| // 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 engine.utilities.general; |
| |
| import 'dart:profiler'; |
| |
| /** |
| * Jenkins hash function, optimized for small integers. |
| * Borrowed from sdk/lib/math/jenkins_smi_hash.dart. |
| */ |
| class JenkinsSmiHash { |
| static int combine(int hash, int value) { |
| hash = 0x1fffffff & (hash + value); |
| hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10)); |
| return hash ^ (hash >> 6); |
| } |
| |
| static int finish(int hash) { |
| hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3)); |
| hash = hash ^ (hash >> 11); |
| return 0x1fffffff & (hash + ((0x00003fff & hash) << 15)); |
| } |
| |
| static int hash2(a, b) => finish(combine(combine(0, a), b)); |
| |
| static int hash3(a, b, c) => finish(combine(combine(combine(0, a), b), c)); |
| |
| static int hash4(a, b, c, d) => |
| finish(combine(combine(combine(combine(0, a), b), c), d)); |
| } |
| |
| /** |
| * Helper class for gathering performance statistics. This class is modeled on |
| * the UserTag class in dart:profiler so that it can interoperate easily with |
| * it. |
| */ |
| abstract class PerformanceTag { |
| /** |
| * Return a list of all [PerformanceTag]s which have been created. |
| */ |
| static List<PerformanceTag> get all => _PerformanceTagImpl.all.toList(); |
| |
| /** |
| * Return the current [PerformanceTag] for the isolate. |
| */ |
| static PerformanceTag get current => _PerformanceTagImpl.current; |
| |
| /** |
| * Return the [PerformanceTag] that is initially current. This is intended |
| * to track time when the system is performing unknown operations. |
| */ |
| static PerformanceTag get UNKNOWN => _PerformanceTagImpl.UNKNOWN; |
| |
| /** |
| * Create a [PerformanceTag] having the given [label]. A [UserTag] will also |
| * be created, having the same [label], so that performance information can |
| * be queried using the observatory. |
| */ |
| factory PerformanceTag(String label) = _PerformanceTagImpl; |
| |
| /** |
| * Return the total number of milliseconds that this [PerformanceTag] has |
| * been the current [PerformanceTag] for the isolate. |
| * |
| * This call is safe even if this [PerformanceTag] is current. |
| */ |
| int get elapsedMs; |
| |
| /** |
| * Return the label for this [PerformanceTag]. |
| */ |
| String get label; |
| |
| /** |
| * Make this the current tag for the isolate, and return the previous tag. |
| */ |
| PerformanceTag makeCurrent(); |
| |
| /** |
| * Make this the current tag for the isolate, run [f], and restore the |
| * previous tag. Returns the result of invoking [f]. |
| */ |
| makeCurrentWhile(f()); |
| |
| /** |
| * Reset the total time tracked by all [PerformanceTag]s to zero. |
| */ |
| static void reset() { |
| for (_PerformanceTagImpl tag in _PerformanceTagImpl.all) { |
| tag.stopwatch.reset(); |
| } |
| } |
| } |
| |
| class _PerformanceTagImpl implements PerformanceTag { |
| /** |
| * The current performance tag for the isolate. |
| */ |
| static _PerformanceTagImpl current = UNKNOWN; |
| |
| static final _PerformanceTagImpl UNKNOWN = new _PerformanceTagImpl('unknown'); |
| |
| /** |
| * A list of all performance tags that have been created so far. |
| */ |
| static List<_PerformanceTagImpl> all = <_PerformanceTagImpl>[]; |
| |
| /** |
| * The [UserTag] associated with this [PerformanceTag]. |
| */ |
| final UserTag userTag; |
| |
| /** |
| * Stopwatch tracking the amount of time this [PerformanceTag] has been the |
| * current tag for the isolate. |
| */ |
| final Stopwatch stopwatch; |
| |
| _PerformanceTagImpl(String label) |
| : userTag = new UserTag(label), |
| stopwatch = new Stopwatch() { |
| all.add(this); |
| } |
| |
| @override |
| int get elapsedMs => stopwatch.elapsedMilliseconds; |
| |
| @override |
| String get label => userTag.label; |
| |
| @override |
| PerformanceTag makeCurrent() { |
| if (identical(this, current)) { |
| return current; |
| } |
| _PerformanceTagImpl previous = current; |
| previous.stopwatch.stop(); |
| stopwatch.start(); |
| current = this; |
| userTag.makeCurrent(); |
| return previous; |
| } |
| |
| makeCurrentWhile(f()) { |
| PerformanceTag prevTag = makeCurrent(); |
| try { |
| return f(); |
| } finally { |
| prevTag.makeCurrent(); |
| } |
| } |
| } |