Escape field separator

pkg/analyzer/lib/instrumentation/instrumentation.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library instrumentation;
 
 /**
  * The interface used by client code to communicate with an instrumentation
  * server.
  */
@@ skipping 66 matching lines @@
   }
 
   /**
    * Log that the given non-priority [exception] was thrown, with the given
    * [stackTrace].
    */
   void logException(dynamic exception, StackTrace stackTrace) {
     if (_instrumentationServer != null) {
       String message = _toString(exception);
       String trace = _toString(stackTrace);
-      _instrumentationServer.log('$_timestamp:$TAG_EXCEPTION:$message:$trace');
+      _instrumentationServer.log(_join([TAG_EXCEPTION, message, trace]));
     }
   }
 
   /**
    * Log that a notification has been sent to the client.
    */
   void logNotification(String notification) {
     _log(TAG_NOTIFICATION, notification);
   }
 
   /**
    * Log that the given priority [exception] was thrown, with the given
    * [stackTrace].
    */
   void logPriorityException(dynamic exception, StackTrace stackTrace) {
     if (_instrumentationServer != null) {
       String message = _toString(exception);
       String trace = _toString(stackTrace);
       _instrumentationServer.logWithPriority(
-          '$_timestamp:$TAG_EXCEPTION:$message:$trace');
+          _join([TAG_EXCEPTION, message, trace]));
     }
   }
 
   /**
    * Log that a request has been sent to the client.
    */
   void logRequest(String request) {
     _log(TAG_REQUEST, request);
   }
 
@@ skipping 10 matching lines @@
    * should be invoked on this instance after this method has been invoked.
    */
   void shutdown() {
     if (_instrumentationServer != null) {
       _instrumentationServer.shutdown();
       _instrumentationServer = null;
     }
   }
 
   /**
+   * Write an escaped version of the given [string] to the given [buffer].
+   */
+  void _escape(StringBuffer buffer, String field) {
+    int index = field.indexOf(':');
+    if (index < 0) {
+      buffer.write(field);
+      return;
+    }
+    int start = 0;
+    while (index > 0) {
+      buffer.write(field.substring(start, index));
+      buffer.write('::');
+      start = index + 1;
+      index = field.indexOf(':', start);
+    }
+    buffer.write(field.substring(start));
+  }
+
+  /**
+   * Return the result of joining the values of the given fields, escaping the
+   * separator character by doubling it.
+   */
+  String _join(List<String> fields) {
+    StringBuffer buffer = new StringBuffer();
+    buffer.write(_timestamp);
+    for (String field in fields) {
+      buffer.write(':');
+      _escape(buffer, field);
+    }
+    return buffer.toString();
+  }
+
+  /**
    * Log the given message with the given tag.
    */
   void _log(String tag, String message) {
     if (_instrumentationServer != null) {
-      _instrumentationServer.log('$_timestamp:$tag:$message');
+      _instrumentationServer.log(_join([tag, message]));
     }
   }
 
   /**
    * Convert the given [object] to a string.
    */
   String _toString(Object object) {
     if (object == null) {
       return 'null';
     }
     return object.toString();
   }
 }