🧹 Aeon::CacheInvalidation – 4 + 1 Architecture

Ensures that when time changes, memory follows.

---

1️⃣ Logical View

Purpose:
Detect changes to Aeon::Timestamp records and purge affected cache windows.

Responsibilities - Subscribe to model events (create, update, destroy). - Compute affected CacheWindow keys based on timestamp period. - Delete or mark stale keys in Redis. - Optionally trigger Refresher jobs.

---

2️⃣ Process View

1. Aeon::Timestamp commits transaction.
2. Observer fires after_commit.
3. CacheInvalidation computes window keys.
4. Deletes cached occurrences.
5. Argus logs and Refresher schedules rebuild.

---

3️⃣ Development View

File: app/services/aeon/cache_invalidation.rb

class Aeon::CacheInvalidation
  def self.on_change(timestamp)
    period = timestamp.to_period
    key = Aeon::CacheWindow.key_for(period)
    Aeon::CacheManager.delete(key)
    Argus.emit("aeon.cache.invalidated", meta: { key:, id: timestamp.id })
  end
end

Observer Integration

class Aeon::TimestampObserver < ActiveRecord::Observer
  observe :aeon_timestamp
  def after_commit(record) = Aeon::CacheInvalidation.on_change(record)
end

---

4️⃣ Physical View

Attribute	Description
Runtime	Rails ActiveRecord callbacks
Store	Redis (through CacheManager)
Events	Argus aeon.cache.invalidated

---

➕ 1 Scenario View

Scenario A: Timestamp Modified

User updates event → Invalidation removes affected window.

Scenario B: Deletion

destroy → cache purged immediately.

Observability:
Metrics aeon_cache_invalidations_total.

---