Increase WebRTC file transfer speed by implementing the bufferamountlow event properly

.github/ISSUE_TEMPLATE/bug-report.md

@@ -36,7 +36,7 @@ If applicable, add screenshots to help explain your problem.
 
 **Bug occurs on official PairDrop instance https://pairdrop.net/**
 No | Yes
-Version: v1.9.0
+Version: v1.9.1
 
 **Bug occurs on self-hosted PairDrop instance**
 No | Yes
@@ -44,7 +44,7 @@ No | Yes
 **Self-Hosted Setup**
 Proxy: Nginx | Apache2
 Deployment: docker run | docker-compose | npm run start:prod
-Version: v1.9.0
+Version: v1.9.1
 
 **Additional context**
 Add any other context about the problem here.

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "pairdrop",
-  "version": "1.9.0",
+  "version": "1.9.1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "pairdrop",
-      "version": "1.9.0",
+      "version": "1.9.1",
       "license": "ISC",
       "dependencies": {
         "express": "^4.18.2",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pairdrop",
-  "version": "1.9.0",
+  "version": "1.9.1",
   "description": "",
   "main": "index.js",
   "scripts": {

public/index.html

@@ -480,7 +480,7 @@
             </svg>
             <div class="title-wrapper" dir="ltr">
                 <h1>PairDrop</h1>
-                <div class="font-subheading">v1.9.0</div>
+                <div class="font-subheading">v1.9.1</div>
             </div>
             <div class="font-subheading" data-i18n-key="about.claim" data-i18n-attrs="text"></div>
             <div class="row">

public/scripts/network.js

@@ -37,7 +37,7 @@ class ServerConnection {
 
     _connect() {
         clearTimeout(this._reconnectTimer);
-        if (this._isConnected() || this._isConnecting()) return;
+        if (this._isConnected() || this._isConnecting() || this._isOffline()) return;
         if (this._isReconnect) {
             Events.fire('notify-user', {
                 message: Localization.getTranslation("notifications.connecting"),
@@ -246,6 +246,10 @@ class ServerConnection {
         return this._socket && this._socket.readyState === this._socket.CONNECTING;
     }
 
+    _isOffline() {
+        return !navigator.onLine;
+    }
+
     _onError(e) {
         console.error(e);
     }
@@ -266,6 +270,9 @@ class Peer {
         this._roomIds = {};
         this._updateRoomIds(roomType, roomId);
 
+        this._chunkSize = 262144;
+        this._lowWaterMark = 2* this._chunkSize;
+
         this._filesQueue = [];
         this._busy = false;
 
@@ -444,22 +451,9 @@ class Peer {
             mime: file.type
         });
         this._chunker = new FileChunker(file,
-            chunk => this._send(chunk),
+            this._chunkSize,
-            offset => this._onPartitionEnd(offset));
+            chunk => this._send(chunk));
-        this._chunker.nextPartition();
+        this._chunker._readChunksIntoBuffer(this._channel ? this._channel.bufferedAmount : 0);
-    }
-
-    _onPartitionEnd(offset) {
-        this.sendJSON({ type: 'partition', offset: offset });
-    }
-
-    _onReceivedPartitionEnd(offset) {
-        this.sendJSON({ type: 'partition-received', offset: offset });
-    }
-
-    _sendNextPartition() {
-        if (!this._chunker || this._chunker.isFileEnd()) return;
-        this._chunker.nextPartition();
     }
 
     _sendProgress(progress) {
@@ -479,12 +473,6 @@ class Peer {
             case 'header':
                 this._onFileHeader(messageJSON);
                 break;
-            case 'partition':
-                this._onReceivedPartitionEnd(messageJSON);
-                break;
-            case 'partition-received':
-                this._sendNextPartition();
-                break;
             case 'progress':
                 this._onDownloadProgress(messageJSON.progress);
                 break;
@@ -492,7 +480,7 @@ class Peer {
                 this._onFileTransferRequestResponded(messageJSON);
                 break;
             case 'file-transfer-complete':
-                this._onFileTransferCompleted();
+                this._onFileTransferCompleted(messageJSON);
                 break;
             case 'message-transfer-complete':
                 this._onMessageTransferCompleted();
@@ -548,6 +536,7 @@ class Peer {
     _onFileHeader(header) {
         if (this._requestAccepted && this._requestAccepted.header.length) {
             this._lastProgress = 0;
+            this._timeStart = Date.now();
             this._digester = new FileDigester({size: header.size, name: header.name, mime: header.mime},
                 this._requestAccepted.totalSize,
                 this._totalBytesReceived,
@@ -567,7 +556,6 @@ class Peer {
 
     _onChunkReceived(chunk) {
         if(!this._digester || !(chunk.byteLength || chunk.size)) return;
-
         this._digester.unchunk(chunk);
         const progress = this._digester.progress;
 
