thedesk/app/node_modules/progress-stream/README.md

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2019-09-13 00:38:13 +10:00
# progress-stream
Read the progress of a stream. Supports speed and eta.
Gets the lengths of the stream automatically if you're using the request or http module. You can also pass the length on initiation. Progress-stream will also check to see if the stream already have a length property.
npm install progress-stream
## Usage
This example copies a large file, and prints out the percentage, speed and remaining every 100ms.
```js
var progress = require('progress-stream');
var fs = require('fs');
var stat = fs.statSync(filename);
var str = progress({
length: stat.size,
time: 100
});
str.on('progress', function(progress) {
console.log(progress);
/*
{
percentage: 9.05,
transferred: 949624,
length: 10485760,
remaining: 9536136,
eta: 42,
runtime: 3,
delta: 295396,
speed: 949624
}
*/
});
fs.createReadStream(filename)
.pipe(str)
.pipe(fs.createWriteStream(output));
```
## Methods
### progress([options], [onprogress])
You can instantiate in two ways:
``` js
var str = progress({time:100});
str.on('progress', function(progress) { ... });
```
or inline the progress listener
``` js
var str = progress({time:100}, function(progress) { ... });
```
## Properties
### .progress
You can get the progress from the progress property.
``` js
var str = progress({time:100});
console.log(str.progress);
/*
{
percentage: 9.05,
transferred: 949624,
length: 10485760,
remaining: 9536136,
eta: 10,
runtime: 0,
delta: 295396,
speed: 949624
}
*/
```
## Events
### on('progress', function(progress) { ... })
``` js
var str = progress({time:100});
str.on('progress', function(progress) { ... });
```
## Options
### time(integer)
Sets how often progress events is emitted. If omitted then defaults to emit every time a chunk is received.
### speed(integer)
Sets how long the speedometer needs to calculate the speed. Defaults to 5 sec.
### length(integer)
If you already know the length of the stream, then you can set it. Defaults to 0.
### drain(boolean)
In case you don't want to include a readstream after progress-stream, set to true to drain automatically. Defaults to false.
### transferred(integer)
If you want to set how much data have previous been downloaded. Useful for a resumed download.
## Examples
### Using the request module
This example uses request to download a 100 MB file, and writes out the percentage every second.
You can also find an example in `test/request.js`.
``` js
var progress = require('progress-stream');
var req = require('request');
var fs = require('fs');
var str = progress({
time: 1000
});
str.on('progress', function(progress) {
console.log(Math.round(progress.percentage)+'%');
});
req('http://cachefly.cachefly.net/100mb.test', { headers: { 'user-agent': 'test' }})
.pipe(str)
.pipe(fs.createWriteStream('test.data'));
```
### Using the http module
In `test/http.js` it's shown how to do it with the http module.
## Methods
### `setLength(newLength)`
Sometimes, you don't know how big a stream is right away (e.g. multipart file uploads). You might find out after a few chunks have already passed through the stream, seconds or even minutes later. In this case, you can use the `setLength` method to recalculate the relevant tracked progress data.
```js
var str = progress({});
someFickleStreamInstance.pipe(str).pipe(fs.createWriteStream('test.data'));
someFickleStreamInstance.on('conviction', function nowIKnowMyLength (actualLength) {
str.setLength(actualLength);
});
```