01. 背景
最近项目需求里有个文件上传功能，而客户需求里的文件基本上是比较大的，基本上得有 1 GiB 以上的大小，而上传大文件尤其是读大文件，可能会造成卡 UI 或者说点不动的问题。而用后台的 Worker 去实现是一个比较不错的解决办法。
02. 原理讲解
02.01. Shared Worker
Shared Worker 的好处是可以从几个浏览上下文中访问，例如几个窗口、iframe 或其他 worker。这样我们可以保证全局的页面上传任务都在我们的控制之下，甚至可以防止重复提交等功能。
02.02. 组合式函数
组合式函数的好处是在 Vue 3 是可以在任何 *.vue 文件中使用，并且是响应式方法，可以侦听 pinia 内 token 等的变化，传递给 Worker
02.03 简单流程设计
03. 代码
upload-worker.ts 代码
import { sha256 } from '@noble/hashes/sha256';
import { bytesToHex as toHex } from '@noble/hashes/utils';
interface SharedWorkerGlobalScope {
onconnect: (event: MessageEvent<any>) => void;
}
const _self: SharedWorkerGlobalScope = self as any;
/**
* 分片大小
*/
const pieceSize = 1024 * 1024;
/**
* 消息参数
*/
interface MessageArg {
/**
* 函数名
*/
func: string;
/**
* 参数
*/
arg: T;
}
/**
* 上传任务信息
*/
interface UploadTaskInfo {
/**
* 文件名
*/
fileName: string;
/**
* 上传路径
*/
uploadPath: string;
/**
* 任务 id
*/
id: string;
/**
* 文件大小
*/
size: number;
/**
* 上传进度
*/
progress: number;
/**
* 上传速度
*/
speed?: number;
/**
* 任务状态
*/
status: 'uploading' | 'paused' | 'canceled' | 'done' | 'error' | 'waiting';
/**
* 开始时间
*/
startTime?: Date;
/**
* 结束时间
*/
endTime?: Date;
/**
* 错误信息
*/
errorMessage?: string;
}
/**
* 上传任务
*/
interface UploadTask extends UploadTaskInfo {
file: File;
pieces: Array<boolean>;
abort?: AbortController;
}
/**
* 任务/哈希值映射
*/
const hashs = new Map();
/**
* 上传任务列表
*/
const uploadTasks: Array<UploadTask> = [];
/**
* 状态接收器
*/
const statusReceivers = new Map<string, MessagePort>();
/**
* token 仓库
*/
const tokenStore = {
/**
* token
*/
BearerToken: '',
};
/**
* 返回上传状态
* @param task 上传任务
*/
const updateStatus = (task: UploadTaskInfo) => {
const taskInfo: UploadTaskInfo = {
fileName: task.fileName,
uploadPath: task.uploadPath,
id: task.id,
size: task.size,
progress: task.progress,
speed: task.speed,
status: task.status,
startTime: task.startTime,
endTime: task.endTime,
errorMessage: task.errorMessage,
};
statusReceivers.forEach((item) => {
item.postMessage(taskInfo);
});
};
/**
* 运行上传任务
* @param task 上传任务
*/
const runUpload = async (task: UploadTask) => {
task.status = 'uploading';
const hash = hashs.get(task.id) || sha256.create();
hashs.set(task.id, hash);
let retryCount = 0;
const abort = new AbortController();
task.abort = abort;
while (task.status === 'uploading') {
const startTime = Date.now();
const index = task.pieces.findIndex((item) => !item);
if (index === -1) {
try {
const response: { code: number; message: string } = await fetch(
'/api/File/Upload',
{
method: 'PUT',
headers: {
Authorization: tokenStore.BearerToken,
'Content-Type': 'application/json',
},
body: JSON.stringify({
id: task.id,
fileHash: toHex(hash.digest()),
filePath: task.uploadPath,
}),
}
).then((res) => res.json());
if (response.code !== 200) {
throw new Error(response.message);
}
task.status = 'done';
task.endTime = new Date();
updateStatus(task);
} catch (e: any) {
task.status = 'error';
task.errorMessage = e.toString();
task.endTime = new Date();
deleteUpload(task.id);
updateStatus(task);
}
break;
}
const start = index * pieceSize;
const end = start + pieceSize >= task.size ? task.size : start + pieceSize;
const buffer = task.file.slice(index * pieceSize, end);
hash.update(new Uint8Array(await buffer.arrayBuffer()));
const form = new FormData();
form.append('file', buffer);
let isTimeout = false;
try {
const timer = setTimeout(() => {
isTimeout = true;
abort.abort();
}, 8000);
const response: { code: number; message: string } = await fetch(
`/api/File/Upload?id=${task.id}&offset=${start}`,
{
method: 'POST',
body: form,
headers: {
Authorization: tokenStore.BearerToken,
},
signal: abort.signal,
}
).then((res) => res.json());
clearTimeout(timer);
if (response.code !== 200) {
throw new Error(response.message);
}
task.pieces[index] = true;
task.progress =
task.pieces.filter((item) => item).length / task.pieces.length;
task.speed = (pieceSize / (Date.now() - startTime)) * 1000;
updateStatus(task);
} catch (e: any) {
retryCount++;
if (retryCount > 3) {
task.status = 'error';
if (isTimeout) {
task.errorMessage = 'UploadTimeout';
} else {
task.errorMessage = e.toString();