@@ -591,7 +579,13 @@ class Peer {
         const acceptedHeader = this._requestAccepted.header.shift();
         this._totalBytesReceived += fileBlob.size;
 
-        this.sendJSON({type: 'file-transfer-complete'});
+        let duration = (Date.now() - this._timeStart) / 1000;
+        let size = Math.round(10 * fileBlob.size / 1000000) / 10;
+        let speed = Math.round(100 * fileBlob.size / 1000000 / duration) / 100;
+
+        console.log(`File received.\n\nSize: ${size} MB\tDuration: ${duration} s\tSpeed: ${speed} MB/s`);
+
+        this.sendJSON({type: 'file-transfer-complete', size: size, duration: duration, speed: speed});
 
         const sameSize = fileBlob.size === acceptedHeader.size;
         const sameName = fileBlob.name === acceptedHeader.name
@@ -612,8 +606,10 @@ class Peer {
         }
     }
 
-    _onFileTransferCompleted() {
+    _onFileTransferCompleted(message) {
-        this._chunker = null;
+        console.log(`File sent.\n\nSize: ${message.size} MB\tDuration: ${message.duration} s\tSpeed: ${message.speed} MB/s`);
+
+
         if (!this._filesQueue.length) {
             this._busy = false;
             Events.fire('notify-user', Localization.getTranslation("notifications.file-transfer-completed"));
@@ -621,6 +617,8 @@ class Peer {
         } else {
             this._dequeueFile();
         }
+        this._chunker._removeEventListener();
+        this._chunker = null;
     }
 
     _onFileTransferRequestResponded(message) {
@@ -698,8 +696,7 @@ class RTCPeer extends Peer {
         if (!this._conn) return;
 
         const channel = this._conn.createDataChannel('data-channel', {
-            ordered: true,
+            ordered: false,
-            reliable: true // Obsolete. See https://developer.mozilla.org/en-US/docs/Web/API/RTCDataChannel/reliable
         });
         channel.onopen = e => this._onChannelOpened(e);
         channel.onerror = e => this._onError(e);
@@ -745,7 +742,15 @@ class RTCPeer extends Peer {
         channel.binaryType = 'arraybuffer';
         channel.onmessage = e => this._onMessage(e.data);
         channel.onclose = _ => this._onChannelClosed();
+
+        this._chunkSize = Math.min(this._conn.sctp.maxMessageSize, 262144); // max chunk size: 256 KB
+        this._lowWaterMark = 2 * this._chunkSize;
+
+        channel.bufferedAmountLowThreshold = this._lowWaterMark;
+        channel.onbufferedamountlow = () => Events.fire("bufferedamountlow", channel.bufferedAmount);
+
         this._channel = channel;
+
         Events.on('beforeunload', e => this._onBeforeUnload(e));
         Events.on('pagehide', _ => this._onPageHide());
         Events.fire('peer-connected', {peerId: this._peerId, connectionHash: this.getConnectionHash()});
@@ -1091,51 +1096,56 @@ class PeersManager {
 
 class FileChunker {
 
-    constructor(file, onChunk, onPartitionEnd) {
+    constructor(file, chunkSize, onChunk) {
-        this._chunkSize = 64000; // 64 KB
-        this._maxPartitionSize = 1e6; // 1 MB
-        this._offset = 0;
-        this._partitionSize = 0;
         this._file = file;
+        this._chunkSize = chunkSize;
+        this._highWaterMark = 8 * chunkSize;
+        this._bytesToSend = file.size;
+        this._sendProgress = 0;
+
         this._onChunk = onChunk;
-        this._onPartitionEnd = onPartitionEnd;
+
         this._reader = new FileReader();
+
+        this._reader.addEventListener('error', err => console.error('Error reading file:', err));
+        this._reader.addEventListener('abort', e => console.log('File reading aborted:', e));
         this._reader.addEventListener('load', e => this._onChunkRead(e.target.result));
+
+        this.bufferedAmountCallback = e => this._readChunksIntoBuffer(e.detail);
+
+        Events.on('bufferedamountlow', this.bufferedAmountCallback);
     }
 
-    nextPartition() {
+    _removeEventListener() {
-        this._partitionSize = 0;
+        Events.off('bufferedamountlow', this.bufferedAmountCallback);
+    }
+
+    _readChunksIntoBuffer(bufferedAmount) {
+        this._bufferedAmount = bufferedAmount;
         this._readChunk();
     }
 
     _readChunk() {
-        const chunk = this._file.slice(this._offset, this._offset + this._chunkSize);
+        const chunk = this._file.slice(this._sendProgress, this._sendProgress + this._chunkSize);
         this._reader.readAsArrayBuffer(chunk);
     }
 
