gulp-download-2

Heavily derived from gulp-download-stream and gulp-download

A tiny hyperquest gulp wrapper to download files over HTTP/HTTPS/FTP/FTPS + following redirects.

Features

• Progress bar
• Concurrent downloads without busy-waiting
• Redirect support (up to 10 hops)
• ftp(s):// support

Here's a nice example:

Downloading http://ipv4.download.thinkbroadband.com/512MB.zip...
  downloading [====================] 205491/bps 100% 0.0s
Done

  downloading [====================] 358297/bps 100% 0.0s
Done

  downloading [====================] 2664869/bps 100% 0.0s
Done

  downloading [=======-------------] 2126399/bps 33% 65.9s
Done

Problem

Other gulp download plugins buffer file contents in full before flushing to disk. gulp-download2 bypasses extra buffering by directly writing chunks to disk.

Solution

gulp-download2 avoids unnecessary and connection pooling.

Benchmarks: gulp-download vs. gulp-download2

In gulp-download2 we saw an average increase of CPU utilization by 31% whereas gulp-download writes the file content to a buffer and writes to the disk. This process is not as labor intensive as system calls:

gulp-download2	gulp-download

Looking at the memory consumption in gulp-download2 shows a max memory consumption of 262 MB whereas gulp-download buffers the content into memory leading to a steady increase:

gulp-download2	gulp-download

Note: Profiling done with Syrupy.py and v8-profile.

Installation

npm install gulp-download2 --save-dev # or to use yarn...
yarn add gulp-download2 --dev

Basic Usage

const gulp = require('gulp');
const download = require('gulp-download2');

gulp.task('download', () => download('http://example.com/file.jpg').pipe(gulp.dest('build')));

Download Multiple Files

To download multiple files, pass an array of strings to download.

gulp.task('download', function () {
    return download(['http://example.com/file.a', 'https://example.com/file.b']).pipe(
        gulp.dest('build')
    );
});

The files are downloaded concurrently into stream of Vinyl files, and so are suitable to be piped into other gulp plugins. Each Vinyl file is also itself a stream, and so any downstream plugins must also support stream-based Vinyl files.

Specify Local File Name

You can specify the local file names of files downloaded. You can do this for one file:

gulp.task('download', function () {
    return download({
        url: 'http://example.com/file.txt',
        file: 'foo.txt',
    }).pipe(gulp.dest('build'));
});

or for multiple files:

gulp.task('download', function () {
    const files = [
        {
            url: 'http://example.com/file.txt',
            file: 'foo.txt',
        },
        {
            url: 'http://example.com/file2.csv',
            file: 'data.csv',
        },
    ];

    return download(files).pipe(gulp.dest('build'));
});

Handling Errors

There are two different kinds of errors that can arise when we attempt to download from a remote resource:

1. Hyperquest encounters an error with the stream
   • Sends event object as a callback parameter
2. Hyperquest returns an error status code (i.e. 404)
   • res.statusCode is passed as a callback parameter

In either case, we can handle these by providing an error callback in our gulp task:

gulp.task('download', function () {
    return download('http://foo.com/sample.txt', {
        errorCallback: function (code) {
            if (code === 404) {
                console.error('Un oh, something bad happened!');
                doSomethingElse();
            } else if (code === 500) {
                console.error('Fatal exception :(');
                process.exit(1);
            }
        },
    });
});

Pass Options to Hyperquest

You can pass options to request as the second argument. For example, you can request using HTTP authentication:

gulp.task('download', function () {
    const config = {
        auth: {
            user: 'john_doe',
            pass: '123_secret',
        },
    };

    return download(
        {
            url: 'http://example.com/file.txt',
            file: 'foo.txt',
        },
        config
    ).pipe(gulp.dest('build'));
});

See hyperquest options for more details.

Options