有没有办法设置log4net配置,如果日志文件的大小超过某个限制,现有的日志文件应该用时间戳重命名？
例如,当大小超过1MB时,我的日志应该是这样的
Log.txt
Log.12-07-2018.txt
Log.11-07-2018.txt
等,其中Log.txt是当前/最新的日志.
注意:
这是我正在使用的log4net配置:
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender" >
<file value="${LOCALAPPDATA}\foobar\Log.txt" />
<encoding value="utf-8" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maximumFileSize value="1MB" />
<maxSizeRollBackups value="1000" />
<preserveLogFileNameExtension value="true" />
<datePattern value=".dd-MM-yyyy" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level [%thread] %type.%method - %message%n" />
</layout>
</appender>
<root>
<level value="All" />
<!-- If the following line is not included the log file will not be created even if log4net is configured with this file. -->
<appender-ref ref="RollingFileAppender" />
</root>
</log4net>
Log.txt
Log.1.txt
Log.2.txt
我希望重命名部分基于时间戳和基于大小的备份逻辑.当我尝试:
<rollingStyle value="Date" />
<datePattern value=".dd-MM-yyyy" />
备份日志文件的命名有效,但随后根据日期而不是大小进行滚动.
它可以实现，但不能仅通过配置来实现。
必须创建自定义RollingFileAppender并在配置中引用Log4net，如下所示，其中PFX.RollingFileAppender从 assembly 加载PFX.Lib。
该设置staticLogFileName可确保始终命名最新的文件Log.txt（按照配置）。我们（重新）使用该datePattern选项来配置日志文件名中的日期部分。
（出于性能原因，countDirection设置为值 0 以减少翻转次数；最新/最后的备份文件将是编号最高的文件。）
<log4net>
<appender name="RollingFileAppender" type="PFX.CustomRollingFileAppender, PFX.Lib" >
<datePattern value="yyyy-MM-dd" />
<staticLogFileName value="true" />
<countDirection value="0" />
<file value="${LOCALAPPDATA}\foobar\Log.txt" />
<encoding value="utf-8" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maximumFileSize value="1MB" />
<maxSizeRollBackups value="1000" />
<preserveLogFileNameExtension value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level [%thread] %type.%method - %message%n" />
</layout>
</appender>
<root>
<level value="All" />
<appender-ref ref="RollingFileAppender" />
</root>
</log4net>
要求中最具挑战性的部分是排除文件名中的索引/计数器后缀；例如。日志-2018-07-16。1 .txt 作为 Log4net 内部跟踪并使用此计数器编号来处理例如。备份文件删除。因此，我们必须自己管理清理工作。
Log4net的实现RollingFileAppender不是很开放；覆盖的方法很少，并且无法访问当前计数器编号跟踪。
如果您不能或不想RollingFileAppender在自己的项目中包含和修改原始代码的完整源代码，您可以继承原始代码，以便进行尽可能少的更改，如下所示。
如果发生基于文件大小的汇总，我们将检查今天的日志文件（与今天的日期匹配；请参阅要求）是否已存在。如果是，则不会发生汇总；只有内容被Log.txt移至今天的日志文件。
如果今天的日志文件不存在，则会发生开箱即用的翻转。这将创建一个名称中带有索引/计数器后缀的文件；此后该文件立即被重命名以与配置的日期模式匹配。由于创建了新文件，因此任何已降级的日志文件（超过配置的阈值）都会被删除。
（为简洁起见，下面的代码不包含异常处理。）
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using log4net.Appender;
using log4net.Util;
namespace PFX
{
public class CustomRollingFileAppender : RollingFileAppender
{
private String _baseFileExtension;
private String _baseFileNameWithoutExtension;
private String _fileDeletePattern;
private String _folder;
private String _backupSearchPattern;
public CustomRollingFileAppender()
{}
public override void ActivateOptions()
{
base.ActivateOptions();
this._baseFileNameWithoutExtension = Path.GetFileNameWithoutExtension(this.File);
this._baseFileExtension = Path.GetExtension(this.File);
this._folder = Path.GetDirectoryName(this.File);
this._fileDeletePattern = $"{this._baseFileNameWithoutExtension}*{this._baseFileExtension}";
this._backupSearchPattern = $"{this._baseFileNameWithoutExtension}.*{this._baseFileExtension}";
}
protected override void AdjustFileBeforeAppend()
{
if ((RollingMode.Size == this.RollingStyle)
&& (this.File != null)
&& (((CountingQuietTextWriter)base.QuietWriter).Count >= this.MaxFileSize)
)
{
DateTime now = DateTime.Now;
String todayFileSuffix = now.ToString(this.DatePattern, CultureInfo.InvariantCulture);
String todayFileName = $"{this._baseFileNameWithoutExtension}{todayFileSuffix}{this._baseFileExtension}";
String todayFile = Path.Combine(this._folder, todayFileName);
if (base.FileExists(todayFile))
{
/* Todays logfile already exist; append content to todays file. */
base.CloseFile(); // Close current file in order to allow reading todays file.
this.moveContentToTodaysFile(todayFile);
// Delete and open todays file for a fresh start.
base.DeleteFile(this.File);
base.OpenFile(this.File, false);
}
else
{
/* Do a roll-over. */
base.RollOverSize();
using (base.SecurityContext.Impersonate(this))
{
this.deleteDepricatedBackupFiles();
this.renameBackupFiles(todayFile);
}
}
}
else
{
base.AdjustFileBeforeAppend();
}
}
// Moves the content from the current log file to todays file.
private void moveContentToTodaysFile(String todayFile)
{
using (FileStream logFile = new FileStream(this.File, FileMode.Open, FileAccess.Read, FileShare.Read))
using (StreamReader reader = new StreamReader(logFile))
using (FileStream backupFile = new FileStream(todayFile, FileMode.Append, FileAccess.Write, FileShare.ReadWrite))
using (StreamWriter writer = new StreamWriter(backupFile))
{
const Int32 BUFFER_SIZE = 1024;
Char[] buffer = new Char[BUFFER_SIZE];
while (true)
{
Int32 nrOfCharsRead = reader.Read(buffer, 0, BUFFER_SIZE);
if (nrOfCharsRead <= 0) { break; }
writer.Write(buffer, 0, nrOfCharsRead);
}
}
}
// Rename backup files according to the configured date pattern, removing the counter/index suffix.
private void renameBackupFiles(String todayFile)
{
IEnumerable<String> backupFiles = Directory.EnumerateFiles(this._folder, this._backupSearchPattern, SearchOption.TopDirectoryOnly);
foreach (String backupFile in backupFiles)
{
base.RollFile(backupFile, todayFile);
}
}
// Keep the number of allowed backup files and delete all others.
private void deleteDepricatedBackupFiles()
{
DirectoryInfo folder = new DirectoryInfo(this._folder);
IEnumerable<FileInfo> filesToDelete =
folder
.EnumerateFiles(this._fileDeletePattern, SearchOption.TopDirectoryOnly)
.OrderByDescending(o => o.LastWriteTime)
.Skip(this.MaxSizeRollBackups + 1)
;
foreach (FileSystemInfo fileToDelete in filesToDelete)
{
base.DeleteFile(fileToDelete.FullName);
}
}
}
}