1 files changed, 204 insertions, 0 deletions
diff --git a/browser/components/sessionstore/TabState.sys.mjs b/browser/components/sessionstore/TabState.sys.mjs
new file mode 100644
index 0000000000..26f5671c84
--- /dev/null
+++ b/browser/components/sessionstore/TabState.sys.mjs
@@ -0,0 +1,204 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  PrivacyFilter: "resource://gre/modules/sessionstore/PrivacyFilter.sys.mjs",
+  TabAttributes: "resource:///modules/sessionstore/TabAttributes.sys.mjs",
+  TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
+});
+
+/**
+ * Module that contains tab state collection methods.
+ */
+export var TabState = Object.freeze({
+  update(permanentKey, data) {
+    TabStateInternal.update(permanentKey, data);
+  },
+
+  collect(tab, extData) {
+    return TabStateInternal.collect(tab, extData);
+  },
+
+  clone(tab, extData) {
+    return TabStateInternal.clone(tab, extData);
+  },
+
+  copyFromCache(permanentKey, tabData, options) {
+    TabStateInternal.copyFromCache(permanentKey, tabData, options);
+  },
+});
+
+var TabStateInternal = {
+  /**
+   * Processes a data update sent by the content script.
+   */
+  update(permanentKey, { data }) {
+    lazy.TabStateCache.update(permanentKey, data);
+  },
+
+  /**
+   * Collect data related to a single tab, synchronously.
+   *
+   * @param tab
+   *        tabbrowser tab
+   * @param [extData]
+   *        optional dictionary object, containing custom tab values.
+   *
+   * @returns {TabData} An object with the data for this tab.  If the
+   * tab has not been invalidated since the last call to
+   * collect(aTab), the same object is returned.
+   */
+  collect(tab, extData) {
+    return this._collectBaseTabData(tab, { extData });
+  },
+
+  /**
+   * Collect data related to a single tab, including private data.
+   * Use with caution.
+   *
+   * @param tab
+   *        tabbrowser tab
+   * @param [extData]
+   *        optional dictionary object, containing custom tab values.
+   *
+   * @returns {object} An object with the data for this tab. This data is never
+   *                   cached, it will always be read from the tab and thus be
+   *                   up-to-date.
+   */
+  clone(tab, extData) {
+    return this._collectBaseTabData(tab, { extData, includePrivateData: true });
+  },
+
+  /**
+   * Collects basic tab data for a given tab.
+   *
+   * @param tab
+   *        tabbrowser tab
+   * @param options (object)
+   *        {extData: object} optional dictionary object, containing custom tab values
+   *        {includePrivateData: true} to always include private data
+   *
+   * @returns {object} An object with the basic data for this tab.
+   */
+  _collectBaseTabData(tab, options) {
+    let tabData = { entries: [], lastAccessed: tab.lastAccessed };
+    let browser = tab.linkedBrowser;
+
+    if (tab.pinned) {
+      tabData.pinned = true;
+    }
+
+    tabData.hidden = tab.hidden;
+
+    if (browser.audioMuted) {
+      tabData.muted = true;
+      tabData.muteReason = tab.muteReason;
+    }
+
+    tabData.searchMode = tab.ownerGlobal.gURLBar.getSearchMode(browser, true);
+
+    tabData.userContextId = tab.userContextId || 0;
+
+    // Save tab attributes.
+    tabData.attributes = lazy.TabAttributes.get(tab);
+
+    if (options.extData) {
+      tabData.extData = options.extData;
+    }
+
+    // Copy data from the tab state cache only if the tab has fully finished
+    // restoring. We don't want to overwrite data contained in __SS_data.
+    this.copyFromCache(browser.permanentKey, tabData, options);
+
+    // After copyFromCache() was called we check for properties that are kept
+    // in the cache only while the tab is pending or restoring. Once that
+    // happened those properties will be removed from the cache and will
+    // be read from the tab/browser every time we collect data.
+
+    // Store the tab icon.
+    if (!("image" in tabData)) {
+      let tabbrowser = tab.ownerGlobal.gBrowser;
+      tabData.image = tabbrowser.getIcon(tab);
+    }
+
+    // If there is a userTypedValue set, then either the user has typed something
+    // in the URL bar, or a new tab was opened with a URI to load.
+    // If so, we also track whether we were still in the process of loading something.
+    if (!("userTypedValue" in tabData) && browser.userTypedValue) {
+      tabData.userTypedValue = browser.userTypedValue;
+      // We always used to keep track of the loading state as an integer, where
+      // '0' indicated the user had typed since the last load (or no load was
+      // ongoing), and any positive value indicated we had started a load since
+      // the last time the user typed in the URL bar. Mimic this to keep the
+      // session store representation in sync, even though we now represent this
+      // more explicitly:
+      tabData.userTypedClear = browser.didStartLoadSinceLastUserTyping()
+        ? 1
+        : 0;
+    }
+
+    return tabData;
+  },
+
+  /**
+   * Copy data for the given |browser| from the cache to |tabData|.
+   *
+   * @param permanentKey (object)
+   *        The browser belonging to the given |tabData| object.
+   * @param tabData (object)
+   *        The tab data belonging to the given |tab|.
+   * @param options (object)
+   *        {includePrivateData: true} to always include private data
+   */
+  copyFromCache(permanentKey, tabData, options = {}) {
+    let data = lazy.TabStateCache.get(permanentKey);
+    if (!data) {
+      return;
+    }
+
+    // The caller may explicitly request to omit privacy checks.
+    let includePrivateData = options && options.includePrivateData;
+
+    for (let key of Object.keys(data)) {
+      let value = data[key];
+
+      // Filter sensitive data according to the current privacy level.
+      if (!includePrivateData) {
+        if (key === "storage") {
+          value = lazy.PrivacyFilter.filterSessionStorageData(value);
+        } else if (key === "formdata") {
+          value = lazy.PrivacyFilter.filterFormData(value);
+        }
+      }
+
+      if (key === "history") {
+        // Make a shallow copy of the entries array. We (currently) don't update
+        // entries in place, so we don't have to worry about performing a deep
+        // copy.
+        tabData.entries = [...value.entries];
+
+        if (value.hasOwnProperty("index")) {
+          tabData.index = value.index;
+        }
+
+        if (value.hasOwnProperty("requestedIndex")) {
+          tabData.requestedIndex = value.requestedIndex;
+        }
+      } else if (!value && (key == "scroll" || key == "formdata")) {
+        // [Bug 1554512]
+
+        // If scroll or formdata null it indicates that the update to
+        // be performed is to remove them, and not copy a null
+        // value. Scroll will be null when the position is at the top
+        // of the document, formdata will be null when there is only
+        // default data.
+        delete tabData[key];
+      } else {
+        tabData[key] = value;
+      }
+    }
+  },
+};