}
task.endTime = new Date();
deleteUpload(task.id);
updateStatus(task);
}
}
runNextUpload();
}
};
/**
* 运行下一个上传任务
*/
const runNextUpload = async () => {
if (uploadTasks.filter((item) => item.status === 'uploading').length > 3) {
return;
}
const task = uploadTasks.find((item) => item.status === 'waiting');
if (task) {
await runUpload(task);
}
};
/**
* 排队上传
* @param e 消息事件
*/
const queueUpload = async (
e: MessageEvent<
MessageArg<{
id: string;
file: File;
uploadPath: string;
}>
>
) => {
uploadTasks.push({
file: e.data.arg.file,
fileName: e.data.arg.file.name,
id: e.data.arg.id,
uploadPath: e.data.arg.uploadPath,
size: e.data.arg.file.size,
progress: 0,
speed: 0,
status: 'waiting',
pieces: new Array(Math.ceil(e.data.arg.file.size / pieceSize)).fill(false),
errorMessage: undefined,
});
updateStatus(uploadTasks[uploadTasks.length - 1]);
await runNextUpload();
};
/**
* 注册状态接收器
* @param e 消息事件
* @param sender 发送者
*/
const registerStatusReceiver = (
e: MessageEventstring >>,
sender?: MessagePort
) => {
if (sender) statusReceivers.set(e.data.arg, sender);
};
/**
* 注销状态接收器
* @param e 消息事件
*/
const unregisterStatusReceiver = (e: MessageEventstring >>) => {
statusReceivers.delete(e.data.arg);
};
/**
* 更新 token
* @param e 消息事件
*/
const updateToken = (e: MessageEventstring >>) => {
tokenStore.BearerToken = 'Bearer ' + e.data.arg;
};
/**
* 暂停上传
* @param e 消息事件
*/
const pauseUpload = (e: MessageEventstring >>) => {
const task = uploadTasks.find((item) => item.id === e.data.arg);
if (task) {
task.status = 'paused';
if (task.abort) {
task.abort.abort();
}
updateStatus(task);
}
};
/**
* 取消上传
* @param e 消息事件
*/
const cancelUpload = (e: MessageEventstring >>) => {
const task = uploadTasks.find((item) => item.id === e.data.arg);
if (task) {
task.status = 'canceled';
if (task.abort) {
task.abort.abort();
}
deleteUpload(task.id);
updateStatus(task);
}
};
/**
* 删除上传
* @param id 任务 id
*/
const deleteUpload = async (id: string) => {
uploadTasks.splice(
uploadTasks.findIndex((item) => item.id === id),
1
);
hashs.delete(id);
await fetch(`/api/File/Upload?id=${id}`, {
method: 'DELETE',
headers: {
Authorization: tokenStore.BearerToken,
},
}).then((res) => res.json());
};
/**
* 消息路由
*/
const messageRoute = new Map<
string,
(e: MessageEventany >>, sender?: MessagePort) => void
>([
['queueUpload', queueUpload],
['registerStatusReceiver', registerStatusReceiver],
['updateToken', updateToken],
['pauseUpload', pauseUpload],
['cancelUpload', cancelUpload],
['unregisterStatusReceiver', unregisterStatusReceiver],
]);
// 监听连接
_self.onconnect = (e) => {
const port = e.ports[0];
port.onmessage = async (e) => {
// 调用函数
const func = messageRoute.get(e.data.func);
if (func) {
func(e, port);
}
};
port.start();
};
upload-service.ts 代码
import UploadWorker from './upload-worker?sharedworker';
import { onUnmounted, ref, watch } from 'vue';
import { storeToRefs } from 'pinia';
import { useAuthStore } from 'src/stores/auth';
/**
* 上传任务信息
*/
interface UploadTaskInfo {
/**
* 文件名
*/
fileName: string;
/**
* 上传路径
*/
uploadPath: string;
/**
* 任务 id
*/
id: string;
/**
* 文件大小
*/
size: number;
/**
* 上传进度
*/
progress: number;
/**
* 上传速度
*/
speed?: number;
/**
* 任务状态
*/
status: 'uploading' | 'paused' | 'canceled' | 'done' | 'error' | 'waiting';
/**
* 开始时间
*/
startTime?: Date;
/**
* 结束时间
*/
endTime?: Date;
/**
* 错误信息
*/
errorMessage?: string;
}
/**
* 上传服务
*/
export const useUploadService = () => {
const store = storeToRefs(useAuthStore());
// 创建共享 worker
const worker = new UploadWorker();
/**
* 上传任务列表
*/
const uploadTasks = ref<Map<string, UploadTaskInfo>>(
new Map<string, UploadTaskInfo>()
);
// 是否已注册状态接收器
const isRegistered = ref(false);
// 服务 id
const serviceId = crypto.randomUUID();
// 监听上传任务列表变化（只有在注册状态接收器后才会收到消息）
worker.port.onmessage = (e: MessageEvent04. 用法
// 引入组合式函数
const uploadService = useUploadService();
// 注册状态接收器
uploadService.registerStatusReceiver();
// 表单绑定上传方法
const upload = (file: File, filePath: string) => {
uploadService.queueUpload(file, filePath);
}
// 监听上传进度，当然也可以直接展示在界面，毕竟是 Ref
watch(uploadService.uploadTasks, console.log);