Class: Observability::Observer

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

Constant Summary collapse

SNAKE_CASE_SEPARATOR =

Pattern for finding places for underscores when changing a camel-cased string to a snake-cased one.

/(\P{Upper}\p{Upper}|\p{Lower}\P{Lower})/

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sender_type = nil) ⇒ Observer

Create a new Observer that will send events via the specified sender.



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# File 'lib/observability/observer.rb', line 24

def initialize( sender_type=nil )
	@sender = self.configured_sender( sender_type )
	@event_stack = Concurrent::ThreadLocalVar.new( &Array.method(:new) )
	@context_stack = Concurrent::ThreadLocalVar.new( &Array.method(:new) )
end

Instance Attribute Details

#sender ⇒ Object (readonly)

The Observability::Sender used to deliver events



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# File 'lib/observability/observer.rb', line 37

def sender
  @sender
end

Instance Method Details

#add(object = nil, **fields) ⇒ Object

Add an object and/or a Hash of fields to the current event.



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# File 'lib/observability/observer.rb', line 104

def add( object=nil, **fields )
	self.log.debug "Adding %p" % [ object || fields ]
	event = @event_stack.value.last or return

	if object
		object_fields = self.fields_from_object( object )
		fields = fields.merge( object_fields )
	end

	event.merge( fields )
end

#add_context(object = nil, **fields) ⇒ Object

Add the specified fields to the current event and any that are created before the current event is finished.



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# File 'lib/observability/observer.rb', line 119

def add_context( object=nil, **fields )
	self.log.debug "Adding context from %p" % [ object || fields ]
	current_context = @context_stack.value.last or return

	if object
		object_fields = self.fields_from_object( object )
		fields = fields.merge( object_fields )
	end

	current_context.merge!( fields )
end

#event(type, **options, &block) ⇒ Object

Create a new event with the specified type and make it the current one.



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# File 'lib/observability/observer.rb', line 53

def event( type, **options, &block )
	type = self.type_from_object( type )
	fields = self.fields_from_options( options )

	parent = @event_stack.value.last
	event = Observability::Event.new( type, parent, **fields )
	@event_stack.value.push( event )

	new_context = @context_stack.value.last&.dup || {}
	@context_stack.value.push( new_context )

	return self.finish_after_block( event.object_id, &block ) if block
	return event.object_id
end

#finish(event_marker = nil) ⇒ Object

Finish the and send the current event, comparing it against event_marker and raising an exception if it’s provided but doesn’t match. – :TODO: Instead of raising, dequeue events up to the given marker if it

exists in the queue?



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# File 'lib/observability/observer.rb', line 74

def finish( event_marker=nil )
	raise "Event mismatch" if
		event_marker && @event_stack.value.last.object_id != event_marker

	event = @event_stack.value.pop
	context = @context_stack.value.pop
	self.log.debug "Adding context %p (%d left) to finishing event." %
		[ context, @context_stack.value.length ]
	event.merge( context )

	self.log.debug "Finishing event: %p" % [ event ]
	self.sender.enqueue( event )

	return event
end

#finish_after_block(event_marker = nil, &block) ⇒ Object

Call the given block, then when it returns, finish the event that corresponds to the given marker.



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# File 'lib/observability/observer.rb', line 93

def finish_after_block( event_marker=nil, &block )
	block.call( self )
rescue Exception => err
	self.add( err )
	raise
ensure
	self.finish( event_marker )
end

#has_pending_events? ⇒ Boolean Also known as: pending_events?

Returns true if the Observer has events that are under construction.

Returns:

  • (Boolean) 


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# File 'lib/observability/observer.rb', line 139

def has_pending_events?
	return self.pending_event_count.nonzero? ? true : false
end

#pending_event_count ⇒ Object

Return the depth of the stack of pending events.



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# File 'lib/observability/observer.rb', line 133

def pending_event_count
	return @event_stack.value.length
end

#start ⇒ Object

Start recording events and sending them.



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# File 'lib/observability/observer.rb', line 41

def start
	self.sender.start
end

#stop ⇒ Object

Stop recording and sending events.



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# File 'lib/observability/observer.rb', line 47

def stop
	self.sender.stop
end