cache download metadata to speedup resume phase.

server/src/core/Process.ts

@@ -20,6 +20,7 @@ class Process {
     private settings: ISettings;
     private stdout: Readable;
     private pid: number;
+    private metadata?: IDownloadInfo;
     private exePath = join(__dirname, 'yt-dlp');
 
     constructor(url: string, params: Array<string>, settings: any) {
@@ -28,6 +29,7 @@ class Process {
         this.settings = settings
         this.stdout = undefined;
         this.pid = undefined;
+        this.metadata = undefined;
     }
 
     /**
@@ -58,6 +60,7 @@ class Process {
      * @returns Promise to the lock
      */
     public getInfo(): Promise<IDownloadInfo> {
+        if (!this.metadata) {
             let stdoutChunks = [];
             const ytdlpInfo = spawn(this.exePath, ['-j', this.url]);
 
@@ -70,7 +73,7 @@ class Process {
                     try {
                         const buffer = Buffer.concat(stdoutChunks);
                         const json = JSON.parse(buffer.toString());
-                    resolve({
+                        const info = {
                             formats: json.formats.map((format: IDownloadInfoSection) => {
                                 return {
                                     format_id: format.format_id ?? '',
@@ -91,7 +94,9 @@ class Process {
                             },
                             thumbnail: json.thumbnail,
                             title: json.title,
-                    });
+                        }
+                        resolve(info);
+                        this.metadata = info;
 
                     } catch (e) {
                         reject('failed fetching formats, downloading best available');
@@ -99,6 +104,8 @@ class Process {
                 });
             })
         }
+        return new Promise((resolve) => { resolve(this.metadata!) });
+    }
 
     /**
      * function that kills the current process