| 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
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| new file mode 100644
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| index 0000000000000000000000000000000000000000..25d96427110f76a22b134fbaa2634025225434cd
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| --- /dev/null
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| +++ b/mojo/public/dart/third_party/stack_trace/lib/src/stack_zone_specification.dart
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| @@ -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.
|
| + ///
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| + /// 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,
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| + 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,
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| + 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,
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| + 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,
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| + 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);
|
| + }
|
| +}
|
|
|