1 files changed, 92 insertions, 0 deletions
diff --git a/ext/bg/js/mecab.js b/ext/bg/js/mecab.js
new file mode 100644
index 00000000..62111f73
--- /dev/null
+++ b/ext/bg/js/mecab.js
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2019  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 <http://www.gnu.org/licenses/>.
+ */
+
+
+class Mecab {
+    constructor() {
+        this.port = null;
+        this.listeners = {};
+        this.sequence = 0;
+    }
+
+    onError(error) {
+        logError(error, false);
+    }
+
+    async checkVersion() {
+        try {
+            const {version} = await this.invoke('get_version', {});
+            if (version !== Mecab.version) {
+                this.stopListener();
+                throw new Error(`Unsupported MeCab native messenger version ${version}. Yomichan supports version ${Mecab.version}.`);
+            }
+        } catch (error) {
+            this.onError(error);
+        }
+    }
+
+    async parseText(text) {
+        return await this.invoke('parse_text', {text});
+    }
+
+    startListener() {
+        if (this.port !== null) { return; }
+        this.port = chrome.runtime.connectNative('yomichan_mecab');
+        this.port.onMessage.addListener(this.onNativeMessage.bind(this));
+        this.checkVersion();
+    }
+
+    stopListener() {
+        if (this.port === null) { return; }
+        this.port.disconnect();
+        this.port = null;
+        this.listeners = {};
+        this.sequence = 0;
+    }
+
+    onNativeMessage({sequence, data}) {
+        if (hasOwn(this.listeners, sequence)) {
+            const {callback, timer} = this.listeners[sequence];
+            clearTimeout(timer);
+            callback(data);
+            delete this.listeners[sequence];
+        }
+    }
+
+    invoke(action, params) {
+        if (this.port === null) {
+            return Promise.resolve({});
+        }
+        return new Promise((resolve, reject) => {
+            const sequence = this.sequence++;
+
+            this.listeners[sequence] = {
+                callback: resolve,
+                timer: setTimeout(() => {
+                    delete this.listeners[sequence];
+                    reject(new Error(`Mecab invoke timed out in ${Mecab.timeout} ms`));
+                }, Mecab.timeout)
+            };
+
+            this.port.postMessage({action, params, sequence});
+        });
+    }
+}
+
+Mecab.timeout = 5000;
+Mecab.version = 1;