     _onChunkRead(chunk) {
-        this._offset += chunk.byteLength;
-        this._partitionSize += chunk.byteLength;
         this._onChunk(chunk);
-        if (this.isFileEnd()) return;
+        this._bufferedAmount += this._chunkSize;
-        if (this._isPartitionEnd()) {
+        this._sendProgress += this._chunkSize;
-            this._onPartitionEnd(this._offset);
+
-            return;
+        if (this._isBufferFull() || this._isFileEnd()) return;
-        }
+
         this._readChunk();
     }
 
-    repeatPartition() {
+    _isBufferFull() {
-        this._offset -= this._partitionSize;
+        return this._bufferedAmount >= this._highWaterMark;
-        this.nextPartition();
     }
 
-    _isPartitionEnd() {
+    _isFileEnd() {
-        return this._partitionSize >= this._maxPartitionSize;
+        return this._sendProgress >= this._bytesToSend;
-    }
-
-    isFileEnd() {
-        return this._offset >= this._file.size;
     }
 }
 
@@ -1159,6 +1169,7 @@ class FileDigester {
         if (isNaN(this.progress)) this.progress = 1
 
         if (this._bytesReceived < this._size) return;
+
         // we are done
         const blob = new Blob(this._buffer)
         this._buffer = null;

public/scripts/ui.js

@@ -68,12 +68,25 @@ class PeersUI {
         this.fadedIn = false;
 
         this.$header = document.querySelector('header.opacity-0');
-        Events.on('header-evaluated', () => this._fadeInHeader());
+        Events.on('header-evaluated', e => this._fadeInHeader(e.detail));
+
+        // wait for evaluation of notification, install and edit-paired-devices buttons
+        this.evaluateHeaderCount = 3;
+        if (!('Notification' in window)) this.evaluateHeaderCount -= 1;
+        if (
+            !('BeforeInstallPromptEvent' in window) ||
+            ('BeforeInstallPromptEvent' in window && window.matchMedia('(display-mode: minimal-ui)').matches)
+        ) {
+            this.evaluateHeaderCount -= 1;
+        }
     }
 
-    _fadeInHeader() {
+    _fadeInHeader(id) {
-        //prevent flickering
+        this.evaluateHeaderCount -= 1;
-        setTimeout(() => this.$header.classList.remove('opacity-0'), 50);
+        console.log(`Header btn ${id} evaluated. ${this.evaluateHeaderCount} to go.`);
+        if (this.evaluateHeaderCount !== 0) return;
+
+        this.$header.classList.remove('opacity-0');
     }
 
     _fadeInUI() {
@@ -735,14 +748,14 @@ class ReceiveDialog extends Dialog {
     _formatFileSize(bytes) {
         // 1 GB = 1024 MB = 1024^2 KB = 1024^3 B
         // 1024^2 = 104876; 1024^3 = 1073741824
-        if (bytes >= 1073741824) {
+        if (bytes >= 1000000000) {
-            return Math.round(10 * bytes / 1073741824) / 10 + ' GB';
+            return Math.round(10 * bytes / 1000000000) / 10 + ' GB';
-        } else if (bytes >= 1048576) {
+        } else if (bytes >= 1000000) {
-            return Math.round(bytes / 1048576) + ' MB';
+            return Math.round(10 * bytes / 1000000) / 10 + ' MB';
-        } else if (bytes > 1024) {
+        } else if (bytes >= (1000)) {
-            return Math.round(bytes / 1024) + ' KB';
+            return Math.round(10 * bytes / 1000) / 10 + ' KB';
         } else {
-            return bytes + ' Bytes';
+            return bytes + ' bytes';
         }
     }
 
@@ -1413,6 +1426,7 @@ class PairDeviceDialog extends Dialog {
                     this.$footerInstructionsPairedDevices.setAttribute('hidden', '');
                 }
                 Events.fire('evaluate-footer-badges');
+                Events.fire('header-evaluated', 'edit-paired-devices');
             });
     }
 }
@@ -2092,10 +2106,7 @@ class Notifications {
 
     constructor() {
         // Check if the browser supports notifications
-        if (!('Notification' in window)) {
+        if (!('Notification' in window)) return;
-            Events.fire('header-evaluated');
-            return;
-        }
 
         // Check whether notification permissions have already been granted
         if (Notification.permission !== 'granted') {
@@ -2104,7 +2115,7 @@ class Notifications {
             this.$headerNotificationButton.addEventListener('click', _ => this._requestPermission());
         }
 
-        Events.fire('header-evaluated');
+        Events.fire('header-evaluated', 'notification');
 
         Events.on('text-received', e => this._messageNotification(e.detail.text, e.detail.peerId));
         Events.on('files-received', e => this._downloadNotification(e.detail.files));
@@ -2258,7 +2269,10 @@ class NetworkStatusUI {
     }
 
     _showOfflineMessage() {
-        Events.fire('notify-user', Localization.getTranslation("notifications.offline"));
+        Events.fire('notify-user', {
+            message: Localization.getTranslation("notifications.offline"),
+            persistent: true
+        });
     }
 
