src/performance/storage/JSONFileStorage.ts

   1 // Copyright Jerome Benoit. 2021. All Rights Reserved.
   2
   3 import Constants from '../../utils/Constants';
   4 import FileUtils from '../../utils/FileUtils';
   5 import Statistics from '../../types/Statistics';
   6 import { Storage } from './Storage';
   7 import fs from 'fs';
   8
   9 export class JSONFileStorage extends Storage {
  10   private fd: number | null = null;
  11
  12   constructor(storageURI: string, logPrefix: string) {
  13     super(storageURI, logPrefix);
  14     this.dbName = this.storageURI.pathname;
  15   }
  16
  17   public storePerformanceStatistics(performanceStatistics: Statistics): void {
  18     this.checkPerformanceRecordsFile();
  19     fs.readFile(this.dbName, 'utf-8', (error, data) => {
  20       if (error) {
  21         FileUtils.handleFileException(this.logPrefix, Constants.PERFORMANCE_RECORDS_FILETYPE, this.dbName, error);
  22       } else {
  23         const performanceRecords: Statistics[] = data ? JSON.parse(data) as Statistics[] : [];
  24         performanceRecords.push(performanceStatistics);
  25         fs.writeFile(this.dbName, JSON.stringify(performanceRecords, null, 2), 'utf-8', (err) => {
  26           if (err) {
  27             FileUtils.handleFileException(this.logPrefix, Constants.PERFORMANCE_RECORDS_FILETYPE, this.dbName, err);
  28           }
  29         });
  30       }
  31     });
  32   }
  33
  34   public open(): void {
  35     try {
  36       this.fd = fs.openSync(this.dbName, 'a+');
  37     } catch (error) {
  38       FileUtils.handleFileException(this.logPrefix, Constants.PERFORMANCE_RECORDS_FILETYPE, this.dbName, error);
  39     }
  40   }
  41
  42   public close(): void {
  43     try {
  44       if (this.fd) {
  45         fs.closeSync(this.fd);
  46         this.fd = null;
  47       }
  48     } catch (error) {
  49       FileUtils.handleFileException(this.logPrefix, Constants.PERFORMANCE_RECORDS_FILETYPE, this.dbName, error);
  50     }
  51   }
  52
  53   private checkPerformanceRecordsFile(): void {
  54     if (!this.fd) {
  55       throw new Error(`${this.logPrefix} Performance records '${this.dbName}' file descriptor not found`);
  56     }
  57   }
  58 }