.net core日志系統相關總結
前言
本節開始整理日志相關的東西。先整理一下日志的基本原理。
正文
首先介紹一下包:
1.Microsoft.Extengsion.Logging.Abstrations
這個是接口包。
2.Microsoft.Extengsion.Logging
這個是實現包
3.Microsoft.Extengsion.Logging.Console
這個是擴展包
代碼如下:
static void Main(string[] args) { IConfigurationBuilder configurationBuilder = new ConfigurationBuilder(); configurationBuilder.AddJsonFile("appsettings.json",optional:false,reloadOnChange:true); var config = configurationBuilder.Build(); IServiceCollection serviceCollection = new ServiceCollection(); serviceCollection.AddSingleton<IConfiguration>(p=>config); serviceCollection.AddLogging(builder => { builder.AddConfiguration(config.GetSection("Logging")); builder.AddConsole(); }); IServiceProvider service = serviceCollection.BuildServiceProvider(); ILoggerFactory loggerFactory = service.GetService<ILoggerFactory>(); var loggerObj = loggerFactory.CreateLogger("Default"); loggerObj.LogInformation(2021, "Default,now that is 2021"); var loggerObj2 = loggerFactory.CreateLogger("loggerObj"); loggerObj2.LogDebug(2021, "loggerObj,now that is 2021"); Console.ReadKey(); }
配置文件:
{ "Logging": { "LogLevel": { "Default": "Debug", "Microsoft": "Warning", "Microsoft.Hosting.Lifetime": "Information" }, "Console": { "LogLevel": { "Default": "Information", "Program": "Trace", "loggerObj": "Debug" } } } }
結果:
首先是配置級別的問題,查看loglevel 文件:
public enum LogLevel { /// <summary>Logs that contain the most detailed messages. These messages may contain sensitive application data. /// These messages are disabled by default and should never be enabled in a production environment.</summary> Trace, /// <summary>Logs that are used for interactive investigation during development. These logs should primarily contain /// information useful for debugging and have no long-term value.</summary> Debug, /// <summary>Logs that track the general flow of the application. These logs should have long-term value.</summary> Information, /// <summary>Logs that highlight an abnormal or unexpected event in the application flow, but do not otherwise cause the /// application execution to stop.</summary> Warning, /// <summary>Logs that highlight when the current flow of execution is stopped due to a failure. These should indicate a /// failure in the current activity, not an application-wide failure.</summary> Error, /// <summary>Logs that describe an unrecoverable application or system crash, or a catastrophic failure that requires /// immediate attention.</summary> Critical, /// <summary>Not used for writing log messages. Specifies that a logging category should not write any messages.</summary> None, }
從上之下,依次提高log級別。
比如說設置瞭log 級別是Error,那麼Debug、Information、Warning 都不會被答應出來。
那麼就來分析一下代碼吧。
AddLogging:
public static IServiceCollection AddLogging(this IServiceCollection services, Action<ILoggingBuilder> configure) { if (services == null) { throw new ArgumentNullException(nameof(services)); } services.AddOptions(); services.TryAdd(ServiceDescriptor.Singleton<ILoggerFactory, LoggerFactory>()); services.TryAdd(ServiceDescriptor.Singleton(typeof(ILogger<>), typeof(Logger<>))); services.TryAddEnumerable(ServiceDescriptor.Singleton<IConfigureOptions<LoggerFilterOptions>>( new DefaultLoggerLevelConfigureOptions(LogLevel.Information))); configure(new LoggingBuilder(services)); return services; }
這裡面給註冊瞭ILoggerFactory和ILogger。然後設置瞭一個打印log的級別配置,LogLevel.Information,這個就是如果我們沒有配置文件默認就是Information這種級別瞭。
configure(new LoggingBuilder(services)) 給我們的委托提供瞭一個LoggingBuilder的實例化對象。這個對象就是用來專門做擴展的,是解耦的一種方式。
internal class LoggingBuilder : ILoggingBuilder { public LoggingBuilder(IServiceCollection services) { Services = services; } public IServiceCollection Services { get; } }
這個LoggingBuilder 類基本什麼功能都沒有,但是因為有瞭這樣一個類,就可以作為擴展的標志瞭。
比如說上文的:
builder.AddConfiguration(config.GetSection("Logging")); builder.AddConsole();
看下AddConfiguration:
public static ILoggingBuilder AddConfiguration(this ILoggingBuilder builder, IConfiguration configuration) { builder.AddConfiguration(); builder.Services.AddSingleton<IConfigureOptions<LoggerFilterOptions>>(new LoggerFilterConfigureOptions(configuration)); builder.Services.AddSingleton<IOptionsChangeTokenSource<LoggerFilterOptions>>(new ConfigurationChangeTokenSource<LoggerFilterOptions>(configuration)); builder.Services.AddSingleton(new LoggingConfiguration(configuration)); return builder; }
