1 files changed, 321 insertions, 0 deletions
diff --git a/ext/js/comm/cross-frame-api.js b/ext/js/comm/cross-frame-api.js
new file mode 100644
index 00000000..997249c8
--- /dev/null
+++ b/ext/js/comm/cross-frame-api.js
@@ -0,0 +1,321 @@
+/*
+ * Copyright (C) 2020-2021  Yomichan Authors
+ *
+ * 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 CrossFrameAPIPort extends EventDispatcher {
+    constructor(otherTabId, otherFrameId, port, messageHandlers) {
+        super();
+        this._otherTabId = otherTabId;
+        this._otherFrameId = otherFrameId;
+        this._port = port;
+        this._messageHandlers = messageHandlers;
+        this._activeInvocations = new Map();
+        this._invocationId = 0;
+        this._eventListeners = new EventListenerCollection();
+    }
+
+    get otherTabId() {
+        return this._otherTabId;
+    }
+
+    get otherFrameId() {
+        return this._otherFrameId;
+    }
+
+    prepare() {
+        this._eventListeners.addListener(this._port.onDisconnect, this._onDisconnect.bind(this));
+        this._eventListeners.addListener(this._port.onMessage, this._onMessage.bind(this));
+    }
+
+    invoke(action, params, ackTimeout, responseTimeout) {
+        return new Promise((resolve, reject) => {
+            if (this._port === null) {
+                reject(new Error(`Port is disconnected (${action})`));
+                return;
+            }
+
+            const id = this._invocationId++;
+            const invocation = {
+                id,
+                resolve,
+                reject,
+                responseTimeout,
+                action,
+                ack: false,
+                timer: null
+            };
+            this._activeInvocations.set(id, invocation);
+
+            if (ackTimeout !== null) {
+                try {
+                    invocation.timer = setTimeout(() => this._onError(id, 'Acknowledgement timeout'), ackTimeout);
+                } catch (e) {
+                    this._onError(id, 'Failed to set timeout');
+                    return;
+                }
+            }
+
+            try {
+                this._port.postMessage({type: 'invoke', id, data: {action, params}});
+            } catch (e) {
+                this._onError(id, e);
+            }
+        });
+    }
+
+    disconnect() {
+        this._onDisconnect();
+    }
+
+    // Private
+
+    _onDisconnect() {
+        if (this._port === null) { return; }
+        this._eventListeners.removeAllEventListeners();
+        this._port = null;
+        for (const id of this._activeInvocations.keys()) {
+            this._onError(id, 'Disconnected');
+        }
+        this.trigger('disconnect', this);
+    }
+
+    _onMessage({type, id, data}) {
+        switch (type) {
+            case 'invoke':
+                this._onInvoke(id, data);
+                break;
+            case 'ack':
+                this._onAck(id);
+                break;
+            case 'result':
+                this._onResult(id, data);
+                break;
+        }
+    }
+
+    // Response handlers
+
+    _onAck(id) {
+        const invocation = this._activeInvocations.get(id);
+        if (typeof invocation === 'undefined') {
+            yomichan.logWarning(new Error(`Request ${id} not found for acknowledgement`));
+            return;
+        }
+
+        if (invocation.ack) {
+            this._onError(id, `Request ${id} already acknowledged`);
+            return;
+        }
+
+        invocation.ack = true;
+
+        if (invocation.timer !== null) {
+            clearTimeout(invocation.timer);
+            invocation.timer = null;
+        }
+
+        const responseTimeout = invocation.responseTimeout;
+        if (responseTimeout !== null) {
+            try {
+                invocation.timer = setTimeout(() => this._onError(id, 'Response timeout'), responseTimeout);
+            } catch (e) {
+                this._onError(id, 'Failed to set timeout');
+            }
+        }
+    }
+
+    _onResult(id, data) {
+        const invocation = this._activeInvocations.get(id);
+        if (typeof invocation === 'undefined') {
+            yomichan.logWarning(new Error(`Request ${id} not found`));
+            return;
+        }
+
+        if (!invocation.ack) {
+            this._onError(id, `Request ${id} not acknowledged`);
+            return;
+        }
+
+        this._activeInvocations.delete(id);
+
+        if (invocation.timer !== null) {
+            clearTimeout(invocation.timer);
+            invocation.timer = null;
+        }
+
+        const error = data.error;
+        if (typeof error !== 'undefined') {
+            invocation.reject(deserializeError(error));
+        } else {
+            invocation.resolve(data.result);
+        }
+    }
+
+    _onError(id, error) {
+        const invocation = this._activeInvocations.get(id);
+        if (typeof invocation === 'undefined') { return; }
