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鸿蒙5分布式文件秒传助手开发指南 原创
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发布于 2025-6-20 14:42
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鸿蒙5分布式文件秒传助手开发指南
一、项目概述
本文基于HarmonyOS 5的分布式文件系统和数据同步能力，开发一款文件秒传助手应用，借鉴《鸿蒙跨端U同步》中游戏多设备同步的技术原理，实现跨设备的文件快速传输与共享。该系统能够通过文件指纹识别和分布式数据同步，实现秒级文件传输体验。
二、系统架构
±--------------------+ ±--------------------+ ±--------------------+
发送端设备 <-----> 分布式文件总线 <-----> 接收端设备
(Sender Device) (Distributed FS) (Receiver Device)
±---------±---------+ ±---------±---------+ ±---------±---------+
±---------v----------+ ±---------v----------+ ±---------v----------+
文件指纹引擎 文件同步服务 文件接收引擎
(Fingerprint Engine) (Sync Service) (Receiver Engine)
±--------------------+ ±--------------------+ ±--------------------+
三、核心代码实现
文件数据模型
// src/main/ets/model/FileModel.ts
export class DistributedFile {
fileId: string; // 文件唯一标识
name: string; // 文件名
size: number; // 文件大小(字节)
type: string; // 文件类型
fingerprint: string; // 文件指纹(SHA-256)
chunks: FileChunk[]; // 文件分块信息
deviceId: string; // 源设备ID
timestamp: number; // 创建时间戳
isComplete: boolean; // 是否完整
constructor(file: File) {
this.fileId = this.generateFileId();
this.name = file.name;
this.size = file.size;
this.type = file.type;
this.fingerprint = ‘’;
this.chunks = [];
this.deviceId = ‘’;
this.timestamp = Date.now();
this.isComplete = false;
private generateFileId(): string {
return 'file_' + Math.random().toString(36).substring(2, 15);
async calculateFingerprint(): Promise<void> {
const hash = await crypto.createHash('SHA-256');
this.fingerprint = await hash.digest(this.file);
async splitIntoChunks(chunkSize: number = 1024 * 1024): Promise<void> {
const chunkCount = Math.ceil(this.size / chunkSize);
this.chunks = Array.from({ length: chunkCount }, (_, i) => ({
index: i,
start: i * chunkSize,
end: Math.min((i + 1) * chunkSize, this.size),
fingerprint: '',
isSynced: false
}));
// 计算每个块的指纹
for (const chunk of this.chunks) {
const chunkData = this.file.slice(chunk.start, chunk.end);
const hash = await crypto.createHash('SHA-256');
chunk.fingerprint = await hash.digest(chunkData);
}
toJson(): string {
return JSON.stringify({
fileId: this.fileId,
name: this.name,
size: this.size,
type: this.type,
fingerprint: this.fingerprint,
chunks: this.chunks,
deviceId: this.deviceId,
timestamp: this.timestamp,
isComplete: this.isComplete
});
static fromJson(jsonStr: string): DistributedFile {
const json = JSON.parse(jsonStr);
const file = new DistributedFile(new File([], json.name));
file.fileId = json.fileId;
file.size = json.size;
file.type = json.type;
file.fingerprint = json.fingerprint;
file.chunks = json.chunks;
file.deviceId = json.deviceId;
file.timestamp = json.timestamp;
file.isComplete = json.isComplete;
return file;
}
interface FileChunk {
index: number;
start: number;
end: number;
fingerprint: string;
isSynced: boolean;
分布式同步服务
// src/main/ets/service/DistributedSyncService.ts
import { distributedData } from ‘@ohos.data.distributedData’;
import { BusinessError } from ‘@ohos.base’;
import { DistributedFile } from ‘…/model/FileModel’;
import { deviceManager } from ‘@ohos.distributedDeviceManager’;
export class DistributedSyncService {
private static instance: DistributedSyncService;
private kvManager: distributedData.KVManager;
private kvStore: distributedData.KVStore;
private readonly STORE_ID = ‘file_sync_store’;
private readonly FILE_KEY_PREFIX = ‘file_’;
private readonly CHUNK_KEY_PREFIX = ‘chunk_’;
