.net core 自带一个基础的logger框架Microsoft.Extensions.Logging。
微软默认实现了Microsoft.Extensions.Logging.Console.dll。控制台的日志输出和Microsoft.Extensions.Logging.Debug.dll调试输出。
下面我们写一个我们自己的本地文件输出模块demo，简单理解一下自带的这个logger系统。.
logger框架主要几个类：LoggerFactory，Logger，LoggerProvider。
看名字就很好理解，都不需要解释。
实现我们自己的file logger只需要实现logger，loggerProvider即可。
第一步：入口。
loggerFactory.AddFile(this.Configuration.GetSection("FileLogging"));
为LoggerFactory扩张一个方法，提供增加日志写文件方式的入口。相关的配置来自appsettings.json
public static class FileLoggerExtensions
{
//add 日志文件创建规则，分割规则，格式化规则，过滤规则 to appsettings.json
public static ILoggerFactory AddFile(this ILoggerFactory factory, IConfiguration configuration)
{
return AddFile(factory, new FileLoggerSettings(configuration));
}
public static ILoggerFactory AddFile(this ILoggerFactory factory, FileLoggerSettings fileLoggerSettings)
{
factory.AddProvider(new FileLoggerProvider(fileLoggerSettings));
return factory;
}
}
第二步：实现我们的logger提供程序，实现ILoggerProvider接口
public class FileLoggerProvider : ILoggerProvider, Idisposable
关键方法CreateLogger，创建真正写日志的logger。对当前的logger可以做适当的缓存，配置logger
public class FileLoggerProvider : ILoggerProvider, IDisposable
{
FileLoggerSettings _configuration;
readonly ConcurrentDictionary<string, InitLoggerModel> _loggerKeys = new ConcurrentDictionary<string, InitLoggerModel>();
readonly ConcurrentDictionary<string, FileLogger> _loggers = new ConcurrentDictionary<string, FileLogger>();
public FileLoggerProvider(FileLoggerSettings configuration)
{
_configuration = configuration;
_configuration.ChangeToken.RegisterChangeCallback(p =>
{
//appsettings.json changed. reload settings.
_configuration.Reload();
//update loggers settings form new settings
foreach (var item in this._loggers.Values)
{
InitLoggerModel model = new InitLoggerModel();
InitLoggerSettings(item.Name, model);
InitLogger(model, item);
}
}, null);
}
public ILogger CreateLogger(string categoryName)
{
var loggerKey = this._loggerKeys.GetOrAdd(categoryName, p =>
{
InitLoggerModel model = new InitLoggerModel();
InitLoggerSettings(categoryName, model);
return model;
});
var key = loggerKey.FileDiretoryPath + loggerKey.FileNameTemplate;
return this._loggers.GetOrAdd(key, p =>
{
var logger = new FileLogger(categoryName);
InitLogger(loggerKey, logger);
return logger;
});
}
private static void InitLogger(InitLoggerModel model, FileLogger logger)
{
logger.FileNameTemplate = model.FileNameTemplate;
logger.FileDiretoryPath = model.FileDiretoryPath;
logger.MinLevel = model.MinLevel;
}
class InitLoggerModel
{
public LogLevel MinLevel { get; set; }
public string FileDiretoryPath { get; set; }
public string FileNameTemplate { get; set; }
public override int GetHashCode()
{
return this.MinLevel.GetHashCode() + this.FileDiretoryPath.GetHashCode() + this.FileNameTemplate.GetHashCode();
}
public override bool Equals(object obj)
{
var b = obj as InitLoggerModel;
if (b == null)
return false;
return this.MinLevel == b.MinLevel && this.FileDiretoryPath == b.FileDiretoryPath && this.FileNameTemplate == b.FileNameTemplate;
}
}
private void InitLoggerSettings(string categoryName, InitLoggerModel model)
{
model.MinLevel = LogLevel.Debug;
var keys = this.GetKeys(categoryName);
foreach (var item in keys)
{
var switchV = _configuration.GetSwitch(item);
if (switchV.Item1)
{
model.MinLevel = switchV.Item2;