這裡面給我們註入瞭配置文件的配置:builder.Services.AddSingleton<IConfigureOptions>(new LoggerFilterConfigureOptions(configuration))
同時給我們註冊監聽令牌:builder.Services.AddSingleton<IOptionsChangeTokenSource>(new ConfigurationChangeTokenSource(configuration));
這裡給我們註冊配置保存在LoggingConfiguration中:builder.Services.AddSingleton(new LoggingConfiguration(configuration));
因為LoggingConfiguration 保存瞭,故而我們隨時可以獲取到LoggingConfiguration 的配置。
看下AddConsole:
/// <param name="builder">The <see cref="ILoggingBuilder"/> to use.</param> public static ILoggingBuilder AddConsole(this ILoggingBuilder builder) { builder.AddConfiguration(); builder.AddConsoleFormatter<JsonConsoleFormatter, JsonConsoleFormatterOptions>(); builder.AddConsoleFormatter<SystemdConsoleFormatter, ConsoleFormatterOptions>(); builder.AddConsoleFormatter<SimpleConsoleFormatter, SimpleConsoleFormatterOptions>(); builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<ILoggerProvider, ConsoleLoggerProvider>()); LoggerProviderOptions.RegisterProviderOptions<ConsoleLoggerOptions, ConsoleLoggerProvider>(builder.Services); return builder; }
builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<ILoggerProvider, ConsoleLoggerProvider>()) 裡面給我們ILoggerProvider 增加瞭一個ConsoleLoggerProvider,故而我們多瞭一個打印的功能。
LoggerProviderOptions.RegisterProviderOptions<ConsoleLoggerOptions, ConsoleLoggerProvider>(builder.Services) 給我們加上瞭ConsoleLoggerOptions 綁定為ConsoleLoggerProvider的配置。
RegisterProviderOptions 如下:
public static void RegisterProviderOptions<TOptions, TProvider>(IServiceCollection services) where TOptions : class { services.TryAddEnumerable(ServiceDescriptor.Singleton<IConfigureOptions<TOptions>, LoggerProviderConfigureOptions<TOptions, TProvider>>()); services.TryAddEnumerable(ServiceDescriptor.Singleton<IOptionsChangeTokenSource<TOptions>, LoggerProviderOptionsChangeTokenSource<TOptions, TProvider>>()); }
接下來就是調用服務:
var loggerObj = loggerFactory.CreateLogger("Default"); loggerObj.LogInformation(2021, "Default,now that is 2021");
看下LoggerFactory的CreateLogger:
public ILogger CreateLogger(string categoryName) { if (CheckDisposed()) { throw new ObjectDisposedException(nameof(LoggerFactory)); } lock (_sync) { if (!_loggers.TryGetValue(categoryName, out Logger logger)) { logger = new Logger { Loggers = CreateLoggers(categoryName), }; (logger.MessageLoggers, logger.ScopeLoggers) = ApplyFilters(logger.Loggers); _loggers[categoryName] = logger; } return logger; } }
裡面做瞭緩存,如果categoryName有緩存的話直接使用緩存,如果沒有那麼調用CreateLoggers創建。
查看CreateLoggers:
private LoggerInformation[] CreateLoggers(string categoryName) { var loggers = new LoggerInformation[_providerRegistrations.Count]; for (int i = 0; i < _providerRegistrations.Count; i++) { loggers[i] = new LoggerInformation(_providerRegistrations[i].Provider, categoryName); } return loggers; }
這裡面就用我們前面註冊過的全部logger的provider,封裝進LoggerInformation。
查看LoggerInformation:
internal readonly struct LoggerInformation { public LoggerInformation(ILoggerProvider provider, string category) : this() { ProviderType = provider.GetType(); Logger = provider.CreateLogger(category); Category = category; ExternalScope = provider is ISupportExternalScope; } public ILogger Logger { get; } public string Category { get; } public Type ProviderType { get; } public bool ExternalScope { get; } }
裡面調用瞭我們,每個provider的CreateLogger。
那麼這個時候我們就找一個provider 看下CreateLogger到底做瞭什麼,這裡就找一下ConsoleLoggerProvider,因為我們添加瞭這個。
[ProviderAlias("Console")] public class ConsoleLoggerProvider : ILoggerProvider, ISupportExternalScope { private readonly IOptionsMonitor<ConsoleLoggerOptions> _options; public ILogger CreateLogger(string name) { if (_options.CurrentValue.FormatterName == null || !_formatters.TryGetValue(_options.CurrentValue.FormatterName, out ConsoleFormatter logFormatter)) { #pragma warning disable CS0618 logFormatter = _options.CurrentValue.Format switch { ConsoleLoggerFormat.Systemd => _formatters[ConsoleFormatterNames.Systemd], _ => _formatters[ConsoleFormatterNames.Simple], }; if (_options.CurrentValue.FormatterName == null) { UpdateFormatterOptions(logFormatter, _options.CurrentValue); } #pragma warning disable CS0618 } return _loggers.GetOrAdd(name, loggerName => new ConsoleLogger(name, _messageQueue) { Options = _options.CurrentValue, ScopeProvider = _scopeProvider, Formatter = logFormatter, }); } }
看到這個IOptionsMonitor,就知道console 配置是支持熱更新的,裡面創建瞭ConsoleLogger,這個ConsoleLogger就是用來打log正在的調用類。
