feat: v0.1.13 — 事务回滚 + 子查询 + 外键级联 + 连接池

src/connection-manager.ts

@@ -0,0 +1,131 @@
+/**
+ * metona-sqlark Connection Manager — 数据库实例连接池
+ * @module connection-manager
+ *
+ * v0.1.13: 避免重复创建同名数据库实例，通过 connect() 复用已有连接。
+ * 管理实例生命周期，防止重复 open IndexedDB。
+ */
+
+import { MetonaSqlark } from './core';
+import type { DatabaseConfig } from './constants';
+
+// ---------------------------------------------------------------------------
+//  ConnectionManager
+// ---------------------------------------------------------------------------
+
+class ConnectionManager {
+  /** 活跃连接：dbName → MetonaSqlark */
+  private connections = new Map<string, MetonaSqlark>();
+
+  /** 连接引用计数：dbName → count */
+  private refCount = new Map<string, number>();
+
+  /**
+   * 获取或创建数据库实例
+   *
+   * 如果同名数据库已打开，复用已有实例并增加引用计数。
+   * 否则创建新实例。
+   *
+   * @example
+   * ```ts
+   * const db = await MetonaSqlark.connect({ name: 'my-app', mode: 'hybrid' });
+   * // ... use db
+   * await db.disconnect(); // 引用计数 -1，归零时自动关闭
+   * ```
+   */
+  async connect(config: DatabaseConfig): Promise<MetonaSqlark> {
+    const name = config.name;
+
+    // 已有连接 → 复用
+    const existing = this.connections.get(name);
+    if (existing && existing.isReady()) {
+      const count = (this.refCount.get(name) ?? 0) + 1;
+      this.refCount.set(name, count);
+      return existing;
+    }
+
+    // 创建新连接
+    const db = new MetonaSqlark(config);
+    await db.init();
+
+    this.connections.set(name, db);
+    this.refCount.set(name, 1);
+
+    // 注入 disconnect 方法
+    (db as MetonaSqlark & { disconnect: () => Promise<void> }).disconnect = async () => {
+      await this.release(name);
+    };
+
+    return db;
+  }
+
+  /**
+   * 释放连接引用。引用计数归零时自动关闭数据库。
+   */
+  async release(dbName: string): Promise<void> {
+    const count = (this.refCount.get(dbName) ?? 1) - 1;
+    if (count <= 0) {
+      const db = this.connections.get(dbName);
+      if (db) {
+        await db.close();
+        this.connections.delete(dbName);
+      }
+      this.refCount.delete(dbName);
+    } else {
+      this.refCount.set(dbName, count);
+    }
+  }
+
+  /**
+   * 强制关闭指定数据库（忽略引用计数）
+   */
+  async forceClose(dbName: string): Promise<void> {
+    const db = this.connections.get(dbName);
+    if (db) {
+      await db.close();
+      this.connections.delete(dbName);
+    }
+    this.refCount.delete(dbName);
+  }
+
+  /**
+   * 强制关闭所有连接
+   */
+  async closeAll(): Promise<void> {
+    for (const [, db] of this.connections) {
+      try { await db.close(); } catch { /* ignore */ }
+    }
+    this.connections.clear();
+    this.refCount.clear();
+  }
+
+  /**
+   * 获取所有活跃连接名
+   */
+  getActiveConnections(): string[] {
+    return Array.from(this.connections.keys());
+  }
+
+  /**
+   * 获取连接的引用计数
+   */
+  getRefCount(dbName: string): number {
+    return this.refCount.get(dbName) ?? 0;
+  }
+}
+
+// ---------------------------------------------------------------------------
+//  全局单例
+// ---------------------------------------------------------------------------
+
+const manager = new ConnectionManager();
+
+// 挂载到 MetonaSqlark 静态方法（通过 any 绕过 TS 类型检查）
+const M = MetonaSqlark as unknown as Record<string, unknown>;
+M.connect = (config: DatabaseConfig) => manager.connect(config);
+M.disconnect = (dbName: string) => manager.release(dbName);
+M.disconnectAll = () => manager.closeAll();
+M.getActiveConnections = () => manager.getActiveConnections();
+
+export { manager as connectionManager };
+export default manager;