| | | 1 | | using System; |
| | | 2 | | using System.Collections.Concurrent; |
| | | 3 | | using System.Collections.Generic; |
| | | 4 | | |
| | | 5 | | namespace AmbientServices; |
| | | 6 | | |
| | | 7 | | /// <summary> |
| | | 8 | | /// Event arguments for a failed ambient setting string-to-typed conversion. |
| | | 9 | | /// </summary> |
| | | 10 | | /// <param name="key">The setting key.</param> |
| | | 11 | | /// <param name="rawValue">The raw string value that could not be converted.</param> |
| | | 12 | | /// <param name="exception">The exception thrown by the conversion delegate.</param> |
| | | 13 | | /// <param name="defaultValue">The default value that will be used instead.</param> |
| | | 14 | | public class SettingConversionFailedEventArgs(string key, string rawValue, Exception exception, object? defaultValue) : |
| | | 15 | | { |
| | | 16 | | /// <summary>The setting key.</summary> |
| | | 17 | | public string Key { get; } = key; |
| | | 18 | | /// <summary>The raw string value that could not be converted.</summary> |
| | | 19 | | public string RawValue { get; } = rawValue; |
| | | 20 | | /// <summary>The exception thrown by the conversion delegate.</summary> |
| | | 21 | | public Exception Exception { get; } = exception; |
| | | 22 | | /// <summary>The default value that will be used instead.</summary> |
| | | 23 | | public object? DefaultValue { get; } = defaultValue; |
| | | 24 | | } |
| | | 25 | | |
| | | 26 | | /// <summary> |
| | | 27 | | /// A static factory class for declaring strongly-typed <see cref="IAmbientSetting{T}"/> settings and registering them f |
| | | 28 | | /// </summary> |
| | | 29 | | /// <remarks> |
| | | 30 | | /// <pitch>The factory callers use to declare typed settings: give it a key, description, conversion, and default and ge |
| | | 31 | | /// <pledge> |
| | | 32 | | /// Every factory call registers the setting's key, description, and default in the process-wide <see cref="SettingsRegi |
| | | 33 | | /// </pledge> |
| | | 34 | | /// <priority> |
| | | 35 | | /// 1. A setting that always reads over surfacing a bad value: a missing setting yields the declared default and a faile |
| | | 36 | | /// 2. Process-wide discoverability over a free declaration: every factory call registers the key, description, and defa |
| | | 37 | | /// </priority> |
| | | 38 | | /// </remarks> |
| | | 39 | | public static class AmbientSettings |
| | | 40 | | { |
| | | 41 | | /// <summary> |
| | | 42 | | /// Raised when a registered setting's conversion delegate throws. The default value is used instead. |
| | | 43 | | /// Subscribers must not call back into ambient logging or settings retrieval for the same key, as that may recurse. |
| | | 44 | | /// </summary> |
| | | 45 | | public static event EventHandler<SettingConversionFailedEventArgs>? ConversionFailed; |
| | | 46 | | |
| | | 47 | | internal static void NotifyConversionFailed(string key, string rawValue, Exception exception, object? defaultValue) |
| | | 48 | | { |
| | | 49 | | ConversionFailed?.Invoke(null, new SettingConversionFailedEventArgs(key, rawValue, exception, defaultValue)); |
| | | 50 | | } |
| | | 51 | | /// <summary> |
| | | 52 | | /// Gets an enumeration of <see cref="IAmbientSettingInfo"/> with descriptions and the last time used for all ambien |
| | | 53 | | /// </summary> |
| | | 54 | | public static IEnumerable<IAmbientSettingInfo> AmbientSettingsInfo => SettingsRegistry.DefaultRegistry.Settings; |
| | | 55 | | /// <summary> |
| | | 56 | | /// Construct a setting instance. |
| | | 57 | | /// If a non-null settings set is specified, the setting will be attached to that, otherwise the ambient settings se |
| | | 58 | | /// Never returns a setting whose value is always the default value. |
| | | 59 | | /// </summary> |
| | | 60 | | /// <param name="settingsSet">The <see cref="IAmbientSettingsSet"/> to get the setting value from. If null, returns |
| | | 61 | | /// <param name="key">A key string identifying the setting.</param> |
| | | 62 | | /// <param name="description">A description of the setting.</param> |
| | | 63 | | /// <param name="convert">A delegate that takes a string and returns the type.</param> |
| | | 64 | | /// <param name="defaultValueString">The default string value for the setting. This will be converted for the curre |
| | | 65 | | public static IAmbientSetting<T> GetSetting<T>(IAmbientSettingsSet? settingsSet, string key, string description, Fun |
| | | 66 | | { |
| | | 67 | | return (settingsSet == null) ? GetAmbientSetting<T>(key, description, convert, defaultValueString) : GetSettings |
| | | 68 | | } |
| | | 69 | | /// <summary> |
| | | 70 | | /// Construct a setting instance. |
| | | 71 | | /// If a non-null settings set is specified, the setting will be attached to that, otherwise the ambient settings se |
| | | 72 | | /// Never returns a setting whose value is always the default value. |
| | | 73 | | /// </summary> |
| | | 74 | | /// <param name="settingsSet">The <see cref="IAmbientSettingsSet"/> to get the setting value from. If null, returns |
| | | 75 | | /// <param name="key">A key string identifying the setting.</param> |
