Module: HLS::Instrumentation

Defined in:
lib/hls/instrumentation.rb

Overview

Lightweight instrumentation wrapper around ActiveSupport::Notifications.

Subscribe to the events from your host app to wire up logging, metrics, or tracing. Event names follow the Rails convention ‘<action>.<library>` so they show up nicely in LogSubscriber output.

ActiveSupport::Notifications.subscribe("encode.hls") do |name, start, finish, _, payload|
  Rails.logger.info "[hls] encoded #{payload[:profile]} in #{((finish - start) * 1000).round}ms"
end

Events emitted:

encode.hls         — encode! finished. payload: profile, output, renditions
poster.hls         — poster! finished. payload: profile, output, count
verify.hls         — verify_encode! passed. payload: profile, output
upload_object.hls  — single object PUT to the bucket. payload: key, bytes, content_type
process.hls        — full process pipeline. payload: profile, key_prefix, uploaded, skipped

When ActiveSupport::Notifications isn’t loaded (plain-Ruby usage, specs without Rails), the helper is a no-op that still yields.

Class Method Summary collapse

Class Method Details

.instrument(event, payload = {}) ⇒ Object

Wraps a block in an ActiveSupport::Notifications event. Yields the mutable payload hash to the block so callers can attach result data (e.g., uploaded counts) before the event is published. When ActiveSupport::Notifications isn’t loaded, yields the same payload hash with no surrounding instrumentation.



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# File 'lib/hls/instrumentation.rb', line 32

def instrument(event, payload = {})
  if defined?(ActiveSupport::Notifications)
    ActiveSupport::Notifications.instrument("#{event}.hls", payload) { yield payload if block_given? }
  else
    yield payload if block_given?
  end
end