Add better caching, seek command

package.json

@@ -25,6 +25,7 @@
   },
   "devDependencies": {
     "@types/bluebird": "^3.5.30",
+    "@types/fs-capacitor": "^2.0.0",
     "@types/node": "^13.9.1",
     "@types/spotify-web-api-node": "^4.0.1",
     "@types/validator": "^12.0.1",
@@ -66,6 +67,7 @@
     "delay": "^4.3.0",
     "discord.js": "^12.0.2",
     "dotenv": "^8.2.0",
+    "fs-capacitor": "^6.1.0",
     "got": "^10.6.0",
     "hasha": "^5.2.0",
     "inversify": "^5.0.1",

src/commands/seek.ts

@@ -0,0 +1,33 @@
+import {Message, TextChannel} from 'discord.js';
+import {TYPES} from '../types';
+import {inject, injectable} from 'inversify';
+import Player from '../services/player';
+import LoadingMessage from '../utils/loading-message';
+import Command from '.';
+
+@injectable()
+export default class implements Command {
+  public name = 'seek';
+  public description = 'seeks position in currently playing song';
+  private readonly player: Player;
+
+  constructor(@inject(TYPES.Services.Player) player: Player) {
+    this.player = player;
+  }
+
+  public async execute(msg: Message, args: string []): Promise<void> {
+    const seekTime = parseInt(args[0], 10);
+
+    const loading = new LoadingMessage(msg.channel as TextChannel, 'hold on a sec');
+
+    await loading.start();
+
+    try {
+      await this.player.seek(msg.guild!.id, seekTime);
+
+      await loading.stop('seeked');
+    } catch (_) {
+      await loading.stop('error somewhere');
+    }
+  }
+}

src/inversify.config.ts

@@ -24,6 +24,7 @@ import Command from './commands';
 import Config from './commands/config';
 import Play from './commands/play';
 import QueueCommad from './commands/queue';
+import Seek from './commands/seek';
 
 let container = new Container();
 
@@ -39,6 +40,7 @@ container.bind<Queue>(TYPES.Services.Queue).to(Queue).inSingletonScope();
 container.bind<Command>(TYPES.Command).to(Config).inSingletonScope();
 container.bind<Command>(TYPES.Command).to(Play).inSingletonScope();
 container.bind<Command>(TYPES.Command).to(QueueCommad).inSingletonScope();
+container.bind<Command>(TYPES.Command).to(Seek).inSingletonScope();
 
 // Config values
 container.bind<string>(TYPES.Config.DISCORD_TOKEN).toConstantValue(DISCORD_TOKEN);

src/services/player.ts

@@ -1,8 +1,14 @@
 import {inject, injectable} from 'inversify';
 import {VoiceConnection, VoiceChannel} from 'discord.js';
+import {promises as fs, createWriteStream} from 'fs';
+import {Readable} from 'stream';
+import path from 'path';
+import hasha from 'hasha';
+import ytdl from 'ytdl-core';
+import {WriteStream} from 'fs-capacitor';
+import prism from 'prism-media';
 import {TYPES} from '../types';
-import Queue from './queue';
+import Queue, {QueuedSong} from './queue';
-import getYouTubeStream from '../utils/get-youtube-stream';
 
 export enum Status {
   Playing,
@@ -19,9 +25,11 @@ export interface GuildPlayer {
 export default class {
   private readonly guildPlayers = new Map<string, GuildPlayer>();
   private readonly queue: Queue;
+  private readonly cacheDir: string;
 
-  constructor(@inject(TYPES.Services.Queue) queue: Queue) {
+  constructor(@inject(TYPES.Services.Queue) queue: Queue, @inject(TYPES.Config.CACHE_DIR) cacheDir: string) {
     this.queue = queue;
+    this.cacheDir = cacheDir;
   }
 
   async connect(guildId: string, channel: VoiceChannel): Promise<void> {
@@ -46,6 +54,23 @@ export default class {
     }
   }
 
+  async seek(guildId: string, positionSeconds: number): Promise<void> {
+    const guildPlayer = this.get(guildId);
+    if (guildPlayer.voiceConnection === null) {
+      throw new Error('Not connected to a voice channel.');
+    }
+
+    const currentSong = this.getCurrentSong(guildId);
+
+    if (!currentSong) {
+      throw new Error('No song currently playing');
+    }
+
+    await this.waitForCache(currentSong.url);
+
+    guildPlayer.voiceConnection.play(this.getCachedPath(currentSong.url), {seek: positionSeconds});
+  }
+
   async play(guildId: string): Promise<void> {
     const guildPlayer = this.get(guildId);
     if (guildPlayer.voiceConnection === null) {
@@ -57,17 +82,18 @@ export default class {
       return;
     }
 
