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#region Apache License
//
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to you 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
#if !NETCF
using System;
using System.Collections;
using log4net.Core;
namespace log4net.Util
{
/// <summary>
/// Delegate type used for LogicalThreadContextStack's callbacks.
/// </summary>
#if NET_2_0 || MONO_2_0
public delegate void TwoArgAction<T1, T2>(T1 t1, T2 t2);
#else
public delegate void TwoArgAction(string t1, LogicalThreadContextStack t2);
#endif
/// <summary>
/// Implementation of Stack for the <see cref="log4net.LogicalThreadContext"/>
/// </summary>
/// <remarks>
/// <para>
/// Implementation of Stack for the <see cref="log4net.LogicalThreadContext"/>
/// </para>
/// </remarks>
/// <author>Nicko Cadell</author>
public sealed class LogicalThreadContextStack : IFixingRequired
{
#region Private Instance Fields
/// <summary>
/// The stack store.
/// </summary>
private Stack m_stack = new Stack();
/// <summary>
/// The name of this <see cref="log4net.Util.LogicalThreadContextStack"/> within the
/// <see cref="log4net.Util.LogicalThreadContextProperties"/>.
/// </summary>
private string m_propertyKey;
/// <summary>
/// The callback used to let the <see cref="log4net.Util.LogicalThreadContextStacks"/> register a
/// new instance of a <see cref="log4net.Util.LogicalThreadContextStack"/>.
/// </summary>
#if NET_2_0 || MONO_2_0
private TwoArgAction<string, LogicalThreadContextStack> m_registerNew;
#else
private TwoArgAction m_registerNew;
#endif
#endregion Private Instance Fields
#region Public Instance Constructors
/// <summary>
/// Internal constructor
/// </summary>
/// <remarks>
/// <para>
/// Initializes a new instance of the <see cref="LogicalThreadContextStack" /> class.
/// </para>
/// </remarks>
#if NET_2_0 || MONO_2_0
internal LogicalThreadContextStack(string propertyKey, TwoArgAction<string, LogicalThreadContextStack> registerNew)
#else
internal LogicalThreadContextStack(string propertyKey, TwoArgAction registerNew)
#endif
{
m_propertyKey = propertyKey;
m_registerNew = registerNew;
}
#endregion Public Instance Constructors
#region Public Properties
/// <summary>
/// The number of messages in the stack
/// </summary>
/// <value>
/// The current number of messages in the stack
/// </value>
/// <remarks>
/// <para>
/// The current number of messages in the stack. That is
/// the number of times <see cref="Push"/> has been called
/// minus the number of times <see cref="Pop"/> has been called.
/// </para>
/// </remarks>
public int Count
{
get { return m_stack.Count; }
}
#endregion // Public Properties
#region Public Methods
/// <summary>
/// Clears all the contextual information held in this stack.
/// </summary>
/// <remarks>
/// <para>
/// Clears all the contextual information held in this stack.
/// Only call this if you think that this thread is being reused after
/// a previous call execution which may not have completed correctly.
/// You do not need to use this method if you always guarantee to call
/// the <see cref="IDisposable.Dispose"/> method of the <see cref="IDisposable"/>
/// returned from <see cref="Push"/> even in exceptional circumstances,
/// for example by using the <c>using(log4net.LogicalThreadContext.Stacks["NDC"].Push("Stack_Message"))</c>
/// syntax.
/// </para>
/// </remarks>
public void Clear()
{
m_registerNew(m_propertyKey, new LogicalThreadContextStack(m_propertyKey, m_registerNew));
}
/// <summary>
/// Removes the top context from this stack.
/// </summary>
/// <returns>The message in the context that was removed from the top of this stack.</returns>
/// <remarks>
/// <para>
/// Remove the top context from this stack, and return
/// it to the caller. If this stack is empty then an
/// empty string (not <see langword="null"/>) is returned.
/// </para>
/// </remarks>
public string Pop()
{
// copy current stack
Stack stack = new Stack(new Stack(m_stack));
string result = "";
if (stack.Count > 0)
{
result = ((StackFrame)(stack.Pop())).Message;
}
LogicalThreadContextStack ltcs = new LogicalThreadContextStack(m_propertyKey, m_registerNew);
ltcs.m_stack = stack;
m_registerNew(m_propertyKey, ltcs);
return result;
}
/// <summary>
/// Pushes a new context message into this stack.