     _showOnlineMessage() {
@@ -2815,12 +2829,16 @@ if ('serviceWorker' in navigator) {
         });
 }
 
-window.addEventListener('beforeinstallprompt', e => {
+window.addEventListener('beforeinstallprompt', installEvent => {
     if (!window.matchMedia('(display-mode: minimal-ui)').matches) {
-        // only display install btn when installed
+        // only display install btn when not installed
-        const btn = document.querySelector('#install')
+        const installBtn = document.querySelector('#install')
-        btn.hidden = false;
+        installBtn.removeAttribute('hidden');
-        btn.onclick = _ => e.prompt();
+        installBtn.addEventListener('click', () => {
+            installBtn.setAttribute('hidden', '');
+            installEvent.prompt();
+        });
+        Events.fire('header-evaluated', 'install');
     }
-    return e.preventDefault();
+    return installEvent.preventDefault();
 });

public/service-worker.js

@@ -1,16 +1,18 @@
-const cacheVersion = 'v1.9.0';
+const cacheVersion = 'v1.9.1';
 const cacheTitle = `pairdrop-cache-${cacheVersion}`;
 const urlsToCache = [
-    'index.html',
     './',
+    'index.html',
+    'manifest.json',
     'styles.css',
+    'scripts/localization.js',
     'scripts/network.js',
+    'scripts/NoSleep.min.js',
+    'scripts/QRCode.min.js',
+    'scripts/theme.js',
     'scripts/ui.js',
     'scripts/util.js',
-    'scripts/qrcode.js',
     'scripts/zip.min.js',
-    'scripts/NoSleep.min.js',
-    'scripts/theme.js',
     'sounds/blop.mp3',
     'images/favicon-96x96.png',
     'images/favicon-96x96-notification.png',
@@ -53,7 +55,7 @@ const fromNetwork = (request, timeout) =>
         fetch(request).then(response => {
             clearTimeout(timeoutId);
             fulfill(response);
-            update(request);
+            update(request).then(() => console.log("Cache successfully updated for", request.url));
         }, reject);
     });
 
@@ -62,9 +64,7 @@ const fromCache = request =>
     caches
         .open(cacheTitle)
         .then(cache =>
-            cache
+            cache.match(request)
-                .match(request)
-                .then(matching => matching || cache.match('/offline/'))
         );
 
 // cache the current page to make it available for offline
@@ -72,15 +72,16 @@ const update = request =>
     caches
         .open(cacheTitle)
         .then(cache =>
-            fetch(request).then(response => {
+            fetch(request)
-                cache.put(request, response).then(_ => {
+                .then(async response => {
-                    console.log("Page successfully cached.")
+                    await cache.put(request, response);
                 })
-            })
+                .catch(() => console.log(`Cache could not be updated. ${request.url}`))
         );
 
 // general strategy when making a request (eg if online try to fetch it
-// from the network with a timeout, if something fails serve from cache)
+// from cache, if something fails fetch from network. Update cache everytime files are fetched.
+// This way files should only be fetched if cacheVersion is changed
 self.addEventListener('fetch', function(event) {
     if (event.request.method === "POST") {
         // Requests related to Web Share Target.
@@ -90,27 +91,33 @@ self.addEventListener('fetch', function(event) {
         })());
     } else {
         // Regular requests not related to Web Share Target.
+
+        // FOR DEVELOPMENT: Comment in next line to always update assets instead of using cached versions
+        // event.respondWith(fromNetwork(event.request, 10000));return;
         event.respondWith(
-            fromNetwork(event.request, 10000).catch(() => fromCache(event.request))
+            fromCache(event.request).then(rsp => {
+                // if fromCache resolves to undefined fetch from network instead
+                return rsp || fromNetwork(event.request, 10000);
+            })
         );
-        event.waitUntil(update(event.request));
     }
 });
 
 
 // on activation, we clean up the previously registered service workers
-self.addEventListener('activate', evt =>
+self.addEventListener('activate', evt => {
-    evt.waitUntil(
+        return evt.waitUntil(
-        caches.keys().then(cacheNames => {
+            caches.keys().then(cacheNames => {
-            return Promise.all(
+                return Promise.all(
-                cacheNames.map(cacheName => {
+                    cacheNames.map(cacheName => {
-                    if (cacheName !== cacheTitle) {
+                        if (cacheName !== cacheTitle) {
-                        return caches.delete(cacheName);
+                            return caches.delete(cacheName);
-                    }
+                        }
-                })
+                    })
-            );
+                );
-        })
+            })
-    )
+        )
+    }
 );
 
