1 files changed, 57 insertions, 0 deletions

diff --git a/client/src/assets/player/p2p-media-loader/redundancy-url-manager.ts b/client/src/assets/player/p2p-media-loader/redundancy-url-manager.ts
new file mode 100644
index 000000000..7fc2b6ab1
--- /dev/null
+++ b/client/src/assets/player/p2p-media-loader/redundancy-url-manager.ts
@@ -0,0 +1,57 @@
+import { basename, dirname } from 'path'
+
+class RedundancyUrlManager {
+
+  // Remember by what new URL we replaced an origin URL
+  private replacedSegmentUrls: { [originUrl: string]: string } = {}
+
+  constructor (private baseUrls: string[] = []) {
+    // empty
+  }
+
+  removeBySegmentUrl (segmentUrl: string) {
+    console.log('Removing redundancy of segment URL %s.', segmentUrl)
+
+    const baseUrl = dirname(segmentUrl)
+
+    this.baseUrls = this.baseUrls.filter(u => u !== baseUrl && u !== baseUrl + '/')
+  }
+
+  removeByOriginUrl (originUrl: string) {
+    const replaced = this.replacedSegmentUrls[originUrl]
+    if (!replaced) return
+
+    return this.removeBySegmentUrl(replaced)
+  }
+
+  buildUrl (url: string) {
+    delete this.replacedSegmentUrls[url]
+
+    const max = this.baseUrls.length + 1
+    const i = this.getRandomInt(max)
+
+    if (i === max - 1) return url
+
+    const newBaseUrl = this.baseUrls[i]
+    const slashPart = newBaseUrl.endsWith('/') ? '' : '/'
+
+    const newUrl = newBaseUrl + slashPart + basename(url)
+    this.replacedSegmentUrls[url] = newUrl
+
+    return newUrl
+  }
+
+  countBaseUrls () {
+    return this.baseUrls.length
+  }
+
+  private getRandomInt (max: number) {
+    return Math.floor(Math.random() * Math.floor(max))
+  }
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  RedundancyUrlManager
+}