Method ApplyDecay

pkg/memory/preference.go:315–350

ApplyDecay 应用强度衰减

(ctx context.Context)

// ApplyDecay 应用强度衰减
func (pm *PreferenceManager) ApplyDecay(ctx context.Context) int {
	pm.mu.Lock()
	defer pm.mu.Unlock()

	removed := 0

	for userID, prefs := range pm.preferences {
		newPrefs := []*Preference{}

		for _, pref := range prefs {
			// 计算衰减
			daysSinceUpdate := time.Since(pref.UpdatedAt).Hours() / 24
			decay := 1.0 - (pm.config.StrengthDecay * daysSinceUpdate)

			if decay < 0 {
				decay = 0
			}

			pref.Strength *= decay

			// 如果强度低于阈值，删除
			if pref.Strength >= pm.config.MinStrength {
				newPrefs = append(newPrefs, pref)
			} else {
				removed++
			}
		}

		pm.preferences[userID] = newPrefs
	}

	// 重建索引
	pm.rebuildIndex()

	return removed
}

// rebuildIndex 重建类别索引
func (pm *PreferenceManager) rebuildIndex() {