 const evaluateRequestData = function (request) {

public_included_ws_fallback/index.html

@@ -485,7 +485,7 @@
             </svg>
             <div class="title-wrapper" dir="ltr">
                 <h1>PairDrop</h1>
-                <div class="font-subheading">v1.9.0</div>
+                <div class="font-subheading">v1.9.1</div>
             </div>
             <div class="font-subheading" data-i18n-key="about.claim" data-i18n-attrs="text"></div>
             <div class="row">

public_included_ws_fallback/scripts/network.js

@@ -1,5 +1,5 @@
 window.URL = window.URL || window.webkitURL;
-window.isRtcSupported = false; //!!(window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection);
+window.isRtcSupported = !!(window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection);
 
 window.hiddenProperty = 'hidden' in document ? 'hidden' :
     'webkitHidden' in document ? 'webkitHidden' :
@@ -35,7 +35,7 @@ class ServerConnection {
 
     _connect() {
         clearTimeout(this._reconnectTimer);
-        if (this._isConnected() || this._isConnecting()) return;
+        if (this._isConnected() || this._isConnecting() || this._isOffline()) return;
         if (this._isReconnect) {
             Events.fire('notify-user', {
                 message: Localization.getTranslation("notifications.connecting"),
@@ -158,8 +158,6 @@ class ServerConnection {
                 break;
             case 'request':
             case 'header':
-            case 'partition':
-            case 'partition-received':
             case 'progress':
             case 'files-transfer-response':
             case 'file-transfer-complete':
@@ -257,6 +255,10 @@ class ServerConnection {
         return this._socket && this._socket.readyState === this._socket.CONNECTING;
     }
 
+    _isOffline() {
+        return !navigator.onLine;
+    }
+
     _onError(e) {
         console.error(e);
     }
@@ -277,6 +279,9 @@ class Peer {
         this._roomIds = {};
         this._updateRoomIds(roomType, roomId);
 
+        this._chunkSize = 262144;
+        this._lowWaterMark = 2* this._chunkSize;
+
         this._filesQueue = [];
         this._busy = false;
 
@@ -455,22 +460,9 @@ class Peer {
             mime: file.type
         });
         this._chunker = new FileChunker(file,
-            chunk => this._send(chunk),
+            this._chunkSize,
-            offset => this._onPartitionEnd(offset));
+            chunk => this._send(chunk));
-        this._chunker.nextPartition();
+        this._chunker._readChunksIntoBuffer(this._channel ? this._channel.bufferedAmount : 0);
-    }
-
-    _onPartitionEnd(offset) {
-        this.sendJSON({ type: 'partition', offset: offset });
-    }
-
-    _onReceivedPartitionEnd(offset) {
-        this.sendJSON({ type: 'partition-received', offset: offset });
-    }
-
-    _sendNextPartition() {
-        if (!this._chunker || this._chunker.isFileEnd()) return;
-        this._chunker.nextPartition();
     }
 
     _sendProgress(progress) {
@@ -490,12 +482,6 @@ class Peer {
             case 'header':
                 this._onFileHeader(messageJSON);
                 break;
-            case 'partition':
-                this._onReceivedPartitionEnd(messageJSON);
-                break;
-            case 'partition-received':
-                this._sendNextPartition();
-                break;
             case 'progress':
                 this._onDownloadProgress(messageJSON.progress);
                 break;
@@ -503,7 +489,7 @@ class Peer {
                 this._onFileTransferRequestResponded(messageJSON);
                 break;
             case 'file-transfer-complete':
-                this._onFileTransferCompleted();
+                this._onFileTransferCompleted(messageJSON);
                 break;
             case 'message-transfer-complete':
                 this._onMessageTransferCompleted();
@@ -559,6 +545,7 @@ class Peer {
     _onFileHeader(header) {
         if (this._requestAccepted && this._requestAccepted.header.length) {
             this._lastProgress = 0;
+            this._timeStart = Date.now();
             this._digester = new FileDigester({size: header.size, name: header.name, mime: header.mime},
                 this._requestAccepted.totalSize,
                 this._totalBytesReceived,
@@ -578,7 +565,6 @@ class Peer {
 
     _onChunkReceived(chunk) {
         if(!this._digester || !(chunk.byteLength || chunk.size)) return;
-
         this._digester.unchunk(chunk);
         const progress = this._digester.progress;
 
@@ -602,7 +588,13 @@ class Peer {
         const acceptedHeader = this._requestAccepted.header.shift();
         this._totalBytesReceived += fileBlob.size;
 
-        this.sendJSON({type: 'file-transfer-complete'});
+        let duration = (Date.now() - this._timeStart) / 1000;
+        let size = Math.round(10 * fileBlob.size / 1000000) / 10;
+        let speed = Math.round(100 * fileBlob.size / 1000000 / duration) / 100;
+
+        console.log(`File received.\n\nSize: ${size} MB\tDuration: ${duration} s\tSpeed: ${speed} MB/s`);
+
+        this.sendJSON({type: 'file-transfer-complete', size: size, duration: duration, speed: speed});
 
         const sameSize = fileBlob.size === acceptedHeader.size;
         const sameName = fileBlob.name === acceptedHeader.name
@@ -623,8 +615,10 @@ class Peer {
         }
     }
 