| | | 76 | | /// <param name="description">A description of the setting.</param> |
| | | 77 | | /// <param name="defaultValue">The default value for the setting. This will be used as the current value if the set |
| | | 78 | | /// <param name="convert">A delegate that takes a string and returns the type.</param> |
| | | 79 | | public static IAmbientSetting<T> GetSetting<T>(IAmbientSettingsSet? settingsSet, string key, string description, T d |
| | | 80 | | { |
| | | 81 | | return (settingsSet == null) ? GetAmbientSetting<T>(key, description, defaultValue, convert) : GetSettingsSetSet |
| | | 82 | | } |
| | | 83 | | /// <summary> |
| | | 84 | | /// Construct a setting instance that uses a specific settings set and caches the setting with the specified key, co |
| | | 85 | | /// </summary> |
| | | 86 | | /// <param name="settingsSet">The <see cref="IAmbientSettingsSet"/> to get the setting value from. If null, the set |
| | | 87 | | /// <param name="key">A key string identifying the setting.</param> |
| | | 88 | | /// <param name="description">A description of the setting.</param> |
| | | 89 | | /// <param name="convert">A delegate that takes a string and returns the type.</param> |
| | | 90 | | /// <param name="defaultValueString">The default string value for the setting. This will be converted for the curre |
| | | 91 | | public static IAmbientSetting<T> GetSettingsSetSetting<T>(IAmbientSettingsSet? settingsSet, string key, string descr |
| | | 92 | | { |
| | | 93 | | return new SettingsSetSetting<T>(settingsSet, key, description, convert, defaultValueString); |
| | | 94 | | } |
| | | 95 | | /// <summary> |
| | | 96 | | /// Construct a setting instance that uses a specific settings set and caches the setting with the specified key, co |
| | | 97 | | /// </summary> |
| | | 98 | | /// <param name="settingsSet">The <see cref="IAmbientSettingsSet"/> to get the setting value from. If null, the set |
| | | 99 | | /// <param name="key">A key string identifying the setting.</param> |
| | | 100 | | /// <param name="description">A description of the setting.</param> |
| | | 101 | | /// <param name="defaultValue">The default value for the setting. This will be used as the current value if the set |
| | | 102 | | /// <param name="convert">A delegate that takes a string and returns the type.</param> |
| | | 103 | | public static IAmbientSetting<T> GetSettingsSetSetting<T>(IAmbientSettingsSet? settingsSet, string key, string descr |
| | | 104 | | { |
| | | 105 | | return new SettingsSetSetting<T>(settingsSet, key, description, defaultValue, convert); |
| | | 106 | | } |
| | | 107 | | /// <summary> |
| | | 108 | | /// Construct an ambient setting instance that caches the setting with the specified key, converting it from a strin |
| | | 109 | | /// Settings will be gathered from the ambient local settings set, if one exists. |
| | | 110 | | /// </summary> |
| | | 111 | | /// <param name="key">A key string identifying the setting.</param> |
| | | 112 | | /// <param name="description">A description of the setting.</param> |
| | | 113 | | /// <param name="convert">A delegate that takes a string and returns the type.</param> |
| | | 114 | | /// <param name="defaultValueString">The default string value for the setting. This will be converted for the curre |
| | | 115 | | public static IAmbientSetting<T> GetAmbientSetting<T>(string key, string description, Func<string, T> convert, strin |
| | | 116 | | { |
| | | 117 | | return new AmbientSetting<T>(key, description, convert, defaultValueString); |
| | | 118 | | } |
| | | 119 | | /// <summary> |
| | | 120 | | /// Construct an ambient setting instance that caches the setting with the specified key, converting it from a strin |
| | | 121 | | /// Settings will be gathered from the ambient local settings set, if one exists. |
| | | 122 | | /// </summary> |
| | | 123 | | /// <param name="key">A key string identifying the setting.</param> |
| | | 124 | | /// <param name="description">A description of the setting.</param> |
| | | 125 | | /// <param name="defaultValue">The default value for the setting. This will be used as the current value if the set |
| | | 126 | | /// <param name="convert">A delegate that takes a string and returns the type.</param> |
| | | 127 | | public static IAmbientSetting<T> GetAmbientSetting<T>(string key, string description, T defaultValue, Func<string, T |
| | | 128 | | { |
| | | 129 | | return new AmbientSetting<T>(key, description, defaultValue, convert); |
| | | 130 | | } |
| | | 131 | | } |
| | | 132 | | |
| | | 133 | | /// <summary> |
| | | 134 | | /// An abstraction of a setting that holds a strongly-typed value read from the ambient settings. |
| | | 135 | | /// </summary> |
| | | 136 | | /// <remarks> |
| | | 137 | | /// <pitch>A strongly-typed handle to one setting: read it at any time and get the current, already-converted value with |
| | | 138 | | /// <pledge>Reading the value never fails and is cheap enough for hot paths — conversion results are cached, so reads do |
| | | 139 | | /// </remarks> |
| | | 140 | | /// <typeparam name="T">The type represented by the the setting.</typeparam> |
