david_bai
333 lines
12 KiB
TypeScript
333 lines
12 KiB
TypeScript
//发送文件（夹）的流程：先发送文件 meta 信息，等待接收端请求，再发送文件内容，文件发送完再发送endMeta，等待接收端ack，结束
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//发送文件夹的流程（同上）：接收批量文件请求
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//循环发送所有文件的meta，然后把属于folder的部分关于文件大小的记录下来，用于计算进度。接收展示端来区分单文件和文件夹
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import {SpeedCalculator,generateFileId} from '@/lib/myUtils';
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import WebRTC_Initiator from './webrtc_Initiator';
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import {
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CustomFile,
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fileMetadata,
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WebRTCMessage,
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PeerState,
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FolderMeta,
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FileRequest
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} from '@/lib/types/file';
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class FileSender {
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private webrtcConnection: WebRTC_Initiator;
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private peerStates: Map<string, PeerState>;
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private readonly chunkSize: number;
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private readonly maxBufferSize: number;
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private pendingFiles: Map<string, CustomFile>;
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private pendingFolerMeta: Record<string, FolderMeta>;
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private speedCalculator: SpeedCalculator;
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constructor(WebRTC_initiator: WebRTC_Initiator) {
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this.webrtcConnection = WebRTC_initiator;
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// 为每个接收方维护独立的发送状态
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this.peerStates = new Map(); // Map<peerId, PeerState>
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this.chunkSize = 65536; // 64 KB chunks
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this.maxBufferSize = 5; // 预读取的块数
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this.pendingFiles = new Map();//所有待发送的文件（引用）{fileId:CustomFile}
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this.pendingFolerMeta = {};//文件夹对应的meta属性(总大小、文件总个数)，用于记录传输进度,fileId:{totalSize:0 , fileIds:[]}
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// 创建 SpeedCalculator 实例
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this.speedCalculator = new SpeedCalculator();
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this.setupDataHandler();
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}
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// 初始化新接收方的状态
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private getPeerState(peerId: string): PeerState {
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if (!this.peerStates.has(peerId)) {
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this.peerStates.set(peerId, {
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isSending: false,//用来判断文件是否发送成功，发送前是 true， 发送完接收到ack是 false
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bufferQueue: [],//预读取buffer，提高发送效率
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readOffset: 0,//读取位置，发送函数用
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isReading: false,//是否正在读取，发送函数用，避免重复读取
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currentFolderName: '',//如果当前发送的文件属于文件夹，则赋 文件夹名
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totalBytesSent:{},//文件(夹)已发送字节数，用于计算进度;{fileId:0}
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progressCallback: null,//进度回调
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});
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}
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return this.peerStates.get(peerId)!;//! 非空断言（Non-Null Assertion Operator）
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}
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private setupDataHandler(): void {
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this.webrtcConnection.onDataReceived = (data: string | ArrayBuffer, peerId: string) => {
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this.handleReceivedData(data, peerId);
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};
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}
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public setProgressCallback(
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callback: (fileId: string, progress: number, speed: number) => void,
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peerId: string
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): void {
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const peerState = this.getPeerState(peerId);
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peerState.progressCallback = callback;
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}
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private handleReceivedData(data: string | ArrayBuffer, peerId: string): void {
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if (typeof data === 'string') {
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try {
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const parsedData = JSON.parse(data) as WebRTCMessage;
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const peerState = this.getPeerState(peerId);
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const handlers: Record<string, () => void> = {
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fileRequest: () => this.handleFileRequest(parsedData as FileRequest, peerId),
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fileAck: () => {
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peerState.isSending = false;
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console.log(`Receive file-finish ack from peer ${peerId}`);
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}
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};
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const handler = handlers[parsedData.type];
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if (handler) handler();
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} catch (error) {
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console.error('Error parsing JSON:', error);
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}
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}
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}
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//响应 文件请求，发送文件
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private async handleFileRequest(
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request: FileRequest,
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peerId: string
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): Promise<void> {
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const file = this.pendingFiles.get(request.fileId);
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console.log('handleFileRequest',file,peerId);
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if (file) {
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await this.sendSingleFile(file, peerId);
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}
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}
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// 修改发送字符串的方法为异步方法
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public async sendString(content: string, peerId: string): Promise<void> {
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const chunks: string[] = [];
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for (let i = 0; i < content.length; i += this.chunkSize) {
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chunks.push(content.slice(i, i + this.chunkSize));
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}
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// 先发送元数据
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await this.sendWithBackpressure(
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JSON.stringify({