-    _onFileTransferCompleted() {
+    _onFileTransferCompleted(message) {
-        this._chunker = null;
+        console.log(`File sent.\n\nSize: ${message.size} MB\tDuration: ${message.duration} s\tSpeed: ${message.speed} MB/s`);
+
+
         if (!this._filesQueue.length) {
             this._busy = false;
             Events.fire('notify-user', Localization.getTranslation("notifications.file-transfer-completed"));
@@ -632,6 +626,8 @@ class Peer {
         } else {
             this._dequeueFile();
         }
+        this._chunker._removeEventListener();
+        this._chunker = null;
     }
 
     _onFileTransferRequestResponded(message) {
@@ -709,8 +705,7 @@ class RTCPeer extends Peer {
         if (!this._conn) return;
 
         const channel = this._conn.createDataChannel('data-channel', {
-            ordered: true,
+            ordered: false,
-            reliable: true // Obsolete. See https://developer.mozilla.org/en-US/docs/Web/API/RTCDataChannel/reliable
         });
         channel.onopen = e => this._onChannelOpened(e);
         channel.onerror = e => this._onError(e);
@@ -756,7 +751,15 @@ class RTCPeer extends Peer {
         channel.binaryType = 'arraybuffer';
         channel.onmessage = e => this._onMessage(e.data);
         channel.onclose = _ => this._onChannelClosed();
+
+        this._chunkSize = Math.min(this._conn.sctp.maxMessageSize, 262144); // max chunk size: 256 KB
+        this._lowWaterMark = 2 * this._chunkSize;
+
+        channel.bufferedAmountLowThreshold = this._lowWaterMark;
+        channel.onbufferedamountlow = () => Events.fire("bufferedamountlow", channel.bufferedAmount);
+
         this._channel = channel;
+
         Events.on('beforeunload', e => this._onBeforeUnload(e));
         Events.on('pagehide', _ => this._onPageHide());
         Events.fire('peer-connected', {peerId: this._peerId, connectionHash: this.getConnectionHash()});
@@ -900,6 +903,7 @@ class WSPeer extends Peer {
             type: 'ws-chunk',
             chunk: arrayBufferToBase64(chunk)
         });
+        Events.fire("bufferedamountlow", 0);
     }
 
     sendJSON(message) {
@@ -988,7 +992,7 @@ class PeersManager {
         }
 
         if (window.isRtcSupported && rtcSupported) {
-            this.peers[peerId] = new RTCPeer(this._server,isCaller, peerId, roomType, roomId);
+            this.peers[peerId] = new RTCPeer(this._server, isCaller, peerId, roomType, roomId);
         } else {
             this.peers[peerId] = new WSPeer(this._server, isCaller, peerId, roomType, roomId);
         }
@@ -1163,51 +1167,56 @@ class PeersManager {
 
 class FileChunker {
 
-    constructor(file, onChunk, onPartitionEnd) {
+    constructor(file, chunkSize, onChunk) {
-        this._chunkSize = 64000; // 64 KB
-        this._maxPartitionSize = 1e6; // 1 MB
-        this._offset = 0;
-        this._partitionSize = 0;
         this._file = file;
+        this._chunkSize = chunkSize;
+        this._highWaterMark = 8 * chunkSize;
+        this._bytesToSend = file.size;
+        this._sendProgress = 0;
+
         this._onChunk = onChunk;
-        this._onPartitionEnd = onPartitionEnd;
+
         this._reader = new FileReader();
+
+        this._reader.addEventListener('error', err => console.error('Error reading file:', err));
+        this._reader.addEventListener('abort', e => console.log('File reading aborted:', e));
         this._reader.addEventListener('load', e => this._onChunkRead(e.target.result));
+
+        this.bufferedAmountCallback = e => this._readChunksIntoBuffer(e.detail);
+
+        Events.on('bufferedamountlow', this.bufferedAmountCallback);
     }
 
-    nextPartition() {
+    _removeEventListener() {
-        this._partitionSize = 0;
+        Events.off('bufferedamountlow', this.bufferedAmountCallback);
+    }
+
+    _readChunksIntoBuffer(bufferedAmount) {
+        this._bufferedAmount = bufferedAmount;
         this._readChunk();
     }
 
     _readChunk() {
-        const chunk = this._file.slice(this._offset, this._offset + this._chunkSize);
+        const chunk = this._file.slice(this._sendProgress, this._sendProgress + this._chunkSize);
         this._reader.readAsArrayBuffer(chunk);
     }
 
