Update charted to 0.4.8 and roll

packages/stack_trace/lib/src/stack_zone_specification.dart

 // 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 stack_trace.stack_zone_specification;
-
 import 'dart:async';
 
+import 'chain.dart';
+import 'lazy_trace.dart';
 import 'trace.dart';
-import 'chain.dart';
+import 'utils.dart';
+
+/// A function that handles errors in the zone wrapped by [Chain.capture].
+typedef void _ChainHandler(error, Chain chain);
 
 /// A class encapsulating the zone specification for a [Chain.capture] zone.
 ///
 /// Until they're materialized and exposed to the user, stack chains are tracked
 /// as linked lists of [Trace]s using the [_Node] class. These nodes are stored
 /// in three distinct ways:
 ///
 /// * When a callback is registered, a node is created and stored as a captured
 ///   local variable until the callback is run.
 ///
 /// * When a callback is run, its captured node is set as the [_currentNode] so
 ///   it can be available to [Chain.current] and to be linked into additional
 ///   chains when more callbacks are scheduled.
 ///
 /// * When a callback throws an error or a Future or Stream emits an error, the
 ///   current node is associated with that error's stack trace using the
 ///   [_chains] expando.
 ///
 /// Since [ZoneSpecification] can't be extended or even implemented, in order to
 /// get a real [ZoneSpecification] instance it's necessary to call [toSpec].
 class StackZoneSpecification {
+  /// An opaque object used as a zone value to disable chain tracking in a given
+  /// zone.
+  ///
+  /// If `Zone.current[disableKey]` is `true`, no stack chains will be tracked.
+  static final disableKey = new Object();
+
+  /// Whether chain-tracking is disabled in the current zone.
+  bool get _disabled => Zone.current[disableKey] == true;
+
   /// The expando that associates stack chains with [StackTrace]s.
   ///
   /// The chains are associated with stack traces rather than errors themselves
   /// because it's a common practice to throw strings as errors, which can't be
   /// used with expandos.
   ///
   /// The chain associated with a given stack trace doesn't contain a node for
   /// that stack trace.
   final _chains = new Expando<_Node>("stack chains");
 
   /// The error handler for the zone.
   ///
   /// If this is null, that indicates that any unhandled errors should be passed
   /// to the parent zone.
-  final ChainHandler _onError;
+  final _ChainHandler _onError;
 
   /// The most recent node of the current stack chain.
   _Node _currentNode;
 
   StackZoneSpecification([this._onError]);
 
   /// Converts [this] to a real [ZoneSpecification].
   ZoneSpecification toSpec() {
     return new ZoneSpecification(
-        handleUncaughtError: handleUncaughtError,
-        registerCallback: registerCallback,
-        registerUnaryCallback: registerUnaryCallback,
-        registerBinaryCallback: registerBinaryCallback,
-        errorCallback: errorCallback);
+        handleUncaughtError: _handleUncaughtError,
+        registerCallback: _registerCallback,
+        registerUnaryCallback: _registerUnaryCallback,
+        registerBinaryCallback: _registerBinaryCallback,
+        errorCallback: _errorCallback);
   }
 
   /// Returns the current stack chain.
   ///
   /// By default, the first frame of the first trace will be the line where
   /// [currentChain] is called. If [level] is passed, the first trace will start
   /// that many frames up instead.
-  Chain currentChain([int level=0]) => _createNode(level + 1).toChain();
+  Chain currentChain([int level = 0]) => _createNode(level + 1).toChain();
 
   /// Returns the stack chain associated with [trace], if one exists.
   ///
   /// The first stack trace in the returned chain will always be [trace]
   /// (converted to a [Trace] if necessary). If there is no chain associated
   /// with [trace], this just returns a single-trace chain containing [trace].
   Chain chainFor(StackTrace trace) {
     if (trace is Chain) return trace;
     var previous = trace == null ? null : _chains[trace];
     return new _Node(trace, previous).toChain();
   }
 