值得註意的是_messageQueue這個,看瞭打印log還是有一個隊列的,按照先進先出原則。
那麼最後來看一下loggerObj.LogInformation(2021, “Default,now that is 2021”);:
第一層 public static void LogInformation(this ILogger logger, EventId eventId, string message, params object[] args) { logger.Log(LogLevel.Information, eventId, message, args); } 第二層 public static void Log(this ILogger logger, LogLevel logLevel, EventId eventId, string message, params object[] args) { logger.Log(logLevel, eventId, null, message, args); } 第三層 public static void Log(this ILogger logger, LogLevel logLevel, EventId eventId, Exception exception, string message, params object[] args) { if (logger == null) { throw new ArgumentNullException(nameof(logger)); } logger.Log(logLevel, eventId, new FormattedLogValues(message, args), exception, _messageFormatter); }
那麼這個logger.Log 是調用具體某個logger,像consoleLogger 嗎? 不是,我們看LoggerFactory的CreateLogger時候封裝瞭:
logger = new Logger { Loggers = CreateLoggers(categoryName), };
那麼看下Logger的Log到底幹瞭什麼。
internal class Logger : ILogger { public LoggerInformation[] Loggers { get; set; } public MessageLogger[] MessageLoggers { get; set; } public ScopeLogger[] ScopeLoggers { get; set; } public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter) { MessageLogger[] loggers = MessageLoggers; if (loggers == null) { return; } List<Exception> exceptions = null; for (int i = 0; i < loggers.Length; i++) { ref readonly MessageLogger loggerInfo = ref loggers[i]; if (!loggerInfo.IsEnabled(logLevel)) { continue; } LoggerLog(logLevel, eventId, loggerInfo.Logger, exception, formatter, ref exceptions, state); } if (exceptions != null && exceptions.Count > 0) { ThrowLoggingError(exceptions); } static void LoggerLog(LogLevel logLevel, EventId eventId, ILogger logger, Exception exception, Func<TState, Exception, string> formatter, ref List<Exception> exceptions, in TState state) { try { logger.Log(logLevel, eventId, state, exception, formatter); } catch (Exception ex) { if (exceptions == null) { exceptions = new List<Exception>(); } exceptions.Add(ex); } } } }
裡面循環判斷是否當前級別能夠輸出:!loggerInfo.IsEnabled(logLevel)
然後調用對應的具體ILog實現的Log,這裡貼一下ConsoleLogger 的實現:
[ThreadStatic] private static StringWriter t_stringWriter; public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter) { if (!IsEnabled(logLevel)) { return; } if (formatter == null) { throw new ArgumentNullException(nameof(formatter)); } t_stringWriter ??= new StringWriter(); LogEntry<TState> logEntry = new LogEntry<TState>(logLevel, _name, eventId, state, exception, formatter); Formatter.Write(in logEntry, ScopeProvider, t_stringWriter); var sb = t_stringWriter.GetStringBuilder(); if (sb.Length == 0) { return; } string computedAnsiString = sb.ToString(); sb.Clear(); if (sb.Capacity > 1024) { sb.Capacity = 1024; } _queueProcessor.EnqueueMessage(new LogMessageEntry(computedAnsiString, logAsError: logLevel >= Options.LogToStandardErrorThreshold)); }
把這個隊列的也貼一下,比較經典吧。
internal class ConsoleLoggerProcessor : IDisposable { private const int _maxQueuedMessages = 1024; private readonly BlockingCollection<LogMessageEntry> _messageQueue = new BlockingCollection<LogMessageEntry>(_maxQueuedMessages); private readonly Thread _outputThread; public IConsole Console; public IConsole ErrorConsole; public ConsoleLoggerProcessor() { // Start Console message queue processor _outputThread = new Thread(ProcessLogQueue) { IsBackground = true, Name = "Console logger queue processing thread" }; _outputThread.Start(); } public virtual void EnqueueMessage(LogMessageEntry message) { if (!_messageQueue.IsAddingCompleted) { try { _messageQueue.Add(message); return; } catch (InvalidOperationException) { } } // Adding is completed so just log the message try { WriteMessage(message); } catch (Exception) { } } // for testing internal virtual void WriteMessage(LogMessageEntry entry) { IConsole console = entry.LogAsError ? ErrorConsole : Console; console.Write(entry.Message); } private void ProcessLogQueue() { try { foreach (LogMessageEntry message in _messageQueue.GetConsumingEnumerable()) { WriteMessage(message); } } catch { try { _messageQueue.CompleteAdding(); } catch { } } } public void Dispose() { _messageQueue.CompleteAdding(); try { _outputThread.Join(1500); // with timeout in-case Console is locked by user input } catch (ThreadStateException) { } } }
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