-    const songs = this.queue.get(guildId);
+    const currentSong = this.getCurrentSong(guildId);
 
-    if (songs.length === 0) {
+    if (!currentSong) {
       throw new Error('Queue empty.');
     }
 
-    const song = songs[0];
+    if (await this.isCached(currentSong.url)) {
-
+      this.get(guildId).voiceConnection!.play(this.getCachedPath(currentSong.url));
-    const stream = await getYouTubeStream(song.url);
+    } else {
-
+      const stream = await this.getStream(currentSong.url);
       this.get(guildId).voiceConnection!.play(stream, {type: 'webm/opus'});
+    }
 
     guildPlayer.status = Status.Playing;
 
@@ -80,9 +106,136 @@ export default class {
     return this.guildPlayers.get(guildId) as GuildPlayer;
   }
 
+  private getCurrentSong(guildId: string): QueuedSong|null {
+    const songs = this.queue.get(guildId);
+
+    if (songs.length === 0) {
+      return null;
+    }
+
+    return songs[0];
+  }
+
   private initGuild(guildId: string): void {
     if (!this.guildPlayers.get(guildId)) {
       this.guildPlayers.set(guildId, {status: Status.Disconnected, voiceConnection: null});
     }
   }
+
+  private getCachedPath(url: string): string {
+    const hash = hasha(url);
+    return path.join(this.cacheDir, `${hash}.webm`);
+  }
+
+  private getCachedPathTemp(url: string): string {
+    const hash = hasha(url);
+
+    return path.join('/tmp', `${hash}.webm`);
+  }
+
+  private async isCached(url: string): Promise<boolean> {
+    try {
+      await fs.access(this.getCachedPath(url));
+
+      return true;
+    } catch (_) {
+      return false;
+    }
+  }
+
+  private async waitForCache(url: string, maxRetries = 50, retryDelay = 500): Promise<void> {
+    // eslint-disable-next-line no-async-promise-executor
+    return new Promise(async (resolve, reject) => {
+      if (await this.isCached(url)) {
+        resolve();
+      } else {
+        let nOfChecks = 0;
+
+        const cachedCheck = setInterval(async () => {
+          if (await this.isCached(url)) {
+            clearInterval(cachedCheck);
+            resolve();
+          } else {
+            nOfChecks++;
+
+            if (nOfChecks > maxRetries) {
+              clearInterval(cachedCheck);
+              reject(new Error('Timed out waiting for file to become cached.'));
+            }
+          }
+        }, retryDelay);
+      }
+    });
+  }
+
+  private async getStream(url: string): Promise<Readable|string> {
+    const cachedPath = this.getCachedPath(url);
+
+    if (await this.isCached(url)) {
+      return cachedPath;
+    }
+
+    // Not yet cached, must download
+    const info = await ytdl.getInfo(url);
+
+    const {formats} = info;
+
+    const filter = (format: ytdl.videoFormat): boolean => format.codecs === 'opus' && format.container === 'webm' && format.audioSampleRate !== undefined && parseInt(format.audioSampleRate, 10) === 48000;
+
+    let format = formats.find(filter);
+    let canDirectPlay = true;
+
+    const nextBestFormat = (formats: ytdl.videoFormat[]): ytdl.videoFormat => {
+      formats = formats
+        .filter(format => format.averageBitrate)
+        .sort((a, b) => b.averageBitrate - a.averageBitrate);
+      return formats.find(format => !format.bitrate) ?? formats[0];
+    };
+
+    if (!format) {
+      format = nextBestFormat(info.formats);
+      canDirectPlay = false;
+    }
+
+    const cacheTempPath = this.getCachedPathTemp(url);
+    const cacheStream = createWriteStream(cacheTempPath);
+
+    cacheStream.on('finish', async () => {
+      await fs.rename(cacheTempPath, cachedPath);
+    });
+
+    let youtubeStream: Readable;
+
+    if (canDirectPlay) {
+      youtubeStream = ytdl.downloadFromInfo(info, {format});
+    } else {
+      youtubeStream = new prism.FFmpeg({
+        args: [
+          '-reconnect',
+          '1',
+          '-reconnect_streamed',
+          '1',
+          '-reconnect_delay_max',
+          '5',
+          '-i',
+          format.url,
+          '-loglevel',
+          'verbose',
+          '-vn',
+          '-acodec',
+          'libopus',
+          '-f',
+          'webm'
+        ]
+      });
+    }
+
+    const capacitor = new WriteStream();
+
+    youtubeStream.pipe(capacitor);
+
+    capacitor.createReadStream().pipe(cacheStream);
+
+    return capacitor.createReadStream();
+  }
 }