     _onChunkRead(chunk) {
-        this._offset += chunk.byteLength;
-        this._partitionSize += chunk.byteLength;
         this._onChunk(chunk);
-        if (this.isFileEnd()) return;
+        this._bufferedAmount += this._chunkSize;
-        if (this._isPartitionEnd()) {
+        this._sendProgress += this._chunkSize;
-            this._onPartitionEnd(this._offset);
+
-            return;
+        if (this._isBufferFull() || this._isFileEnd()) return;
-        }
+
         this._readChunk();
     }
 
-    repeatPartition() {
+    _isBufferFull() {
-        this._offset -= this._partitionSize;
+        return this._bufferedAmount >= this._highWaterMark;
-        this.nextPartition();
     }
 
-    _isPartitionEnd() {
+    _isFileEnd() {
-        return this._partitionSize >= this._maxPartitionSize;
+        return this._sendProgress >= this._bytesToSend;
-    }
-
-    isFileEnd() {
-        return this._offset >= this._file.size;
     }
 }
 
@@ -1231,6 +1240,7 @@ class FileDigester {
         if (isNaN(this.progress)) this.progress = 1
 
         if (this._bytesReceived < this._size) return;
+
         // we are done
         const blob = new Blob(this._buffer)
         this._buffer = null;

public_included_ws_fallback/scripts/ui.js

@@ -68,12 +68,25 @@ class PeersUI {
         this.fadedIn = false;
 
         this.$header = document.querySelector('header.opacity-0');
-        Events.on('header-evaluated', () => this._fadeInHeader());
+        Events.on('header-evaluated', e => this._fadeInHeader(e.detail));
+
+        // wait for evaluation of notification, install and edit-paired-devices buttons
+        this.evaluateHeaderCount = 3;
+        if (!('Notification' in window)) this.evaluateHeaderCount -= 1;
+        if (
+            !('BeforeInstallPromptEvent' in window) ||
+            ('BeforeInstallPromptEvent' in window && window.matchMedia('(display-mode: minimal-ui)').matches)
+        ) {
+            this.evaluateHeaderCount -= 1;
+        }
     }
 
-    _fadeInHeader() {
+    _fadeInHeader(id) {
-        //prevent flickering
+        this.evaluateHeaderCount -= 1;
-        setTimeout(() => this.$header.classList.remove('opacity-0'), 50);
+        console.log(`Header btn ${id} evaluated. ${this.evaluateHeaderCount} to go.`);
+        if (this.evaluateHeaderCount !== 0) return;
+
+        this.$header.classList.remove('opacity-0');
     }
 
     _fadeInUI() {
@@ -737,14 +750,14 @@ class ReceiveDialog extends Dialog {
     _formatFileSize(bytes) {
         // 1 GB = 1024 MB = 1024^2 KB = 1024^3 B
         // 1024^2 = 104876; 1024^3 = 1073741824
-        if (bytes >= 1073741824) {
+        if (bytes >= 1000000000) {
-            return Math.round(10 * bytes / 1073741824) / 10 + ' GB';
+            return Math.round(10 * bytes / 1000000000) / 10 + ' GB';
-        } else if (bytes >= 1048576) {
+        } else if (bytes >= 1000000) {
-            return Math.round(bytes / 1048576) + ' MB';
+            return Math.round(10 * bytes / 1000000) / 10 + ' MB';
-        } else if (bytes > 1024) {
+        } else if (bytes >= (1000)) {
-            return Math.round(bytes / 1024) + ' KB';
+            return Math.round(10 * bytes / 1000) / 10 + ' KB';
         } else {
-            return bytes + ' Bytes';
+            return bytes + ' bytes';
         }
     }
 
@@ -1415,6 +1428,7 @@ class PairDeviceDialog extends Dialog {
                     this.$footerInstructionsPairedDevices.setAttribute('hidden', '');
                 }
                 Events.fire('evaluate-footer-badges');
+                Events.fire('header-evaluated', 'edit-paired-devices');
             });
     }
 }
@@ -2094,10 +2108,7 @@ class Notifications {
 
     constructor() {
         // Check if the browser supports notifications
-        if (!('Notification' in window)) {
+        if (!('Notification' in window)) return;
-            Events.fire('header-evaluated');
-            return;
-        }
 
         // Check whether notification permissions have already been granted
         if (Notification.permission !== 'granted') {
@@ -2106,7 +2117,7 @@ class Notifications {
             this.$headerNotificationButton.addEventListener('click', _ => this._requestPermission());
         }
 
-        Events.fire('header-evaluated');
+        Events.fire('header-evaluated', 'notification');
 
         Events.on('text-received', e => this._messageNotification(e.detail.text, e.detail.peerId));
         Events.on('files-received', e => this._downloadNotification(e.detail.files));
@@ -2260,7 +2271,10 @@ class NetworkStatusUI {
     }
 