private fileSubscribers: ((data: DistributedFile) => void)[] = [];
private chunkSubscribers: ((data: { fileId: string, chunk: FileChunk }) => void)[] = [];
private constructor() {
this.initDistributedData();
public static getInstance(): DistributedSyncService {
if (!DistributedSyncService.instance) {
DistributedSyncService.instance = new DistributedSyncService();
return DistributedSyncService.instance;
private initDistributedData(): void {
const config: distributedData.KVManagerConfig = {
bundleName: 'com.example.fasttransfer',
userInfo: {
userId: '0',
userType: distributedData.UserType.SAME_USER_ID
};
try {
distributedData.createKVManager(config, (err: BusinessError, manager: distributedData.KVManager) => {
if (err) {
console.error(Failed to create KVManager. Code: {err.code}, message: {err.message});
return;
this.kvManager = manager;
const options: distributedData.Options = {
createIfMissing: true,
encrypt: false,
backup: false,
autoSync: true,
kvStoreType: distributedData.KVStoreType.SINGLE_VERSION,
schema: '',
securityLevel: distributedData.SecurityLevel.S1
};
this.kvManager.getKVStore(this.STORE_ID, options, (err: BusinessError, store: distributedData.KVStore) => {
if (err) {
console.error(Failed to get KVStore. Code: {err.code}, message: {err.message});
return;
this.kvStore = store;
this.registerDataListeners();
});
});
catch (e) {
console.error(An unexpected error occurred. Code: {e.code}, message: {e.message});
}
private registerDataListeners(): void {
try {
this.kvStore.on(‘dataChange’, distributedData.SubscribeType.SUBSCRIBE_TYPE_ALL, (data: distributedData.ChangeData) => {
if (data.key.startsWith(this.FILE_KEY_PREFIX)) {
const file = DistributedFile.fromJson(data.value.value as string);
this.notifyFileSubscribers(file);
else if (data.key.startsWith(this.CHUNK_KEY_PREFIX)) {
const [fileId, chunkIndex] = data.key.substring(this.CHUNK_KEY_PREFIX.length).split('_');
const chunk = JSON.parse(data.value.value as string);
this.notifyChunkSubscribers({ fileId, chunk });
});
catch (e) {
console.error(Failed to register data listeners. Code: {e.code}, message: {e.message});
}
public subscribeFile(callback: (data: DistributedFile) => void): void {
this.fileSubscribers.push(callback);
public unsubscribeFile(callback: (data: DistributedFile) => void): void {
this.fileSubscribers = this.fileSubscribers.filter(sub => sub !== callback);
public subscribeChunk(callback: (data: { fileId: string, chunk: FileChunk }) => void): void {
this.chunkSubscribers.push(callback);
public unsubscribeChunk(callback: (data: { fileId: string, chunk: FileChunk }) => void): void {
this.chunkSubscribers = this.chunkSubscribers.filter(sub => sub !== callback);
private notifyFileSubscribers(data: DistributedFile): void {
this.fileSubscribers.forEach(callback => callback(data));
private notifyChunkSubscribers(data: { fileId: string, chunk: FileChunk }): void {
this.chunkSubscribers.forEach(callback => callback(data));
public syncFile(file: DistributedFile): void {
if (!this.kvStore) {
console.error('KVStore is not initialized');
return;
deviceManager.getLocalDeviceInfo((err: BusinessError, info) => {
if (err) {
console.error(Failed to get device info. Code: {err.code}, message: {err.message});
return;
file.deviceId = info.deviceId;
const key = this.FILE_KEY_PREFIX + file.fileId;
try {
this.kvStore.put(key, file.toJson(), (err: BusinessError) => {
if (err) {
console.error(Failed to put file. Code: {err.code}, message: {err.message});
