loggingevent.cs

精通SQL Server2005项目开发

		/// <c>false</c>.
		/// </para>
		/// <para>
		/// See <see cref="FixVolatileData(bool)"/> for more
		/// information.
		/// </para>
		/// </remarks>
		[Obsolete("Use Fix property")]
		public void FixVolatileData()
		{
			Fix = FixFlags.All;
		}

		/// <summary>
		/// Fixes instance fields that hold volatile data.
		/// </summary>
		/// <param name="fastButLoose">Set to <c>true</c> to not fix data that takes a long time to fix.</param>
		/// <remarks>
		/// <para>
		/// Some of the values in instances of <see cref="LoggingEvent"/>
		/// are considered volatile, that is the values are correct at the
		/// time the event is delivered to appenders, but will not be consistent
		/// at any time afterwards. If an event is to be stored and then processed
		/// at a later time these volatile values must be fixed by calling
		/// <see cref="FixVolatileData()"/>. There is a performance penalty
		/// for incurred by calling <see cref="FixVolatileData()"/> but it
		/// is essential to maintaining data consistency.
		/// </para>
		/// <para>
		/// The <paramref name="fastButLoose"/> param controls the data that
		/// is fixed. Some of the data that can be fixed takes a long time to 
		/// generate, therefore if you do not require those settings to be fixed
		/// they can be ignored by setting the <paramref name="fastButLoose"/> param
		/// to <c>true</c>. This setting will ignore the <see cref="LocationInformation"/>
		/// and <see cref="UserName"/> settings.
		/// </para>
		/// <para>
		/// Set <paramref name="fastButLoose"/> to <c>false</c> to ensure that all 
		/// settings are fixed.
		/// </para>
		/// </remarks>
		[Obsolete("Use Fix property")]
		public void FixVolatileData(bool fastButLoose)
		{
			if (fastButLoose)
			{
				Fix = FixFlags.Partial;
			}
			else
			{
				Fix = FixFlags.All;
			}
		}

		/// <summary>
		/// Fix the fields specified by the <see cref="FixFlags"/> parameter
		/// </summary>
		/// <param name="flags">the fields to fix</param>
		/// <remarks>
		/// <para>
		/// Only fields specified in the <paramref name="flags"/> will be fixed.
		/// Fields will not be fixed if they have previously been fixed.
		/// It is not possible to 'unfix' a field.
		/// </para>
		/// </remarks>
		protected void FixVolatileData(FixFlags flags)
		{
			object forceCreation = null;

			//Unlock the cache so that new values can be stored
			//This may not be ideal if we are no longer in the correct context
			//and someone calls fix. 
			m_cacheUpdatable=true;

			// determine the flags that we are actually fixing
			FixFlags updateFlags = (FixFlags)((flags ^ m_fixFlags) & flags);

			if (updateFlags > 0) 
			{
				if ((updateFlags & FixFlags.Message) != 0)
				{
					// Force the message to be rendered
					forceCreation = this.RenderedMessage;

					m_fixFlags |= FixFlags.Message;
				}
				if ((updateFlags & FixFlags.ThreadName) != 0)
				{
					// Grab the thread name
					forceCreation = this.ThreadName;

					m_fixFlags |= FixFlags.ThreadName;
				}

				if ((updateFlags & FixFlags.LocationInfo) != 0)
				{
					// Force the location information to be loaded
					forceCreation = this.LocationInformation;

					m_fixFlags |= FixFlags.LocationInfo;
				}
				if ((updateFlags & FixFlags.UserName) != 0)
				{
					// Grab the user name
					forceCreation = this.UserName;

					m_fixFlags |= FixFlags.UserName;
				}
				if ((updateFlags & FixFlags.Domain) != 0)
				{
					// Grab the domain name
					forceCreation = this.Domain;

					m_fixFlags |= FixFlags.Domain;
				}
				if ((updateFlags & FixFlags.Identity) != 0)
				{
					// Grab the identity
					forceCreation = this.Identity;

					m_fixFlags |= FixFlags.Identity;
				}

				if ((updateFlags & FixFlags.Exception) != 0)
				{
					// Force the exception text to be loaded
					forceCreation = GetExceptionString();

					m_fixFlags |= FixFlags.Exception;
				}

				if ((updateFlags & FixFlags.Properties) != 0)
				{
					CacheProperties();

					m_fixFlags |= FixFlags.Properties;
				}
			}

			// avoid warning CS0219
			if (forceCreation != null) 
			{
			}

			//Finaly lock everything we've cached.
			m_cacheUpdatable=false;
		}

		#endregion Public Instance Methods

		#region Protected Instance Methods

		private void CreateCompositeProperties()
		{
			m_compositeProperties = new CompositeProperties();

			if (m_eventProperties != null)
			{
				m_compositeProperties.Add(m_eventProperties);
			}
#if !NETCF
			PropertiesDictionary logicalThreadProperties = LogicalThreadContext.Properties.GetProperties(false);
			if (logicalThreadProperties != null)
			{
				m_compositeProperties.Add(logicalThreadProperties);
			}
#endif
			PropertiesDictionary threadProperties = ThreadContext.Properties.GetProperties(false);
			if (threadProperties != null)
			{
				m_compositeProperties.Add(threadProperties);
			}

