Class: Observability::Event

Inherits:
Object
  • Object
show all
Extended by:
Forwardable, Loggability
Defined in:
lib/observability/event.rb

Constant Summary collapse

FORMAT_VERSION =

The event format version to send with all events

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Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, parent = nil, **fields) ⇒ Event

Create a new event



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# File 'lib/observability/event.rb', line 40

def initialize( type, parent=nil, **fields )
	@id        = self.class.generate_id
	@parent_id = parent&.id
	@type      = type.freeze
	@timestamp = Time.now
	@start     = Concurrent.monotonic_time
	@fields    = fields
end

Instance Attribute Details

#fields ⇒ Object (readonly)

Delegate some read-only methods to the #fields Hash.



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# File 'lib/observability/event.rb', line 76

def fields
  @fields
end

#id ⇒ Object (readonly)

The ID of the event, used to pass context through application boundaries



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# File 'lib/observability/event.rb', line 56

def id
  @id
end

#parent_id ⇒ Object (readonly)

The ID of the containing context event, if there is one



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# File 'lib/observability/event.rb', line 60

def parent_id
  @parent_id
end

#start ⇒ Object (readonly)

The monotonic clock time of when the event was created



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# File 'lib/observability/event.rb', line 72

def start
  @start
end

#timestamp ⇒ Object (readonly)

The Time the event was created



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# File 'lib/observability/event.rb', line 68

def timestamp
  @timestamp
end

#type ⇒ Object (readonly)

The type of the event, which should be a string of the form: ‘foo.bar.baz’



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# File 'lib/observability/event.rb', line 64

def type
  @type
end

Class Method Details

.generate_id ⇒ Object

Generate a new Event ID.



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# File 'lib/observability/event.rb', line 34

def self::generate_id
	return self.id_generator.generate
end

.id_generator ⇒ Object

Return a generator that can return a unique ID string for identifying Events across application boundaries.



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# File 'lib/observability/event.rb', line 28

def self::id_generator
	return @id_generator ||= UUID.new
end

Instance Method Details

#merge(fields) ⇒ Object

Merge the specified fields into the event’s data. :TODO: Handle conflicts?



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# File 'lib/observability/event.rb', line 86

def merge( fields )
	self.fields.merge!( fields )
rescue FrozenError => err
	raise "event is already resolved", cause: err
end

#resolve ⇒ Object Also known as: to_h

Finalize all of the event’s data and return it as a Hash.



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# File 'lib/observability/event.rb', line 94

def resolve
	unless @fields.frozen?
		self.log.debug "Resolving event %#x" % [ self.object_id ]
		data = self.fields.merge(
			:@id => self.id,
			:@parent_id => self.parent_id,
			:@type => self.type,
			:@timestamp => self.timestamp,
			:@version => FORMAT_VERSION
		)
		data = data.transform_values( &self.method(:resolve_value) )
		@fields = data.freeze
	end

	return @fields
end

#resolve_value(value) ⇒ Object

Resolve the given value into a serializable object.



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# File 'lib/observability/event.rb', line 114

def resolve_value( value )
	case

	when value.respond_to?( :call ) # Procs, Methods
		return value.call( self )

	when value.respond_to?( :iso8601 ) # Time, Date, DateTime, etc.
		return value.iso8601( 6 )

	else
		return value
	end
end