module Datadog::Utils

Utils contains low-level utilities, typically to provide pseudo-random trace IDs.

Constants

EMPTY_STRING

Public Class Methods

next_id() click to toggle source

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

# File lib/ddtrace/utils.rb, line 17
def self.next_id
  after_fork! { reset! }
  id_rng.rand(Datadog::Span::RUBY_MAX_ID) # TODO: This should never return zero
end
truncate(value, size, omission = '...'.freeze) click to toggle source

Stringifies `value` and ensures the outcome is string is no longer than `size`. `omission` replaces the end of the output if `value.to_s` does not fit in `size`, to signify truncation.

If `omission.size` is larger than `size`, the output will still be `omission.size` in length.

# File lib/ddtrace/utils.rb, line 40
def self.truncate(value, size, omission = '...'.freeze)
  string = value.to_s

  return string if string.size <= size

  string = string.slice(0, size - 1)

  if size < omission.size
    string[0, size] = omission
  else
    string[size - omission.size, size] = omission
  end

  string
end
utf8_encode(str, options = {}) click to toggle source

Ensure `str` is a valid UTF-8, ready to be sent through the tracer transport.

# File lib/ddtrace/utils.rb, line 58
def self.utf8_encode(str, options = {})
  str = str.to_s

  if options[:binary]
    # This option is useful for "gracefully" displaying binary data that
    # often contains text such as marshalled objects
    str.encode('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '')
  elsif str.encoding == ::Encoding::UTF_8
    str
  elsif str.empty?
    # DEV Optimization as `nil.to_s` is a very common source for an empty string,
    # DEV but it comes encoded as US_ASCII.
    EMPTY_STRING
  else
    str.encode(::Encoding::UTF_8)
  end
rescue => e
  Datadog.logger.debug("Error encoding string in UTF-8: #{e}")

  options.fetch(:placeholder, EMPTY_STRING)
end

Private Class Methods

id_rng() click to toggle source
# File lib/ddtrace/utils.rb, line 22
def self.id_rng
  @id_rng ||= Random.new
end
reset!() click to toggle source
# File lib/ddtrace/utils.rb, line 26
def self.reset!
  @id_rng = Random.new
end