strapi/packages/core/upload/server/services/metrics.js

'use strict';

const { scheduleJob } = require('node-schedule');
const { FOLDER_MODEL_UID, FILE_MODEL_UID } = require('../constants');

const rand = max => Math.floor(Math.random() * max);
const getCronRandomWeekly = () => `${rand(60)} ${rand(60)} ${rand(24)} * * ${rand(7)}`;

module.exports = ({ strapi }) => {
  const crons = [];
  let running = false;

  return {
    async computeWeeklyMetrics() {
      // Folder metrics
      const pathColName = strapi.db.metadata.get(FOLDER_MODEL_UID).attributes.path.columnName;
      const folderTable = strapi.getModel(FOLDER_MODEL_UID).collectionName;

      let keepOnlySlashesSQLString = '??';
      let queryParams = [pathColName];
      for (let i = 0; i < 10; i += 1) {
        keepOnlySlashesSQLString = `REPLACE(${keepOnlySlashesSQLString}, ?, ?)`;
        queryParams.push(String(i), '');
      }

      const knex = strapi.db.connection;
      const folderLevelsArray = (
        await knex(folderTable)
          .select(
            knex.raw(
              `LENGTH(${keepOnlySlashesSQLString}) as depth, count(*) as occurence`,
              queryParams
            )
          )
          .groupBy('depth')
      ).map(map => ({ depth: Number(map.depth), occurence: Number(map.occurence) })); // values can be strings depending on the database

      let product = 0;
      let folderNumber = 0;
      let maxDepth = 0;
      for (const folderLevel of folderLevelsArray) {
        product += folderLevel.depth * folderLevel.occurence;
        folderNumber += folderLevel.occurence;
        if (folderLevel.depth > maxDepth) {
          maxDepth = folderLevel.depth;
        }
      }
      const averageDepth = folderNumber !== 0 ? product / folderNumber : 0;

      let sumOfDeviation = 0;
      for (const folderLevel of folderLevelsArray) {
        sumOfDeviation += Math.abs(folderLevel.depth - averageDepth) * folderLevel.occurence;
      }

      const averageDeviationDepth = folderNumber !== 0 ? sumOfDeviation / folderNumber : 0;

      // File metrics
      const assetNumber = await strapi.entityService.count(FILE_MODEL_UID);

      return {
        assetNumber,
        folderNumber,
        averageDepth,
        maxDepth,
        averageDeviationDepth,
      };
    },

    async startRegularMetricsUpdate() {
      if (running) {
        throw new Error('Regular metrics updates are already running');
      }
      running = true;

      const pingCron = scheduleJob(getCronRandomWeekly(), async () => {
        const metrics = await this.computeWeeklyMetrics();
        strapi.telemetry.send('didSendUploadPropertiesOnceAWeek', metrics);
      });

      crons.push(pingCron);
    },

    stopRegularMetricsUpdate() {
      crons.forEach(cron => cron.cancel());
      running = false;
    },
  };
};