+
+        if (typeof error === 'string') {
+            error = new Error(`${error} (${invocation.action})`);
+        }
+
+        this._activeInvocations.delete(id);
+        if (invocation.timer !== null) {
+            clearTimeout(invocation.timer);
+            invocation.timer = null;
+        }
+        invocation.reject(error);
+    }
+
+    // Invocation
+
+    _onInvoke(id, {action, params}) {
+        const messageHandler = this._messageHandlers.get(action);
+        this._sendAck(id);
+        if (typeof messageHandler === 'undefined') {
+            this._sendError(id, new Error(`Unknown action: ${action}`));
+            return false;
+        }
+
+        const callback = (data) => this._sendResult(id, data);
+        return yomichan.invokeMessageHandler(messageHandler, params, callback);
+    }
+
+    _sendResponse(data) {
+        if (this._port === null) { return; }
+        try {
+            this._port.postMessage(data);
+        } catch (e) {
+            // NOP
+        }
+    }
+
+    _sendAck(id) {
+        this._sendResponse({type: 'ack', id});
+    }
+
+    _sendResult(id, data) {
+        this._sendResponse({type: 'result', id, data});
+    }
+
+    _sendError(id, error) {
+        this._sendResponse({type: 'result', id, data: {error: serializeError(error)}});
+    }
+}
+
+class CrossFrameAPI {
+    constructor() {
+        this._ackTimeout = 3000; // 3 seconds
+        this._responseTimeout = 10000; // 10 seconds
+        this._commPorts = new Map();
+        this._messageHandlers = new Map();
+        this._onDisconnectBind = this._onDisconnect.bind(this);
+    }
+
+    prepare() {
+        chrome.runtime.onConnect.addListener(this._onConnect.bind(this));
+    }
+
+    invoke(targetFrameId, action, params={}) {
+        return this.invokeTab(null, targetFrameId, action, params);
+    }
+
+    async invokeTab(targetTabId, targetFrameId, action, params={}) {
+        if (typeof targetTabId !== 'number') { targetTabId = null; }
+        const commPort = this._getOrCreateCommPort(targetTabId, targetFrameId);
+        return await commPort.invoke(action, params, this._ackTimeout, this._responseTimeout);
+    }
+
+    registerHandlers(messageHandlers) {
+        for (const [key, value] of messageHandlers) {
+            if (this._messageHandlers.has(key)) {
+                throw new Error(`Handler ${key} is already registered`);
+            }
+            this._messageHandlers.set(key, value);
+        }
+    }
+
+    unregisterHandler(key) {
+        return this._messageHandlers.delete(key);
+    }
+
+    // Private
+
+    _onConnect(port) {
+        try {
+            let details;
+            try {
+                details = JSON.parse(port.name);
+            } catch (e) {
+                return;
+            }
+            if (details.name !== 'cross-frame-communication-port') { return; }
+
+            const otherTabId = details.sourceTabId;
+            const otherFrameId = details.sourceFrameId;
+            this._setupCommPort(otherTabId, otherFrameId, port);
+        } catch (e) {
+            port.disconnect();
+            yomichan.logError(e);
+        }
+    }
+
+    _onDisconnect(commPort) {
+        commPort.off('disconnect', this._onDisconnectBind);
+        const {otherTabId, otherFrameId} = commPort;
+        const tabPorts = this._commPorts.get(otherTabId);
+        if (typeof tabPorts !== 'undefined') {
+            tabPorts.delete(otherFrameId);
+            if (tabPorts.size === 0) {
+                this._commPorts.delete(otherTabId);
+            }
+        }
+    }
+
+    _getOrCreateCommPort(otherTabId, otherFrameId) {
+        const tabPorts = this._commPorts.get(otherTabId);
+        if (typeof tabPorts !== 'undefined') {
+            const commPort = tabPorts.get(otherFrameId);
+            if (typeof commPort !== 'undefined') {
+                return commPort;
+            }
+        }
+        return this._createCommPort(otherTabId, otherFrameId);
+    }
+
+    _createCommPort(otherTabId, otherFrameId) {
+        const details = {
+            name: 'background-cross-frame-communication-port',
+            targetTabId: otherTabId,
+            targetFrameId: otherFrameId
+        };
+        const port = yomichan.connect(null, {name: JSON.stringify(details)});
+        return this._setupCommPort(otherTabId, otherFrameId, port);
+    }
+
+    _setupCommPort(otherTabId, otherFrameId, port) {
+        const commPort = new CrossFrameAPIPort(otherTabId, otherFrameId, port, this._messageHandlers);
+        let tabPorts = this._commPorts.get(otherTabId);
+        if (typeof tabPorts === 'undefined') {
+            tabPorts = new Map();
+            this._commPorts.set(otherTabId, tabPorts);
+        }
+        tabPorts.set(otherFrameId, commPort);
+        commPort.prepare();
+        commPort.on('disconnect', this._onDisconnectBind);
+        return commPort;
+    }
+}