src/utils/get-youtube-stream.ts

@@ -1,78 +0,0 @@
-import {promises as fs, createReadStream, createWriteStream} from 'fs';
-import {Readable, PassThrough} from 'stream';
-import path from 'path';
-import hasha from 'hasha';
-import ytdl from 'ytdl-core';
-import prism from 'prism-media';
-import {CACHE_DIR} from './config';
-
-const nextBestFormat = (formats: ytdl.videoFormat[]): ytdl.videoFormat => {
-  formats = formats
-    .filter(format => format.averageBitrate)
-    .sort((a, b) => b.averageBitrate - a.averageBitrate);
-  return formats.find(format => !format.bitrate) ?? formats[0];
-};
-
-// TODO: are some videos not available in webm/opus?
-export default async (url: string): Promise<Readable> => {
-  const hash = hasha(url);
-  const cachedPath = path.join(CACHE_DIR, `${hash}.webm`);
-
-  const info = await ytdl.getInfo(url);
-
-  const {formats} = info;
-
-  const filter = (format: ytdl.videoFormat): boolean => format.codecs === 'opus' && format.container === 'webm' && format.audioSampleRate !== undefined && parseInt(format.audioSampleRate, 10) === 48000;
-
-  let format = formats.find(filter);
-  let canDirectPlay = true;
-
-  if (!format) {
-    format = nextBestFormat(info.formats);
-    canDirectPlay = false;
-  }
-
-  try {
-    // Test if file exists
-    await fs.access(cachedPath);
-
-    // If so, return cached stream
-    return createReadStream(cachedPath);
-  } catch (_) {
-    // Not yet cached, must download
-    const cacheTempPath = path.join('/tmp', `${hash}.webm`);
-    const cacheStream = createWriteStream(cacheTempPath);
-
-    const pass = new PassThrough();
-
-    pass.pipe(cacheStream).on('finish', async () => {
-      await fs.rename(cacheTempPath, cachedPath);
-    });
-
-    if (canDirectPlay) {
-      return ytdl.downloadFromInfo(info, {format}).pipe(pass);
-    }
-
-    const transcoder = new prism.FFmpeg({
-      args: [
-        '-reconnect',
-        '1',
-        '-reconnect_streamed',
-        '1',
-        '-reconnect_delay_max',
-        '5',
-        '-i',
-        format.url,
-        '-loglevel',
-        'verbose',
-        '-vn',
-        '-acodec',
-        'libopus',
-        '-f',
-        'webm'
-      ]
-    });
-
-    return transcoder.pipe(pass);
-  }
-};

yarn.lock

@@ -65,6 +65,13 @@
     "@types/node" "*"
     "@types/responselike" "*"
 
+"@types/cloneable-readable@^2.0.0":
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/@types/cloneable-readable/-/cloneable-readable-2.0.0.tgz#b5bc6602d4771a5db9d80f3867427e9da5f68a63"
+  integrity sha512-Q9fTsA3hEbOXmGIZ7StMunr/SCvtdfXDfJcDadYk/MPbS3Xh/fWCsdhW26NVx1XNNcX3SkdBqPkfbOiD6p3q2Q==
+  dependencies:
+    "@types/node" "*"
+
 "@types/color-name@^1.1.1":
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/@types/color-name/-/color-name-1.1.1.tgz#1c1261bbeaa10a8055bbc5d8ab84b7b2afc846a0"
@@ -75,6 +82,13 @@
   resolved "https://registry.yarnpkg.com/@types/eslint-visitor-keys/-/eslint-visitor-keys-1.0.0.tgz#1ee30d79544ca84d68d4b3cdb0af4f205663dd2d"
   integrity sha512-OCutwjDZ4aFS6PB1UZ988C4YgwlBHJd6wCeQqaLdmadZ/7e+w79+hbMUFC1QXDNCmdyoRfAFdm0RypzwR+Qpag==
 
