perf: Use transferable objects when posting audio buffers to avoid data copying (#264)

* feat(ws-tools): add sentence-level audio streaming support

* chore: Publish feat/sentence

* feat(coze-api): Use transferable objects when posting audio buffers to avoid data copying

---------

Co-authored-by: shenxiaojie.316 <shenxiaojie.316@bytedance.com>

Author: jackshen310

common/changes/@coze/api/feat-perf2_2025-06-16-13-08.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@coze/api",
+      "comment": "Use transferable objects when posting audio buffers to avoid data copying",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@coze/api",
+  "email": "shenxiaojie.316@bytedance.com"
+}

packages/coze-js/src/ws-tools/chat/base.ts

@@ -23,7 +23,7 @@ import {
   WebsocketsEventType,
 } from '../../index';
 
-class BaseWsChatClient {
+abstract class BaseWsChatClient {
   public ws: WebSocketAPI<CreateChatWsReq, CreateChatWsRes> | null = null;
   protected listeners: Map<string, Set<WsChatCallbackHandler>> = new Map();
   protected wavStreamPlayer?: WavStreamPlayer;
@@ -170,6 +170,7 @@ class BaseWsChatClient {
   }
 
   sendTextMessage(text: string) {
+    this.clear();
     this.sendMessage({
       id: uuid(),
       event_type: WebsocketsEventType.CONVERSATION_MESSAGE_CREATE,

packages/coze-js/src/ws-tools/chat/index.ts

@@ -86,7 +86,6 @@ class WsChatClient extends BaseWsChatClient {
     // init stream player
     await this.wavStreamPlayer?.add16BitPCM(new ArrayBuffer(0), this.trackId);
 
-    // let startTime = performance.now();
     // 2. recording
     await this.recorder.record({
       pcmAudioCallback: data => {

packages/coze-js/src/ws-tools/wavtools/lib/wav_stream_player.ts

@@ -31,19 +31,17 @@ export class WavStreamPlayer {
   defaultFormat: AudioFormat;
   localLoopbackStream: MediaStream | undefined;
   private volume: number = 1.0;
-  private firstFrameCallback?: (timestamp: number) => void;
 
   /**
    * Creates a new WavStreamPlayer instance
    * @param {{sampleRate?: number, enableLocalLoopback?: boolean, defaultFormat?: AudioFormat, volume?: number}} options
    * @returns {WavStreamPlayer}
    */
-  constructor({ sampleRate = 44100, enableLocalLoopback = false, defaultFormat = 'pcm', volume = 1.0, firstFrameCallback }: {
+  constructor({ sampleRate = 44100, enableLocalLoopback = false, defaultFormat = 'pcm', volume = 1.0 }: {
     sampleRate?: number,
     enableLocalLoopback?: boolean,
     defaultFormat?: AudioFormat,
     volume?: number,
-    firstFrameCallback?: (timestamp: number) => void
   } = {}) {
     this.scriptSrc = StreamProcessorSrc;
     this.sampleRate = sampleRate;
@@ -59,7 +57,6 @@ export class WavStreamPlayer {
       this.localLoopback = new LocalLoopback(true);
     }
 
-    this.firstFrameCallback = firstFrameCallback;
 
     // Initialize volume (0 = muted, 1 = full volume)
     this.volume = volume;
@@ -153,8 +150,6 @@ export class WavStreamPlayer {
         const { requestId, trackId, offset } = e.data;
         const currentTime = offset / this.sampleRate;
         this.trackSampleOffsets[requestId] = { trackId, offset, currentTime };
-      } else if (event === 'first_frame') {
-         this.firstFrameCallback?.(Date.now());
       }
     };
 
@@ -214,7 +209,14 @@ export class WavStreamPlayer {
     } else {
       throw new Error(`argument must be Int16Array, Uint8Array, or ArrayBuffer`);
     }
-    this.streamNode!.port.postMessage({ event: 'write', buffer, trackId });
+    // 使用 Transferable 对象传递 ArrayBuffer，避免数据复制
+    // 注意：只能传递 buffer.buffer，因为 buffer 是 Int16Array
+    const transferableBuffer = buffer.buffer;
+    this.streamNode!.port.postMessage({
+      event: 'write',
+      buffer,
+      trackId
+    }, [transferableBuffer]);
     return buffer;
   }