1 files changed, 428 insertions, 0 deletions
diff --git a/browser/components/sessionstore/SessionHistory.jsm b/browser/components/sessionstore/SessionHistory.jsm
new file mode 100644
index 000000000..aa9c10379
--- /dev/null
+++ b/browser/components/sessionstore/SessionHistory.jsm
@@ -0,0 +1,428 @@
+/* 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 = ["SessionHistory"];
+
+const Cu = Components.utils;
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "Utils",
+  "resource://gre/modules/sessionstore/Utils.jsm");
+
+function debug(msg) {
+  Services.console.logStringMessage("SessionHistory: " + msg);
+}
+
+/**
+ * The external API exported by this module.
+ */
+this.SessionHistory = Object.freeze({
+  isEmpty: function (docShell) {
+    return SessionHistoryInternal.isEmpty(docShell);
+  },
+
+  collect: function (docShell) {
+    return SessionHistoryInternal.collect(docShell);
+  },
+
+  restore: function (docShell, tabData) {
+    SessionHistoryInternal.restore(docShell, tabData);
+  }
+});
+
+/**
+ * The internal API for the SessionHistory module.
+ */
+var SessionHistoryInternal = {
+  /**
+   * Returns whether the given docShell's session history is empty.
+   *
+   * @param docShell
+   *        The docShell that owns the session history.
+   */
+  isEmpty: function (docShell) {
+    let webNavigation = docShell.QueryInterface(Ci.nsIWebNavigation);
+    let history = webNavigation.sessionHistory;
+    if (!webNavigation.currentURI) {
+      return true;
+    }
+    let uri = webNavigation.currentURI.spec;
+    return uri == "about:blank" && history.count == 0;
+  },
+
+  /**
+   * Collects session history data for a given docShell.
+   *
+   * @param docShell
+   *        The docShell that owns the session history.
+   */
+  collect: function (docShell) {
+    let loadContext = docShell.QueryInterface(Ci.nsILoadContext);
+    let webNavigation = docShell.QueryInterface(Ci.nsIWebNavigation);
+    let history = webNavigation.sessionHistory.QueryInterface(Ci.nsISHistoryInternal);
+
+    let data = {entries: [], userContextId: loadContext.originAttributes.userContextId };
+
+    if (history && history.count > 0) {
+      // Loop over the transaction linked list directly so we can get the
+      // persist property for each transaction.
+      for (let txn = history.rootTransaction; txn; txn = txn.next) {
+        let entry = this.serializeEntry(txn.sHEntry);
+        entry.persist = txn.persist;
+        data.entries.push(entry);
+      }
+
+      // Ensure the index isn't out of bounds if an exception was thrown above.
+      data.index = Math.min(history.index + 1, data.entries.length);
+    }
+
+    // If either the session history isn't available yet or doesn't have any
+    // valid entries, make sure we at least include the current page.
+    if (data.entries.length == 0) {
+      let uri = webNavigation.currentURI.spec;
+      let body = webNavigation.document.body;
+      // We landed here because the history is inaccessible or there are no
+      // history entries. In that case we should at least record the docShell's
+      // current URL as a single history entry. If the URL is not about:blank
+      // or it's a blank tab that was modified (like a custom newtab page),
+      // record it. For about:blank we explicitly want an empty array without
+      // an 'index' property to denote that there are no history entries.
+      if (uri != "about:blank" || (body && body.hasChildNodes())) {
+        data.entries.push({ url: uri });
+        data.index = 1;
+      }
+    }
+
+    return data;
+  },
+
+  /**
+   * Get an object that is a serialized representation of a History entry.
+   *
+   * @param shEntry
+   *        nsISHEntry instance
+   * @return object
+   */
+  serializeEntry: function (shEntry) {
+    let entry = { url: shEntry.URI.spec };
+
+    // Save some bytes and don't include the title property
+    // if that's identical to the current entry's URL.