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type: 'stringMetadata',
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length: content.length
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}),
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peerId
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);
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// 依次发送每个分片，使用背压控制
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for (let i = 0; i < chunks.length; i++) {
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const data = JSON.stringify({
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type: 'string',
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chunk: chunks[i],
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index: i,
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total: chunks.length
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});
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await this.sendWithBackpressure(data, peerId);
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}
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}
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public sendFileMeta(files: CustomFile[], peerId?: string): void {
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//把属于folder的部分关于文件大小的记录下来，用于计算进度
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for (const file of files) {
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if (file.folderName){
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const fileId = file.folderName;
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//folderName:{totalSize:0 , fileIds:[]}
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if (!(file.folderName in this.pendingFolerMeta)) {//初始化
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this.pendingFolerMeta[fileId] = {totalSize:0 , fileIds:[]};
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}
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const folderMeta = this.pendingFolerMeta[fileId];
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const fileId2 = generateFileId(file);
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if (!folderMeta.fileIds.includes(fileId2)){//如果文件没被添加过
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folderMeta.fileIds.push(fileId2);
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folderMeta.totalSize += file.size;
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}
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}
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}
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//循环发送所有文件的meta
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const sendToPeers = peerId ? [peerId] : Array.from(this.peerStates.keys());
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for (const currentPeerId of sendToPeers) {
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for (const file of files) {
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const fileId = generateFileId(file);
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this.pendingFiles.set(fileId, file);
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const fileMeta = this.getFileMeta(file);
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console.log('fileMeta',fileMeta);
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this.webrtcConnection.sendData(JSON.stringify(fileMeta), currentPeerId);
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}
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}
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}
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//发送单个文件
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private async sendSingleFile(file: CustomFile, peerId: string): Promise<void> {
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const fileId = generateFileId(file);
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const peerState = this.getPeerState(peerId);
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peerState.isSending = true;
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peerState.currentFolderName = file.folderName;
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console.log('sendSingleFile',peerId,peerState);
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await this.startSendingFile(fileId, peerId);
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// 如果当前正在传输文件,则等待传输完成--接收方确认
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await this.waitForTransferComplete(peerId);
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console.log(`fileId:${fileId} send done or already sent to peer ${peerId}`);
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}
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private async waitForTransferComplete(peerId: string): Promise<void> {
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const peerState = this.getPeerState(peerId);
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while (peerState?.isSending) {
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await new Promise(resolve => setTimeout(resolve, 50));
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}
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}
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private getFileMeta(file: CustomFile): fileMetadata {
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const fileId = generateFileId(file);
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const metadata = {type: 'fileMeta',fileId,name: file.name,
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size: file.size,fileType: file.type,fullName: file.fullName,folderName:file.folderName
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};
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return metadata;
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}
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//同步 文件夹 进度--包含回调
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private syncFolderProgress(fileId: string, peerId: string): void {
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const folderMeta = this.pendingFolerMeta[fileId];//fileId:{totalSize:0 , fileIds:[]}
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const peerState = this.getPeerState(peerId);
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if (!peerState) return;
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this.speedCalculator.updateSendSpeed(peerId, peerState.totalBytesSent[fileId]);// 使用累计接收量
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const speed = this.speedCalculator.getSendSpeed(peerId);
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const progress = peerState.totalBytesSent[fileId] / folderMeta.totalSize;
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peerState.progressCallback?.(fileId, progress, speed);
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}
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//更新传输进度,并进行回调
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private async updateProgress(byteLength: number, fileId: string, fileSize: number, peerId: string): Promise<void> {
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const peerState = this.getPeerState(peerId);
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if (!peerState) return;
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if (peerState.currentFolderName) {//文件夹状态
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this.syncFolderProgress(fileId, peerId);
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} else {// 单文件状态
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const progress = peerState.totalBytesSent[fileId] / fileSize;
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this.speedCalculator.updateSendSpeed(peerId, peerState.totalBytesSent[fileId]);// 使用累计接收量
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const speed = this.speedCalculator.getSendSpeed(peerId);
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peerState.progressCallback?.(fileId, progress, speed);
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}
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}
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private async sendWithBackpressure(data: string | ArrayBuffer, peerId: string) : Promise<boolean>{
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const dataChannel = this.webrtcConnection.dataChannels.get(peerId);