| | | 141 | | public interface IAmbientSetting<T> |
| | | 142 | | { |
| | | 143 | | /// <summary> |
| | | 144 | | /// Gets the key of the setting, which may be useful in providing an override without having to match the name with |
| | | 145 | | /// </summary> |
| | | 146 | | string Key { get; } |
| | | 147 | | /// <summary> |
| | | 148 | | /// Gets the current value of the setting (cached from the value given by the settings set). |
| | | 149 | | /// </summary> |
| | | 150 | | T Value { get; } |
| | | 151 | | /// <summary> |
| | | 152 | | /// Gets the current value of the setting along with the name of the set that the value came from (or null if the de |
| | | 153 | | /// </summary> |
| | | 154 | | /// <returns>The current value of the setting along with the name of the set that the value came from (or null if th |
| | | 155 | | (T, string) GetValueWithSetName(); |
| | | 156 | | } |
| | | 157 | | /// <summary> |
| | | 158 | | /// An abstraction that provides access to a setting's description and last time used. |
| | | 159 | | /// </summary> |
| | | 160 | | /// <remarks> |
| | | 161 | | /// <pitch>The declaration-side view of a registered setting — its key, description, default, string-to-typed conversion |
| | | 162 | | /// <pledge>Conversion is called inline by settings sets whenever a raw value needs typing, so it must always return a u |
| | | 163 | | /// </remarks> |
| | | 164 | | public interface IAmbientSettingInfo |
| | | 165 | | { |
| | | 166 | | /// <summary> |
| | | 167 | | /// Gets the setting key. |
| | | 168 | | /// </summary> |
| | | 169 | | string Key { get; } |
| | | 170 | | /// <summary> |
| | | 171 | | /// Gets the default value for the setting. |
| | | 172 | | /// </summary> |
| | | 173 | | string DefaultValueString { get; } |
| | | 174 | | /// <summary> |
| | | 175 | | /// Gets a description of the setting. |
| | | 176 | | /// </summary> |
| | | 177 | | string Description { get; } |
| | | 178 | | /// <summary> |
| | | 179 | | /// Gets the last time the setting's value was retrieved. |
| | | 180 | | /// </summary> |
| | | 181 | | DateTime LastUsed { get; } |
| | | 182 | | /// <summary> |
| | | 183 | | /// Gets the default value that is used when the value is not found in the settings set. |
| | | 184 | | /// </summary> |
| | | 185 | | object? DefaultValue { get; } |
| | | 186 | | /// <summary> |
| | | 187 | | /// Converts the setting value from the specified string to a typed value. |
| | | 188 | | /// The implementor may cache the value being generated if the settings set is the global settings set. |
| | | 189 | | /// </summary> |
| | | 190 | | /// <param name="settingsSet">The settings set asking for the setting value.</param> |
| | | 191 | | /// <param name="value">The typed value for the setting.</param> |
| | | 192 | | /// <returns>The typed value for the setting.</returns> |
| | | 193 | | object Convert(IAmbientSettingsSet settingsSet, string value); |
| | | 194 | | } |
| | | 195 | | /// <summary> |
| | | 196 | | /// A global registry for settings that includes their keys, descriptions, last used time, conversion functions, and def |
| | | 197 | | /// </summary> |
| | | 198 | | /// <remarks> |
| | | 199 | | /// <pitch>The process-wide directory of every setting declared anywhere in the process: settings sets consult it to con |
| | | 200 | | /// <pledge>Registering the same key again is harmless when the description and default match and an error when they con |
| | | 201 | | /// <plan>A <see cref="ConcurrentDictionary{TKey,TValue}"/> maps each key to a <see cref="WeakReference{T}"/> to the set |
| | | 202 | | /// </remarks> |
| | | 203 | | public class SettingsRegistry |
| | | 204 | | { |
| | | 205 | | /// <summary> |
| | | 206 | | /// Gets the default registry. |
| | | 207 | | /// </summary> |
| | | 208 | | public static SettingsRegistry DefaultRegistry { get; } = new(); |
| | | 209 | | |
| | | 210 | | private readonly int _registerLoopLimit; |
| | | 211 | | private readonly ConcurrentDictionary<string, WeakReference<IAmbientSettingInfo>> _settings = new(); |
| | | 212 | | |
| | | 213 | | /// <summary> |
| | | 214 | | /// Constructs a registry with the default register retry limit. |
| | | 215 | | /// </summary> |
| | | 216 | | public SettingsRegistry() : this(10) |
| | | 217 | | { |
| | | 218 | | } |
| | | 219 | | |
| | | 220 | | /// <summary> |
| | | 221 | | /// Constructs a registry (used by tests to exercise rare contention paths with a low retry limit). |
| | | 222 | | /// </summary> |
| | | 223 | | /// <param name="registerLoopLimit">Maximum register retry iterations before timing out.</param> |
| | | 224 | | internal SettingsRegistry(int registerLoopLimit) |
| | | 225 | | { |
| | | 226 | | _registerLoopLimit = registerLoopLimit; |
| | | 227 | | } |
| | | 228 | | /// <summary> |
| | | 229 | | /// Registers an <see cref="IAmbientSettingInfo"/> in the global registry. |
| | | 230 | | /// </summary> |
| | | 231 | | /// <param name="setting">The <see cref="IAmbientSettingInfo"/> to register.</param> |
| | | 232 | | public void Register(IAmbientSettingInfo setting) |