			// TODO: Add Repository Properties

			m_compositeProperties.Add(GlobalContext.Properties.GetReadOnlyProperties());
		}

		private void CacheProperties()
		{
			if (m_data.Properties == null  && this.m_cacheUpdatable)
			{
				if (m_compositeProperties == null)
				{
					CreateCompositeProperties();
				}

				PropertiesDictionary flattenedProperties = m_compositeProperties.Flatten();

				PropertiesDictionary fixedProperties = new PropertiesDictionary();

				// Validate properties
				foreach(DictionaryEntry entry in flattenedProperties)
				{
					string key = entry.Key as string;

					if (key != null)
					{
						object val = entry.Value;

						// Fix any IFixingRequired objects
						IFixingRequired fixingRequired = val as IFixingRequired;
						if (fixingRequired != null)
						{
							val = fixingRequired.GetFixedObject();
						}

						// Strip keys with null values
						if (val != null)
						{
							fixedProperties[key] = val;
						}
					}
				}

				m_data.Properties = fixedProperties;
			}
		}

		/// <summary>
		/// Lookup a composite property in this event
		/// </summary>
		/// <param name="key">the key for the property to lookup</param>
		/// <returns>the value for the property</returns>
		/// <remarks>
		/// <para>
		/// This event has composite properties that combine together properties from
		/// several different contexts in the following order:
		/// <list type="definition">
		///		<item>
		/// 		<term>this events properties</term>
		/// 		<description>
		/// 		This event has <see cref="Properties"/> that can be set. These 
		/// 		properties are specific to this event only.
		/// 		</description>
		/// 	</item>
		/// 	<item>
		/// 		<term>the thread properties</term>
		/// 		<description>
		/// 		The <see cref="ThreadContext.Properties"/> that are set on the current
		/// 		thread. These properties are shared by all events logged on this thread.
		/// 		</description>
		/// 	</item>
		/// 	<item>
		/// 		<term>the global properties</term>
		/// 		<description>
		/// 		The <see cref="GlobalContext.Properties"/> that are set globally. These 
		/// 		properties are shared by all the threads in the AppDomain.
		/// 		</description>
		/// 	</item>
		/// </list>
		/// </para>
		/// </remarks>
		public object LookupProperty(string key)
		{
			if (m_data.Properties != null)
			{
				return m_data.Properties[key];
			}
			if (m_compositeProperties == null)
			{
				CreateCompositeProperties();
			}
			return m_compositeProperties[key];
		}

		/// <summary>
		/// Get all the composite properties in this event
		/// </summary>
		/// <returns>the <see cref="PropertiesDictionary"/> containing all the properties</returns>
		/// <remarks>
		/// <para>
		/// See <see cref="LookupProperty"/> for details of the composite properties 
		/// stored by the event.
		/// </para>
		/// <para>
		/// This method returns a single <see cref="PropertiesDictionary"/> containing all the
		/// properties defined for this event.
		/// </para>
		/// </remarks>
		public PropertiesDictionary GetProperties()
		{
			if (m_data.Properties != null)
			{
				return m_data.Properties;
			}
			if (m_compositeProperties == null)
			{
				CreateCompositeProperties();
			}
			return m_compositeProperties.Flatten();
		}

		#endregion Public Instance Methods

		#region Private Instance Fields

		/// <summary>
		/// The internal logging event data.
		/// </summary>
		private LoggingEventData m_data;

		/// <summary>
		/// The internal logging event data.
		/// </summary>
		private CompositeProperties m_compositeProperties;

		/// <summary>
		/// The internal logging event data.
		/// </summary>
		private PropertiesDictionary m_eventProperties;

		/// <summary>
		/// The fully qualified Type of the calling 
		/// logger class in the stack frame (i.e. the declaring type of the method).
		/// </summary>
		private readonly Type m_callerStackBoundaryDeclaringType;

		/// <summary>
		/// The application supplied message of logging event.
		/// </summary>
		private readonly object m_message;

		/// <summary>
		/// The exception that was thrown.
		/// </summary>
		/// <remarks>
		/// This is not serialized. The string representation
		/// is serialized instead.
		/// </remarks>
		private readonly Exception m_thrownException;

		/// <summary>
		/// The repository that generated the logging event
		/// </summary>
		/// <remarks>
		/// This is not serialized.
		/// </remarks>
		private ILoggerRepository m_repository = null;

		/// <summary>
		/// The fix state for this event
		/// </summary>
		/// <remarks>
		/// These flags indicate which fields have been fixed.
		/// Not serialized.
		/// </remarks>
		private FixFlags m_fixFlags = FixFlags.None;

		/// <summary>
		/// Indicated that the internal cache is updateable (ie not fixed)
		/// </summary>
		/// <remarks>
		/// This is a seperate flag to m_fixFlags as it allows incrementel fixing and simpler
		/// changes in the caching strategy.
		/// </remarks>
		private bool m_cacheUpdatable = true;

		#endregion Private Instance Fields

		#region Constants

		/// <summary>
		/// The key into the Properties map for the host name value.
		/// </summary>
		public const string HostNameProperty = "log4net:HostName";

		/// <summary>
		/// The key into the Properties map for the thread identity value.
		/// </summary>
		public const string IdentityProperty = "log4net:Identity";

		/// <summary>
		/// The key into the Properties map for the user name value.
		/// </summary>
		public const string UserNameProperty = "log4net:UserName";

		#endregion
	}
}