lib/sentry/propagation_context.rb', line 30

def incoming_trace
  @incoming_trace
end

#parent_sampled ⇒ Boolean? (readonly)

The sampling decision of the parent transaction.

Returns:

  • (Boolean, nil) 


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# File 'lib/sentry/propagation_context.rb', line 27

def parent_sampled
  @parent_sampled
end

#parent_span_id ⇒ String? (readonly)

Span parent’s span_id.

Returns:

  • (String, nil) 


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# File 'lib/sentry/propagation_context.rb', line 24

def parent_span_id
  @parent_span_id
end

#sample_rand ⇒ Float? (readonly)

The propagated random value used for sampling decisions.

Returns:

  • (Float, nil) 


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# File 'lib/sentry/propagation_context.rb', line 37

def sample_rand
  @sample_rand
end

#span_id ⇒ String (readonly)

An uuid that can be used to identify the span.

Returns:

  • (String) 


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# File 'lib/sentry/propagation_context.rb', line 21

def span_id
  @span_id
end

#trace_id ⇒ String (readonly)

An uuid that can be used to identify a trace.

Returns:

  • (String) 


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# File 'lib/sentry/propagation_context.rb', line 18

def trace_id
  @trace_id
end

Class Method Details

.extract_sample_rand_from_baggage(baggage, trace_id = nil) ⇒ Object 



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# File 'lib/sentry/propagation_context.rb', line 56

def self.extract_sample_rand_from_baggage(baggage, trace_id = nil)
  return unless baggage&.items

  sample_rand_str = baggage.items["sample_rand"]
  return unless sample_rand_str

  generator = Utils::SampleRand.new(trace_id: trace_id)
  generator.generate_from_value(sample_rand_str)
end

.extract_sentry_trace(sentry_trace) ⇒ Array?

Extract the trace_id, parent_span_id and parent_sampled values from a sentry-trace header.

Parameters:

  • sentry_trace (String) —

    the sentry-trace header value from the previous transaction.

Returns:

  • (Array, nil) 


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# File 'lib/sentry/propagation_context.rb', line 43

def self.extract_sentry_trace(sentry_trace)
  value = sentry_trace.to_s.strip
  return if value.empty?

  match = SENTRY_TRACE_REGEXP.match(value)
  return if match.nil?

  trace_id, parent_span_id, sampled_flag = match[1..3]
  parent_sampled = sampled_flag.nil? ? nil : sampled_flag != "0"

  [trace_id, parent_span_id, parent_sampled]
end

.generate_sample_rand(baggage, trace_id, parent_sampled) ⇒ Object 



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# File 'lib/sentry/propagation_context.rb', line 66

def self.generate_sample_rand(baggage, trace_id, parent_sampled)
  generator = Utils::SampleRand.new(trace_id: trace_id)

  if baggage&.items && !parent_sampled.nil?
    sample_rate_str = baggage.items["sample_rate"]
    sample_rate = sample_rate_str&.to_f

    if sample_rate && !parent_sampled.nil?
      generator.generate_from_sampling_decision(parent_sampled, sample_rate)
    else
      generator.generate_from_trace_id
    end
  else
    generator.generate_from_trace_id
  end
end

Instance Method Details

#get_baggage ⇒ Baggage?

Returns the Baggage from the propagation context or populates as head SDK if empty.

Returns:



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# File 'lib/sentry/propagation_context.rb', line 142

def get_baggage
  populate_head_baggage if @baggage.nil? || @baggage.mutable
  @baggage
end

#get_dynamic_sampling_context ⇒ Hash?

Returns the Dynamic Sampling Context from the baggage.

Returns:

  • (Hash, nil) 


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# File 'lib/sentry/propagation_context.rb', line 149

def get_dynamic_sampling_context
  get_baggage&.dynamic_sampling_context
end

#get_trace_context ⇒ Hash

Returns the trace context that can be used to embed in an Event.

Returns:

  • (Hash) 


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# File 'lib/sentry/propagation_context.rb', line 126

def get_trace_context
  {
    trace_id: trace_id,
    span_id: span_id,
    parent_span_id: parent_span_id
  }
end

#get_traceparent ⇒ String

Returns the sentry-trace header from the propagation context.

Returns:

  • (String) 


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# File 'lib/sentry/propagation_context.rb', line 136

def get_traceparent
  "#{trace_id}-#{span_id}"
end