| | | 233 | | { |
| | | 234 | | #if NET5_0_OR_GREATER |
| | | 235 | | ArgumentNullException.ThrowIfNull(setting); |
| | | 236 | | #else |
| | | 237 | | if (setting is null) throw new ArgumentNullException(nameof(setting)); |
| | | 238 | | #endif |
| | | 239 | | WeakReference<IAmbientSettingInfo> newReference = new(setting); |
| | | 240 | | WeakReference<IAmbientSettingInfo> existingReference; |
| | | 241 | | int loopCount = 0; |
| | | 242 | | do |
| | | 243 | | { |
| | | 244 | | IAmbientSettingInfo? existingSetting; |
| | | 245 | | existingReference = _settings.GetOrAdd(setting.Key, newReference); |
| | | 246 | | // did we NOT succeed? |
| | | 247 | | if (newReference != existingReference) |
| | | 248 | | { |
| | | 249 | | // is the old one gone? |
| | | 250 | | if (!existingReference.TryGetTarget(out existingSetting)) |
| | | 251 | | { |
| | | 252 | | // overwrite that one--were we NOT able to overwrite it? |
| | | 253 | | if (!_settings.TryUpdate(setting.Key, newReference, existingReference)) |
| | | 254 | | { // Coverage note: the inside of this loop is nearly impossible to cover in tests |
| | | 255 | | // wait a bit and try again |
| | | 256 | | System.Threading.Thread.Sleep((int)Math.Pow(2, loopCount + 1)); |
| | | 257 | | continue; |
| | | 258 | | } // else we successfully overwrote it and there is no need to look for a conflict |
| | | 259 | | existingSetting = setting; |
| | | 260 | | } |
| | | 261 | | // the old one is still there, so we need to check for a conflict |
| | | 262 | | string existingDescription = existingSetting.Description ?? "<null>"; |
| | | 263 | | string description = setting.Description ?? "<null>"; |
| | | 264 | | string existingDefaultValueString = existingSetting.DefaultValueString; |
| | | 265 | | string defaultValueString = setting.DefaultValueString; |
| | | 266 | | if (!string.Equals(existingDescription, description, StringComparison.Ordinal) || !string.Equals(existin |
| | | 267 | | { |
| | | 268 | | throw new ArgumentException($"A setting with the key {setting.Key} has already been registered ({exi |
| | | 269 | | } // else we didn't succeed, but it doesn't look like there is a conflict anyway, so we're probably fine |
| | | 270 | | } // else we succeeded |
| | | 271 | | // raise the registered event |
| | | 272 | | SettingRegistered?.Invoke(null, setting); |
| | | 273 | | return; |
| | | 274 | | // Coverage note: the loop and exception is nearly impossible to cover in tests |
| | | 275 | | } while (loopCount++ < _registerLoopLimit); |
| | | 276 | | throw new TimeoutException("Timeout attempting to register setting!"); |
| | | 277 | | } |
| | | 278 | | /// <summary> |
| | | 279 | | /// Gets an enumeration of all the settings in the system. |
| | | 280 | | /// </summary> |
| | | 281 | | public IEnumerable<IAmbientSettingInfo> Settings |
| | | 282 | | { |
| | | 283 | | get |
| | | 284 | | { |
| | | 285 | | foreach (KeyValuePair<string, WeakReference<IAmbientSettingInfo>> s in _settings) |
| | | 286 | | { |
| | | 287 | | IAmbientSettingInfo? setting; |
| | | 288 | | if (s.Value.TryGetTarget(out setting)) |
| | | 289 | | { |
| | | 290 | | yield return setting; |
| | | 291 | | } |
| | | 292 | | else |
| | | 293 | | { |
| | | 294 | | _settings.TryRemove(s.Key, out _); |
| | | 295 | | } |
| | | 296 | | } |
| | | 297 | | } |
| | | 298 | | } |
| | | 299 | | /// <summary> |
| | | 300 | | /// Attempts to get the <see cref="IAmbientSettingInfo"/> for the specified settings key. |
| | | 301 | | /// </summary> |
| | | 302 | | /// <param name="key">The key for the setting.</param> |
| | | 303 | | /// <returns>An <see cref="IAmbientSettingInfo"/> for the specified setting.</returns> |
| | | 304 | | public IAmbientSettingInfo? TryGetSetting(string key) |
| | | 305 | | { |
| | | 306 | | WeakReference<IAmbientSettingInfo>? wrSetting; |
| | | 307 | | IAmbientSettingInfo? setting; |
| | | 308 | | return _settings.TryGetValue(key, out wrSetting) ? (wrSetting.TryGetTarget(out setting) ? setting : null) : null |
| | | 309 | | } |
| | | 310 | | /// <summary> |
| | | 311 | | /// An event the is raised when a new setting is registered, allowing settings sets to call the setting's conversion |
| | | 312 | | /// </summary> |
| | | 313 | | #pragma warning disable CA1003 // this event is performance critical |
| | | 314 | | public event EventHandler<IAmbientSettingInfo>? SettingRegistered; |
| | | 315 | | #pragma warning restore CA1003 |
| | | 316 | | } |
| | | 317 | | |
| | | 318 | | /// <summary> |
| | | 319 | | /// An immutable class that contains a typed setting value and the settings set it came from. |
| | | 320 | | /// </summary> |
| | | 321 | | /// <typeparam name="T">The type for the setting.</typeparam> |
| | | 322 | | internal class SettingsSetSettingValue<T> |
| | | 323 | | { |
| | | 324 | | public T Value { get; private set; } |
| | | 325 | | public IAmbientSettingsSet SettingsSet { get; private set; } |
| | | 326 | | |
| | | 327 | | public SettingsSetSettingValue(T value, IAmbientSettingsSet settingsSet) |
| | | 328 | | { |
| | | 329 | | Value = value; |
| | | 330 | | SettingsSet = settingsSet; |
| | | 331 | | } |
