keal/keal.js

keal is key value storage

const fs = require('fs');
const path = require('path');

class Keal {
  constructor({ databasePath, databaseName } = {}) {
    if (databasePath === undefined) {
      throw 'databasePath is undefined. please set databasePath.';
    }
    if (databaseName === undefined) {
      throw 'databaseName is undefined. please set databaseName.';
    }

    this.saveTimeoutId = null;
    this.saveDelay = 500;

    this.databasePath = databasePath;
    this.databaseName = databaseName;

    const time = this.getTime();


    this.database = {
      name: this.databaseName,
      path: this.databasePath,
      createdAt: time,
      updatedAt: time,
      data: {},
    };

    this.connect();
  }

  getTime() {
    return new Date().getTime();
  }

  getFilePath() {
    return path.join(this.databasePath, `${this.databaseName}.keal`);
  }

  connect() {
    const filePath = this.getFilePath();
    if (fs.existsSync(filePath)) {
      const file = fs.readFileSync(filePath, { encoding: 'utf8' });
      this.database = JSON.parse(file);
    } else {
      this.save();
    }
  }

  put(key, value) {
    this.database.updatedAt = this.getTime();
    this.database.data[key] = value;
    this.save();
  }

  get(key) {
    return this.database.data[key];
  }

  gets(keys) {
    return keys.map(key => {
      return this.get(key);
    })
  }

  save() {
    clearTimeout(this.saveTimeoutId);
    this.saveTimeoutId = setTimeout(() => {
      const filePath = this.getFilePath();
      fs.writeFileSync(filePath, JSON.stringify(this.database), { encoding: 'utf8' })
    }, this.saveDelay);
  }

  keys() {
    return Object.keys(this.database.data);
  }

  values() {
    return Object.values(this.database.data);
  }
}

module.exports = Keal;