+    if (shEntry.title && shEntry.title != entry.url) {
+      entry.title = shEntry.title;
+    }
+    if (shEntry.isSubFrame) {
+      entry.subframe = true;
+    }
+
+    entry.charset = shEntry.URI.originCharset;
+
+    let cacheKey = shEntry.cacheKey;
+    if (cacheKey && cacheKey instanceof Ci.nsISupportsPRUint32 &&
+        cacheKey.data != 0) {
+      // XXXbz would be better to have cache keys implement
+      // nsISerializable or something.
+      entry.cacheKey = cacheKey.data;
+    }
+    entry.ID = shEntry.ID;
+    entry.docshellID = shEntry.docshellID;
+
+    // We will include the property only if it's truthy to save a couple of
+    // bytes when the resulting object is stringified and saved to disk.
+    if (shEntry.referrerURI) {
+      entry.referrer = shEntry.referrerURI.spec;
+      entry.referrerPolicy = shEntry.referrerPolicy;
+    }
+
+    if (shEntry.originalURI) {
+      entry.originalURI = shEntry.originalURI.spec;
+    }
+
+    if (shEntry.loadReplace) {
+      entry.loadReplace = shEntry.loadReplace;
+    }
+
+    if (shEntry.srcdocData)
+      entry.srcdocData = shEntry.srcdocData;
+
+    if (shEntry.isSrcdocEntry)
+      entry.isSrcdocEntry = shEntry.isSrcdocEntry;
+
+    if (shEntry.baseURI)
+      entry.baseURI = shEntry.baseURI.spec;
+
+    if (shEntry.contentType)
+      entry.contentType = shEntry.contentType;
+
+    if (shEntry.scrollRestorationIsManual) {
+      entry.scrollRestorationIsManual = true;
+    } else {
+      let x = {}, y = {};
+      shEntry.getScrollPosition(x, y);
+      if (x.value != 0 || y.value != 0)
+        entry.scroll = x.value + "," + y.value;
+    }
+
+    // Collect triggeringPrincipal data for the current history entry.
+    // Please note that before Bug 1297338 there was no concept of a
+    // principalToInherit. To remain backward/forward compatible we
+    // serialize the principalToInherit as triggeringPrincipal_b64.
+    // Once principalToInherit is well established (within FF55)
+    // we can update this code, remove triggeringPrincipal_b64 and
+    // just keep triggeringPrincipal_base64 as well as
+    // principalToInherit_base64;  see Bug 1301666.
+    if (shEntry.principalToInherit) {
+      try {
+        let principalToInherit = Utils.serializePrincipal(shEntry.principalToInherit);
+        if (principalToInherit) {
+          entry.triggeringPrincipal_b64 = principalToInherit;
+          entry.principalToInherit_base64 = principalToInherit;
+        }
+      } catch (e) {
+        debug(e);
+      }
+    }
+
+    if (shEntry.triggeringPrincipal) {
+      try {
+        let triggeringPrincipal = Utils.serializePrincipal(shEntry.triggeringPrincipal);
+        if (triggeringPrincipal) {
+          entry.triggeringPrincipal_base64 = triggeringPrincipal;
+        }
+      } catch (e) {
+        debug(e);
+      }
+    }
+
+    entry.docIdentifier = shEntry.BFCacheEntry.ID;
+
+    if (shEntry.stateData != null) {
+      entry.structuredCloneState = shEntry.stateData.getDataAsBase64();
+      entry.structuredCloneVersion = shEntry.stateData.formatVersion;
+    }
+
+    if (!(shEntry instanceof Ci.nsISHContainer)) {
+      return entry;
+    }
+
+    if (shEntry.childCount > 0 && !shEntry.hasDynamicallyAddedChild()) {
+      let children = [];
+      for (let i = 0; i < shEntry.childCount; i++) {
+        let child = shEntry.GetChildAt(i);
+
+        if (child) {
+          // Don't try to restore framesets containing wyciwyg URLs.
+          // (cf. bug 424689 and bug 450595)
+          if (child.URI.schemeIs("wyciwyg")) {
+            children.length = 0;
+            break;
+          }
+
+          children.push(this.serializeEntry(child));
+        }
+      }
+
+      if (children.length) {
+        entry.children = children;
+      }
+    }
+
+    return entry;
+  },
+
+  /**
+   * Restores session history data for a given docShell.
