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authorwolfbeast <mcwerewolf@gmail.com>2018-06-04 13:17:38 +0200
committerwolfbeast <mcwerewolf@gmail.com>2018-06-04 13:17:38 +0200
commita1be17c1cea81ebb1e8b131a662c698d78f3f7f2 (patch)
treea92f7de513be600cc07bac458183e9af40e00c06 /application/basilisk/components/sessionstore/TabStateCache.jsm
parentbf11fdd304898ac675e39b01b280d39550e419d0 (diff)
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Issue #303 Part 1: Move basilisk files from /browser to /application/basilisk
Diffstat (limited to 'application/basilisk/components/sessionstore/TabStateCache.jsm')
-rw-r--r--application/basilisk/components/sessionstore/TabStateCache.jsm163
1 files changed, 163 insertions, 0 deletions
diff --git a/application/basilisk/components/sessionstore/TabStateCache.jsm b/application/basilisk/components/sessionstore/TabStateCache.jsm
new file mode 100644
index 000000000..9bed315a0
--- /dev/null
+++ b/application/basilisk/components/sessionstore/TabStateCache.jsm
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+/* 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/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["TabStateCache"];
+
+/**
+ * A cache for tabs data.
+ *
+ * This cache implements a weak map from tabs (as XUL elements)
+ * to tab data (as objects).
+ *
+ * Note that we should never cache private data, as:
+ * - that data is used very seldom by SessionStore;
+ * - caching private data in addition to public data is memory consuming.
+ */
+this.TabStateCache = Object.freeze({
+ /**
+ * Retrieves cached data for a given |tab| or associated |browser|.
+ *
+ * @param browserOrTab (xul:tab or xul:browser)
+ * The tab or browser to retrieve cached data for.
+ * @return (object)
+ * The cached data stored for the given |tab|
+ * or associated |browser|.
+ */
+ get: function (browserOrTab) {
+ return TabStateCacheInternal.get(browserOrTab);
+ },
+
+ /**
+ * Updates cached data for a given |tab| or associated |browser|.
+ *
+ * @param browserOrTab (xul:tab or xul:browser)
+ * The tab or browser belonging to the given tab data.
+ * @param newData (object)
+ * The new data to be stored for the given |tab|
+ * or associated |browser|.
+ */
+ update: function (browserOrTab, newData) {
+ TabStateCacheInternal.update(browserOrTab, newData);
+ }
+});
+
+var TabStateCacheInternal = {
+ _data: new WeakMap(),
+
+ /**
+ * Retrieves cached data for a given |tab| or associated |browser|.
+ *
+ * @param browserOrTab (xul:tab or xul:browser)
+ * The tab or browser to retrieve cached data for.
+ * @return (object)
+ * The cached data stored for the given |tab|
+ * or associated |browser|.
+ */
+ get: function (browserOrTab) {
+ return this._data.get(browserOrTab.permanentKey);
+ },
+
+ /**
+ * Helper function used by update (see below). For message size
+ * optimization sometimes we don't update the whole session storage
+ * only the values that have been changed.
+ *
+ * @param data (object)
+ * The cached data where we want to update the changes.
+ * @param change (object)
+ * The actual changed values per domain.
+ */
+ updatePartialStorageChange: function (data, change) {
+ if (!data.storage) {
+ data.storage = {};
+ }
+
+ let storage = data.storage;
+ for (let domain of Object.keys(change)) {
+ for (let key of Object.keys(change[domain])) {
+ let value = change[domain][key];
+ if (value === null) {
+ if (storage[domain] && storage[domain][key]) {
+ delete storage[domain][key];
+ }
+ } else {
+ if (!storage[domain]) {
+ storage[domain] = {};
+ }
+ storage[domain][key] = value;
+ }
+ }
+ }
+ },
+
+ /**
+ * Helper function used by update (see below). For message size
+ * optimization sometimes we don't update the whole browser history
+ * only the current index and the tail of the history from a certain
+ * index (specified by change.fromIdx)
+ *
+ * @param data (object)
+ * The cached data where we want to update the changes.
+ * @param change (object)
+ * Object containing the tail of the history array, and
+ * some additional metadata.
+ */
+ updatePartialHistoryChange: function (data, change) {
+ const kLastIndex = Number.MAX_SAFE_INTEGER - 1;
+
+ if (!data.history) {
+ data.history = { entries: [] };
+ }
+
+ let history = data.history;
+ for (let key of Object.keys(change)) {
+ if (key == "entries") {
+ if (change.fromIdx != kLastIndex) {
+ history.entries.splice(change.fromIdx + 1);
+ while (change.entries.length) {
+ history.entries.push(change.entries.shift());
+ }
+ }
+ } else if (key != "fromIndex") {
+ history[key] = change[key];
+ }
+ }
+ },
+
+ /**
+ * Updates cached data for a given |tab| or associated |browser|.
+ *
+ * @param browserOrTab (xul:tab or xul:browser)
+ * The tab or browser belonging to the given tab data.
+ * @param newData (object)
+ * The new data to be stored for the given |tab|
+ * or associated |browser|.
+ */
+ update: function (browserOrTab, newData) {
+ let data = this._data.get(browserOrTab.permanentKey) || {};
+
+ for (let key of Object.keys(newData)) {
+ if (key == "storagechange") {
+ this.updatePartialStorageChange(data, newData.storagechange);
+ continue;
+ }
+
+ if (key == "historychange") {
+ this.updatePartialHistoryChange(data, newData.historychange);
+ continue;
+ }
+
+ let value = newData[key];
+ if (value === null) {
+ delete data[key];
+ } else {
+ data[key] = value;
+ }
+ }
+
+ this._data.set(browserOrTab.permanentKey, data);
+ }
+};