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if (!dataChannel) return false;
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const threshold = dataChannel.bufferedAmountLowThreshold;
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if (dataChannel.bufferedAmount > threshold) {
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await new Promise<void>(resolve => {
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const onBufferedAmountLow = () => {
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dataChannel.removeEventListener('bufferedamountlow', onBufferedAmountLow);
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resolve();
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};
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dataChannel.addEventListener('bufferedamountlow', onBufferedAmountLow);
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});
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}
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return this.webrtcConnection.sendData(data, peerId);
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}
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//开始发送文件内容
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private async startSendingFile(fileId: string, peerId: string): Promise<void> {
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const file = this.pendingFiles.get(fileId);
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if (!file) return;
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const peerState = this.getPeerState(peerId);
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const folderId = peerState.currentFolderName?? '';//fileId
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if(peerState.currentFolderName){//当前属于文件夹
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const index = this.pendingFolerMeta[folderId].fileIds.indexOf(fileId);
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if (index === 0){//发送第一个时清零
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peerState.totalBytesSent[folderId] = 0;//记录文件夹 总发送字节数
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}
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}
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peerState.totalBytesSent[fileId] = 0;//记录 当前文件 总发送字节数
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peerState.readOffset = 0;
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peerState.isReading = false;
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const fileReader = new FileReader();
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const readNextChunk = async (): Promise<void> => {
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if (peerState.isReading) return;
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peerState.isReading = true;
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while (peerState.bufferQueue.length < this.maxBufferSize && peerState.readOffset < file.size) {
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const slice = file.slice(peerState.readOffset, peerState.readOffset + this.chunkSize);
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try {
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const chunk = await this.readChunkAsArrayBuffer(fileReader, slice);
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peerState.bufferQueue.push(chunk);
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peerState.readOffset += chunk.byteLength;
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} catch (error) {
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console.error("Error reading file chunk:", error);
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break;
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}
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}
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peerState.isReading = false;
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};
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const sendNextChunk = async (): Promise<void> => {
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if (peerState.bufferQueue.length > 0) {
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const chunk = peerState.bufferQueue.shift()!;
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await this.sendWithBackpressure(chunk, peerId);
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if(peerState.currentFolderName){//当前属于文件夹
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peerState.totalBytesSent[folderId] += chunk.byteLength;
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await this.updateProgress(chunk.byteLength, folderId, file.size, peerId);//更新文件（夹）的进度
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}else{
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await this.updateProgress(chunk.byteLength, fileId, file.size, peerId);//更新文件的进度
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}
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peerState.totalBytesSent[fileId] += chunk.byteLength;
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if (peerState.totalBytesSent[fileId] < file.size) {//没发送完，继续发送
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await readNextChunk();
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sendNextChunk();
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} else {
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const speed = this.speedCalculator.getSendSpeed(peerId);
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if(!peerState.currentFolderName)
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peerState.progressCallback?.(fileId, 1, speed);//传输单文件时回传
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this.finalizeSendFile(fileId, peerId);//发送完，再发送 fileEnd 信号
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}
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} else if (peerState.totalBytesSent[fileId] < file.size) {//缓冲队列为空，继续读取和发送
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await readNextChunk();
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sendNextChunk();
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}
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};
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await readNextChunk();//开始读取和发送
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sendNextChunk();
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}
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private readChunkAsArrayBuffer(fileReader: FileReader, blob: Blob): Promise<ArrayBuffer> {
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return new Promise((resolve, reject) => {
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fileReader.onload = (e) => {
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// 确保 e.target.result 是 ArrayBuffer
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if (e.target?.result instanceof ArrayBuffer) {
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resolve(e.target.result);
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} else {
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reject(new Error("Failed to read blob as ArrayBuffer"));
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}
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};
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fileReader.onerror = (error) => reject(error);
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fileReader.readAsArrayBuffer(blob);
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});
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}
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//发送 fileEnd 信号
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private finalizeSendFile(fileId: string, peerId: string): void {
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const endMessage = JSON.stringify({
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type: 'fileEnd',
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fileId: fileId
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});
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this.webrtcConnection.sendData(endMessage, peerId);
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}
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}
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export default FileSender; |