request-progress

2018-09-24 admin

request-progress是什么

什么是request-progress,Tracks the download progress of a request made with mikeal/request, giving insight of various metrics including progress percent, download speed and time remaining

request-progress使用教程帮助文档

request-progress

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Tracks the download progress of a request made with request, giving insight of various metrics including progress percentage, download speed and time remaining.

Installation

$ npm install request-progress

Usage

var fs = require('fs');
var request = require('request');
var progress = require('request-progress');

// The options argument is optional so you can omit it
progress(request('https://az412801.vo.msecnd.net/vhd/VMBuild_20141027/VirtualBox/IE11/Windows/IE11.Win8.1.For.Windows.VirtualBox.zip'), {
    // throttle: 2000,                    // Throttle the progress event to 2000ms, defaults to 1000ms
    // delay: 1000,                       // Only start to emit after 1000ms delay, defaults to 0ms
    // lengthHeader: 'x-transfer-length'  // Length header to use, defaults to content-length
})
.on('progress', function (state) {
    // The state is an object that looks like this:
    // {
    //     percent: 0.5,               // Overall percent (between 0 to 1)
    //     speed: 554732,              // The download speed in bytes/sec
    //     size: {
    //         total: 90044871,        // The total payload size in bytes
    //         transferred: 27610959   // The transferred payload size in bytes
    //     },
    //     time: {
    //         elapsed: 36.235,        // The total elapsed seconds since the start (3 decimals)
    //         remaining: 81.403       // The remaining seconds to finish (3 decimals)
    //     }
    // }
    console.log('progress', state);
})
.on('error', function (err) {
    // Do something with err
})
.on('end', function () {
    // Do something after request finishes
})
.pipe(fs.createWriteStream('IE11.Win8.1.For.Windows.VirtualBox.zip'));

If the request’s response does not include the content-length header, the values of some metrics will be null. Also speed and time.remaining will be null until it can be calculated.

The state object emitted in the progress event is reused to avoid creating a new object for each event. If you wish to peek the state object at any time, it is available in request.progressState.

Tests

$ npm test $ npm test-cov to get coverage report

License

Released under the MIT License.

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