1 files changed, 103 insertions, 0 deletions
diff --git a/comm/suite/chatzilla/js/lib/json-serializer.js b/comm/suite/chatzilla/js/lib/json-serializer.js
new file mode 100644
index 0000000000..93333f2bb1
--- /dev/null
+++ b/comm/suite/chatzilla/js/lib/json-serializer.js
@@ -0,0 +1,103 @@
+/* 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/. */
+
+/* This is a simple set of functions for serializing and parsing JS objects
+ * to and from files.
+ */
+
+function JSONSerializer(file) {
+  if (typeof file == "string")
+    this._file = new nsLocalFile(file);
+  else
+    this._file = file;
+  this._open = false;
+}
+
+JSONSerializer.prototype = {
+  /*
+   * Opens the serializer on the file specified when created, in either the read
+   * ("<") or write (">") directions. When the file is open, only the
+   * appropriate direction of serialization/deserialization may be performed.
+   *
+   * Note: serialize and deserialize automatically open the file if it is not
+   *       open.
+   *
+   * @param dir   The string representing the direction of serialization.
+   * @returns     Value indicating whether the file was opened successfully.
+   */
+  open: function(dir) {
+    if (!ASSERT((dir == ">") || (dir == "<"), "Bad serialization direction!")) {
+      return false;
+    }
+    if (this._open) {
+      return false;
+    }
+
+    this._fileStream = new LocalFile(this._file, dir);
+    if ((typeof this._fileStream == "object") && this._fileStream) {
+      this._open = true;
+    }
+
+    return this._open;
+  },
+
+  /*
+   * Closes the file stream and ends reading or writing.
+   *
+   * @returns     Value indicating whether the file was closed successfully.
+   */
+  close: function() {
+    if (this._open) {
+      this._fileStream.close();
+      delete this._fileStream;
+      this._open = false;
+    }
+    return true;
+  },
+
+  /*
+   * Serializes a single object into the file stream. All properties of the
+   * object are stored in the stream, including properties that contain other
+   * objects.
+   *
+   * @param obj   JS object to serialize to the file.
+   */
+  serialize: function(obj) {
+    if (!this._open) {
+      this.open(">");
+    }
+    if (!ASSERT(this._open, "Unable to open the file for writing!")) {
+      return;
+    }
+
+    this._fileStream.write(JSON.stringify(obj, null, 2));
+  },
+
+  /*
+   * Reads in enough of the file to deserialize (realize) a single object. The
+   * object deserialized is returned; all sub-properties of the object are
+   * deserialized with it.
+   *
+   * @returns     JS object parsed from the file.
+   */
+  deserialize: function() {
+    if (!this._open) {
+      this.open("<");
+    }
+    if (!ASSERT(this._open, "Unable to open the file for reading!"))
+      return false;
+
+    let rv = null;
+    try {
+      rv = JSON.parse(this._fileStream.read());
+    }
+    catch(ex) {
+      dd("Syntax error while deserializing file!");
+      dd(ex.message);
+      dd(ex.stack);
+    }
+
+    return rv;
+  },
+};