+"@types/fs-capacitor@^2.0.0":
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/@types/fs-capacitor/-/fs-capacitor-2.0.0.tgz#17113e25817f584f58100fb7a08eed288b81956e"
+  integrity sha512-FKVPOCFbhCvZxpVAMhdBdTfVfXUpsh15wFHgqOKxh9N9vzWZVuWCSijZ5T4U34XYNnuj2oduh6xcs1i+LPI+BQ==
+  dependencies:
+    "@types/node" "*"
+
 "@types/http-cache-semantics@*":
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/@types/http-cache-semantics/-/http-cache-semantics-4.0.0.tgz#9140779736aa2655635ee756e2467d787cfe8a2a"
@@ -107,6 +121,13 @@
   resolved "https://registry.yarnpkg.com/@types/parse-json/-/parse-json-4.0.0.tgz#2f8bb441434d163b35fb8ffdccd7138927ffb8c0"
   integrity sha512-//oorEZjL6sbPcKUaCdIGlIUeH26mgzimjBB77G6XRgnDl/L5wOnpyBGRe/Mmf5CVW3PwEBE1NjiMZ/ssFh4wA==
 
+"@types/pump@^1.1.0":
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/@types/pump/-/pump-1.1.0.tgz#ed5214af511da32b6ee85c8d33ad3d59bb79ad8f"
+  integrity sha512-YGGbsqf5o7sF8gGANP8ZYxgaRGlFgEAImx5tCvA4YKRCfqbsDQZO48UmWynZzSjbhn0ZWSlsWOcb5NwvOx8KcQ==
+  dependencies:
+    "@types/node" "*"
+
 "@types/responselike@*":
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/@types/responselike/-/responselike-1.0.0.tgz#251f4fe7d154d2bad125abe1b429b23afd262e29"
@@ -510,6 +531,14 @@ clone-response@^1.0.2:
   dependencies:
     mimic-response "^1.0.0"
 
+cloneable-readable@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/cloneable-readable/-/cloneable-readable-2.0.1.tgz#fc2240beddbe5621b872acad8104dcc86574e225"
+  integrity sha512-1ke/wckhpSevGPQzKb+qGHMsuFrSUKQlsKh0PTmscmfAzw8MgONqrg5a0e0Un1YO/cOSS4wAepfXSGus5RoonQ==
+  dependencies:
+    inherits "^2.0.1"
+    readable-stream "^3.3.0"
+
 cls-bluebird@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/cls-bluebird/-/cls-bluebird-2.1.0.tgz#37ef1e080a8ffb55c2f4164f536f1919e7968aee"
@@ -1070,6 +1099,11 @@ formidable@^1.2.0:
   resolved "https://registry.yarnpkg.com/formidable/-/formidable-1.2.2.tgz#bf69aea2972982675f00865342b982986f6b8dd9"
   integrity sha512-V8gLm+41I/8kguQ4/o1D3RIHRmhYFG4pnNyonvua+40rqcEmT4+V71yaZ3B457xbbgCsCfjSPi65u/W6vK1U5Q==
 
+fs-capacitor@^6.1.0:
+  version "6.1.0"
+  resolved "https://registry.yarnpkg.com/fs-capacitor/-/fs-capacitor-6.1.0.tgz#457f5868a743fe662caa9bd825be966c3d4641a4"
+  integrity sha512-YsKGCLAB40P3OKeciIa7cKzt7WkY8QT9ETa2wVIG3fQDHW2h3xtRo0770lUIbPrjCr5Sa+zFhixNJ+2xNxaraQ==
+
 fs-minipass@^1.2.5:
   version "1.2.7"
   resolved "https://registry.yarnpkg.com/fs-minipass/-/fs-minipass-1.2.7.tgz#ccff8570841e7fe4265693da88936c55aed7f7c7"
@@ -1339,7 +1373,7 @@ inflight@^1.0.4:
     once "^1.3.0"
     wrappy "1"
 
-inherits@2, inherits@~2.0.3:
+inherits@2, inherits@^2.0.1, inherits@^2.0.3, inherits@~2.0.1, inherits@~2.0.3:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.4.tgz#0fa2c64f932917c3433a0ded55363aae37416b7c"
   integrity sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==
@@ -1486,6 +1520,11 @@ is-typedarray@~1.0.0:
   resolved "https://registry.yarnpkg.com/is-typedarray/-/is-typedarray-1.0.0.tgz#e479c80858df0c1b11ddda6940f96011fcda4a9a"
   integrity sha1-5HnICFjfDBsR3dppQPlgEfzaSpo=
 
