Index: mojo/public/dart/third_party/stack_trace/lib/src/stack_zone_specification.dart |
diff --git a/mojo/public/dart/third_party/stack_trace/lib/src/stack_zone_specification.dart b/mojo/public/dart/third_party/stack_trace/lib/src/stack_zone_specification.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..25d96427110f76a22b134fbaa2634025225434cd |
--- /dev/null |
+++ b/mojo/public/dart/third_party/stack_trace/lib/src/stack_zone_specification.dart |
@@ -0,0 +1,236 @@ |
+// 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 'trace.dart'; |
+import 'chain.dart'; |
+ |
+/// 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 { |
+ /// 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; |
+ |
+ /// 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); |
+ } |
+ |
+ /// 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(); |
+ |
+ /// 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); |
+ 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); |
+ 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); |
+ 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) { |
+ 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); |
+ } 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, |
+ Object error, StackTrace 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); |
+ |
+ // 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; |
+ try { |
+ return f(); |
+ } catch (e, stackTrace) { |
+ _chains[stackTrace] = node; |
+ rethrow; |
+ } finally { |
+ _currentNode = previousNode; |
+ } |
+ } |
+} |
+ |
+/// 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); |
+ |
+ /// 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); |
+ } |
+} |