Refactor caching and memory management components

- Updated the caching logic to utilize a predictive cache warmer, enhancing content prefetching based on access patterns.
- Replaced the legacy warming system with a more efficient predictive approach, allowing for better performance and resource management.
- Refactored memory management to integrate dynamic cache size adjustments based on system memory usage, improving overall efficiency.
- Simplified the VFS interface and improved concurrency handling with sharded locks for better performance in multi-threaded environments.
- Enhanced tests to validate the new caching and memory management behaviors, ensuring reliability and performance improvements.

vfs/memory/monitor.go

@@ -17,6 +17,15 @@ type MemoryMonitor struct {
 	ctx                 chan struct{}
 	stopChan            chan struct{}
 	isMonitoring        int32
+
+	// Dynamic cache management fields
+	originalCacheSize  uint64
+	currentCacheSize   uint64
+	cache              interface{} // Generic cache interface
+	adjustmentInterval time.Duration
+	lastAdjustment     time.Time
+	adjustmentCount    int64
+	isAdjusting        int32
 }
 
 // NewMemoryMonitor creates a new memory monitor
@@ -27,9 +36,19 @@ func NewMemoryMonitor(targetMemoryUsage uint64, monitoringInterval time.Duration
 		adjustmentThreshold: adjustmentThreshold,
 		ctx:                 make(chan struct{}),
 		stopChan:            make(chan struct{}),
+		adjustmentInterval:  30 * time.Second, // Default adjustment interval
 	}
 }
 
+// NewMemoryMonitorWithCache creates a new memory monitor with cache management
+func NewMemoryMonitorWithCache(targetMemoryUsage uint64, monitoringInterval time.Duration, adjustmentThreshold float64, cache interface{}, originalCacheSize uint64) *MemoryMonitor {
+	mm := NewMemoryMonitor(targetMemoryUsage, monitoringInterval, adjustmentThreshold)
+	mm.cache = cache
+	mm.originalCacheSize = originalCacheSize
+	mm.currentCacheSize = originalCacheSize
+	return mm
+}
+
 // Start begins monitoring memory usage
 func (mm *MemoryMonitor) Start() {
 	if atomic.CompareAndSwapInt32(&mm.isMonitoring, 0, 1) {
@@ -151,3 +170,105 @@ func (mm *MemoryMonitor) GetMemoryStats() map[string]interface{} {
 		"gc_pause_total": m.PauseTotalNs,
 	}
 }
+
+// Dynamic Cache Management Methods
+
+// StartDynamicAdjustment begins the dynamic cache size adjustment process
+func (mm *MemoryMonitor) StartDynamicAdjustment() {
+	if mm.cache != nil {
+		go mm.adjustmentLoop()
+	}
+}
+
+// GetCurrentCacheSize returns the current cache size
+func (mm *MemoryMonitor) GetCurrentCacheSize() uint64 {
+	mm.mu.RLock()
+	defer mm.mu.RUnlock()
+	return atomic.LoadUint64(&mm.currentCacheSize)
+}
+
+// GetOriginalCacheSize returns the original cache size
+func (mm *MemoryMonitor) GetOriginalCacheSize() uint64 {
+	mm.mu.RLock()
+	defer mm.mu.RUnlock()
+	return mm.originalCacheSize
+}
+
+// GetAdjustmentCount returns the number of adjustments made
+func (mm *MemoryMonitor) GetAdjustmentCount() int64 {
+	return atomic.LoadInt64(&mm.adjustmentCount)
+}
+
+// adjustmentLoop runs the cache size adjustment loop
+func (mm *MemoryMonitor) adjustmentLoop() {
+	ticker := time.NewTicker(mm.adjustmentInterval)
+	defer ticker.Stop()
+
+	for range ticker.C {
+		mm.performAdjustment()
+	}
+}
+
+// performAdjustment performs a cache size adjustment if needed
+func (mm *MemoryMonitor) performAdjustment() {
+	// Prevent concurrent adjustments
+	if !atomic.CompareAndSwapInt32(&mm.isAdjusting, 0, 1) {
+		return
+	}
+	defer atomic.StoreInt32(&mm.isAdjusting, 0)
+
+	// Check if enough time has passed since last adjustment
+	if time.Since(mm.lastAdjustment) < mm.adjustmentInterval {
+		return
+	}
+
+	// Get recommended cache size
+	recommendedSize := mm.GetRecommendedCacheSize(mm.originalCacheSize)
+	currentSize := atomic.LoadUint64(&mm.currentCacheSize)
+
+	// Only adjust if there's a significant difference (more than 5%)
+	sizeDiff := float64(recommendedSize) / float64(currentSize)
+	if sizeDiff < 0.95 || sizeDiff > 1.05 {
+		mm.adjustCacheSize(recommendedSize)
+		mm.lastAdjustment = time.Now()
+		atomic.AddInt64(&mm.adjustmentCount, 1)
+	}
+}
+
+// adjustCacheSize adjusts the cache size to the recommended size
+func (mm *MemoryMonitor) adjustCacheSize(newSize uint64) {
+	mm.mu.Lock()
+	defer mm.mu.Unlock()
+
+	oldSize := atomic.LoadUint64(&mm.currentCacheSize)
+	atomic.StoreUint64(&mm.currentCacheSize, newSize)
+
+	// If we're reducing the cache size, trigger GC to free up memory
+	if newSize < oldSize {
+		// Calculate how much to free
+		bytesToFree := oldSize - newSize
+
+		// Trigger GC on the cache to free up the excess memory
+		// This is a simplified approach - in practice, you'd want to integrate
+		// with the actual GC system to free the right amount
+		if gcCache, ok := mm.cache.(interface{ ForceGC(uint) }); ok {
+			gcCache.ForceGC(uint(bytesToFree))
+		}
+	}
+}
+
+// GetDynamicStats returns statistics about the dynamic cache manager
+func (mm *MemoryMonitor) GetDynamicStats() map[string]interface{} {
+	mm.mu.RLock()
+	defer mm.mu.RUnlock()
+
+	return map[string]interface{}{
+		"original_cache_size":  mm.originalCacheSize,
+		"current_cache_size":   atomic.LoadUint64(&mm.currentCacheSize),
+		"adjustment_count":     atomic.LoadInt64(&mm.adjustmentCount),
+		"last_adjustment":      mm.lastAdjustment,
+		"memory_utilization":   mm.GetMemoryUtilization(),
+		"target_memory_usage":  mm.GetTargetMemoryUsage(),
+		"current_memory_usage": mm.GetCurrentMemoryUsage(),
+	}
+}