| | | 332 | | } |
| | | 333 | | /// <summary> |
| | | 334 | | /// The <see cref="IAmbientSettingsSet"/> that is attached to default values. |
| | | 335 | | /// Note that this settings set does NOT actually contain any settings, it returns null for all keys. |
| | | 336 | | /// Default values are stored with their individual <see cref="IAmbientSettingInfo"/> instance. |
| | | 337 | | /// </summary> |
| | | 338 | | /// <remarks> |
| | | 339 | | /// <pitch>The provenance marker for default values: a singleton, deliberately empty settings set whose name is reported |
| | | 340 | | /// <pledge><see cref="IAmbientSettingsSet"/></pledge> |
| | | 341 | | /// <pledge>Returns null for every key and is immutable (changing a setting throws <see cref="InvalidOperationException" |
| | | 342 | | /// <plan>A stateless singleton; every lookup returns null unconditionally.</plan> |
| | | 343 | | /// </remarks> |
| | | 344 | | public class DefaultSettingsSet : IAmbientSettingsSet |
| | | 345 | | { |
| | | 346 | | /// <summary> |
| | | 347 | | /// Gets the singleton instance of <see cref="DefaultSettingsSet"/>. |
| | | 348 | | /// </summary> |
| | | 349 | | public static DefaultSettingsSet Instance { get; } = new(); |
| | | 350 | | |
| | | 351 | | private DefaultSettingsSet() |
| | | 352 | | { |
| | | 353 | | } |
| | | 354 | | /// <summary> |
| | | 355 | | /// Gets the name of the set of settings so that a settings consumer can know where a changed setting value came fro |
| | | 356 | | /// </summary> |
| | | 357 | | public string SetName => "DefaultSettingsValues"; |
| | | 358 | | /// <summary> |
| | | 359 | | /// Gets the current raw value for the setting with the specified key, or null if the setting is not set. |
| | | 360 | | /// </summary> |
| | | 361 | | /// <param name="key">A key identifying the setting whose value is to be retrieved.</param> |
| | | 362 | | /// <returns>The setting value, or null if the setting is not set.</returns> |
| | | 363 | | public string? GetRawValue(string key) |
| | | 364 | | { |
| | | 365 | | return null; |
| | | 366 | | } |
| | | 367 | | /// <summary> |
| | | 368 | | /// Gets the current typed value for the setting with the specified key, or null if the setting is not set. |
| | | 369 | | /// </summary> |
| | | 370 | | /// <param name="key">A key identifying the setting whose value is to be retrieved.</param> |
| | | 371 | | /// <returns>The setting value, or null if the setting is not set.</returns> |
| | | 372 | | public object? GetTypedValue(string key) |
| | | 373 | | { |
| | | 374 | | return null; |
| | | 375 | | } |
| | | 376 | | /// <summary> |
| | | 377 | | /// Gets whether or not the settings set is mutable. |
| | | 378 | | /// </summary> |
| | | 379 | | public bool SettingsAreMutable => false; |
| | | 380 | | /// <summary> |
| | | 381 | | /// Changes the specified setting, if possible. |
| | | 382 | | /// For many ambient settings services, the value will only be reflected in memory until the process shuts down, but |
| | | 383 | | /// </summary> |
| | | 384 | | /// <param name="key">A string that uniquely identifies the setting.</param> |
| | | 385 | | /// <param name="value">The new string value for the setting, or null if the setting should be removed.</param> |
| | | 386 | | /// <returns>Whether or not the setting actually changed (it may have had already the same value).</returns> |
| | | 387 | | public bool ChangeSetting(string key, string? value) => throw new InvalidOperationException($"{nameof(DefaultSetting |
| | | 388 | | } |
| | | 389 | | |
| | | 390 | | /// <summary> |
| | | 391 | | /// The realization of <see cref="IAmbientSettingInfo"/> that backs every setting declared through <see cref="AmbientSet |
| | | 392 | | /// </summary> |
| | | 393 | | /// <remarks> |
| | | 394 | | /// <pitch>The single realization behind every declared setting: it owns the conversion delegate, the typed default, the |
| | | 395 | | /// <pledge><see cref="IAmbientSettingInfo"/></pledge> |
| | | 396 | | /// <pledge>Registers itself in <see cref="SettingsRegistry.DefaultRegistry"/> at construction, so constructing one whos |
| | | 397 | | /// <plan>Conversion wraps the caller's delegate in a catch-all that reports failures through <see cref="AmbientSettings |
| | | 398 | | /// </remarks> |
| | | 399 | | /// <typeparam name="T">The type for the setting.</typeparam> |
| | | 400 | | internal class SettingInfo<T> : IAmbientSettingInfo |
| | | 401 | | { |
| | | 402 | | protected static readonly AmbientService<IAmbientSettingsSet> _SettingsSet = AmbientService<IAmbientSettingsSet>.Ins |
| | | 403 | | private readonly Func<string, T> _convert; |
| | | 404 | | private long _lastUsedTicks = DateTime.MinValue.Ticks; // interlocked |
| | | 405 | | private SettingsSetSettingValue<T>? _globalSetAndValue; // interlocked |
| | | 406 | | |
| | | 407 | | public SettingInfo(string key, string description, T defaultValue, Func<string, T>? convert) |
| | | 408 | | { |
| | | 409 | | if (convert == null) |
| | | 410 | | { |
| | | 411 | | if (typeof(T) != typeof(string)) throw new ArgumentNullException(nameof(convert)); |
