| // Copyright (c) 2018, 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. |
| |
| import 'dart:typed_data'; |
| |
| import 'package:analyzer/dart/analysis/features.dart'; |
| import 'package:analyzer/src/dart/analysis/experiments_impl.dart'; |
| import 'package:meta/meta.dart'; |
| import 'package:pub_semver/src/version.dart'; |
| |
| export 'package:analyzer/src/dart/analysis/experiments_impl.dart' |
| show |
| ConflictingFlags, |
| ExperimentalFeature, |
| IllegalUseOfExpiredFlag, |
| UnnecessaryUseOfExpiredFlag, |
| UnrecognizedFlag, |
| validateFlags, |
| ValidationResult; |
| |
| part 'experiments.g.dart'; |
| |
| /// Gets access to the private list of boolean flags in an [ExperimentStatus] |
| /// object. For testing use only. |
| @visibleForTesting |
| List<bool> getExperimentalFlags_forTesting(ExperimentStatus status) => |
| status._flags; |
| |
| /// Gets access to the private SDK language version in an [ExperimentStatus] |
| /// object. For testing use only. |
| @visibleForTesting |
| Version getSdkLanguageVersion_forTesting(ExperimentStatus status) => |
| status._sdkLanguageVersion; |
| |
| /// A representation of the set of experiments that are active and whether they |
| /// are enabled. |
| class ExperimentStatus with _CurrentState implements FeatureSet { |
| /// The current language version. |
| static final Version currentVersion = Version.parse(_currentVersion); |
| |
| /// A map containing information about all known experimental flags. |
| static final Map<String, ExperimentalFeature> knownFeatures = _knownFeatures; |
| |
| final Version _sdkLanguageVersion; |
| final List<bool> _explicitEnabledFlags; |
| final List<bool> _explicitDisabledFlags; |
| final List<bool> _flags; |
| |
| factory ExperimentStatus() { |
| return ExperimentStatus.latestLanguageVersion(); |
| } |
| |
| factory ExperimentStatus.fromStorage(Uint8List encoded) { |
| var byteIndex = 0; |
| |
| int getByte() { |
| return encoded[byteIndex++]; |
| } |
| |
| List<bool> getBoolList(int length) { |
| var result = List<bool>.filled(length, false); |
| var byteValue = 0; |
| var bitIndex = 0; |
| for (var i = 0; i < length; i++) { |
| if (bitIndex == 0) { |
| byteValue = getByte(); |
| } |
| if ((byteValue & (1 << bitIndex)) != 0) { |
| result[i] = true; |
| } |
| bitIndex = (bitIndex + 1) % 8; |
| } |
| return result; |
| } |
| |
| var sdkLanguageVersion = Version(getByte(), getByte(), 0); |
| var featureCount = getByte(); |
| return ExperimentStatus._( |
| sdkLanguageVersion, |
| getBoolList(featureCount), |
| getBoolList(featureCount), |
| getBoolList(featureCount), |
| ); |
| } |
| |
| /// Decodes the strings given in [flags] into a representation of the set of |
| /// experiments that should be enabled. |
| /// |
| /// Always succeeds, even if the input flags are invalid. Expired and |
| /// unrecognized flags are ignored, conflicting flags are resolved in favor of |
| /// the flag appearing last. |
| factory ExperimentStatus.fromStrings2({ |
| required Version sdkLanguageVersion, |
| required List<String> flags, |
| // TODO(scheglov) use restrictEnableFlagsToVersion |
| }) { |
| var explicitFlags = decodeExplicitFlags(flags); |
| |
| var decodedFlags = restrictEnableFlagsToVersion( |
| sdkLanguageVersion: sdkLanguageVersion, |
| explicitEnabledFlags: explicitFlags.enabled, |
| explicitDisabledFlags: explicitFlags.disabled, |
| version: sdkLanguageVersion, |
| ); |
| |
| return ExperimentStatus._( |
| sdkLanguageVersion, |
| explicitFlags.enabled, |
| explicitFlags.disabled, |
| decodedFlags, |
| ); |
| } |
| |
| factory ExperimentStatus.latestLanguageVersion() { |
| return ExperimentStatus.fromStrings2( |
| sdkLanguageVersion: currentVersion, |
| flags: [], |
| ); |
| } |
| |
| ExperimentStatus._( |
| this._sdkLanguageVersion, |
| this._explicitEnabledFlags, |
| this._explicitDisabledFlags, |
| this._flags, |
| ); |
| |
| @override |
| int get hashCode => Object.hashAll(_flags); |
| |
| @override |
| bool operator ==(Object other) { |
| if (other is ExperimentStatus) { |
| if (_sdkLanguageVersion != other._sdkLanguageVersion) { |
| return false; |
| } |
| if (!_equalListOfBool( |
| _explicitEnabledFlags, other._explicitEnabledFlags)) { |
| return false; |
| } |
| if (!_equalListOfBool( |
| _explicitDisabledFlags, other._explicitDisabledFlags)) { |
| return false; |
| } |
| if (!_equalListOfBool(_flags, other._flags)) { |
| return false; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| /// Queries whether the given [feature] is enabled or disabled. |
| @override |
| bool isEnabled(covariant ExperimentalFeature feature) => |
| _flags[feature.index]; |
| |
| @override |
| FeatureSet restrictToVersion(Version version) { |
| return ExperimentStatus._( |
| _sdkLanguageVersion, |
| _explicitEnabledFlags, |
| _explicitDisabledFlags, |
| restrictEnableFlagsToVersion( |
| sdkLanguageVersion: _sdkLanguageVersion, |
| explicitEnabledFlags: _explicitEnabledFlags, |
| explicitDisabledFlags: _explicitDisabledFlags, |
| version: version, |
| ), |
| ); |
| } |
| |
| /// Encode into the format suitable for [ExperimentStatus.fromStorage]. |
| Uint8List toStorage() { |
| var result = Uint8List(16); |
| var resultIndex = 0; |
| |
| void addByte(int value) { |
| assert(value >= 0 && value < 256); |
| result[resultIndex++] = value; |
| } |
| |
| addByte(_sdkLanguageVersion.major); |
| addByte(_sdkLanguageVersion.minor); |
| |
| void addBoolList(List<bool> values) { |
| var byteValue = 0; |
| var bitIndex = 0; |
| for (var value in values) { |
| if (value) { |
| byteValue |= 1 << bitIndex; |
| } |
| bitIndex++; |
| if (bitIndex == 8) { |
| addByte(byteValue); |
| byteValue = 0; |
| bitIndex = 0; |
| } |
| } |
| if (bitIndex != 0) { |
| addByte(byteValue); |
| } |
| } |
| |
| addByte(_flags.length); |
| addBoolList(_explicitEnabledFlags); |
| addBoolList(_explicitDisabledFlags); |
| addBoolList(_flags); |
| |
| return result.sublist(0, resultIndex); |
| } |
| |
| @override |
| String toString() => experimentStatusToString(_flags); |
| |
| static bool _equalListOfBool(List<bool> first, List<bool> second) { |
| if (first.length != second.length) return false; |
| for (var i = 0; i < first.length; i++) { |
| if (first[i] != second[i]) return false; |
| } |
| return true; |
| } |
| } |