Merge pull request #399 from toasted-nutbread/audio-system-refactor

Audio system refactor

3 files changed, 198 insertions, 188 deletions

diff --git a/ext/mixed/js/audio-system.js b/ext/mixed/js/audio-system.js
new file mode 100644
index 00000000..31c476b1
--- /dev/null
+++ b/ext/mixed/js/audio-system.js
@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) 2019-2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+class TextToSpeechAudio {
+    constructor(text, voice) {
+        this.text = text;
+        this.voice = voice;
+        this._utterance = null;
+        this._volume = 1;
+    }
+
+    get currentTime() {
+        return 0;
+    }
+    set currentTime(value) {
+        // NOP
+    }
+
+    get volume() {
+        return this._volume;
+    }
+    set volume(value) {
+        this._volume = value;
+        if (this._utterance !== null) {
+            this._utterance.volume = value;
+        }
+    }
+
+    play() {
+        try {
+            if (this._utterance === null) {
+                this._utterance = new SpeechSynthesisUtterance(this.text || '');
+                this._utterance.lang = 'ja-JP';
+                this._utterance.volume = this._volume;
+                this._utterance.voice = this.voice;
+            }
+
+            speechSynthesis.cancel();
+            speechSynthesis.speak(this._utterance);
+        } catch (e) {
+            // NOP
+        }
+    }
+
+    pause() {
+        try {
+            speechSynthesis.cancel();
+        } catch (e) {
+            // NOP
+        }
+    }
+}
+
+class AudioSystem {
+    constructor({getAudioUri}) {
+        this._cache = new Map();
+        this._cacheSizeMaximum = 32;
+        this._getAudioUri = getAudioUri;
+
+        if (typeof speechSynthesis !== 'undefined') {
+            // speechSynthesis.getVoices() will not be populated unless some API call is made.
+            speechSynthesis.addEventListener('voiceschanged', this._onVoicesChanged.bind(this));
+        }
+    }
+
+    async getDefinitionAudio(definition, sources, details) {
+        const key = `${definition.expression}:${definition.reading}`;
+        const cacheValue = this._cache.get(definition);
+        if (typeof cacheValue !== 'undefined') {
+            const {audio, uri, source} = cacheValue;
+            return {audio, uri, source};
+        }
+
+        for (const source of sources) {
+            const uri = await this._getAudioUri(definition, source, details);
+            if (uri === null) { continue; }
+
+            try {
+                const audio = await this._createAudio(uri, details);
+                this._cacheCheck();
+                this._cache.set(key, {audio, uri, source});
+                return {audio, uri, source};
+            } catch (e) {
+                // NOP
+            }
+        }
+
+        throw new Error('Could not create audio');
+    }
+
+    createTextToSpeechAudio({text, voiceUri}) {
+        const voice = this._getTextToSpeechVoiceFromVoiceUri(voiceUri);
+        if (voice === null) {
+            throw new Error('Invalid text-to-speech voice');
+        }
+        return new TextToSpeechAudio(text, voice);
+    }
+
+    _onVoicesChanged() {
+        // NOP
+    }
+
+    async _createAudio(uri, details) {
+        const ttsParameters = this._getTextToSpeechParameters(uri);
+        if (ttsParameters !== null) {
+            if (typeof details === 'object' && details !== null) {
+                if (details.tts === false) {
+                    throw new Error('Text-to-speech not permitted');
+                }
+            }
+            return this.createTextToSpeechAudio(ttsParameters);
+        }
+
+        return await this._createAudioFromUrl(uri);
+    }
+
+    _createAudioFromUrl(url) {
+        return new Promise((resolve, reject) => {
+            const audio = new Audio(url);
+            audio.addEventListener('loadeddata', () => {
+                const duration = audio.duration;
+                if (duration === 5.694694 || duration === 5.720718) {
+                    // Hardcoded values for invalid audio
+                    reject(new Error('Could not retrieve audio'));
+                } else {
+                    resolve(audio);
+                }
+            });
+            audio.addEventListener('error', () => reject(audio.error));
+        });
+    }
+
+    _getTextToSpeechVoiceFromVoiceUri(voiceUri) {
+        try {
+            for (const voice of speechSynthesis.getVoices()) {
+                if (voice.voiceURI === voiceUri) {
+                    return voice;
+                }
+            }
+        } catch (e) {
+            // NOP
+        }
+        return null;
+    }
+
+    _getTextToSpeechParameters(uri) {
+        const m = /^tts:[^#?]*\?([^#]*)/.exec(uri);
+        if (m === null) { return null; }
+
+        const searchParameters = new URLSearchParams(m[1]);
+        const text = searchParameters.get('text');
+        const voiceUri = searchParameters.get('voice');
+        return (text !== null && voiceUri !== null ? {text, voiceUri} : null);
+    }
+
+    _cacheCheck() {
+        const removeCount = this._cache.size - this._cacheSizeMaximum;
+        if (removeCount <= 0) { return; }
+
+        const removeKeys = [];
+        for (const key of this._cache.keys()) {
