Improve viewer counter

More precise, avoid weird decrease, reuse an id to federate viewers

1 files changed, 185 insertions, 0 deletions

diff --git a/server/lib/views/shared/video-viewer-stats.ts b/server/lib/views/shared/video-viewer-stats.ts
new file mode 100644
index 000000000..fd66fd5c7
--- /dev/null
+++ b/server/lib/views/shared/video-viewer-stats.ts
@@ -0,0 +1,185 @@
+import { Transaction } from 'sequelize/types'
+import { isTestInstance } from '@server/helpers/core-utils'
+import { GeoIP } from '@server/helpers/geo-ip'
+import { logger, loggerTagsFactory } from '@server/helpers/logger'
+import { MAX_LOCAL_VIEWER_WATCH_SECTIONS, VIEW_LIFETIME } from '@server/initializers/constants'
+import { sequelizeTypescript } from '@server/initializers/database'
+import { sendCreateWatchAction } from '@server/lib/activitypub/send'
+import { getLocalVideoViewerActivityPubUrl } from '@server/lib/activitypub/url'
+import { Redis } from '@server/lib/redis'
+import { VideoModel } from '@server/models/video/video'
+import { LocalVideoViewerModel } from '@server/models/view/local-video-viewer'
+import { LocalVideoViewerWatchSectionModel } from '@server/models/view/local-video-viewer-watch-section'
+import { MVideo } from '@server/types/models'
+import { VideoViewEvent } from '@shared/models'
+
+const lTags = loggerTagsFactory('views')
+
+type LocalViewerStats = {
+  firstUpdated: number // Date.getTime()
+  lastUpdated: number // Date.getTime()
+
+  watchSections: {
+    start: number
+    end: number
+  }[]
+
+  watchTime: number
+
+  country: string
+
+  videoId: number
+}
+
+export class VideoViewerStats {
+  private processingViewersStats = false
+
+  constructor () {
+    setInterval(() => this.processViewerStats(), VIEW_LIFETIME.VIEWER_STATS)
+  }
+
+  // ---------------------------------------------------------------------------
+
+  async addLocalViewer (options: {
+    video: MVideo
+    currentTime: number
+    ip: string
+    viewEvent?: VideoViewEvent
+  }) {
+    const { video, ip, viewEvent, currentTime } = options
+
+    logger.debug('Adding local viewer to video stats %s.', video.uuid, { currentTime, viewEvent, ...lTags(video.uuid) })
+
+    return this.updateLocalViewerStats({ video, viewEvent, currentTime, ip })
+  }
+
+  // ---------------------------------------------------------------------------
+
+  async getWatchTime (videoId: number, ip: string) {
+    const stats: LocalViewerStats = await Redis.Instance.getLocalVideoViewer({ ip, videoId })
+
+    return stats?.watchTime || 0
+  }
+
+  // ---------------------------------------------------------------------------
+
+  private async updateLocalViewerStats (options: {
+    video: MVideo
+    ip: string
+    currentTime: number
+    viewEvent?: VideoViewEvent
+  }) {
+    const { video, ip, viewEvent, currentTime } = options
+    const nowMs = new Date().getTime()
+
+    let stats: LocalViewerStats = await Redis.Instance.getLocalVideoViewer({ ip, videoId: video.id })
+
+    if (stats && stats.watchSections.length >= MAX_LOCAL_VIEWER_WATCH_SECTIONS) {
+      logger.warn('Too much watch section to store for a viewer, skipping this one', { currentTime, viewEvent, ...lTags(video.uuid) })
+      return
+    }
+
+    if (!stats) {
+      const country = await GeoIP.Instance.safeCountryISOLookup(ip)
+
+      stats = {
+        firstUpdated: nowMs,
+        lastUpdated: nowMs,
+
+        watchSections: [],
+
+        watchTime: 0,
+
+        country,
+        videoId: video.id
+      }
+    }
+
+    stats.lastUpdated = nowMs
+
+    if (viewEvent === 'seek' || stats.watchSections.length === 0) {
+      stats.watchSections.push({
+        start: currentTime,
+        end: currentTime
+      })
+    } else {
+      const lastSection = stats.watchSections[stats.watchSections.length - 1]
+      lastSection.end = currentTime
+    }
+
+    stats.watchTime = this.buildWatchTimeFromSections(stats.watchSections)
+
+    logger.debug('Set local video viewer stats for video %s.', video.uuid, { stats, ...lTags(video.uuid) })
+
+    await Redis.Instance.setLocalVideoViewer(ip, video.id, stats)
+  }
+
+  async processViewerStats () {
+    if (this.processingViewersStats) return
+    this.processingViewersStats = true
+
+    if (!isTestInstance()) logger.info('Processing viewer statistics.', lTags())
+
+    const now = new Date().getTime()
+
+    try {
+      const allKeys = await Redis.Instance.listLocalVideoViewerKeys()
+
+      for (const key of allKeys) {
+        const stats: LocalViewerStats = await Redis.Instance.getLocalVideoViewer({ key })
+
+        // Process expired stats
+        if (stats.lastUpdated > now - VIEW_LIFETIME.VIEWER_STATS) {
+          continue
+        }
+
+        try {
+          await sequelizeTypescript.transaction(async t => {
+            const video = await VideoModel.load(stats.videoId, t)
+
+            const statsModel = await this.saveViewerStats(video, stats, t)
+
+            if (video.remote) {
+              await sendCreateWatchAction(statsModel, t)
+            }
+          })
+
+          await Redis.Instance.deleteLocalVideoViewersKeys(key)
+        } catch (err) {
+          logger.error('Cannot process viewer stats for Redis key %s.', key, { err, ...lTags() })
+        }
+      }
+    } catch (err) {
+      logger.error('Error in video save viewers stats scheduler.', { err, ...lTags() })
+    }
+
+    this.processingViewersStats = false
+  }
+
+  private async saveViewerStats (video: MVideo, stats: LocalViewerStats, transaction: Transaction) {
+    const statsModel = new LocalVideoViewerModel({
+      startDate: new Date(stats.firstUpdated),
+      endDate: new Date(stats.lastUpdated),
+      watchTime: stats.watchTime,
+      country: stats.country,
+      videoId: video.id
+    })
+
+    statsModel.url = getLocalVideoViewerActivityPubUrl(statsModel)
+    statsModel.Video = video as VideoModel
+
+    await statsModel.save({ transaction })
+
+    statsModel.WatchSections = await LocalVideoViewerWatchSectionModel.bulkCreateSections({
+      localVideoViewerId: statsModel.id,
+      watchSections: stats.watchSections,
+      transaction
+    })
+
+    return statsModel
+  }
+
+  private buildWatchTimeFromSections (sections: { start: number, end: number }[]) {
+    return sections.reduce((p, current) => p + (current.end - current.start), 0)
+  }
+}