1 files changed, 83 insertions, 0 deletions
diff --git a/data/extensions/jsr@javascriptrestrictor/nscl/service/NavCache.js b/data/extensions/jsr@javascriptrestrictor/nscl/service/NavCache.js
new file mode 100644
index 0000000..43ee91c
--- /dev/null
+++ b/data/extensions/jsr@javascriptrestrictor/nscl/service/NavCache.js
@@ -0,0 +1,83 @@
+/*
+ * NoScript Commons Library
+ * Reusable building blocks for cross-browser security/privacy WebExtensions.
+ * Copyright (C) 2020-2021 Giorgio Maone <https://maone.net>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ * 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/>.
+ */
+
+var NavCache = (() => {
+
+  let tabs = {};
+  let listeners = new Set();
+
+  let clone = structuredClone || (o => JSON.parse(JSON.stringify(o)));
+
+  browser.webNavigation.onCommitted.addListener(({tabId, frameId, url, parentFrameId}) => {
+    let tab = tabs[tabId];
+    let frame = tab && tab[frameId];
+    if (!tab || frameId == 0) {
+      tabs[tabId] = tab = {};
+    }
+    let previousUrl = frame && frame.url;
+    frame = tab[frameId] = {previousUrl, url, parentFrameId};
+    if (previousUrl !== url) {
+      for (let l of listeners) {
+        try {
+          l(Object.assign({tabId, frameId}, frame));
+        } catch (e) {
+          console.error(e);
+        }
+      }
+    }
+  });
+
+  browser.tabs.onRemoved.addListener(tabId => {
+    tabs.delete(tabId);
+  });
+
+
+  (async () => {
+
+    async function populateFrames(tab) {
+      let tabId = tab.id;
+      let frames =  await browser.webNavigation.getAllFrames({tabId});
+      if (!frames) return; // invalid tab
+      if (!tabs[tabId]) tabs[tabId] = {};
+      let top = tabs[tabId];
+      for ({frameId, url, parentFrameId} of frames) {
+        tab[frameId] = {url, parentFrameId};
+      }
+    }
+    await Promise.all((await browser.tabs.query({})).map(populateFrames));
+  })();
+
+  return {
+    getTab(tabId) {
+      return clone(tabs[tabId] || {});
+    },
+    getFrame(tabId, frameId) {
+      return clone((tabs[tabId] || {})[frameId]);
+    },
+    onUrlChanged: {
+      addListener(listener) {
+        listeners.add(listener);
+      },
+      removeListener(listener) {
+        listeners.remove(listeners);
+      }
+    }
+  };
+})();