blob: fb16fc10e0dca7d8d208898ad857facc3f42d3bc (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
# DIY Dat
This document shows how to write your own compatible `dat` client using node modules.
The three essential node modules are called [hyperdrive](https://npmjs.org/hyperdrive), [hyperdrive-archive-swarm](https://npmjs.org/hyperdrive-archive-swarm) and [level](https://npmjs.org/level). Hyperdrive does file synchronization and versioning, hyperdrive-archive-swarm does peer discovery over local networks and the Internet, and level provides a local LevelDB for storing metadata. More details are available in [How Dat Works](how-dat-works.md). The [dat](https://npmjs.org/dat) module itself is just some code that combines these modules and wraps them in a command-line API.
Here's the minimal code needed to download data from a dat:
```js
// run this like: node thisfile.js 4c325f7874b4070blahblahetc
// the dat link someone sent us, we want to download the data from it
var link = new Buffer(process.argv[2], 'hex')
var Hyperdrive = require('hyperdrive')
var Swarm = require('hyperdrive-archive-swarm')
var level = require('level')
var raf = require('random-access-file')
var each = require('stream-each')
var db = level('./dat.db')
var drive = Hyperdrive(db)
var archive = drive.createArchive(link, {
file: function (name) {
return raf(path.join(self.dir, name))
}
})
var swarm = Swarm(archive)
archive.open(function (err) {
if (err) return console.error(err)
each(archive.list({live: archive.live}), function (data, next) {
var startBytes = self.stats.bytesDown
archive.download(data, function (err) {
if (err) return console.error(err)
console.log('file downloaded', data.relname)
next()
})
}, done)
})
```
|