Class: LightStep::Span

Inherits:
Object
  • Object
show all
Defined in:
lib/lightstep/span.rb

Overview

Span represents an OpenTracer Span

See www.opentracing.io for more information.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(tracer:, operation_name:, child_of_guid: nil, trace_guid:, start_micros:, tags: nil, max_log_records:) ⇒ Span

Creates a new LightStep::Span

Parameters:

  • tracer (Tracer) —

    the tracer that created this span

  • operation_name (String) —

    the operation name of this span

  • child_of_guid (String) (defaults to: nil) —

    the guid of the span this span is a child of

  • trace_guid (String) —

    the guid of this span’s trace

  • start_micros (Numeric) —

    start time of the span in microseconds



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# File 'lib/lightstep/span.rb', line 20

def initialize(
  tracer:,
  operation_name:,
  child_of_guid: nil,
  trace_guid:,
  start_micros:,
  tags: nil,
  max_log_records:
)
  @tags = Concurrent::Hash.new
  @tags.update(tags) unless tags.nil?
  @baggage = Concurrent::Hash.new
  @log_records = Concurrent::Array.new
  @dropped_logs = Concurrent::AtomicFixnum.new
  @max_log_records = max_log_records

  @tracer = tracer
  @guid = LightStep.guid
  self.operation_name = operation_name
  self.start_micros = start_micros
  self.trace_guid = trace_guid
  set_tag(:parent_span_guid, child_of_guid) if !child_of_guid.nil?
end

Instance Attribute Details

#baggage ⇒ Object (readonly)

Internal use only



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# File 'lib/lightstep/span.rb', line 10

def baggage
  @baggage
end

#end_micros ⇒ Object

Internal use only



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# File 'lib/lightstep/span.rb', line 10

def end_micros
  @end_micros
end

#guid ⇒ Object

Internal use only



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# File 'lib/lightstep/span.rb', line 10

def guid
  @guid
end

#start_micros ⇒ Object

Internal use only



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# File 'lib/lightstep/span.rb', line 10

def start_micros
  @start_micros
end

#tags ⇒ Object (readonly)

Internal use only



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# File 'lib/lightstep/span.rb', line 10

def tags
  @tags
end

#trace_guid ⇒ Object

Internal use only



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# File 'lib/lightstep/span.rb', line 10

def trace_guid
  @trace_guid
end

Instance Method Details

#dropped_logs_count ⇒ Object

Internal use only



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# File 'lib/lightstep/span.rb', line 133

def dropped_logs_count
  dropped_logs.value
end

#finish(end_time: Time.now) ⇒ Object

Finish the LightStep::Span

Parameters:

  • end_time (Time) (defaults to: Time.now) —

    custom end time, if not now



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# File 'lib/lightstep/span.rb', line 105

def finish(end_time: Time.now)
  if end_micros.nil?
    self.end_micros = LightStep.micros(end_time)
  end
  tracer.finish_span(self)
  self
end

#get_baggage_item(key) ⇒ Object

Get a baggage item

Parameters:

  • key (String) —

    the key of the baggage item

Returns:

  • Value of the baggage item



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# File 'lib/lightstep/span.rb', line 72

def get_baggage_item(key)
  baggage[key]
end

#log(event: nil, timestamp: Time.now, **fields) ⇒ Object

Add a log entry to this span

Parameters:

  • event (String) (defaults to: nil) —

    event name for the log

  • timestamp (Time) (defaults to: Time.now) —

    time of the log

  • fields (Hash) —

    Additional information to log



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# File 'lib/lightstep/span.rb', line 80

def log(event: nil, timestamp: Time.now, **fields)
  return unless tracer.enabled?

  record = {
    runtime_guid: tracer.guid,
    timestamp_micros: LightStep.micros(timestamp)
  }
  record[:stable_name] = event.to_s if !event.nil?

  begin
    record[:payload_json] = JSON.generate(fields, max_nesting: 8)
  rescue
    # TODO: failure to encode a payload as JSON should be recorded in the
    # internal library logs, with catioun not flooding the internal logs.
  end

  log_records.push(record)
  if log_records.size > @max_log_records
    log_records.shift
    dropped_logs.increment
  end
end

#logs_count ⇒ Object

Internal use only



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# File 'lib/lightstep/span.rb', line 139

def logs_count
  log_records.size
end

#set_baggage_item(key, value) ⇒ Object

Set a baggage item on the span

Parameters:

  • key (String) —

    the key of the baggage item

  • value (String) —

    the value of the baggage item



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# File 'lib/lightstep/span.rb', line 64

def set_baggage_item(key, value)
  baggage[key] = value
  self
end

#set_tag(key, value) ⇒ Object

Set a tag value on this span a String, Numeric, or Boolean it will be encoded with to_s

Parameters:

  • key (String) —

    the key of the tag

  • value (String, Numeric, Boolean) —

    the value of the tag. If it’s not



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# File 'lib/lightstep/span.rb', line 48

def set_tag(key, value)
  case value
  when String, Fixnum, TrueClass, FalseClass
    tags[key] = value
  else
    tags[key] = value.to_s
  end
  self
end

#to_h ⇒ Object

Hash representation of a span



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# File 'lib/lightstep/span.rb', line 114

def to_h
  {
    runtime_guid: tracer.guid,
    span_guid: guid,
    trace_guid: trace_guid,
    span_name: operation_name,
    attributes: tags.map {|key, value|
      {Key: key.to_s, Value: value}
    },
    oldest_micros: start_micros,
    youngest_micros: end_micros,
    error_flag: false,
    dropped_logs: dropped_logs_count,
    log_records: log_records
  }
end