+            removeKeys.push(key);
+            if (removeKeys.length >= removeCount) { break; }
+        }
+
+        for (const key of removeKeys) {
+            this._cache.delete(key);
+        }
+    }
+}
diff --git a/ext/mixed/js/audio.js b/ext/mixed/js/audio.js
deleted file mode 100644
index b5a025be..00000000
--- a/ext/mixed/js/audio.js
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Copyright (C) 2019-2020  Alex Yatskov <alex@foosoft.net>
- * Author: Alex Yatskov <alex@foosoft.net>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-/*global apiAudioGetUrl*/
-
-class TextToSpeechAudio {
-    constructor(text, voice) {
-        this.text = text;
-        this.voice = voice;
-        this._utterance = null;
-        this._volume = 1;
-    }
-
-    get currentTime() {
-        return 0;
-    }
-    set currentTime(value) {
-        // NOP
-    }
-
-    get volume() {
-        return this._volume;
-    }
-    set volume(value) {
-        this._volume = value;
-        if (this._utterance !== null) {
-            this._utterance.volume = value;
-        }
-    }
-
-    play() {
-        try {
-            if (this._utterance === null) {
-                this._utterance = new SpeechSynthesisUtterance(this.text || '');
-                this._utterance.lang = 'ja-JP';
-                this._utterance.volume = this._volume;
-                this._utterance.voice = this.voice;
-            }
-
-            speechSynthesis.cancel();
-            speechSynthesis.speak(this._utterance);
-        } catch (e) {
-            // NOP
-        }
-    }
-
-    pause() {
-        try {
-            speechSynthesis.cancel();
-        } catch (e) {
-            // NOP
-        }
-    }
-
-    static createFromUri(ttsUri) {
-        const m = /^tts:[^#?]*\?([^#]*)/.exec(ttsUri);
-        if (m === null) { return null; }
-
-        const searchParameters = new URLSearchParams(m[1]);
-        const text = searchParameters.get('text');
-        let voice = searchParameters.get('voice');
-        if (text === null || voice === null) { return null; }
-
-        voice = audioGetTextToSpeechVoice(voice);
-        if (voice === null) { return null; }
-
-        return new TextToSpeechAudio(text, voice);
-    }
-}
-
-function audioGetFromUrl(url, willDownload) {
-    const tts = TextToSpeechAudio.createFromUri(url);
-    if (tts !== null) {
-        if (willDownload) {
-            throw new Error('AnkiConnect does not support downloading text-to-speech audio.');
-        }
-        return Promise.resolve(tts);
-    }
-
-    return new Promise((resolve, reject) => {
-        const audio = new Audio(url);
-        audio.addEventListener('loadeddata', () => {
-            if (audio.duration === 5.694694 || audio.duration === 5.720718) {
-                // Hardcoded values for invalid audio
-                reject(new Error('Could not retrieve audio'));
-            } else {
-                resolve(audio);
-            }
-        });
-        audio.addEventListener('error', () => reject(audio.error));
-    });
-}
-
-async function audioGetFromSources(expression, sources, optionsContext, willDownload, cache=null) {
-    const key = `${expression.expression}:${expression.reading}`;
-    if (cache !== null) {
-        const cacheValue = cache.get(expression);
-        if (typeof cacheValue !== 'undefined') {
-            return cacheValue;
-        }
-    }
-
-    for (let i = 0, ii = sources.length; i < ii; ++i) {
-        const source = sources[i];
-        const url = await apiAudioGetUrl(expression, source, optionsContext);
-        if (url === null) {
-            continue;
-        }
-
-        try {
-            let audio = await audioGetFromUrl(url, willDownload);
-            if (willDownload) {
-                // AnkiConnect handles downloading URLs into cards
-                audio = null;
-            }
-            const result = {audio, url, source};
-            if (cache !== null) {
-                cache.set(key, result);
-            }
-            return result;
-        } catch (e) {
-            // NOP
-        }
-    }
-    return {audio: null, url: null, source: null};
-}
-
-function audioGetTextToSpeechVoice(voiceURI) {
-    try {
-        for (const voice of speechSynthesis.getVoices()) {
-            if (voice.voiceURI === voiceURI) {
-                return voice;
-            }
-        }
-    } catch (e) {
-        // NOP
-    }
-    return null;
-}
-
-function audioPrepareTextToSpeech(options) {
-    if (
-        audioPrepareTextToSpeech.state ||
-        !options.audio.textToSpeechVoice ||
-        !(
-            options.audio.sources.includes('text-to-speech') ||
-            options.audio.sources.includes('text-to-speech-reading')
-        )
-    ) {
-        // Text-to-speech not in use.
-        return;
-    }
-
-    // Chrome needs this value called once before it will become populated.
-    // The first call will return an empty list.
-    audioPrepareTextToSpeech.state = true;
-    try {
-        speechSynthesis.getVoices();
-    } catch (e) {
-        // NOP
-    }
-}
-audioPrepareTextToSpeech.state = false;
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index 6a762a65..3fe8e684 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -18,9 +18,8 @@
 
