LeDown

$3


A library for nodejs to download http large file in pauseable and resumable way

Prerequisite

Node >= 8.0

Usage

$3

``js
var Task = require('ledown').Task
Task.create({
url: 'url',
downloadPath: 'path'
}).then(function(task) {
task.on('progress', function(){
console.log(task.progress)
})
task.on('error', function(err) {
console.log(err)
})
task.on('end', function() {
console.log('end')
})
task.start()
})
`


$3


`js
import { Task } from 'ledown'
await task = Task.create({
url: 'url',
downloadPath: 'path'
})

task.on('progress', () => {
console.log(task.progress)
})
task.on('error',err => {
console.log(err)
})
task.on('end', () => {
console.log('end')
})
task.start()

setTimeout(() => {
if(task.progress !== 1) {
task.stop()
.then(() => {
task.storeToFile(path.join(__dirname, './task.config'))
})
}
}, 1000)
`

Documentation

$3

Static method on Task class for creating a new download task.

`ts
type TaskOptions = {
url: string
referUrl?: string
downloadDir?: string
downloadPath: string
} | {
url: string
referUrl?: string
downloadDir: string
downloadPath?: string
}
`

You have to specify whether the downloadDir or downloadPath. If you just specify the downloadDir, a random name will be used.

Task.create use HTTP HEAD method to get metadata of the resource. If server respond an error, the returned promise will be rejected.

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Restore task from previous task config file. If ether the specified config file or the previous unfinished downloading file not exists, the returned promise will be rejected.

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+ Task.ERROR.ERR_NO_METADATA
+ Task.ERROR.ERR_DISK_IO_WRITE
+ Task.ERROR.ERR_NETWORK

`js
task.on('error', (e) => {
if(e.message === Task.ERROR.ERR_DISK_IO_WRITE) {
// write disk error
} else if(e.message === Task.ERROR.ERR_NETWORK) {
// download resource error
}
})
`

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Store a task config to specified path. IO error will cause the returned promise to be rejected. This method will not stop the task. You could call task.stop() as needed.

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Start the task. If you specify the numOfThread` argument, it will concurrently start multiple http request.

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Stop the task. We could not stop the task immediately, since we have no method to suspend write task.

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Events that may triggered:

+ on('error')
+ on('progress')
+ on('end')

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Remove the listener of the specific event.

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Progress of the task. When the task complete, task.progress is 1.

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The structure of task.metadata is:

+ url: string
+ createDate: Date
+ mimeType: string
+ downloadPath: string
+ totalBytes: number
+ resumable: boolean

LICENSE

MIT

Copyright (c) 2017-present, Xiaole (Will) Liu