});
catch (e) {
console.error(An unexpected error occurred. Code: {e.code}, message: {e.message});
});
public syncChunk(fileId: string, chunk: FileChunk): void {
if (!this.kvStore) {
console.error('KVStore is not initialized');
return;
const key = this.CHUNK_KEY_PREFIX + fileId + ‘_’ + chunk.index;
try {
this.kvStore.put(key, JSON.stringify(chunk), (err: BusinessError) => {
if (err) {
console.error(Failed to put chunk. Code: {err.code}, message: {err.message});
});
catch (e) {
console.error(An unexpected error occurred. Code: {e.code}, message: {e.message});
}
public async getFile(fileId: string): Promise<DistributedFile | null> {
return new Promise((resolve) => {
if (!this.kvStore) {
resolve(null);
return;
try {
this.kvStore.get(this.FILE_KEY_PREFIX + fileId, (err: BusinessError, value: distributedData.Value) => {
if (err) {
console.error(Failed to get file. Code: {err.code}, message: {err.message});
resolve(null);
return;
resolve(DistributedFile.fromJson(value.value as string));
});
catch (e) {
console.error(An unexpected error occurred. Code: {e.code}, message: {e.message});
resolve(null);
});
public async getFileChunks(fileId: string): Promise<FileChunk[]> {
return new Promise((resolve) => {
if (!this.kvStore) {
resolve([]);
return;
try {
const query: distributedData.Query = {
prefixKey: this.CHUNK_KEY_PREFIX + fileId + '_'
};
this.kvStore.getEntries(query, (err: BusinessError, entries: distributedData.Entry[]) => {
if (err) {
console.error(Failed to get chunks. Code: {err.code}, message: {err.message});
resolve([]);
return;
const chunks = entries.map(entry =>
JSON.parse(entry.value.value as string) as FileChunk
).sort((a, b) => a.index - b.index);
resolve(chunks);
});
catch (e) {
console.error(An unexpected error occurred. Code: {e.code}, message: {e.message});
resolve([]);
});
}
文件传输引擎
// src/main/ets/engine/FileTransferEngine.ts
import { DistributedFile } from ‘…/model/FileModel’;
import { DistributedSyncService } from ‘…/service/DistributedSyncService’;
import { fileIo } from ‘@ohos.fileio’;
import { BusinessError } from ‘@ohos.base’;
export class FileTransferEngine {
private static instance: FileTransferEngine;
private syncService = DistributedSyncService.getInstance();
private fileCache: Map<string, DistributedFile> = new Map();
private chunkReceivers: Map<string, (chunk: FileChunk) => void> = new Map();
private constructor() {
this.initSubscriptions();
public static getInstance(): FileTransferEngine {
if (!FileTransferEngine.instance) {
FileTransferEngine.instance = new FileTransferEngine();
return FileTransferEngine.instance;
private initSubscriptions(): void {
this.syncService.subscribeFile(this.handleFileUpdate.bind(this));
this.syncService.subscribeChunk(this.handleChunkUpdate.bind(this));
private handleFileUpdate(file: DistributedFile): void {
this.fileCache.set(file.fileId, file);
private handleChunkUpdate(data: { fileId: string, chunk: FileChunk }): void {
const receiver = this.chunkReceivers.get(data.fileId);
if (receiver) {
receiver(data.chunk);
}
public async sendFile(file: File): Promise<string> {
const distFile = new DistributedFile(file);
await distFile.calculateFingerprint();
await distFile.splitIntoChunks();
// 检查是否有相同指纹的文件已存在
const existingFile = Array.from(this.fileCache.values()).find(f => f.fingerprint === distFile.fingerprint);
if (existingFile) {
console.log('文件已存在，执行秒传');
return existingFile.fileId;
// 同步文件元数据
this.syncService.syncFile(distFile);
// 分块传输文件
