1 files changed, 88 insertions, 0 deletions
diff --git a/data/extensions/uBlock0@raymondhill.net/js/logger.js b/data/extensions/uBlock0@raymondhill.net/js/logger.js
new file mode 100644
index 0000000..aa6755d
--- /dev/null
+++ b/data/extensions/uBlock0@raymondhill.net/js/logger.js
@@ -0,0 +1,88 @@
+/*******************************************************************************
+
+    uBlock Origin - a comprehensive, efficient content blocker
+    Copyright (C) 2015-present Raymond Hill
+
+    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/}.
+
+    Home: https://github.com/gorhill/uBlock
+*/
+
+import { broadcast, broadcastToAll } from './broadcast.js';
+
+/******************************************************************************/
+
+let buffer = null;
+let lastReadTime = 0;
+let writePtr = 0;
+
+// After 30 seconds without being read, the logger buffer will be considered
+// unused, and thus disabled.
+const logBufferObsoleteAfter = 30 * 1000;
+
+const janitorTimer = vAPI.defer.create(( ) => {
+    if ( buffer === null ) { return; }
+    if ( lastReadTime >= (Date.now() - logBufferObsoleteAfter) ) {
+        return janitorTimer.on(logBufferObsoleteAfter);
+    }
+    logger.enabled = false;
+    buffer = null;
+    writePtr = 0;
+    logger.ownerId = undefined;
+    broadcastToAll({ what: 'loggerDisabled' });
+});
+
+const boxEntry = details => {
+    details.tstamp = Date.now() / 1000 | 0;
+    return JSON.stringify(details);
+};
+
+const pushOne = box => {
+    if ( writePtr !== 0 && box === buffer[writePtr-1] ) { return; }
+    if ( writePtr === buffer.length ) {
+        buffer.push(box);
+    } else {
+        buffer[writePtr] = box;
+    }
+    writePtr += 1;
+};
+
+const logger = {
+    enabled: false,
+    ownerId: undefined,
+    writeOne(details) {
+        if ( buffer === null ) { return; }
+        pushOne(boxEntry(details));
+    },
+    readAll(ownerId) {
+        this.ownerId = ownerId;
+        if ( buffer === null ) {
+            this.enabled = true;
+            buffer = [];
+            janitorTimer.on(logBufferObsoleteAfter);
+            broadcast({ what: 'loggerEnabled' });
+        }
+        const out = buffer.slice(0, writePtr);
+        buffer.fill('', 0, writePtr);
+        writePtr = 0;
+        lastReadTime = Date.now();
+        return out;
+    },
+};
+
+/******************************************************************************/
+
+export default logger;
+
+/******************************************************************************/