module Agents class DelayAgent < Agent include FormConfigurable default_schedule 'every_12h' description <<~MD The DelayAgent stores received Events and emits copies of them on a schedule. Use this as a buffer or queue of Events. `max_events` should be set to the maximum number of events that you'd like to hold in the buffer. When this number is reached, new events will either be ignored, or will displace the oldest event already in the buffer, depending on whether you set `keep` to `newest` or `oldest`. `expected_receive_period_in_days` is used to determine if the Agent is working. Set it to the maximum number of days that you anticipate passing without this Agent receiving an incoming Event. `emit_interval` specifies the interval in seconds between emitting events. This is zero (no interval) by default. `max_emitted_events` is used to limit the number of the maximum events which should be created. If you omit this DelayAgent will create events for every event stored in the memory. # Ordering Events #{description_events_order("events in which buffered events are emitted")} MD def default_options { 'expected_receive_period_in_days' => 10, 'max_events' => 100, 'keep' => 'newest', 'max_emitted_events' => '', 'emit_interval' => 0, 'events_order' => [], } end form_configurable :expected_receive_period_in_days, type: :number, html_options: { min: 1 } form_configurable :max_events, type: :number, html_options: { min: 1 } form_configurable :keep, type: :array, values: %w[newest oldest] form_configurable :max_emitted_events, type: :number, html_options: { min: 0 } form_configurable :emit_interval, type: :number, html_options: { min: 0, step: 0.001 } form_configurable :events_order, type: :json def validate_options unless options['expected_receive_period_in_days'].present? && options['expected_receive_period_in_days'].to_i > 0 errors.add(:base, "Please provide 'expected_receive_period_in_days' to indicate how many days can pass before this Agent is considered to be not working") end unless options['keep'].present? && options['keep'].in?(%w[newest oldest]) errors.add(:base, "The 'keep' option is required and must be set to 'oldest' or 'newest'") end unless interpolated['max_events'].present? && interpolated['max_events'].to_i > 0 errors.add(:base, "The 'max_events' option is required and must be an integer greater than 0") end if interpolated['max_emitted_events'].present? unless interpolated['max_emitted_events'].to_i > 0 errors.add(:base, "The 'max_emitted_events' option is optional and should be an integer greater than 0") end end unless interpolated['emit_interval'] in nil | 0.. | /\A\d+(?:\.\d+)?\z/ errors.add(:base, "The 'emit_interval' option should be a non-negative number if set") end end def working? last_receive_at && last_receive_at > options['expected_receive_period_in_days'].to_i.days.ago && !recent_error_logs? end def receive(incoming_events) incoming_events.each do |event| event_ids = memory['event_ids'] || [] event_ids << event.id if event_ids.length > interpolated['max_events'].to_i if options['keep'] == 'newest' event_ids.shift else event_ids.pop end end memory['event_ids'] = event_ids end end def check return if memory['event_ids'].blank? events = received_events.where(id: memory['event_ids']).reorder(:id).to_a if interpolated[SortableEvents::EVENTS_ORDER_KEY].present? events = sort_events(events) end max_emitted_events = interpolated['max_emitted_events'].presence&.to_i if max_emitted_events&.< events.length events[max_emitted_events..] = [] end interval = (options['emit_interval'].presence&.to_f || 0).clamp(0..) events.each_with_index do |event, i| sleep interval unless i.zero? create_event payload: event.payload memory['event_ids'].delete(event.id) end end end end