-  /// Ensures that an error emitted by [future] has the correct stack
-  /// information associated with it.
-  ///
-  /// By default, the first frame of the first trace will be the line where
-  /// [trackFuture] is called. If [level] is passed, the first trace will start
-  /// that many frames up instead.
-  Future trackFuture(Future future, [int level=0]) {
-    var completer = new Completer.sync();
-    var node = _createNode(level + 1);
-    future.then(completer.complete).catchError((e, stackTrace) {
-      if (stackTrace == null) stackTrace = new Trace.current();
-      if (stackTrace is! Chain && _chains[stackTrace] == null) {
-        _chains[stackTrace] = node;
-      }
-      completer.completeError(e, stackTrace);
-    });
-    return completer.future;
-  }
-
-  /// Ensures that any errors emitted by [stream] have the correct stack
-  /// information associated with them.
-  ///
-  /// By default, the first frame of the first trace will be the line where
-  /// [trackStream] is called. If [level] is passed, the first trace will start
-  /// that many frames up instead.
-  Stream trackStream(Stream stream, [int level=0]) {
-    var node = _createNode(level + 1);
-    return stream.transform(new StreamTransformer.fromHandlers(
-        handleError: (error, stackTrace, sink) {
-      if (stackTrace == null) stackTrace = new Trace.current();
-      if (stackTrace is! Chain && _chains[stackTrace] == null) {
-        _chains[stackTrace] = node;
-      }
-      sink.addError(error, stackTrace);
-    }));
-  }
-
   /// Tracks the current stack chain so it can be set to [_currentChain] when
   /// [f] is run.
-  ZoneCallback registerCallback(Zone self, ZoneDelegate parent, Zone zone,
-      Function f) {
-    if (f == null) return parent.registerCallback(zone, null);
+  ZoneCallback _registerCallback(
+      Zone self, ZoneDelegate parent, Zone zone, Function f) {
+    if (f == null || _disabled) return parent.registerCallback(zone, f);
     var node = _createNode(1);
     return parent.registerCallback(zone, () => _run(f, node));
   }
 
   /// Tracks the current stack chain so it can be set to [_currentChain] when
   /// [f] is run.
-  ZoneUnaryCallback registerUnaryCallback(Zone self, ZoneDelegate parent,
-      Zone zone, Function f) {
-    if (f == null) return parent.registerUnaryCallback(zone, null);
+  ZoneUnaryCallback _registerUnaryCallback(
+      Zone self, ZoneDelegate parent, Zone zone, Function f) {
+    if (f == null || _disabled) return parent.registerUnaryCallback(zone, f);
     var node = _createNode(1);
     return parent.registerUnaryCallback(zone, (arg) {
       return _run(() => f(arg), node);
     });
   }
 
   /// Tracks the current stack chain so it can be set to [_currentChain] when
   /// [f] is run.
-  ZoneBinaryCallback registerBinaryCallback(Zone self, ZoneDelegate parent,
-      Zone zone, Function f) {
-    if (f == null) return parent.registerBinaryCallback(zone, null);
+  ZoneBinaryCallback _registerBinaryCallback(
+      Zone self, ZoneDelegate parent, Zone zone, Function f) {
+    if (f == null || _disabled) return parent.registerBinaryCallback(zone, f);
+
     var node = _createNode(1);
     return parent.registerBinaryCallback(zone, (arg1, arg2) {
       return _run(() => f(arg1, arg2), node);
     });
   }
 
   /// Looks up the chain associated with [stackTrace] and passes it either to
   /// [_onError] or [parent]'s error handler.
-  handleUncaughtError(Zone self, ZoneDelegate parent, Zone zone, error,
-      StackTrace stackTrace) {
+  _handleUncaughtError(
+      Zone self, ZoneDelegate parent, Zone zone, error, StackTrace stackTrace) {
+    if (_disabled) {
+      return parent.handleUncaughtError(zone, error, stackTrace);
+    }
+
     var stackChain = chainFor(stackTrace);
     if (_onError == null) {
       return parent.handleUncaughtError(zone, error, stackChain);
     }
 
