分片请求时立即播放

README.md

@@ -10,7 +10,7 @@ webrtc 实现的 p2p 信道
   - [x] 响应列表时不再广播
   - [x] 对方退出时清除其列表
   - [x] 稳定通信
-  - [ ] 分片请求时立即播放
+  - [x] 分片请求时立即播放
   - [ ] 上锁防止连续重复加载同一个造成分片混乱
 - [ ] 集群分发
 - [ ] 下载加速

public/index.html

@@ -107,15 +107,39 @@
             onerror: error => {
                 console.log('音乐列表错误', error)
             },
-            onload: async item => {
+            onload: async (item, sourceBuffer) => {
                 console.log('加载音乐', item)
                 return await new Promise((resolve) => {
-                    var buffer = new ArrayBuffer(0)
-                    var count = 0
+                    var buffer = new ArrayBuffer(0) // 接收音乐数据
+                    var count = 0                   // 接收分片计数
+                    var bufferCursor = 0            // 加载进度
+                    var partlength = 1024 * 64      // 每次加载1MB
+
+                    // 指针达到音乐数据大小则结束加载
+                    const mediaLoader = async () => {
+                        while (bufferCursor !== item.size) {
+                            if (musicList.audio.paused && musicList.audio.src === '') {
+                                console.log('音乐数据加载中, 但是音频已经停止播放')
+                                break
+                            }
+                            const 当前播放进度 = musicList.audio.currentTime
+                            const 当前结束时间 = sourceBuffer.buffered.length && sourceBuffer.buffered.end(0)
+                            const 剩余数据长度 = buffer.byteLength - bufferCursor
+                            const 本次加载长度 = Math.min(partlength, 剩余数据长度)
+                            const 缓冲时间 = 当前结束时间 - 当前播放进度
+                            if (buffer.byteLength > bufferCursor && !sourceBuffer.updating && 缓冲时间 < 60) {
+                                sourceBuffer.appendBuffer(buffer.slice(bufferCursor, bufferCursor + 本次加载长度))
+                                bufferCursor += 本次加载长度
+                            }
+                            await new Promise((resolve) => setTimeout(resolve, 1000))
+                        }
+                    }
+                    mediaLoader()
+
                     clientList.setChannel(`music-data-${item.id}`, {
                         onmessage: async (event, client) => {
-                            buffer = appendBuffer(buffer, event.data)
                             console.log('收到音乐数据 chunk', count, buffer.byteLength)
+                            buffer = appendBuffer(buffer, event.data)
                             count++
                             if (buffer.byteLength >= item.size) {
                                 console.log('音乐数据接收完毕')

public/music.js

@@ -134,14 +134,26 @@ export default class MusicList {
     }
     async play(item) {
         if (!item.arrayBuffer) {
-            await this.load(item)
-        }
-        this.playing = item
+            // 边加载边播放
+            const mediaSource = new MediaSource()
+            this.audio.src = URL.createObjectURL(mediaSource)
+            mediaSource.addEventListener('sourceopen', async () => {
+                const sourceBuffer = mediaSource.addSourceBuffer(item.type)
+                this.event.onload(item, sourceBuffer)
+                this.audio.play()
+            })
+        } else {
+            // 本地缓存直接播放
             this.audio.src = URL.createObjectURL(new Blob([item.arrayBuffer], { type: item.type }))
             this.audio.play()
+        }
+        this.playing = item
         this.event.onplay(item)
     }
     async stop() {
+        //if (!this.audio.paused) {
+        //    this.audio.pause()
+        //}
         this.audio.pause()
         this.audio.src = ''
         this.event.onstop(this.playing)