feat: many features, check TODO.md

fileproc/cache.go

@@ -0,0 +1,127 @@
+package fileproc
+
+// getNormalizedExtension efficiently extracts and normalizes the file extension with caching.
+func (r *FileTypeRegistry) getNormalizedExtension(filename string) string {
+	// Try cache first (read lock)
+	r.cacheMutex.RLock()
+	if ext, exists := r.extCache[filename]; exists {
+		r.cacheMutex.RUnlock()
+		return ext
+	}
+	r.cacheMutex.RUnlock()
+
+	// Compute normalized extension
+	ext := normalizeExtension(filename)
+
+	// Cache the result (write lock)
+	r.cacheMutex.Lock()
+	// Check cache size and clean if needed
+	if len(r.extCache) >= r.maxCacheSize*2 {
+		r.clearExtCache()
+		r.stats.CacheEvictions++
+	}
+	r.extCache[filename] = ext
+	r.cacheMutex.Unlock()
+
+	return ext
+}
+
+// getFileTypeResult gets cached file type detection result or computes it.
+func (r *FileTypeRegistry) getFileTypeResult(filename string) FileTypeResult {
+	ext := r.getNormalizedExtension(filename)
+
+	// Update statistics
+	r.updateStats(func() {
+		r.stats.TotalLookups++
+	})
+
+	// Try cache first (read lock)
+	r.cacheMutex.RLock()
+	if result, exists := r.resultCache[ext]; exists {
+		r.cacheMutex.RUnlock()
+		r.updateStats(func() {
+			r.stats.CacheHits++
+		})
+		return result
+	}
+	r.cacheMutex.RUnlock()
+
+	// Cache miss
+	r.updateStats(func() {
+		r.stats.CacheMisses++
+	})
+
+	// Compute result
+	result := FileTypeResult{
+		Extension: ext,
+		IsImage:   r.imageExts[ext],
+		IsBinary:  r.binaryExts[ext],
+		Language:  r.languageMap[ext],
+	}
+
+	// Handle special cases for binary detection (like .DS_Store)
+	if !result.IsBinary && isSpecialFile(filename, r.binaryExts) {
+		result.IsBinary = true
+	}
+
+	// Cache the result (write lock)
+	r.cacheMutex.Lock()
+	if len(r.resultCache) >= r.maxCacheSize {
+		r.clearResultCache()
+		r.stats.CacheEvictions++
+	}
+	r.resultCache[ext] = result
+	r.cacheMutex.Unlock()
+
+	return result
+}
+
+// clearExtCache clears half of the extension cache (LRU-like behavior).
+func (r *FileTypeRegistry) clearExtCache() {
+	r.clearCache(&r.extCache, r.maxCacheSize)
+}
+
+// clearResultCache clears half of the result cache.
+func (r *FileTypeRegistry) clearResultCache() {
+	newCache := make(map[string]FileTypeResult, r.maxCacheSize)
+	count := 0
+	for k, v := range r.resultCache {
+		if count >= r.maxCacheSize/2 {
+			break
+		}
+		newCache[k] = v
+		count++
+	}
+	r.resultCache = newCache
+}
+
+// clearCache is a generic cache clearing function.
+func (r *FileTypeRegistry) clearCache(cache *map[string]string, maxSize int) {
+	newCache := make(map[string]string, maxSize)
+	count := 0
+	for k, v := range *cache {
+		if count >= maxSize/2 {
+			break
+		}
+		newCache[k] = v
+		count++
+	}
+	*cache = newCache
+}
+
+// invalidateCache clears both caches when the registry is modified.
+func (r *FileTypeRegistry) invalidateCache() {
+	r.cacheMutex.Lock()
+	defer r.cacheMutex.Unlock()
+
+	r.extCache = make(map[string]string, r.maxCacheSize)
+	r.resultCache = make(map[string]FileTypeResult, r.maxCacheSize)
+	r.stats.CacheEvictions++
+}
+
+// updateStats safely updates statistics.
+func (r *FileTypeRegistry) updateStats(fn func()) {
+	r.cacheMutex.Lock()
+	fn()
+	r.cacheMutex.Unlock()
+}