#region Copyright & License
//
// Copyright 2001-2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion
// MONO 1.0 Beta mcs does not like #if !A && !B && !C syntax
// .NET Compact Framework 1.0 has no support for EventLog
#if !NETCF
// SSCLI 1.0 has no support for EventLog
#if !SSCLI
using System;
using System.Diagnostics;
using System.Globalization;
using log4net.Util;
using log4net.Layout;
using log4net.Core;
namespace log4net.Appender
{
///
/// Writes events to the system event log.
///
///
///
/// The EventID of the event log entry can be
/// set using the EventLogEventID property ()
/// on the .
///
///
/// There is a limit of 32K characters for an event log message
///
///
/// When configuring the EventLogAppender a mapping can be
/// specified to map a logging level to an event log entry type. For example:
///
///
/// <mapping>
/// <level value="ERROR" />
/// <eventLogEntryType value="Error" />
/// </mapping>
/// <mapping>
/// <level value="DEBUG" />
/// <eventLogEntryType value="Information" />
/// </mapping>
///
///
/// The Level is the standard log4net logging level and eventLogEntryType can be any value
/// from the enum, i.e.:
///
/// - Erroran error event
/// - Warninga warning event
/// - Informationan informational event
///
///
///
/// Aspi Havewala
/// Douglas de la Torre
/// Nicko Cadell
/// Gert Driesen
/// Thomas Voss
public class EventLogAppender : AppenderSkeleton
{
#region Public Instance Constructors
///
/// Initializes a new instance of the class.
///
///
///
/// Default constructor.
///
///
public EventLogAppender()
{
m_applicationName = System.Threading.Thread.GetDomain().FriendlyName;
m_logName = "Application"; // Defaults to application log
m_machineName = "."; // Only log on the local machine
}
///
/// Initializes a new instance of the class
/// with the specified .
///
/// The to use with this appender.
///
///
/// Obsolete constructor.
///
///
[Obsolete("Instead use the default constructor and set the Layout property")]
public EventLogAppender(ILayout layout) : this()
{
Layout = layout;
}
#endregion // Public Instance Constructors
#region Public Instance Properties
///
/// The name of the log where messages will be stored.
///
///
/// The string name of the log where messages will be stored.
///
///
/// This is the name of the log as it appears in the Event Viewer
/// tree. The default value is to log into the Application
/// log, this is where most applications write their events. However
/// if you need a separate log for your application (or applications)
/// then you should set the appropriately.
/// This should not be used to distinguish your event log messages
/// from those of other applications, the
/// property should be used to distinguish events. This property should be
/// used to group together events into a single log.
///
///
public string LogName
{
get { return m_logName; }
set { m_logName = value; }
}
///
/// Property used to set the Application name. This appears in the
/// event logs when logging.
///
///
/// The string used to distinguish events from different sources.
///
///
/// Sets the event log source property.
///
public string ApplicationName
{
get { return m_applicationName; }
set { m_applicationName = value; }
}
///
/// This property is used to return the name of the computer to use
/// when accessing the event logs. Currently, this is the current
/// computer, denoted by a dot "."
///
///
/// The string name of the machine holding the event log that
/// will be logged into.
///
///
/// This property cannot be changed. It is currently set to '.'
/// i.e. the local machine. This may be changed in future.
///
public string MachineName
{
get { return m_machineName; }
set { /* Currently we do not allow the machine name to be changed */; }
}
///
/// Add a mapping of level to - done by the config file
///
/// The mapping to add
///
///
/// Add a mapping to this appender.
/// Each mapping defines the event log entry type for a level.
///
///
public void AddMapping(Level2EventLogEntryType mapping)
{
m_levelMapping.Add(mapping);
}
///
/// Gets or sets the used to write to the EventLog.
///
///
/// The used to write to the EventLog.
///
///
///
/// The system security context used to write to the EventLog.
///
///
/// Unless a specified here for this appender
/// the is queried for the
/// security context to use. The default behavior is to use the security context
/// of the current thread.
///
///
public SecurityContext SecurityContext
{
get { return m_securityContext; }
set { m_securityContext = value; }
}
#endregion // Public Instance Properties
#region Implementation of IOptionHandler
///
/// Initialize the appender based on the options set
///
///
///
/// This is part of the delayed object
/// activation scheme. The method must
/// be called on this object after the configuration properties have
/// been set. Until is called this
/// object is in an undefined state and must not be used.
///
///
/// If any of the configuration properties are modified then
/// must be called again.
