Agent Communication MCP Server

import { promises as fs } from 'fs'; import path from 'path'; import { AppError } from '../errors/index.js'; import { getDataDirectory } from '../utils/dataDir.js'; export class LockTimeoutError extends AppError { constructor(filePath: string, timeout: number) { super(`Lock timeout after ${timeout}ms for file: ${filePath}`, 'LOCK_TIMEOUT', 408); } } export class LockService { private static readonly DEFAULT_TIMEOUT = 5000; // 5 seconds private static readonly RETRY_INTERVAL = 50; // 50ms private activeLocks = new Map<string, Promise<void>>(); constructor( private readonly dataDir: string = getDataDirectory(), private readonly lockTimeout: number = parseInt(process.env.AGENT_COMM_LOCK_TIMEOUT || '5000') ) {} /** * Execute a function with exclusive file lock */ async withLock<T>(relativePath: string, operation: () => Promise<T>): Promise<T> { const lockKey = this.normalizePath(relativePath); // Wait for any existing lock on this file if (this.activeLocks.has(lockKey)) { await this.activeLocks.get(lockKey); } // Create new lock let resolveLock: () => void; const lockPromise = new Promise<void>((resolve) => { resolveLock = resolve; }); this.activeLocks.set(lockKey, lockPromise); try { // Acquire file system lock await this.acquireFileLock(lockKey); // Execute the operation const result = await operation(); return result; } finally { // Release file system lock await this.releaseFileLock(lockKey); // Remove from active locks this.activeLocks.delete(lockKey); resolveLock!(); } } /** * Acquire file system lock using lock file */ private async acquireFileLock(filePath: string): Promise<void> { const lockFilePath = `${filePath}.lock`; const startTime = Date.now(); // ロックファイルの親ディレクトリを確保 const lockFileDir = path.dirname(lockFilePath); try { await fs.mkdir(lockFileDir, { recursive: true }); } catch (error: any) { if (error.code !== 'EEXIST') { throw new AppError(`Failed to create lock directory: ${error.message}`, 'LOCK_DIR_ERROR', 500); } } while (Date.now() - startTime < this.lockTimeout) { try { // Try to create lock file exclusively await fs.writeFile(lockFilePath, process.pid.toString(), { flag: 'wx' }); return; // Successfully acquired lock } catch (error: any) { if (error.code === 'EEXIST') { // Lock file exists, check if it's stale const isStale = await this.isLockStale(lockFilePath); if (isStale) { // Remove stale lock and try again try { await fs.unlink(lockFilePath); continue; } catch { // Someone else might have removed it, continue } } // Wait before retry await this.sleep(LockService.RETRY_INTERVAL); continue; } else if (error.code === 'ENOENT') { // ディレクトリが作成されたにも関わらずENOENTが発生した場合は再試行 continue; } else { // Some other error occurred throw new AppError(`Failed to acquire lock: ${error.message}`, 'LOCK_ERROR', 500); } } } throw new LockTimeoutError(filePath, this.lockTimeout); } /** * Release file system lock */ private async releaseFileLock(filePath: string): Promise<void> { const lockFilePath = `${filePath}.lock`; try { await fs.unlink(lockFilePath); } catch (error: any) { if (error.code !== 'ENOENT') { // Log error but don't throw - releasing lock should be best effort console.warn(`Warning: Failed to release lock file ${lockFilePath}:`, error.message); } } } /** * Check if lock file is stale (process no longer exists) */ private async isLockStale(lockFilePath: string): Promise<boolean> { try { const pidString = await fs.readFile(lockFilePath, 'utf8'); const pid = parseInt(pidString.trim()); if (isNaN(pid)) { return true; // Invalid PID format } // Check if process exists try { process.kill(pid, 0); // Signal 0 checks existence without killing return false; // Process exists } catch { return true; // Process doesn't exist } } catch { return true; // Can't read lock file } } /** * Normalize file path for consistent lock keys */ private normalizePath(relativePath: string): string { const fullPath = path.resolve(this.dataDir, relativePath); return path.normalize(fullPath); } /** * Sleep utility */ private sleep(ms: number): Promise<void> { return new Promise(resolve => setTimeout(resolve, ms)); } /** * Ensure directory exists */ async ensureDir(dirPath: string): Promise<void> { const fullPath = path.resolve(this.dataDir, dirPath); try { await fs.mkdir(fullPath, { recursive: true }); } catch (error: any) { if (error.code !== 'EEXIST') { throw new AppError(`Failed to create directory ${fullPath}: ${error.message}`, 'DIR_CREATE_ERROR', 500); } } } /** * Check if file exists */ async fileExists(filePath: string): Promise<boolean> { const fullPath = path.resolve(this.dataDir, filePath); try { await fs.access(fullPath); return true; } catch { return false; } } /** * Read file with automatic directory creation */ async readFile(filePath: string): Promise<string> { const fullPath = path.resolve(this.dataDir, filePath); try { return await fs.readFile(fullPath, 'utf8'); } catch (error: any) { if (error.code === 'ENOENT') { // File doesn't exist, return empty string return ''; } throw new AppError(`Failed to read file ${fullPath}: ${error.message}`, 'FILE_READ_ERROR', 500); } } /** * Write file with automatic directory creation */ async writeFile(filePath: string, content: string): Promise<void> { const fullPath = path.resolve(this.dataDir, filePath); const dirPath = path.dirname(fullPath); // Ensure directory exists await fs.mkdir(dirPath, { recursive: true }); try { await fs.writeFile(fullPath, content, 'utf8'); } catch (error: any) { throw new AppError(`Failed to write file ${fullPath}: ${error.message}`, 'FILE_WRITE_ERROR', 500); } } /** * Append to file with automatic directory creation */ async appendFile(filePath: string, content: string): Promise<void> { const fullPath = path.resolve(this.dataDir, filePath); const dirPath = path.dirname(fullPath); // Ensure directory exists await fs.mkdir(dirPath, { recursive: true }); try { await fs.appendFile(fullPath, content, 'utf8'); } catch (error: any) { throw new AppError(`Failed to append to file ${fullPath}: ${error.message}`, 'FILE_APPEND_ERROR', 500); } } /** * Delete file safely */ async deleteFile(filePath: string): Promise<void> { const fullPath = path.resolve(this.dataDir, filePath); try { await fs.unlink(fullPath); } catch (error: any) { if (error.code !== 'ENOENT') { throw new AppError(`Failed to delete file ${fullPath}: ${error.message}`, 'FILE_DELETE_ERROR', 500); } } } /** * List files in directory */ async listFiles(dirPath: string): Promise<string[]> { const fullPath = path.resolve(this.dataDir, dirPath); try { return await fs.readdir(fullPath); } catch (error: any) { if (error.code === 'ENOENT') { return []; } throw new AppError(`Failed to list directory ${fullPath}: ${error.message}`, 'DIR_READ_ERROR', 500); } } }