micro-image-manager/lib/service/db.js

Manage images in your microservices

"use strict";

const {
  MongoClient,
  ObjectId
} = require('mongodb');

const {
  ObjectID,
  Binary
} = require('mongodb');

const {
  retryPromise
} = require('../util/promise-util');

const fs = require('fs').promises;

class Db {
  constructor(mongodbUrl) {
    this.mongodbUrl = mongodbUrl;
  }

  async connect() {
    this.client = await retryPromise(() => MongoClient.connect(this.mongodbUrl, {
      useUnifiedTopology: true
    }), 3000, 10);
    this.db = this.client.db();
    this.images = this.db.collection('images');
    return this;
  }

  async disconnect() {
    await this.client.close();
  }
  /**
   * @param {{
   * image: string,
   * name: stirng, 
   * format: string, 
   * formatPriority: number,
   * profile: {width: number, height: number, name: string}
   * }} records 
   */


  async add(name, records) {
    const id = ObjectID();

    for (let record of records) {
      const buffer = await fs.readFile(record.image);
      await this.images.insertOne({
        id,
        name: name,
        data: Binary(buffer),
        created: new Date(),
        format: record.format,
        formatPriority: record.formatPriority,
        width: record.profile.width,
        height: record.profile.height,
        profile: record.profile.name,
        size: 35958
      });
    } // remove old records


    await this.images.deleteMany({
      name,
      id: {
        $ne: id
      }
    });
    return id;
  }
  /**
   * 
   * @param {{
   * id: string, 
   * profile: string, 
   * formats: [string]
   * }} query 
   */


  async find(query) {
    const q = {
      format: {
        $in: query.formats
      }
    };
    if (query.id) q.id = ObjectID(query.id);
    if (query.name) q.name = query.name;
    if (query.profile) q.profile = query.profile;
    const sort = {
      width: -1,
      heigh: -1,
      formatPriority: 1
    };
    return (await this.images.find(q).limit(1).sort(sort).toArray())[0];
  }

}

module.exports = Db;