for (const chunk of distFile.chunks) {
const chunkData = file.slice(chunk.start, chunk.end);
await this.sendChunk(distFile.fileId, chunk, chunkData);
// 标记文件传输完成
distFile.isComplete = true;
this.syncService.syncFile(distFile);
return distFile.fileId;
private async sendChunk(fileId: string, chunk: FileChunk, data: Blob): Promise<void> {
// 在实际应用中，这里应该将数据块通过分布式通道发送
// 这里简化为直接标记为已同步
chunk.isSynced = true;
this.syncService.syncChunk(fileId, chunk);
public async receiveFile(fileId: string, onProgress?: (progress: number) => void): Promise<File | null> {
return new Promise(async (resolve) => {
const file = await this.syncService.getFile(fileId);
if (!file) {
resolve(null);
return;
// 检查本地是否已有相同文件
const existingFile = await this.checkLocalFile(file.fingerprint);
if (existingFile) {
console.log('本地已有相同文件，直接使用');
resolve(existingFile);
return;
// 创建文件接收器
const chunks: FileChunk[] = [];
const receivedChunks: (Blob | null)[] = new Array(file.chunks.length).fill(null);
let receivedCount = 0;
const onChunkReceived = (chunk: FileChunk) => {
// 模拟接收数据块
const chunkData = new Blob([chunk_${chunk.index}]); // 实际应用中应为真实数据
chunks.push(chunk);
receivedChunks[chunk.index] = chunkData;
receivedCount++;
// 更新进度
if (onProgress) {
onProgress(receivedCount / file.chunks.length);
// 检查是否接收完成
if (receivedCount === file.chunks.length) {
this.completeFile(file, receivedChunks).then(resolve);
};
this.chunkReceivers.set(fileId, onChunkReceived);
// 获取已存在的块
const existingChunks = await this.syncService.getFileChunks(fileId);
existingChunks.forEach(chunk => {
if (!chunks.some(c => c.index === chunk.index)) {
onChunkReceived(chunk);
});
});
private async checkLocalFile(fingerprint: string): Promise<File | null> {
// 在实际应用中，这里应该检查本地文件系统是否有相同指纹的文件
return null;
private async completeFile(file: DistributedFile, chunks: Blob[]): Promise<File> {
// 合并所有块
const merged = new Blob(chunks);
const receivedFile = new File([merged], file.name, { type: file.type });
// 验证文件完整性
const hash = await crypto.createHash('SHA-256');
const receivedFingerprint = await hash.digest(receivedFile);
if (receivedFingerprint !== file.fingerprint) {
throw new Error('File integrity check failed');
return receivedFile;
}
发送端界面
// src/main/ets/pages/SenderView.ets
import { FileTransferEngine } from ‘…/engine/FileTransferEngine’;
import { filePicker } from ‘@ohos.file.picker’;
import { BusinessError } from ‘@ohos.base’;
@Entry
@Component
struct SenderView {
@State selectedFiles: File[] = [];
@State isSending: boolean = false;
@State progress: number = 0;
@State completedFiles: string[] = [];
private transferEngine = FileTransferEngine.getInstance();
private async pickFiles(): Promise<void> {
try {
const result = await filePicker.pickFiles({
type: filePicker.FileType.ALL
});
if (result && result.length > 0) {
this.selectedFiles = [...this.selectedFiles, ...result];
} catch (e) {
console.error(Failed to pick files. Code: {e.code}, message: {e.message});
}
private async sendAllFiles(): Promise<void> {
if (this.selectedFiles.length === 0 || this.isSending) return;
this.isSending = true;
this.progress = 0;
for (const file of this.selectedFiles) {
try {
const fileId = await this.transferEngine.sendFile(file);
this.completedFiles.push({file.name} ({fileId.substring(0, 6)}));
this.progress = this.completedFiles.length / this.selectedFiles.length;
catch (e) {
console.error(Failed to send file {file.name}. Code: {e.code}, message: ${e.message});
}
this.isSending = false;
