en.javascript.info/5-network/09-resume-upload/upload-resume.view/server.js
2019-11-02 19:37:24 +03:00

123 lines
3 KiB
JavaScript

let http = require('http');
let static = require('node-static');
let fileServer = new static.Server('.');
let path = require('path');
let fs = require('fs');
let debug = require('debug')('example:resume-upload');
let uploads = Object.create(null);
function onUpload(req, res) {
let fileId = req.headers['x-file-id'];
let startByte = +req.headers['x-start-byte'];
if (!fileId) {
res.writeHead(400, "No file id");
res.end();
}
// we'll files "nowhere"
let filePath = '/dev/null';
// could use a real path instead, e.g.
// let filePath = path.join('/tmp', fileId);
debug("onUpload fileId: ", fileId);
// initialize a new upload
if (!uploads[fileId]) uploads[fileId] = {};
let upload = uploads[fileId];
debug("bytesReceived:" + upload.bytesReceived + " startByte:" + startByte)
let fileStream;
// if startByte is 0 or not set, create a new file, otherwise check the size and append to existing one
if (!startByte) {
upload.bytesReceived = 0;
fileStream = fs.createWriteStream(filePath, {
flags: 'w'
});
debug("New file created: " + filePath);
} else {
// we can check on-disk file size as well to be sure
if (upload.bytesReceived != startByte) {
res.writeHead(400, "Wrong start byte");
res.end(upload.bytesReceived);
return;
}
// append to existing file
fileStream = fs.createWriteStream(filePath, {
flags: 'a'
});
debug("File reopened: " + filePath);
}
req.on('data', function(data) {
debug("bytes received", upload.bytesReceived);
upload.bytesReceived += data.length;
});
// send request body to file
req.pipe(fileStream);
// when the request is finished, and all its data is written
fileStream.on('close', function() {
if (upload.bytesReceived == req.headers['x-file-size']) {
debug("Upload finished");
delete uploads[fileId];
// can do something else with the uploaded file here
res.end("Success " + upload.bytesReceived);
} else {
// connection lost, we leave the unfinished file around
debug("File unfinished, stopped at " + upload.bytesReceived);
res.end();
}
});
// in case of I/O error - finish the request
fileStream.on('error', function(err) {
debug("fileStream error");
res.writeHead(500, "File error");
res.end();
});
}
function onStatus(req, res) {
let fileId = req.headers['x-file-id'];
let upload = uploads[fileId];
debug("onStatus fileId:", fileId, " upload:", upload);
if (!upload) {
res.end("0")
} else {
res.end(String(upload.bytesReceived));
}
}
function accept(req, res) {
if (req.url == '/status') {
onStatus(req, res);
} else if (req.url == '/upload' && req.method == 'POST') {
onUpload(req, res);
} else {
fileServer.serve(req, res);
}
}
// -----------------------------------
if (!module.parent) {
http.createServer(accept).listen(8080);
console.log('Server listening at port 8080');
} else {
exports.accept = accept;
}