Javascript 通过服务器将多个文件上载到S3时,如何从故障中恢复?
刚接触NodeJS和S3时,我编写了以下探索性代码,通过我的NodeJS服务器将文件上载到S3,而无需将文件保存到磁盘或内存:Javascript 通过服务器将多个文件上载到S3时,如何从故障中恢复?,javascript,node.js,amazon-s3,busboy,Javascript,Node.js,Amazon S3,Busboy,刚接触NodeJS和S3时,我编写了以下探索性代码,通过我的NodeJS服务器将文件上载到S3,而无需将文件保存到磁盘或内存: var express = require('express'); var Busboy = require('busboy'); var S3 = require('../utils/s3Util'); var router = express.Router(); // mounted at /uploads router.post("/", function (r
var express = require('express');
var Busboy = require('busboy');
var S3 = require('../utils/s3Util');
var router = express.Router(); // mounted at /uploads
router.post("/", function (req, res, next) {
let bb = new Busboy({ headers: req.headers });
const uploads = [];
bb.on('file', (fieldname, stream, filename, encoding, mimeType) => {
console.log(`Uploaded fieldname: ${fieldname}; filename: ${filename}, mimeType: ${mimeType}`);
uploads.push(S3.svc.upload({ Bucket: 'my-test-bucket', Key: filename, Body: stream }).promise());
});
bb.on('finish', () => {
console.log("# of promises:", uploads.length);
Promise.all(uploads).then(retVals => {
for (let i = 0; retVals && i < retVals.length; i++) {
console.log(`File ${i + 1}::`, retVals[i]);
}
res.end();
}).catch(err => {
console.log("Error::", err);
res.status(500).send(`${err.name}: ${err.message}`);
});
});
req.pipe(bb);
});
module.exports = router;
var express=require('express');
var-Busboy=需要(“Busboy”);
var S3=require('../utils/s3Util');
var router=express.router();//装载/上传
router.post(“/”,函数(请求、恢复、下一步){
设bb=new-Busboy({headers:req.headers});
const uploads=[];
bb.on('file',(字段名、流、文件名、编码、mimeType)=>{
log(`upload fieldname:${fieldname};filename:${filename},mimeType:${mimeType}`);
uploads.push(S3.svc.upload({Bucket:'my test Bucket',Key:filename,Body:stream}).promise());
});
bb.on('finish',()=>{
console.log(“#of promises:”,uploads.length);
Promise.all(上传)。然后(retVals=>{
对于(设i=0;retVals&&i{
log(“错误::”,err);
res.status(500).send(`${err.name}:${err.message}`);
});
});
所需管道(bb);
});
module.exports=路由器;
在一般失败的情况下,如何处理上载1个或多个x文件失败的情况?有些上传会成功,有些会失败。然而,在catch
子句中,我不知道哪些失败了
最好能使这个上传过程有点事务性(即,要么所有上传成功,要么没有成功)。当出现错误时,理想情况下我能够“回滚”成功上载的子集。您可以这样做: 将一个对象推送到上载中,其中包含需要重试的数据,因此:
uploads.push({
fieldname,
filename,
mimeType,
uploaded: S3.svc.upload({ Bucket: 'my-test-bucket', Key: filename, Body: stream })
.promise()
.then(() => true)
.catch(() => false)
});
...
const failed = await
(Promise.all(uploads.map(async upload => ({...upload, uploaded: await upload.uploaded})))).then(u => u.filter(upload => !upload.uploaded))
const failedFiles = failed.join(', ')
console.log(`The following files failed to upload: ${failedFiles}`);
您需要使事件处理程序async
在它们内部使用wait
,例如:
bb.on('file', async (fieldname, stream, filename, encoding, mimeType) => {
你可以这样做: 将一个对象推送到上载中,其中包含需要重试的数据,因此:
uploads.push({
fieldname,
filename,
mimeType,
uploaded: S3.svc.upload({ Bucket: 'my-test-bucket', Key: filename, Body: stream })
.promise()
.then(() => true)
.catch(() => false)
});
...
const failed = await
(Promise.all(uploads.map(async upload => ({...upload, uploaded: await upload.uploaded})))).then(u => u.filter(upload => !upload.uploaded))
const failedFiles = failed.join(', ')
console.log(`The following files failed to upload: ${failedFiles}`);
您需要使事件处理程序async
在它们内部使用wait
,例如:
bb.on('file', async (fieldname, stream, filename, encoding, mimeType) => {
我最后使用了以下代码,这是@JoshWulf答案的扩展:
function handleUpload(req, res, bucket, key) {
let bb = new Busboy({ headers: req.headers });
const uploads = [];
bb.on('file', (fieldname, stream, filename, encoding, mimeType) => {
console.log(`Uploaded fieldname: ${fieldname}; filename: ${filename}, mimeType: ${mimeType}`);
const params = { Bucket: bucket, Key: key, Body: stream, ContentType: mimeType };
uploads.push({ filename, result: S3.svc.upload(params).promise().then(data => data).catch(err => err) });
});
bb.on('finish', async () => {
const results = await Promise.all(uploads.map(async (upload) => ({ ...upload, result: await upload.result })));
// handle success/failure with their respective objects
});
req.pipe(bb);
}
这里与@answer的区别在于,在我的上传承诺中,我将按原样返回返回返回的数据对象(如果成功)和返回的错误对象(如果失败)。这使我以后可以根据需要使用它们。我最终使用了以下代码,这是@JoshWulf答案的扩展:
function handleUpload(req, res, bucket, key) {
let bb = new Busboy({ headers: req.headers });
const uploads = [];
bb.on('file', (fieldname, stream, filename, encoding, mimeType) => {
console.log(`Uploaded fieldname: ${fieldname}; filename: ${filename}, mimeType: ${mimeType}`);
const params = { Bucket: bucket, Key: key, Body: stream, ContentType: mimeType };
uploads.push({ filename, result: S3.svc.upload(params).promise().then(data => data).catch(err => err) });
});
bb.on('finish', async () => {
const results = await Promise.all(uploads.map(async (upload) => ({ ...upload, result: await upload.result })));
// handle success/failure with their respective objects
});
req.pipe(bb);
}
这里与@answer的区别在于,在我的上传承诺中,我将按原样返回返回返回的数据对象(如果成功)和返回的错误对象(如果失败)。这使我以后可以根据需要使用它们。非常有趣的解决方案,谢谢!
文件
事件的处理程序的签名不是由busboy
模块指定的吗(我对Javascript还很陌生,不确定这一点)?看:真实的故事,没有想到这一点-这不是你的API,所以你必须用它!非常有趣的解决方案,谢谢!文件
事件的处理程序的签名不是由busboy
模块指定的吗(我对Javascript还很陌生,不确定这一点)?看:真实的故事,没有想到这一点-这不是你的API,所以你必须用它!很好的解决方案!干得好。这将有助于未来的人。很好的解决方案!干得好。这将在将来帮助某人。