CODEWITHSUNDEEP
javascriptnode.jsdownloadstream
user779159
user779159

Reputation: 9602

NodeJS get a count of bytes of streaming file download

In this code I stream a file from a url and save it to a file. Is there a way to also pipe it through something that will count the number of bytes piped? (Which would tell me the file size.)

  request.stream(url)
    .pipe(outputFile)

Is there some library that would do this by piping the download through it, or a simple way for me to do it myself?

Upvotes: 7

Views: 15444

Answers (2)

zemil
zemil

Reputation: 5066

With typings and byteLength property:

const stream: ReadStream = file.createReadStream(); 
const chunks: Buffer[] = [];
let fileSize = 0;

stream.on('data', (chunk: Buffer) => {
  fileSize += chunk.byteLength;

  chunks.push(chunk);
});

stream.once('end', () => {
  const fileBuffer = Buffer.concat(chunks);

  console.log('equal values:', fileBuffer.byteLength === fileSize);
});

Upvotes: 2

Dan Cantir
Dan Cantir

Reputation: 2955

You can do it like this with request library:

const request = require('request');
const fs = require('fs');

var downloaded = 0;
request.get(url)
  .on('data', function(chunk){
    downloaded += chunk.length;
    console.log('downloaded', downloaded);
  })
  .pipe(fs.createWriteStream(fileName));

Also, you can check this link to learn how to do it without request package.

Update #1 (Pure NodeJS solution)

var http = require('http');
var fs = require('fs');

var download = function(url, dest, cb) {
  var file = fs.createWriteStream(dest);
  var downloaded = 0;
  var request = http.get(url, function(response) {
    response.pipe(file);
    response.on('data', function(chunk){
      downloaded += chunk.length;
      console.log(downloaded);
    })
    file.on('finish', function() {
      file.close(cb);
    });
  });
}

Upvotes: 15

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