+   *
+   * @param docShell
+   *        The docShell that owns the session history.
+   * @param tabData
+   *        The tabdata including all history entries.
+   */
+  restore: function (docShell, tabData) {
+    let webNavigation = docShell.QueryInterface(Ci.nsIWebNavigation);
+    let history = webNavigation.sessionHistory;
+    if (history.count > 0) {
+      history.PurgeHistory(history.count);
+    }
+    history.QueryInterface(Ci.nsISHistoryInternal);
+
+    let idMap = { used: {} };
+    let docIdentMap = {};
+    for (let i = 0; i < tabData.entries.length; i++) {
+      let entry = tabData.entries[i];
+      //XXXzpao Wallpaper patch for bug 514751
+      if (!entry.url)
+        continue;
+      let persist = "persist" in entry ? entry.persist : true;
+      history.addEntry(this.deserializeEntry(entry, idMap, docIdentMap), persist);
+    }
+
+    // Select the right history entry.
+    let index = tabData.index - 1;
+    if (index < history.count && history.index != index) {
+      history.getEntryAtIndex(index, true);
+    }
+  },
+
+  /**
+   * Expands serialized history data into a session-history-entry instance.
+   *
+   * @param entry
+   *        Object containing serialized history data for a URL
+   * @param idMap
+   *        Hash for ensuring unique frame IDs
+   * @param docIdentMap
+   *        Hash to ensure reuse of BFCache entries
+   * @returns nsISHEntry
+   */
+  deserializeEntry: function (entry, idMap, docIdentMap) {
+
+    var shEntry = Cc["@mozilla.org/browser/session-history-entry;1"].
+                  createInstance(Ci.nsISHEntry);
+
+    shEntry.setURI(Utils.makeURI(entry.url, entry.charset));
+    shEntry.setTitle(entry.title || entry.url);
+    if (entry.subframe)
+      shEntry.setIsSubFrame(entry.subframe || false);
+    shEntry.loadType = Ci.nsIDocShellLoadInfo.loadHistory;
+    if (entry.contentType)
+      shEntry.contentType = entry.contentType;
+    if (entry.referrer) {
+      shEntry.referrerURI = Utils.makeURI(entry.referrer);
+      shEntry.referrerPolicy = entry.referrerPolicy;
+    }
+    if (entry.originalURI) {
+      shEntry.originalURI = Utils.makeURI(entry.originalURI);
+    }
+    if (entry.loadReplace) {
+      shEntry.loadReplace = entry.loadReplace;
+    }
+    if (entry.isSrcdocEntry)
+      shEntry.srcdocData = entry.srcdocData;
+    if (entry.baseURI)
+      shEntry.baseURI = Utils.makeURI(entry.baseURI);
+
+    if (entry.cacheKey) {
+      var cacheKey = Cc["@mozilla.org/supports-PRUint32;1"].
+                     createInstance(Ci.nsISupportsPRUint32);
+      cacheKey.data = entry.cacheKey;
+      shEntry.cacheKey = cacheKey;
+    }
+
+    if (entry.ID) {
+      // get a new unique ID for this frame (since the one from the last
+      // start might already be in use)
+      var id = idMap[entry.ID] || 0;
+      if (!id) {
+        for (id = Date.now(); id in idMap.used; id++);
+        idMap[entry.ID] = id;
+        idMap.used[id] = true;
+      }
+      shEntry.ID = id;
+    }
+
+    if (entry.docshellID)
+      shEntry.docshellID = entry.docshellID;
+
+    if (entry.structuredCloneState && entry.structuredCloneVersion) {
+      shEntry.stateData =
+        Cc["@mozilla.org/docshell/structured-clone-container;1"].
