| // Copyright (c) 2013, 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 lazy_trace; |
| |
| import 'frame.dart'; |
| import 'trace.dart'; |
| |
| /// A thunk for lazily constructing a [Trace]. |
| typedef Trace TraceThunk(); |
| |
| /// A wrapper around a [TraceThunk]. This works around issue 9579 by avoiding |
| /// the conversion of native [StackTrace]s to strings until it's absolutely |
| /// necessary. |
| class LazyTrace implements Trace { |
| final TraceThunk _thunk; |
| Trace _inner; |
| |
| LazyTrace(this._thunk); |
| |
| Trace get _trace { |
| if (_inner == null) _inner = _thunk(); |
| return _inner; |
| } |
| |
| List<Frame> get frames => _trace.frames; |
| StackTrace get vmTrace => _trace.vmTrace; |
| Trace get terse => new LazyTrace(() => _trace.terse); |
| Trace foldFrames(bool predicate(frame)) => |
| new LazyTrace(() => _trace.foldFrames(predicate)); |
| String toString() => _trace.toString(); |
| } |