///
///
override public void ActivateOptions()
{
base.ActivateOptions();
if (m_securityContext == null)
{
m_securityContext = SecurityContextProvider.DefaultProvider.CreateSecurityContext(this);
}
bool sourceAlreadyExists = false;
string currentLogName = null;
using(SecurityContext.Impersonate(this))
{
sourceAlreadyExists = EventLog.SourceExists(m_applicationName);
if (sourceAlreadyExists)
{
currentLogName = EventLog.LogNameFromSourceName(m_applicationName, m_machineName);
}
}
if (sourceAlreadyExists && currentLogName != m_logName)
{
LogLog.Debug("EventLogAppender: Changing event source [" + m_applicationName + "] from log [" + currentLogName + "] to log [" + m_logName + "]");
}
else if (!sourceAlreadyExists)
{
LogLog.Debug("EventLogAppender: Creating event source Source [" + m_applicationName + "] in log " + m_logName + "]");
}
string registeredLogName = null;
using(SecurityContext.Impersonate(this))
{
if (sourceAlreadyExists && currentLogName != m_logName)
{
//
// Re-register this to the current application if the user has changed
// the application / logfile association
//
EventLog.DeleteEventSource(m_applicationName, m_machineName);
CreateEventSource(m_applicationName, m_logName, m_machineName);
registeredLogName = EventLog.LogNameFromSourceName(m_applicationName, m_machineName);
}
else if (!sourceAlreadyExists)
{
CreateEventSource(m_applicationName, m_logName, m_machineName);
registeredLogName = EventLog.LogNameFromSourceName(m_applicationName, m_machineName);
}
}
m_levelMapping.ActivateOptions();
LogLog.Debug("EventLogAppender: Source [" + m_applicationName + "] is registered to log [" + registeredLogName + "]");
}
#endregion // Implementation of IOptionHandler
///
/// Create an event log source
///
///
/// Uses different API calls under NET_2_0
///
private static void CreateEventSource(string source, string logName, string machineName)
{
#if NET_2_0
EventSourceCreationData eventSourceCreationData = new EventSourceCreationData(source, logName);
eventSourceCreationData.MachineName = machineName;
EventLog.CreateEventSource(eventSourceCreationData);
#else
EventLog.CreateEventSource(source, logName, machineName);
#endif
}
#region Override implementation of AppenderSkeleton
///
/// This method is called by the
/// method.
///
/// the event to log
///
/// Writes the event to the system event log using the
/// .
///
/// If the event has an EventID property (see )
/// set then this integer will be used as the event log event id.
///
///
/// There is a limit of 32K characters for an event log message
///
///
override protected void Append(LoggingEvent loggingEvent)
{
//
// Write the resulting string to the event log system
//
int eventID = 0;
// Look for the EventLogEventID property
object eventIDPropertyObj = loggingEvent.LookupProperty("EventID");
if (eventIDPropertyObj != null)
{
if (eventIDPropertyObj is int)
{
eventID = (int)eventIDPropertyObj;
}
else
{
string eventIDPropertyString = eventIDPropertyObj as string;
if (eventIDPropertyString != null && eventIDPropertyString.Length > 0)
{
// Read the string property into a number
int intVal;
if (SystemInfo.TryParse(eventIDPropertyString, out intVal))
{
eventID = intVal;
}
else
{
ErrorHandler.Error("Unable to parse event ID property [" + eventIDPropertyString + "].");
}
}
}
}
// Write to the event log
try
{
string eventTxt = RenderLoggingEvent(loggingEvent);
// There is a limit of 32K characters for an event log message
if (eventTxt.Length > 32000)
{
eventTxt = eventTxt.Substring(0, 32000);
}
EventLogEntryType entryType = GetEntryType(loggingEvent.Level);
using(SecurityContext.Impersonate(this))
{
EventLog.WriteEntry(m_applicationName, eventTxt, entryType, eventID);
}
}
catch(Exception ex)
{
ErrorHandler.Error("Unable to write to event log [" + m_logName + "] using source [" + m_applicationName + "]", ex);
}
}
///
/// This appender requires a to be set.
///
/// true
///
///
/// This appender requires a to be set.
///
///
override protected bool RequiresLayout
{
get { return true; }
}
#endregion // Override implementation of AppenderSkeleton
#region Protected Instance Methods
///
/// Get the equivalent for a
///
/// the Level to convert to an EventLogEntryType
/// The equivalent for a
///
/// Because there are fewer applicable
/// values to use in logging levels than there are in the
/// this is a one way mapping. There is
/// a loss of information during the conversion.
///
virtual protected EventLogEntryType GetEntryType(Level level)
{
// see if there is a specified lookup.
Level2EventLogEntryType entryType = m_levelMapping.Lookup(level) as Level2EventLogEntryType;
if (entryType != null)
{
return entryType.EventLogEntryType;
}
// Use default behavior
if (level >= Level.Error)
{
return EventLogEntryType.Error;
}
else if (level == Level.Warn)
{
return EventLogEntryType.Warning;
}
// Default setting
return EventLogEntryType.Information;
}
#endregion // Protected Instance Methods
#region Private Instance Fields
///
/// The log name is the section in the event logs where the messages
/// are stored.
///
private string m_logName;
///
/// Name of the application to use when logging. This appears in the
/// application column of the event log named by .
///
private string m_applicationName;
///
/// The name of the machine which holds the event log. This is
/// currently only allowed to be '.' i.e. the current machine.
///
private string m_machineName;
///
/// Mapping from level object to EventLogEntryType
///
private LevelMapping m_levelMapping = new LevelMapping();
///
/// The security context to use for privileged calls
///
private SecurityContext m_securityContext;
#endregion // Private Instance Fields
#region Level2EventLogEntryType LevelMapping Entry
///
/// A class to act as a mapping between the level that a logging call is made at and
/// the color it should be displayed as.
///
///
///
/// Defines the mapping between a level and its event log entry type.
///
///
public class Level2EventLogEntryType : LevelMappingEntry
{
private EventLogEntryType m_entryType;
///
/// The for this entry
///
///
///
/// Required property.
/// The for this entry
///
///
public EventLogEntryType EventLogEntryType
{
get { return m_entryType; }
set { m_entryType = value; }
}
}
#endregion // LevelColors LevelMapping Entry
}
}
#endif // !SSCLI
#endif // !NETCF