feat(downloading): save download session support

src/background/api.js

@@ -576,7 +576,7 @@ module.exports = async ({
 			callback(true)
 	});
 
-	recive('download', (torrentObject) =>
+	torrentClient._add = (torrentObject, savePath) =>
 	{
 		const magnet = `magnet:?xt=urn:btih:${torrentObject.hash}`
 		console.log('download', magnet)
@@ -585,12 +585,12 @@ module.exports = async ({
 			return
 		}
 
-		const torrent = torrentClient.add(magnet, {path: config.client.downloadPath})
+		const torrent = torrentClient.add(magnet, {path: savePath || config.client.downloadPath})
 		torrentClientHashMap[torrent.infoHash] = magnet
 		torrent.torrentObject = torrentObject
 
 		torrent.on('ready', () => {
-			console.log('start downloading', torrent.infoHash)
+			console.log('start downloading', torrent.infoHash, 'to', torrent.path)
 			send('downloading', torrent.infoHash)
 		})
 
@@ -614,7 +614,9 @@ module.exports = async ({
 				timeRemaining: torrent.timeRemaining
 			})
 		})
-	});
+	}
+
+	recive('download', torrentClient._add);
 
 	recive('downloadCancel', (hash, callback) =>
 	{

src/background/spider.js

@@ -771,12 +771,20 @@ setInterval(() => {
 			quotaDebug('disk quota enabled');
 		}
 
+		// load torrents sessions
+		console.log('restore downloading sessions')
+		torrentClient.loadSession(dataDirectory + '/downloads.json')
+
 		this.stop = async (callback) => {
 			this.closing = true
 			console.log('spider closing...')
 			if(upnp)
 				upnp.ratsUnmap()
 
+			// save torrents sessions
+			console.log('save torrents downloads sessions')
+			torrentClient.saveSession(dataDirectory + '/downloads.json')
+
 			// save feed
 			await feed.save()
     

src/background/torrentClient.js

@@ -1,3 +1,44 @@
 const WebTorrent = require('webtorrent')
-let torrentClient = new WebTorrent({webSeeds: false})
+const fs = require('fs')
+
+const torrentClient = new WebTorrent({webSeeds: false})
+torrentClient.saveSession = (sessionFile) => {
+	fs.writeFileSync(sessionFile, JSON.stringify({
+        torrents: torrentClient.torrents.map(torrent => ({
+            infoHash: torrent.infoHash,
+            path: torrent.path,
+            torrent: torrent.torrentObject
+        }))
+    }, null, 4), 'utf8');
+}
+torrentClient.loadSession = (sessionFile) => {
+    if(!fs.existsSync(sessionFile))
+	{
+        console.log('no download sessions - ignore')
+        return
+    }
+
+	const data = fs.readFileSync(sessionFile, 'utf8')
+    const obj = JSON.parse(data);
+    if(!obj.torrents)
+    {
+        console.log('no torrents list for loading session')
+        return
+    }
+    if(!torrentClient._add)
+    {
+        console.log('no overriden _add() method')
+        return
+    }
+    const {torrents} = obj
+    torrents.forEach(({torrent, infoHash, path}) => {
+        if(!torrent || !infoHash || !path)
+        {
+            console.log('no info for starting download this torrent')
+            return
+        }
+        console.log('restore download session:', torrent.name)
+        torrentClient._add(torrent, path)
+    })
+}
 module.exports = torrentClient