Can't add same torrent twice

[zella]

What version of WebTorrent?
v0.104.0

What operating system and Node.js version?
ubuntu 16, node v12.2.0

What did you expect to happen?

'torrent' callback should call 2 times, when I add torrent -> remove it -> add same torrent

What actually happened?

'torrent' callback calls 1 times

Code

const WebTorrent = require('webtorrent');

const client = new WebTorrent();

client.add("08ada5a7a6183aae1e09d831df6748d566095a10");

client.on('torrent', function (torrent) {
    torrent.deselect(0, torrent.pieces.length - 1, false);
    console.log("Torrent ready");
});

setTimeout(function () {
    client.remove('08ada5a7a6183aae1e09d831df6748d566095a10');
}, 5000);

setTimeout(function () {
    client.add("08ada5a7a6183aae1e09d831df6748d566095a10");
}, 10000);

But, when I change values from 5000 to 2000, 10000 to 4000, torrent callback calls twice as expected. Always reproduced on my machine.

[SilentBot1]

Hi @zella

I'm using WebTorrent version 0.105.0 and NodeJS version 10.16.0 on Windows 10 1903 and have ran the example code provided and have been able to replicate the issue.

The torrent event only fires once the metadata for the torrent has been determined and downloaded, it would be expected that lower values leaves the possibility for the metadata to not be downloaded before being deleted, causing the event to not be fired but not the opposite way around as you've described.

Could you please run the following example code and provide me the results?

var Webtorrent = require('webtorrent')
var client = new Webtorrent()

client.on('torrent', (torrent)=>{
    console.log(`Torrent ${torrent.infoHash} has been added!`)
})

setTimeout(()=>{
    var torrent = client.add('magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F')
    torrent.on('ready', ()=>{
        torrent.deselect(0, (torrent.pieces.length-1), 0)
        console.log("Torrent 1 ready!")
    })
}, 0)

setTimeout(()=>{
    client.torrents[0].destroy()
    console.log("Torrent 1 destroyed!")
}, 2000)

setTimeout(()=>{
    var torrent = client.add('magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel&tr=udp%3A%2F%2Fexplodie.org%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.empire-js.us%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.opentrackr.org%3A1337&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.fastcast.nz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&ws=https%3A%2F%2Fwebtorrent.io%2Ftorrents%2F')
    torrent.on('ready', ()=>{
        torrent.deselect(0, (torrent.pieces.length-1), 0)
        console.log("Torrent 2 ready!")
    })
}, 3000)

setTimeout(()=>{
    client.torrents[0].destroy()
    console.log("Torrent 2 destroyed!")
}, 5000)

Kind regards
Brad

[zella]

@SilentBot1 Hi. Stable result (0.104.0, 0.105.0):

Torrent 08ada5a7a6183aae1e09d831df6748d566095a10 has been added!
Torrent 1 ready!
Torrent 1 destroyed!
Torrent 08ada5a7a6183aae1e09d831df6748d566095a10 has been added!
Torrent 2 ready!
Torrent 2 destroyed!

[SilentBot1]

Hi @zella

It sounds like in your example WebTorrent was verifying a previous download of the infohash provided in the example code you provided.

Additionally, you call client.add before you add the `client.on('torrent' callback meaning the first torrent you add won't have all it's pieces deselected, meaning for the first 5 seconds, the torrent is downloading.

I would try clearing your WebTorrent temp folder and trying your example again after updating the code.

Hope this helps!

[feross]

Using setTimeout in this way is bound to be unreliable. You should not attempt to remove a torrent until the torrent's 'metadata' event fires, or the client's 'torrent' event fires.