 /*global docRangeFromPoint, docSentenceExtract
 apiKanjiFind, apiTermsFind, apiNoteView, apiOptionsGet, apiDefinitionsAddable, apiDefinitionAdd
-apiScreenshotGet, apiForward
-audioPrepareTextToSpeech, audioGetFromSources
-DisplayGenerator, WindowScroll, DisplayContext, DOM*/
+apiScreenshotGet, apiForward, apiAudioGetUrl
+AudioSystem, DisplayGenerator, WindowScroll, DisplayContext, DOM*/
 
 class Display {
     constructor(spinner, container) {
@@ -32,7 +31,7 @@ class Display {
         this.index = 0;
         this.audioPlaying = null;
         this.audioFallback = null;
-        this.audioCache = new Map();
+        this.audioSystem = new AudioSystem({getAudioUri: this._getAudioUri.bind(this)});
         this.styleNode = null;
 
         this.eventListeners = new EventListenerCollection();
@@ -364,7 +363,6 @@ class Display {
         this.updateDocumentOptions(this.options);
         this.updateTheme(this.options.general.popupTheme);
         this.setCustomCss(this.options.general.customPopupCss);
-        audioPrepareTextToSpeech(this.options);
     }
 
     updateDocumentOptions(options) {
@@ -775,16 +773,16 @@ class Display {
             }
 
             const sources = this.options.audio.sources;
-            let {audio, source} = await audioGetFromSources(expression, sources, this.getOptionsContext(), false, this.audioCache);
-            let info;
-            if (audio === null) {
+            let audio, source, info;
+            try {
+                ({audio, source} = await this.audioSystem.getDefinitionAudio(expression, sources));
+                info = `From source ${1 + sources.indexOf(source)}: ${source}`;
+            } catch (e) {
                 if (this.audioFallback === null) {
                     this.audioFallback = new Audio('/mixed/mp3/button.mp3');
                 }
                 audio = this.audioFallback;
                 info = 'Could not find audio';
-            } else {
-                info = `From source ${1 + sources.indexOf(source)}: ${source}`;
             }
 
             const button = this.audioButtonFindImage(entryIndex);
@@ -918,4 +916,9 @@ class Display {
         const key = event.key;
         return (typeof key === 'string' ? (key.length === 1 ? key.toUpperCase() : key) : '');
     }
+
+    async _getAudioUri(definition, source) {
+        const optionsContext = this.getOptionsContext();
+        return await apiAudioGetUrl(definition, source, optionsContext);
+    }
 }