init claude-code

utils/fileReadCache.ts

@@ -0,0 +1,96 @@
+import { detectFileEncoding } from './file.js'
+import { getFsImplementation } from './fsOperations.js'
+
+type CachedFileData = {
+  content: string
+  encoding: BufferEncoding
+  mtime: number
+}
+
+/**
+ * A simple in-memory cache for file contents with automatic invalidation based on modification time.
+ * This eliminates redundant file reads in FileEditTool operations.
+ */
+class FileReadCache {
+  private cache = new Map<string, CachedFileData>()
+  private readonly maxCacheSize = 1000
+
+  /**
+   * Reads a file with caching. Returns both content and encoding.
+   * Cache key includes file path and modification time for automatic invalidation.
+   */
+  readFile(filePath: string): { content: string; encoding: BufferEncoding } {
+    const fs = getFsImplementation()
+
+    // Get file stats for cache invalidation
+    let stats
+    try {
+      stats = fs.statSync(filePath)
+    } catch (error) {
+      // File was deleted, remove from cache and re-throw
+      this.cache.delete(filePath)
+      throw error
+    }
+
+    const cacheKey = filePath
+    const cachedData = this.cache.get(cacheKey)
+
+    // Check if we have valid cached data
+    if (cachedData && cachedData.mtime === stats.mtimeMs) {
+      return {
+        content: cachedData.content,
+        encoding: cachedData.encoding,
+      }
+    }
+
+    // Cache miss or stale data - read the file
+    const encoding = detectFileEncoding(filePath)
+    const content = fs
+      .readFileSync(filePath, { encoding })
+      .replaceAll('\r\n', '\n')
+
+    // Update cache
+    this.cache.set(cacheKey, {
+      content,
+      encoding,
+      mtime: stats.mtimeMs,
+    })
+
+    // Evict oldest entries if cache is too large
+    if (this.cache.size > this.maxCacheSize) {
+      const firstKey = this.cache.keys().next().value
+      if (firstKey) {
+        this.cache.delete(firstKey)
+      }
+    }
+
+    return { content, encoding }
+  }
+
+  /**
+   * Clears the entire cache. Useful for testing or memory management.
+   */
+  clear(): void {
+    this.cache.clear()
+  }
+
+  /**
+   * Removes a specific file from the cache.
+   */
+  invalidate(filePath: string): void {
+    this.cache.delete(filePath)
+  }
+
+  /**
+   * Gets cache statistics for debugging/monitoring.
+   */
+  getStats(): { size: number; entries: string[] } {
+    return {
+      size: this.cache.size,
+      entries: Array.from(this.cache.keys()),
+    }
+  }
+}
+
+// Export a singleton instance
+export const fileReadCache = new FileReadCache()