| | | 412 | | convert = s => ((T)(object)s)!; // this should be okay because we've just tested the type above and we only |
| | | 413 | | } |
| | | 414 | | Key = key; |
| | | 415 | | Description = description; |
| | | 416 | | _convert = convert; |
| | | 417 | | DefaultValue = defaultValue; |
| | | 418 | | DefaultValueString = defaultValue?.ToString() ?? ""; |
| | | 419 | | SettingsRegistry.DefaultRegistry.Register(this); |
| | | 420 | | } |
| | | 421 | | |
| | | 422 | | public SettingInfo(string key, string description, Func<string, T>? convert, string defaultValue = "") |
| | | 423 | | { |
| | | 424 | | if (convert == null) |
| | | 425 | | { |
| | | 426 | | if (typeof(T) != typeof(string)) throw new ArgumentNullException(nameof(convert)); |
| | | 427 | | convert = s => (T)(object)s; |
| | | 428 | | } |
| | | 429 | | Key = key; |
| | | 430 | | Description = description; |
| | | 431 | | _convert = convert; |
| | | 432 | | DefaultValueString = defaultValue; |
| | | 433 | | DefaultValue = convert(defaultValue); |
| | | 434 | | SettingsRegistry.DefaultRegistry.Register(this); |
| | | 435 | | } |
| | | 436 | | |
| | | 437 | | /// <summary> |
| | | 438 | | /// Gets the setting key. |
| | | 439 | | /// </summary> |
| | | 440 | | public string Key { get; } |
| | | 441 | | /// <summary> |
| | | 442 | | /// Gets a description of the setting. |
| | | 443 | | /// </summary> |
| | | 444 | | public string Description { get; } |
| | | 445 | | /// <summary> |
| | | 446 | | /// Gets the last time the setting's value was retrieved. |
| | | 447 | | /// </summary> |
| | | 448 | | public DateTime LastUsed => new(_lastUsedTicks); |
| | | 449 | | /// <summary> |
| | | 450 | | /// Gets the default value for the setting. |
| | | 451 | | /// </summary> |
| | | 452 | | public string DefaultValueString { get; } |
| | | 453 | | /// <summary> |
| | | 454 | | /// Gets the typed default value. |
| | | 455 | | /// </summary> |
| | | 456 | | public T DefaultValue { get; } |
| | | 457 | | /// <summary> |
| | | 458 | | /// Gets the untyped default value. |
| | | 459 | | /// </summary> |
| | | 460 | | object? IAmbientSettingInfo.DefaultValue => DefaultValue; |
| | | 461 | | |
| | | 462 | | /// <summary> |
| | | 463 | | /// Converts the specified value for the specified settings set. |
| | | 464 | | /// </summary> |
| | | 465 | | /// <param name="settingsSet">The <see cref="IAmbientSettingsSet"/> for the implementation doing the conversion.</pa |
| | | 466 | | /// <param name="value">The string value for the setting.</param> |
| | | 467 | | /// <returns>A typed value created from the string value.</returns> |
| | | 468 | | public object Convert(IAmbientSettingsSet settingsSet, string value) |
| | | 469 | | { |
| | | 470 | | T ret; |
| | | 471 | | try |
| | | 472 | | { |
| | | 473 | | ret = _convert(value); |
| | | 474 | | } |
| | | 475 | | #pragma warning disable CA1031 // this is a "do your best" kind of function, so we really do want to catch all exception |
| | | 476 | | catch (Exception ex) |
| | | 477 | | #pragma warning restore CA1031 |
| | | 478 | | { |
| | | 479 | | AmbientSettings.NotifyConversionFailed(Key, value, ex, DefaultValue); |
| | | 480 | | ret = DefaultValue; |
| | | 481 | | } |
| | | 482 | | // is this settings set the one for this setting or is it the global settings set? |
| | | 483 | | if (settingsSet == _SettingsSet.Global) |
| | | 484 | | { |
| | | 485 | | System.Threading.Interlocked.Exchange(ref _globalSetAndValue, new SettingsSetSettingValue<T>(ret, settingsSe |
| | | 486 | | } |
| | | 487 | | return ret!; |
| | | 488 | | } |
| | | 489 | | /// <summary> |
| | | 490 | | /// Updates the last used time for this setting to the current time. |
| | | 491 | | /// </summary> |
| | | 492 | | public void UpdateLastUsed() |
| | | 493 | | { |
| | | 494 | | long accessTime = AmbientClock.UtcNow.Ticks; |
| | | 495 | | long oldValue = _lastUsedTicks; |
| | | 496 | | // loop attempting to put it in until we win the race |
| | | 497 | | while (accessTime > oldValue) |
| | | 498 | | { |
| | | 499 | | // Coverage note: this loop is nondeterministic when running with multiple threads, so code coverage may not |
| | | 500 | | // try to put in our value--did we win the race? |
| | | 501 | | if (oldValue == System.Threading.Interlocked.CompareExchange(ref _lastUsedTicks, accessTime, oldValue)) |
| | | 502 | | { |
| | | 503 | | // we're done and we were the new max |
| | | 504 | | break; |
| | | 505 | | } |
| | | 506 | | // update our value |
| | | 507 | | oldValue = _lastUsedTicks; |
| | | 508 | | } |
| | | 509 | | // if we didn't break, we're done but the existing value is the max, not this one |
| | | 510 | | } |
| | | 511 | | /// <summary> |
| | | 512 | | /// Gets the current value of the setting (cached from the value given by the settings set). |
| | | 513 | | /// </summary> |
| | | 514 | | public T GlobalOrDefaultValue |
| | | 515 | | { |
| | | 516 | | get |
| | | 517 | | { |
| | | 518 | | UpdateLastUsed(); |
| | | 519 | | return (_globalSetAndValue != null) ? _globalSetAndValue.Value : DefaultValue; |
| | | 520 | | } |
| | | 521 | | } |
| | | 522 | | /// <summary> |
