Module: Datadog::Tracing::Utils

Defined in:
lib/datadog/tracing/utils.rb

Overview

Utils contains low-level tracing utility functions.

Constant Summary collapse

RUBY_MAX_ID =

The max value for a Span identifier. Span and trace identifiers should be strictly positive and strictly inferior to this limit.

Limited to +2<<62-1+ positive integers, as Ruby is able to represent such numbers "inline", inside a +VALUE+ scalar, thus not requiring memory allocation.

The range of IDs also has to consider portability across different languages and platforms.

(1 << 62) - 1
RUBY_ID_RANGE =

Excludes zero from possible values

(1..RUBY_MAX_ID).freeze
EXTERNAL_MAX_ID =

While we only generate 63-bit integers due to limitations in other languages, we support parsing 64-bit integers for distributed tracing since an upstream system may generate one

1 << 64

Class Method Summary collapse

Class Method Details

.next_id ⇒ Object

Return a randomly generated integer, valid as a Span ID or Trace ID. This method is thread-safe and fork-safe.



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# File 'lib/datadog/tracing/utils.rb', line 35

def self.next_id
  after_fork! { reset! }
  id_rng.rand(RUBY_ID_RANGE)
end

.serialize_attribute(key, value) ⇒ Object

Serialize values into Datadog span tags and metrics. Notably, arrays are exploded into many keys, each with a numeric suffix representing the array index, for example: 'foo' => ['a','b'] becomes 'foo.0' => 'a', 'foo.1' => 'b'



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# File 'lib/datadog/tracing/utils.rb', line 52

def self.serialize_attribute(key, value)
  if value.is_a?(Array)
    value.flat_map.with_index do |v, idx|
      serialize_attribute("#{key}.#{idx}", v)
    end
  elsif value.is_a?(TrueClass) || value.is_a?(FalseClass)
    [[key, value.to_s]]
  else
    [[key, value]]
  end
end