break;
}
}
model.FileDiretoryPath = this._configuration.DefaultPath;
foreach (var item in keys)
{
var switchV = _configuration.GetDiretoryPath(item);
if (switchV.Item1)
{
model.FileDiretoryPath = switchV.Item2;
break;
}
}
model.FileNameTemplate = this._configuration.DefaultFileName;
foreach (var item in keys)
{
var switchV = _configuration.GetFileName(item);
if (switchV.Item1)
{
model.FileNameTemplate = switchV.Item2;
break;
}
}
}
IEnumerable<string> GetKeys(string categoryName)
{
while (!String.IsNullOrEmpty(categoryName))
{
// a.b.c
//--result
// a.b.c，a.b，a，Default
yield return categoryName;
var last = categoryName.LastIndexOf('.');
if (last <= 0)
{
yield return "Default";
yield break;
}
System.Diagnostics.Debug.WriteLine(categoryName + "--" + last);
categoryName = categoryName.Substring(0, last);
}
yield break;
}
public void Dispose()
{
}
}
第三步：实现我们的logger，实现ILogger接口。真正将log写入file
public class FileLogger : Ilogger
public class FileLogger : ILogger
{
static protected string delimiter = new string(new char[] { (char)1 });
public FileLogger(string categoryName)
{
this.Name = categoryName;
}
class Disposable : IDisposable
{
public void Dispose()
{
}
}
Disposable _DisposableInstance = new Disposable();
public IDisposable BeginScope<TState>(TState state)
{
return _DisposableInstance;
}
public bool IsEnabled(LogLevel logLevel)
{
return this.MinLevel <= logLevel;
}
public void Reload()
{
_Expires = true;
}
public string Name { get; private set; }
public LogLevel MinLevel { get; set; }
public string FileDiretoryPath { get; set; }
public string FileNameTemplate { get; set; }
public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception exception, Func<TState, Exception, string> formatter)
{
if (!this.IsEnabled(logLevel))
return;
var msg = formatter(state, exception);
this.Write(logLevel, eventId, msg, exception);
}
void Write(LogLevel logLevel, EventId eventId, string message, Exception ex)
{
EnsureInitFile();
//TODO 提高效率 队列写！！！
var log = String.Concat(DateTime.Now.ToString("HH:mm:ss"), '[', logLevel.ToString(), ']', '[',
Thread.CurrentThread.ManagedThreadId.ToString(), ',', eventId.Id.ToString(), ',', eventId.Name, ']',
delimiter, message, delimiter, ex?.ToString());
lock (this)
{
this._sw.WriteLine(log);
}
}
bool _Expires = true;
string _FileName;
protected StreamWriter _sw;
void EnsureInitFile()
{
if (CheckNeedCreateNewFile())
{
lock (this)
{
if (CheckNeedCreateNewFile())
{
InitFile();
_Expires = false;
}
}
}
}
bool CheckNeedCreateNewFile()
{
if (_Expires)
{
return true;
}
//TODO 使用 RollingType判断是否需要创建文件。提高效率！！！
if (_FileName != DateTime.Now.ToString(this.FileNameTemplate))
{
return true;
}
return false;
}
void InitFile()
{
if (!Directory.Exists(this.FileDiretoryPath))
{
Directory.CreateDirectory(this.FileDiretoryPath);
}
var path = "";
int i = 0;
do
{
_FileName = DateTime.Now.ToString(this.FileNameTemplate);
path = Path.Combine(this.FileDiretoryPath, _FileName + "_" + i + ".log");
i++;
} while (System.IO.File.Exists(path));
var oldsw = _sw;
_sw = new StreamWriter(new FileStream(path, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.Read), Encoding.UTF8);
_sw.AutoFlush = true;
if (oldsw != null)
{
try
{
_sw.Flush();
_sw.Dispose();
}
catch
{
}
}
}
}
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