feat(system-server): refactor db agent;

packages/system-server/src/lib/db-agent.ts

@@ -0,0 +1,65 @@
+/*
+ * @Author: Maslow<wangfugen@126.com>
+ * @Date: 2021-07-30 10:30:29
+ * @LastEditTime: 2021-08-30 17:21:43
+ * @Description: 
+ */
+
+import { MongoAccessor, getDb } from 'less-api'
+import Config from '../config'
+import { createLogger } from './logger'
+
+
+/**
+ * Database agent class
+ */
+export class DatabaseAgent {
+  private static _sys_accessor: MongoAccessor = DatabaseAgent.createAccessor(Config.sys_db.database, Config.sys_db.uri, Config.sys_db.poolSize)
+
+  /**
+   * sys mongo accessor instance
+   */
+  static get sys_accessor() {
+    return this._sys_accessor
+  }
+
+  /**
+   * sys database ORM instance
+   */
+  static get sys_db() {
+    return this.createSysDb()
+  }
+
+  /**
+   * Create sys database ORM instance
+   * @returns 
+   */
+  static createSysDb() {
+    if (null === this._sys_accessor) {
+      throw new Error('Globals.sys_accessor is empty, please run Globals.init() before!')
+    }
+    return getDb(this._sys_accessor)
+  }
+
+  /**
+   * Create MongoAccessor instance
+   * @param database db name
+   * @param uri connection uri of mongodb
+   * @param poolSize max number of connection pool size
+   * @returns 
+   */
+  private static createAccessor(database: string, uri: string, poolSize: number) {
+    const accessor = new MongoAccessor(database, uri, { maxPoolSize: poolSize, directConnection: true })
+
+    const logger = createLogger(`accessor:${database}`, 'warning')
+    accessor.setLogger(logger)
+    accessor.init().then(() => {
+      logger.info(`db:${database} connected`)
+    }).catch(error => {
+      logger.error(`db:${database} connect failed`, error)
+      process.exit(1)
+    })
+
+    return accessor
+  }
+}