     // TODO(nweiz): Currently this copies a lot of logic from [runZoned]. Just
     // allow [runBinary] to throw instead once issue 18134 is fixed.
     try {
-      return parent.runBinary(zone, _onError, error, stackChain);
+      return self.parent.runBinary(_onError, error, stackChain);
     } catch (newError, newStackTrace) {
       if (identical(newError, error)) {
         return parent.handleUncaughtError(zone, error, stackChain);
       } else {
         return parent.handleUncaughtError(zone, newError, newStackTrace);
       }
     }
   }
 
   /// Attaches the current stack chain to [stackTrace], replacing it if
   /// necessary.
-  AsyncError errorCallback(Zone self, ZoneDelegate parent, Zone zone,
+  AsyncError _errorCallback(Zone self, ZoneDelegate parent, Zone zone,
       Object error, StackTrace stackTrace) {
+    if (_disabled) return parent.errorCallback(zone, error, stackTrace);
+
     // Go up two levels to get through [_CustomZone.errorCallback].
     if (stackTrace == null) {
       stackTrace = _createNode(2).toChain();
     } else {
       if (_chains[stackTrace] == null) _chains[stackTrace] = _createNode(2);
     }
 
     var asyncError = parent.errorCallback(zone, error, stackTrace);
     return asyncError == null ? new AsyncError(error, stackTrace) : asyncError;
   }
 
   /// Creates a [_Node] with the current stack trace and linked to
   /// [_currentNode].
   ///
   /// By default, the first frame of the first trace will be the line where
   /// [_createNode] is called. If [level] is passed, the first trace will start
   /// that many frames up instead.
-  _Node _createNode([int level=0]) =>
-    new _Node(new Trace.current(level + 1), _currentNode);
+  _Node _createNode([int level = 0]) =>
+      new _Node(_currentTrace(level + 1), _currentNode);
 
   // TODO(nweiz): use a more robust way of detecting and tracking errors when
   // issue 15105 is fixed.
   /// Runs [f] with [_currentNode] set to [node].
   ///
   /// If [f] throws an error, this associates [node] with that error's stack
   /// trace.
   _run(Function f, _Node node) {
     var previousNode = _currentNode;
     _currentNode = node;
@@ skipping 10 matching lines @@
 
 /// A linked list node representing a single entry in a stack chain.
 class _Node {
   /// The stack trace for this link of the chain.
   final Trace trace;
 
   /// The previous node in the chain.
   final _Node previous;
 
   _Node(StackTrace trace, [this.previous])
-      : trace = trace == null ? new Trace.current() : new Trace.from(trace);
+      : trace = trace == null ? _currentTrace() : new Trace.from(trace);
 
   /// Converts this to a [Chain].
   Chain toChain() {
     var nodes = <Trace>[];
     var node = this;
     while (node != null) {
       nodes.add(node.trace);
       node = node.previous;
     }
     return new Chain(nodes);
   }
 }
+
+/// Like [new Trace.current], but if the current stack trace has VM chaining
+/// enabled, this only returns the innermost sub-trace.
+Trace _currentTrace([int level]) {
+  level ??= 0;
+  var stackTrace = StackTrace.current;
+  return new LazyTrace(() {
+    // Ignore the VM's stack chains when we generate our own. Otherwise we'll
+    // end up with duplicate frames all over the place.
+    var text = stackTrace.toString();
+    var index = text.indexOf(vmChainGap);
+    if (index != -1) text = text.substring(0, index);
+
+    var trace = new Trace.parse(text);
+    // JS includes a frame for the call to StackTrace.current, but the VM
+    // doesn't, so we skip an extra frame in a JS context.
+    return new Trace(trace.frames.skip(level + (inJS ? 2 : 1)), original: text);
+  });
+}