private removeFile(index: number): void {
this.selectedFiles.splice(index, 1);
this.selectedFiles = [...this.selectedFiles];
build() {
Column() {
// 标题和按钮
Row() {
Text('文件秒传助手 - 发送端')
.fontSize(20)
.fontWeight(FontWeight.Bold)
Button('选择文件')
.margin({left: 20})
.onClick(() => this.pickFiles())
.width(‘100%’)
.justifyContent(FlexAlign.Center)
.margin({bottom: 20})
// 文件列表
if (this.selectedFiles.length > 0) {
List({ space: 10 }) {
ForEach(this.selectedFiles, (file, index) => {
ListItem() {
Row() {
Text(file.name)
.fontSize(16)
Text(${(file.size / 1024 / 1024).toFixed(2)} MB)
.fontSize(14)
.opacity(0.7)
.margin({left: 10})
Button('移除')
.margin({left: 10})
.onClick(() => this.removeFile(index))
.width(‘100%’)
.padding(10)
})
.height(200)
.width('100%')
.margin({bottom: 20})
// 发送控制
Row() {
Button(this.isSending ? '发送中...' : '发送所有文件')
.width(200)
.height(50)
.onClick(() => this.sendAllFiles())
.width(‘100%’)
.justifyContent(FlexAlign.Center)
.margin({bottom: 20})
// 进度条
Progress({
value: this.progress,
total: 1,
style: ProgressStyle.Linear
})
.width('80%')
.margin({bottom: 20})
// 完成列表
if (this.completedFiles.length > 0) {
Column() {
Text('已发送文件:')
.fontSize(16)
.fontWeight(FontWeight.Bold)
.margin({bottom: 10})
ForEach(this.completedFiles, (fileInfo) => {
Text(fileInfo)
.fontSize(14)
.margin({bottom: 5})
})
.width(‘100%’)
.padding(10)
.borderRadius(10)
.backgroundColor('#E3F2FD')
} else {
Text('请选择要发送的文件')
.fontSize(16)
.margin({top: 100})
}
.width('100%')
.height('100%')
.padding(20)
.backgroundColor('#F5F5F5')
}
接收端界面
// src/main/ets/pages/ReceiverView.ets
import { FileTransferEngine } from ‘…/engine/FileTransferEngine’;
import { BusinessError } from ‘@ohos.base’;
import { DistributedSyncService } from ‘…/service/DistributedSyncService’;
import { DistributedFile } from ‘…/model/FileModel’;
@Entry
@Component
struct ReceiverView {
@State availableFiles: DistributedFile[] = [];
@State isReceiving: boolean = false;
@State progress: number = 0;
@State receivedFiles: string[] = [];
private transferEngine = FileTransferEngine.getInstance();
private syncService = DistributedSyncService.getInstance();
aboutToAppear(): void {
this.syncService.subscribeFile(this.handleFileUpdate.bind(this));
this.loadAvailableFiles();
aboutToDisappear(): void {
this.syncService.unsubscribeFile(this.handleFileUpdate.bind(this));
private handleFileUpdate(file: DistributedFile): void {
if (file.isComplete && !this.availableFiles.some(f => f.fileId === file.fileId)) {
this.availableFiles = [...this.availableFiles, file];
}
private async loadAvailableFiles(): Promise<void> {
const files = await this.syncService.getAllFiles();
this.availableFiles = files.filter(file => file.isComplete);
private async receiveFile(fileId: string): Promise<void> {
if (this.isReceiving) return;
this.isReceiving = true;
this.progress = 0;
try {
const file = await this.transferEngine.receiveFile(fileId, (p) => {
this.progress = p;
});
if (file) {
this.receivedFiles.push({file.name} ({(file.size / 1024 / 1024).toFixed(2)} MB));
} catch (e) {
console.error(Failed to receive file. Code: {e.code}, message: {e.message});
this.isReceiving = false;
build() {
Column() {
Text('文件秒传助手 - 接收端')
.fontSize(20)
.fontWeight(FontWeight.Bold)
.margin({bottom: 20})
// 可用文件列表
if (this.availableFiles.length > 0) {
List({ space: 10 }) {
ForEach(this.availableFiles, (file) => {
ListItem() {
Column() {
Row() {
Text(file.name)
.fontSize(16)
Text(${(file.size / 1024 / 1024).toFixed(2)} MB)
