Class: Events::Subscribers::Persister

Inherits:
Object
  • Object
show all
Includes:
Events::Subscriber
Defined in:
lib/events/subscribers/persister.rb

Overview

Persists all events to SQLite as they flow through the event bus. Each event is written as a Message record belonging to the active session.

When initialized with a specific session, all events are saved to that session. When initialized without one (global mode), the session is looked up from the event’s session_id payload field.

User messages are NOT persisted here — they are created directly by their callers (SessionChannel#speak, AgentLoop#run) so the message ID is available for bounce-back cleanup. Pending user messages live in the PendingMessage table, outside the event bus.

Examples:

Session-scoped

persister = Events::Subscribers::Persister.new(session)
Events::Bus.subscribe(persister)

Global (persists events for any session)

persister = Events::Subscribers::Persister.new
Events::Bus.subscribe(persister)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(session = nil) ⇒ Persister

Returns a new instance of Persister.



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# File 'lib/events/subscribers/persister.rb', line 29

def initialize(session = nil)
  @session = session
  @mutex = Mutex.new
end

Instance Attribute Details

#session ⇒ Object

Returns the value of attribute session.



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# File 'lib/events/subscribers/persister.rb', line 27

def session
  @session
end

Instance Method Details

#emit(event) ⇒ Object

Receives a Rails.event notification hash and persists it.

Skips user messages — those are persisted by their callers (SessionChannel#speak, AgentLoop#run). Also skips event types not in Message::TYPES (transient events like BounceBack).

Parameters:

  • event (Hash) —

    with :payload containing event data



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# File 'lib/events/subscribers/persister.rb', line 42

def emit(event)
  payload = event[:payload]
  return unless payload.is_a?(Hash)

  event_type = payload[:type]
  return if event_type.nil?
  return unless Message::TYPES.include?(event_type)
  return if event_type == "user_message"

  target_session = @session || Session.find_by(id: payload[:session_id])
  return unless target_session

  @mutex.synchronize do
    target_session.messages.create!(
      message_type: event_type,
      payload: payload,
      tool_use_id: payload[:tool_use_id],
      timestamp: payload[:timestamp] || Time.current.to_ns,
      api_metrics: payload[:api_metrics]
    )
  end
end