+isarray@0.0.1:
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/isarray/-/isarray-0.0.1.tgz#8a18acfca9a8f4177e09abfc6038939b05d1eedf"
+  integrity sha1-ihis/Kmo9Bd+Cav8YDiTmwXR7t8=
+
 isarray@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
@@ -1653,6 +1692,13 @@ make-error@^1.1.1:
   resolved "https://registry.yarnpkg.com/make-error/-/make-error-1.3.6.tgz#2eb2e37ea9b67c4891f684a1394799af484cf7a2"
   integrity sha512-s8UhlNe7vPKomQhC1qFelMokr/Sc3AgNbso3n74mVPA5LTZwkB9NlXf4XPamLxJE8h0gh73rM94xvwRT2CVInw==
 
+memory-streams@^0.1.3:
+  version "0.1.3"
+  resolved "https://registry.yarnpkg.com/memory-streams/-/memory-streams-0.1.3.tgz#d9b0017b4b87f1d92f55f2745c9caacb1dc93ceb"
+  integrity sha512-qVQ/CjkMyMInPaaRMrwWNDvf6boRZXaT/DbQeMYcCWuXPEBf1v8qChOc9OlEVQp2uOvRXa1Qu30fLmKhY6NipA==
+  dependencies:
+    readable-stream "~1.0.2"
+
 methods@^1.1.1:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/methods/-/methods-1.1.2.tgz#5529a4d67654134edcc5266656835b0f851afcee"
@@ -2187,6 +2233,25 @@ readable-stream@^2.0.6, readable-stream@^2.3.5:
     string_decoder "~1.1.1"
     util-deprecate "~1.0.1"
 
+readable-stream@^3.3.0:
+  version "3.6.0"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-3.6.0.tgz#337bbda3adc0706bd3e024426a286d4b4b2c9198"
+  integrity sha512-BViHy7LKeTz4oNnkcLJ+lVSL6vpiFeX6/d3oSH8zCW7UxP2onchk+vTGB143xuFjHS3deTgkKoXXymXqymiIdA==
+  dependencies:
+    inherits "^2.0.3"
+    string_decoder "^1.1.1"
+    util-deprecate "^1.0.1"
+
+readable-stream@~1.0.2:
+  version "1.0.34"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.0.34.tgz#125820e34bc842d2f2aaafafe4c2916ee32c157c"
+  integrity sha1-Elgg40vIQtLyqq+v5MKRbuMsFXw=
+  dependencies:
+    core-util-is "~1.0.0"
+    inherits "~2.0.1"
+    isarray "0.0.1"
+    string_decoder "~0.10.x"
+
 readdirp@~3.3.0:
   version "3.3.0"
   resolved "https://registry.yarnpkg.com/readdirp/-/readdirp-3.3.0.tgz#984458d13a1e42e2e9f5841b129e162f369aff17"
@@ -2310,7 +2375,7 @@ rxjs@^6.5.3:
   dependencies:
     tslib "^1.9.0"
 
-safe-buffer@^5.0.1, safe-buffer@^5.1.2:
+safe-buffer@^5.0.1, safe-buffer@^5.1.2, safe-buffer@~5.2.0:
   version "5.2.0"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.2.0.tgz#b74daec49b1148f88c64b68d49b1e815c1f2f519"
   integrity sha512-fZEwUGbVl7kouZs1jCdMLdt95hdIv0ZeHg6L7qPeciMZhZ+/gdesW4wgTARkrFWEpspjEATAzUGPG8N2jJiwbg==
@@ -2525,6 +2590,18 @@ string-width@^4.1.0:
     is-fullwidth-code-point "^3.0.0"
     strip-ansi "^6.0.0"
 
+string_decoder@^1.1.1:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.3.0.tgz#42f114594a46cf1a8e30b0a84f56c78c3edac21e"
+  integrity sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA==
+  dependencies:
+    safe-buffer "~5.2.0"
+
+string_decoder@~0.10.x:
+  version "0.10.31"
+  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-0.10.31.tgz#62e203bc41766c6c28c9fc84301dab1c5310fa94"
+  integrity sha1-YuIDvEF2bGwoyfyEMB2rHFMQ+pQ=
+
 string_decoder@~1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.1.1.tgz#9cf1611ba62685d7030ae9e4ba34149c3af03fc8"
@@ -2805,7 +2882,7 @@ url-parse-lax@^1.0.0:
   dependencies:
     prepend-http "^1.0.1"
 
-util-deprecate@~1.0.1:
+util-deprecate@^1.0.1, util-deprecate@~1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/util-deprecate/-/util-deprecate-1.0.2.tgz#450d4dc9fa70de732762fbd2d4a28981419a0ccf"
   integrity sha1-RQ1Nyfpw3nMnYvvS1KKJgUGaDM8=