+        createInstance(Ci.nsIStructuredCloneContainer);
+
+      shEntry.stateData.initFromBase64(entry.structuredCloneState,
+                                       entry.structuredCloneVersion);
+    }
+
+    if (entry.scrollRestorationIsManual) {
+      shEntry.scrollRestorationIsManual = true;
+    } else if (entry.scroll) {
+      var scrollPos = (entry.scroll || "0,0").split(",");
+      scrollPos = [parseInt(scrollPos[0]) || 0, parseInt(scrollPos[1]) || 0];
+      shEntry.setScrollPosition(scrollPos[0], scrollPos[1]);
+    }
+
+    let childDocIdents = {};
+    if (entry.docIdentifier) {
+      // If we have a serialized document identifier, try to find an SHEntry
+      // which matches that doc identifier and adopt that SHEntry's
+      // BFCacheEntry.  If we don't find a match, insert shEntry as the match
+      // for the document identifier.
+      let matchingEntry = docIdentMap[entry.docIdentifier];
+      if (!matchingEntry) {
+        matchingEntry = {shEntry: shEntry, childDocIdents: childDocIdents};
+        docIdentMap[entry.docIdentifier] = matchingEntry;
+      }
+      else {
+        shEntry.adoptBFCacheEntry(matchingEntry.shEntry);
+        childDocIdents = matchingEntry.childDocIdents;
+      }
+    }
+
+    // The field entry.owner_b64 got renamed to entry.triggeringPricipal_b64 in
+    // Bug 1286472. To remain backward compatible we still have to support that
+    // field for a few cycles before we can remove it within Bug 1289785.
+    if (entry.owner_b64) {
+      entry.triggeringPricipal_b64 = entry.owner_b64;
+      delete entry.owner_b64;
+    }
+
+    // Before introducing the concept of principalToInherit we only had
+    // a triggeringPrincipal within every entry which basically is the
+    // equivalent of the new principalToInherit. To avoid compatibility
+    // issues, we first check if the entry has entries for
+    // triggeringPrincipal_base64 and principalToInherit_base64. If not
+    // we fall back to using the principalToInherit (which is stored
+    // as triggeringPrincipal_b64) as the triggeringPrincipal and
+    // the principalToInherit.
+    // FF55 will remove the triggeringPrincipal_b64, see Bug 1301666.
+    if (entry.triggeringPrincipal_base64 || entry.principalToInherit_base64) {
+      if (entry.triggeringPrincipal_base64) {
+        shEntry.triggeringPrincipal =
+          Utils.deserializePrincipal(entry.triggeringPrincipal_base64);
+      }
+      if (entry.principalToInherit_base64) {
+        shEntry.principalToInherit =
+          Utils.deserializePrincipal(entry.principalToInherit_base64);
+      }
+    } else if (entry.triggeringPrincipal_b64) {
+      shEntry.triggeringPrincipal = Utils.deserializePrincipal(entry.triggeringPrincipal_b64);
+      shEntry.principalToInherit = shEntry.triggeringPrincipal;
+    }
+
+    if (entry.children && shEntry instanceof Ci.nsISHContainer) {
+      for (var i = 0; i < entry.children.length; i++) {
+        //XXXzpao Wallpaper patch for bug 514751
+        if (!entry.children[i].url)
+          continue;
+
+        // We're getting sessionrestore.js files with a cycle in the
+        // doc-identifier graph, likely due to bug 698656.  (That is, we have
+        // an entry where doc identifier A is an ancestor of doc identifier B,
+        // and another entry where doc identifier B is an ancestor of A.)
+        //
+        // If we were to respect these doc identifiers, we'd create a cycle in
+        // the SHEntries themselves, which causes the docshell to loop forever
+        // when it looks for the root SHEntry.
+        //
+        // So as a hack to fix this, we restrict the scope of a doc identifier
+        // to be a node's siblings and cousins, and pass childDocIdents, not
+        // aDocIdents, to _deserializeHistoryEntry.  That is, we say that two
+        // SHEntries with the same doc identifier have the same document iff
+        // they have the same parent or their parents have the same document.
+
+        shEntry.AddChild(this.deserializeEntry(entry.children[i], idMap,
+                                               childDocIdents), i);
+      }
+    }
+
+    return shEntry;
+  },
+
+};