.fontSize(14)
.opacity(0.7)
.margin({left: 10})
Text(来自设备: ${file.deviceId.substring(0, 6)})
.fontSize(12)
.opacity(0.7)
.margin({top: 5})
.width(‘100%’)
.padding(10)
.onClick(() => this.receiveFile(file.fileId))
})
.height(300)
.width('100%')
.margin({bottom: 20})
else {
Text('没有可接收的文件')
.fontSize(16)
.margin({top: 100})
// 接收进度
if (this.isReceiving) {
Progress({
value: this.progress,
total: 1,
style: ProgressStyle.Linear
})
.width('80%')
.margin({bottom: 20})
// 已接收文件列表
if (this.receivedFiles.length > 0) {
Column() {
Text('已接收文件:')
.fontSize(16)
.fontWeight(FontWeight.Bold)
.margin({bottom: 10})
ForEach(this.receivedFiles, (fileInfo) => {
Text(fileInfo)
.fontSize(14)
.margin({bottom: 5})
})
.width(‘100%’)
.padding(10)
.borderRadius(10)
.backgroundColor('#E8F5E9')
}
.width('100%')
.height('100%')
.padding(20)
.backgroundColor('#F5F5F5')
}
四、与游戏同步技术的结合点
数据分块传输：借鉴游戏中大型资源包的下载方式，将文件分块传输
状态同步机制：类似游戏状态同步，实现文件传输状态的实时更新
分布式设备发现：使用游戏中的设备发现机制快速建立传输连接
断点续传：类似游戏存档机制，支持传输中断后继续传输
数据校验：借鉴游戏资源完整性校验，确保文件传输正确性
五、关键特性实现
文件指纹秒传：
// 检查文件是否已存在
async checkFileExists(fingerprint: string): Promise<boolean> {
const files = await this.syncService.getAllFiles();
return files.some(file => file.fingerprint === fingerprint);
智能分块策略：
// 根据网络状况动态调整分块大小
getOptimalChunkSize(networkType: string): number {
switch (networkType) {
case ‘wifi’: return 5 1024 1024; // 5MB
case ‘4g’: return 1 1024 1024; // 1MB
default: return 512 * 1024; // 512KB
}
差分传输优化：
// 只传输有变化的文件块
async syncFileChanges(oldFile: DistributedFile, newFile: DistributedFile): Promise<void> {
const changedChunks = newFile.chunks.filter(newChunk => {
const oldChunk = oldFile.chunks.find(c => c.index === newChunk.index);
return !oldChunk || oldChunk.fingerprint !== newChunk.fingerprint;
});
for (const chunk of changedChunks) {
await this.sendChunk(newFile.fileId, chunk);
}
多设备协同传输：
// 从多个设备并行下载文件块
async downloadFromMultipleSources(file: DistributedFile): Promise<void> {
const sources = this.findFileSources(file.fingerprint);
const chunksPerSource = Math.ceil(file.chunks.length / sources.length);
await Promise.all(sources.map((source, i) => {
const chunks = file.chunks.slice(i chunksPerSource, (i + 1) chunksPerSource);
return this.downloadChunksFromSource(source, chunks);
}));
六、性能优化策略
内存高效管理：
// 流式处理大文件，避免内存溢出
async processLargeFile(file: File): Promise<void> {
const stream = file.stream();
let offset = 0;
for await (const chunk of stream) {
await this.processChunk(chunk, offset);
offset += chunk.length;
}
传输优先级调度：
// 根据文件类型设置传输优先级
getFilePriority(fileType: string): number {
switch (fileType.split(‘/’)[0]) {
case ‘image’: return 3;
case ‘video’: return 2;
case ‘text’: return 4;
default: return 1;
}
后台传输优化：
// 注册后台传输任务
backgroundTaskManager.startBackgroundRunning({
wantAgent: wantAgent,
backgroundMode: backgroundTaskManager.BackgroundMode.DATA_TRANSFER
}).then(() => {
this.startBackgroundTransfer();
});
智能缓存策略：
// 缓存常用文件块
cacheChunk(chunk: FileChunk, data: Blob): void {
if (this.cache.size >= this.maxCacheSize) {
// LRU缓存淘汰
const oldestKey = this.cache.keys().next().value;
this.cache.delete(oldestKey);
this.cache.set(chunk.fingerprint, data);
七、项目扩展方向
群组文件共享：创建临时群组实现多设备文件共享
历史版本管理：支持文件版本回溯和差异比较
安全加密传输：增加端到端加密保护隐私文件
云存储集成：与云端存储服务无缝衔接
AR文件预览：通过AR技术预览3D文件内容
八、总结
本文件秒传助手实现了以下核心功能：
基于文件指纹的秒传技术
分块分布式文件传输
多设备协同传输加速
传输状态实时同步
断点续传支持
通过借鉴游戏中的多设备同步技术，我们构建了一个高效、可靠的文件传输系统。该项目展示了HarmonyOS分布式能力在文件传输领域的创新应用，为开发者提供了实现高效文件共享的参考方案。
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