| | | 523 | | /// Gets the current value of the setting and the settings set it came from (cached from the value given by the sett |
| | | 524 | | /// </summary> |
| | | 525 | | public SettingsSetSettingValue<T> GlobalSetAndValue |
| | | 526 | | { |
| | | 527 | | get |
| | | 528 | | { |
| | | 529 | | UpdateLastUsed(); |
| | | 530 | | return _globalSetAndValue ?? new SettingsSetSettingValue<T>(DefaultValue, DefaultSettingsSet.Instance); |
| | | 531 | | } |
| | | 532 | | } |
| | | 533 | | } |
| | | 534 | | |
| | | 535 | | /// <summary> |
| | | 536 | | /// A realization of <see cref="IAmbientSetting{T}"/> whose value comes from a specific settings set. |
| | | 537 | | /// </summary> |
| | | 538 | | /// <remarks> |
| | | 539 | | /// <pitch>The realization of <see cref="IAmbientSetting{T}"/> for settings pinned to one specific settings set at decla |
| | | 540 | | /// <pledge><see cref="IAmbientSetting{T}"/></pledge> |
| | | 541 | | /// <plan>Holds a <see cref="SettingInfo{T}"/> (created — and therefore registered — at construction) plus the pinned se |
| | | 542 | | /// </remarks> |
| | | 543 | | /// <typeparam name="T">The type for the setting.</typeparam> |
| | | 544 | | internal class SettingsSetSetting<T> : IAmbientSetting<T> |
| | | 545 | | { |
| | | 546 | | protected static readonly AmbientService<IAmbientSettingsSet> _AmbientSettingsSet = AmbientService<IAmbientSettingsS |
| | | 547 | | |
| | | 548 | | protected readonly AmbientService<IAmbientSettingsSet>? _settingsSet; |
| | | 549 | | protected readonly SettingInfo<T> _settingInfo; |
| | | 550 | | private readonly IAmbientSettingsSet? _fixedSettingsSet; |
| | | 551 | | |
| | | 552 | | public SettingsSetSetting(IAmbientSettingsSet? fixedSettingsSet, string key, string description, Func<string, T>? co |
| | | 553 | | { |
| | | 554 | | _settingInfo = new SettingInfo<T>(key, description, convert, defaultValueString); |
| | | 555 | | _fixedSettingsSet = fixedSettingsSet; |
| | | 556 | | } |
| | | 557 | | |
| | | 558 | | public SettingsSetSetting(IAmbientSettingsSet? fixedSettingsSet, string key, string description, T defaultValue, Fun |
| | | 559 | | { |
| | | 560 | | _settingInfo = new SettingInfo<T>(key, description, defaultValue, convert); |
| | | 561 | | _fixedSettingsSet = fixedSettingsSet; |
| | | 562 | | } |
| | | 563 | | |
| | | 564 | | internal SettingsSetSetting(AmbientService<IAmbientSettingsSet> settings, string key, string description, Func<strin |
| | | 565 | | { |
| | | 566 | | _settingInfo = new SettingInfo<T>(key, description, convert, defaultValueString); |
| | | 567 | | _settingsSet = settings; |
| | | 568 | | } |
| | | 569 | | #if NEEDED |
| | | 570 | | internal SettingsSetSetting(AmbientService<IAmbientSettingsSet> settings, string key, string description, T defaultV |
| | | 571 | | { |
| | | 572 | | _settingInfo = new SettingInfo<T>(key, description, defaultValue, convert); |
| | | 573 | | _settingsSet = settings; |
| | | 574 | | } |
| | | 575 | | #endif |
| | | 576 | | protected IAmbientSettingsSet? GetValueSet() |
| | | 577 | | { |
| | | 578 | | _settingInfo.UpdateLastUsed(); |
| | | 579 | | // internal override for testing? |
| | | 580 | | if (_settingsSet != null) |
| | | 581 | | { |
| | | 582 | | return _settingsSet.Local; |
| | | 583 | | } |
| | | 584 | | // is there a fixed settings set? |
| | | 585 | | else if (_fixedSettingsSet != null) |
| | | 586 | | { |
| | | 587 | | return _fixedSettingsSet; |
| | | 588 | | } |
| | | 589 | | // otherwise use the current ambient settings set |
| | | 590 | | return _AmbientSettingsSet.Local; |
| | | 591 | | } |
| | | 592 | | protected T GetValueFromSet(IAmbientSettingsSet set) |
| | | 593 | | { |
| | | 594 | | object? value = set.GetTypedValue(_settingInfo.Key); |
| | | 595 | | return (value == null) ? _settingInfo.DefaultValue : (T)value; |
| | | 596 | | } |
| | | 597 | | protected (T, string) GetValueAndSet(IAmbientSettingsSet set) |
| | | 598 | | { |
| | | 599 | | object? value = set.GetTypedValue(_settingInfo.Key); |
| | | 600 | | return (value == null) ? (_settingInfo.DefaultValue, DefaultSettingsSet.Instance.SetName) : ((T)value, set.SetNa |
| | | 601 | | } |
| | | 602 | | /// <summary> |
| | | 603 | | /// Gets the key of the setting, which may be useful in providing an override without having to match the name with |
| | | 604 | | /// </summary> |
| | | 605 | | public string Key => _settingInfo.Key; |
| | | 606 | | /// <summary> |
| | | 607 | | /// Gets the current value of the setting (cached from the value given by the settings set). |
| | | 608 | | /// </summary> |
| | | 609 | | public virtual T Value |
| | | 610 | | { |
| | | 611 | | get |
| | | 612 | | { |
| | | 613 | | IAmbientSettingsSet? set = GetValueSet(); |
| | | 614 | | return (set != null) |
| | | 615 | | ? GetValueFromSet(set) |
| | | 616 | | : _settingInfo.GlobalOrDefaultValue; |
| | | 617 | | } |
| | | 618 | | } |
| | | 619 | | /// <summary> |
| | | 620 | | /// Gets the current value of the setting along with the name of the set that the value came from. |
| | | 621 | | /// Note that this function may be significantly slower than <see cref="Value"/>. |