     _showOfflineMessage() {
-        Events.fire('notify-user', Localization.getTranslation("notifications.offline"));
+        Events.fire('notify-user', {
+            message: Localization.getTranslation("notifications.offline"),
+            persistent: true
+        });
     }
 
     _showOnlineMessage() {
@@ -2817,12 +2831,16 @@ if ('serviceWorker' in navigator) {
         });
 }
 
-window.addEventListener('beforeinstallprompt', e => {
+window.addEventListener('beforeinstallprompt', installEvent => {
     if (!window.matchMedia('(display-mode: minimal-ui)').matches) {
-        // only display install btn when installed
+        // only display install btn when not installed
-        const btn = document.querySelector('#install')
+        const installBtn = document.querySelector('#install')
-        btn.hidden = false;
+        installBtn.removeAttribute('hidden');
-        btn.onclick = _ => e.prompt();
+        installBtn.addEventListener('click', () => {
+            installBtn.setAttribute('hidden', '');
+            installEvent.prompt();
+        });
+        Events.fire('header-evaluated', 'install');
     }
-    return e.preventDefault();
+    return installEvent.preventDefault();
 });

public_included_ws_fallback/service-worker.js

@@ -1,16 +1,18 @@
-const cacheVersion = 'v1.9.0';
+const cacheVersion = 'v1.9.1';
 const cacheTitle = `pairdrop-included-ws-fallback-cache-${cacheVersion}`;
 const urlsToCache = [
-    'index.html',
     './',
+    'index.html',
+    'manifest.json',
     'styles.css',
+    'scripts/localization.js',
     'scripts/network.js',
+    'scripts/NoSleep.min.js',
+    'scripts/QRCode.min.js',
+    'scripts/theme.js',
     'scripts/ui.js',
     'scripts/util.js',
-    'scripts/qrcode.js',
     'scripts/zip.min.js',
-    'scripts/NoSleep.min.js',
-    'scripts/theme.js',
     'sounds/blop.mp3',
     'images/favicon-96x96.png',
     'images/favicon-96x96-notification.png',
@@ -53,7 +55,7 @@ const fromNetwork = (request, timeout) =>
         fetch(request).then(response => {
             clearTimeout(timeoutId);
             fulfill(response);
-            update(request);
+            update(request).then(() => console.log("Cache successfully updated for", request.url));
         }, reject);
     });
 
@@ -62,9 +64,7 @@ const fromCache = request =>
     caches
         .open(cacheTitle)
         .then(cache =>
-            cache
+            cache.match(request)
-                .match(request)
-                .then(matching => matching || cache.match('/offline/'))
         );
 
 // cache the current page to make it available for offline
@@ -72,15 +72,16 @@ const update = request =>
     caches
         .open(cacheTitle)
         .then(cache =>
-            fetch(request).then(response => {
+            fetch(request)
-                cache.put(request, response).then(_ => {
+                .then(async response => {
-                    console.log("Page successfully cached.")
+                    await cache.put(request, response);
                 })
-            })
+                .catch(() => console.log(`Cache could not be updated. ${request.url}`))
         );
 
 // general strategy when making a request (eg if online try to fetch it
-// from the network with a timeout, if something fails serve from cache)
+// from cache, if something fails fetch from network. Update cache everytime files are fetched.
+// This way files should only be fetched if cacheVersion is changed
 self.addEventListener('fetch', function(event) {
     if (event.request.method === "POST") {
         // Requests related to Web Share Target.
@@ -90,27 +91,33 @@ self.addEventListener('fetch', function(event) {
         })());
     } else {
         // Regular requests not related to Web Share Target.
+
+        // FOR DEVELOPMENT: Comment in next line to always update assets instead of using cached versions
+        // event.respondWith(fromNetwork(event.request, 10000));return;
         event.respondWith(
-            fromNetwork(event.request, 10000).catch(() => fromCache(event.request))
+            fromCache(event.request).then(rsp => {
+                // if fromCache resolves to undefined fetch from network instead
+                return rsp || fromNetwork(event.request, 10000);
+            })
         );
-        event.waitUntil(update(event.request));
     }
 });
 
 
 // on activation, we clean up the previously registered service workers
-self.addEventListener('activate', evt =>
+self.addEventListener('activate', evt => {
-    evt.waitUntil(
+        return evt.waitUntil(
-        caches.keys().then(cacheNames => {
+            caches.keys().then(cacheNames => {
-            return Promise.all(
+                return Promise.all(
-                cacheNames.map(cacheName => {
+                    cacheNames.map(cacheName => {
-                    if (cacheName !== cacheTitle) {
+                        if (cacheName !== cacheTitle) {
-                        return caches.delete(cacheName);
+                            return caches.delete(cacheName);
-                    }
+                        }
-                })
+                    })
-            );
+                );
-        })
+            })
-    )
+        )
+    }
 );
 
 const evaluateRequestData = function (request) {