Bug 1294866 - Part 1: Move principal serialization to a utils file. r=mikedeboer

--HG--
extra : rebase_source : da212f0a03fff8cfaf5d76256e1558a9f6d095c7

browser/components/sessionstore/SessionHistory.jsm

@@ -172,7 +172,7 @@ var SessionHistoryInternal = {
 
     // Collect triggeringPrincipal data for the current history entry.
     try {
-      let triggeringPrincipal = this.serializeTriggeringPrincipal(shEntry);
+      let triggeringPrincipal = Utils.serializePrincipal(shEntry.triggeringPrincipal);
       if (triggeringPrincipal) {
         entry.triggeringPrincipal_b64 = triggeringPrincipal;
       }
@@ -218,39 +218,6 @@ var SessionHistoryInternal = {
     return entry;
   },
 
-  /**
-   * Serialize triggeringPrincipal data contained in the given session history entry.
-   *
-   * @param shEntry
-   *        The session history entry.
-   * @return The base64 encoded triggeringPrincipal data.
-   */
-  serializeTriggeringPrincipal: function (shEntry) {
-    if (!shEntry.triggeringPrincipal) {
-      return null;
-    }
-
-    let binaryStream = Cc["@mozilla.org/binaryoutputstream;1"].
-                       createInstance(Ci.nsIObjectOutputStream);
-    let pipe = Cc["@mozilla.org/pipe;1"].createInstance(Ci.nsIPipe);
-    pipe.init(false, false, 0, 0xffffffff, null);
-    binaryStream.setOutputStream(pipe.outputStream);
-    binaryStream.writeCompoundObject(shEntry.triggeringPrincipal, Ci.nsIPrincipal, true);
-    binaryStream.close();
-
-    // Now we want to read the data from the pipe's input end and encode it.
-    let scriptableStream = Cc["@mozilla.org/binaryinputstream;1"].
-                           createInstance(Ci.nsIBinaryInputStream);
-    scriptableStream.setInputStream(pipe.inputStream);
-    let triggeringPrincipalBytes =
-      scriptableStream.readByteArray(scriptableStream.available());
-
-    // We can stop doing base64 encoding once our serialization into JSON
-    // is guaranteed to handle all chars in strings, including embedded
-    // nulls.
-    return btoa(String.fromCharCode.apply(null, triggeringPrincipalBytes));
-  },
-
   /**
    * Restores session history data for a given docShell.
    *
@@ -388,16 +355,7 @@ var SessionHistoryInternal = {
     }
 
     if (entry.triggeringPrincipal_b64) {
-      var triggeringPrincipalInput = Cc["@mozilla.org/io/string-input-stream;1"]
-                                       .createInstance(Ci.nsIStringInputStream);
-      var binaryData = atob(entry.triggeringPrincipal_b64);
-      triggeringPrincipalInput.setData(binaryData, binaryData.length);
-      var binaryStream = Cc["@mozilla.org/binaryinputstream;1"].
-                         createInstance(Ci.nsIObjectInputStream);
-      binaryStream.setInputStream(triggeringPrincipalInput);
-      try { // Catch possible deserialization exceptions
-        shEntry.triggeringPrincipal = binaryStream.readObject(true);
-      } catch (ex) { debug(ex); }
+      shEntry.triggeringPrincipal = Utils.deserializePrincipal(entry.triggeringPrincipal_b64);
     }
 
     if (entry.children && shEntry instanceof Ci.nsISHContainer) {

browser/components/sessionstore/Utils.jsm

@@ -11,6 +11,11 @@ const Cc = Components.classes;
 const Ci = Components.interfaces;
 
 Cu.import("resource://gre/modules/Services.jsm", this);
+Cu.import("resource://gre/modules/XPCOMUtils.jsm", this);
+
+XPCOMUtils.defineLazyServiceGetter(this, "serializationHelper",
+                                   "@mozilla.org/network/serialization-helper;1",
+                                   "nsISerializationHelper");
 
 this.Utils = Object.freeze({
   makeURI: function (url) {
@@ -60,5 +65,35 @@ this.Utils = Object.freeze({
     }
 
     return retval;
+  },
+
+  /**
+   * Serialize principal data.
+   *
+   * @param {nsIPrincipal} principal The principal to serialize.
+   * @return {String} The base64 encoded principal data.
+   */
+  serializePrincipal(principal) {
+    if (!principal)
+      return null;
+
+    return serializationHelper.serializeToString(principal);
+  },
+
+  /**
+   * Deserialize a base64 encoded principal (serialized with
+   * Utils::serializePrincipal).
+   *
+   * @param {String} principal_b64 A base64 encoded serialized principal.
+   * @return {nsIPrincipal} A deserialized principal.
+   */
+  deserializePrincipal(principal_b64) {
+    if (!principal_b64)
+      return null;
+
+    let principal = serializationHelper.deserializeObject(principal_b64);
+    principal.QueryInterface(Ci.nsIPrincipal);
+
+    return principal;
   }
 });