| | | 622 | | /// </summary> |
| | | 623 | | /// <returns>The current value of the setting along with the name of the set that the value came from.</returns> |
| | | 624 | | public virtual (T, string) GetValueWithSetName() |
| | | 625 | | { |
| | | 626 | | IAmbientSettingsSet? set = GetValueSet(); |
| | | 627 | | return (set != null) |
| | | 628 | | ? GetValueAndSet(set) |
| | | 629 | | : (_settingInfo.GlobalOrDefaultValue, DefaultSettingsSet.Instance.SetName); |
| | | 630 | | } |
| | | 631 | | /// <summary> |
| | | 632 | | /// Gets a string representation of the setting, which may be useful for debugging. Note that this is not guarantee |
| | | 633 | | /// </summary> |
| | | 634 | | /// <returns>A string representation of the setting.</returns> |
| | | 635 | | public override string ToString() |
| | | 636 | | { |
| | | 637 | | (T value, string setName) = GetValueWithSetName(); |
| | | 638 | | return $"{setName}:{value}"; |
| | | 639 | | } |
| | | 640 | | } |
| | | 641 | | |
| | | 642 | | /// <summary> |
| | | 643 | | /// A realization of <see cref="IAmbientSetting{T}"/> whose value follows the ambient settings set. |
| | | 644 | | /// </summary> |
| | | 645 | | /// <remarks> |
| | | 646 | | /// <pitch>The realization of <see cref="IAmbientSetting{T}"/> that follows the ambient settings service — honoring a ca |
| | | 647 | | /// <pledge><see cref="IAmbientSetting{T}"/></pledge> |
| | | 648 | | /// <plan>Extends <see cref="SettingsSetSetting{T}"/> by resolving the set through the ambient <see cref="AmbientService |
| | | 649 | | /// </remarks> |
| | | 650 | | /// <typeparam name="T">The type for the setting.</typeparam> |
| | | 651 | | internal class AmbientSetting<T> : SettingsSetSetting<T> |
| | | 652 | | { |
| | | 653 | | public AmbientSetting(string key, string description, Func<string, T> convert, string defaultValueString = "") |
| | 2 | 654 | | : base((IAmbientSettingsSet?)null, key, description, convert, defaultValueString) |
| | | 655 | | { |
| | 2 | 656 | | } |
| | | 657 | | |
| | | 658 | | public AmbientSetting(string key, string description, T defaultValue, Func<string, T> convert) |
| | 3 | 659 | | : base(null, key, description, defaultValue, convert) |
| | | 660 | | { |
| | 3 | 661 | | } |
| | | 662 | | |
| | | 663 | | internal AmbientSetting(AmbientService<IAmbientSettingsSet> settingsSet, string key, string description, Func<string |
| | 2 | 664 | | : base(settingsSet, key, description, convert, defaultValueString) |
| | | 665 | | { |
| | 2 | 666 | | } |
| | | 667 | | #if NEEDED // Add this one if needed--it should work fine, but isn't currently used |
| | | 668 | | internal AmbientSetting(AmbientService<IAmbientSettingsSet> settingsSet, string key, string description, T defaultVa |
| | | 669 | | : base(settingsSet, key, description, defaultValue, convert) |
| | | 670 | | { |
| | | 671 | | } |
| | | 672 | | #endif |
| | | 673 | | private IAmbientSettingsSet? GetAmbientValueSet() |
| | | 674 | | { |
| | 3 | 675 | | _settingInfo.UpdateLastUsed(); |
| | 3 | 676 | | AmbientService<IAmbientSettingsSet> settingsSet = _settingsSet ?? _AmbientSettingsSet; |
| | | 677 | | // is there a local settings set override? |
| | 3 | 678 | | IAmbientSettingsSet? localSettingsSetOverride = settingsSet.Override; |
| | 3 | 679 | | if (localSettingsSetOverride != null) return localSettingsSetOverride; |
| | | 680 | | // is there a local settings set suppression? |
| | 2 | 681 | | IAmbientSettingsSet? localSettingsSet = settingsSet.Local; |
| | 2 | 682 | | return (localSettingsSet != null) |
| | 2 | 683 | | ? GetValueSet() // fall through to the base (global settings set) |
| | 2 | 684 | | : null; // service suppressed: no set is consulted, so the value falls back to the cached global-set value |
| | | 685 | | } |
| | | 686 | | |
| | | 687 | | /// <summary> |
| | | 688 | | /// Gets the current value of the setting (cached from the value given by the settings set). |
| | | 689 | | /// </summary> |
| | | 690 | | public override T Value |
| | | 691 | | { |
| | | 692 | | get |
| | | 693 | | { |
| | 3 | 694 | | IAmbientSettingsSet? set = GetAmbientValueSet(); |
| | 3 | 695 | | return (set != null) |
| | 3 | 696 | | ? GetValueFromSet(set) |
| | 3 | 697 | | : _settingInfo.GlobalOrDefaultValue; |
| | | 698 | | } |
| | | 699 | | } |
| | | 700 | | /// <summary> |
| | | 701 | | /// Gets the current value of the setting along with the name of the set that the value came from (or null if the de |
| | | 702 | | /// Note that this function may be significantly slower than <see cref="Value"/>. |
| | | 703 | | /// </summary> |
| | | 704 | | /// <returns>The current value of the setting along with the name of the set that the value came from (or null if th |
| | | 705 | | public override (T, string) GetValueWithSetName() |
| | | 706 | | { |
| | 2 | 707 | | IAmbientSettingsSet? set = GetAmbientValueSet(); |
| | 2 | 708 | | if (set != null) return GetValueAndSet(set); |
| | 2 | 709 | | SettingsSetSettingValue<T> setAndValue = _settingInfo.GlobalSetAndValue; |
| | 2 | 710 | | return (setAndValue.Value, setAndValue.SettingsSet.SetName); |
| | | 711 | | } |
| | | 712 | | } |