/// </summary>
/// <param name="message">The new context message.</param>
/// <returns>
/// An <see cref="IDisposable"/> that can be used to clean up the context stack.
/// </returns>
/// <remarks>
/// <para>
/// Pushes a new context onto this stack. An <see cref="IDisposable"/>
/// is returned that can be used to clean up this stack. This
/// can be easily combined with the <c>using</c> keyword to scope the
/// context.
/// </para>
/// </remarks>
/// <example>Simple example of using the <c>Push</c> method with the <c>using</c> keyword.
/// <code lang="C#">
/// using(log4net.LogicalThreadContext.Stacks["NDC"].Push("Stack_Message"))
/// {
/// log.Warn("This should have an ThreadContext Stack message");
/// }
/// </code>
/// </example>
public IDisposable Push(string message)
{
// do modifications on a copy
Stack stack = new Stack(new Stack(m_stack));
stack.Push(new StackFrame(message, (stack.Count > 0) ? (StackFrame)stack.Peek() : null));
LogicalThreadContextStack contextStack = new LogicalThreadContextStack(m_propertyKey, m_registerNew);
contextStack.m_stack = stack;
m_registerNew(m_propertyKey, contextStack);
return new AutoPopStackFrame(contextStack, stack.Count - 1);
}
#endregion Public Methods
#region Internal Methods
/// <summary>
/// Gets the current context information for this stack.
/// </summary>
/// <returns>The current context information.</returns>
internal string GetFullMessage()
{
Stack stack = m_stack;
if (stack.Count > 0)
{
return ((StackFrame)(stack.Peek())).FullMessage;
}
return null;
}
/// <summary>
/// Gets and sets the internal stack used by this <see cref="LogicalThreadContextStack"/>
/// </summary>
/// <value>The internal storage stack</value>
/// <remarks>
/// <para>
/// This property is provided only to support backward compatability
/// of the <see cref="NDC"/>. Tytpically the internal stack should not
/// be modified.
/// </para>
/// </remarks>
internal Stack InternalStack
{
get { return m_stack; }
set { m_stack = value; }
}
#endregion Internal Methods
/// <summary>
/// Gets the current context information for this stack.
/// </summary>
/// <returns>Gets the current context information</returns>
/// <remarks>
/// <para>
/// Gets the current context information for this stack.
/// </para>
/// </remarks>
public override string ToString()
{
return GetFullMessage();
}
/// <summary>
/// Get a portable version of this object
/// </summary>
/// <returns>the portable instance of this object</returns>
/// <remarks>
/// <para>
/// Get a cross thread portable version of this object
/// </para>
/// </remarks>
object IFixingRequired.GetFixedObject()
{
return GetFullMessage();
}
/// <summary>
/// Inner class used to represent a single context frame in the stack.
/// </summary>
/// <remarks>
/// <para>
/// Inner class used to represent a single context frame in the stack.
/// </para>
/// </remarks>
private sealed class StackFrame
{
#region Private Instance Fields
private readonly string m_message;
private readonly StackFrame m_parent;
private string m_fullMessage = null;
#endregion
#region Internal Instance Constructors
/// <summary>
/// Constructor
/// </summary>
/// <param name="message">The message for this context.</param>
/// <param name="parent">The parent context in the chain.</param>
/// <remarks>
/// <para>
/// Initializes a new instance of the <see cref="StackFrame" /> class
/// with the specified message and parent context.
/// </para>
/// </remarks>
internal StackFrame(string message, StackFrame parent)
{
m_message = message;
m_parent = parent;
if (parent == null)
{
m_fullMessage = message;
}
}
#endregion Internal Instance Constructors
#region Internal Instance Properties
/// <summary>
/// Get the message.
/// </summary>
/// <value>The message.</value>
/// <remarks>
/// <para>
/// Get the message.
/// </para>
/// </remarks>
internal string Message
{
get { return m_message; }
}
/// <summary>
/// Gets the full text of the context down to the root level.
/// </summary>
/// <value>
/// The full text of the context down to the root level.
/// </value>
/// <remarks>
/// <para>
/// Gets the full text of the context down to the root level.
/// </para>
/// </remarks>
internal string FullMessage
{
get
{
if (m_fullMessage == null && m_parent != null)
{
m_fullMessage = string.Concat(m_parent.FullMessage, " ", m_message);
}
return m_fullMessage;
}
}
#endregion Internal Instance Properties
}
/// <summary>
/// Struct returned from the <see cref="LogicalThreadContextStack.Push"/> method.
/// </summary>
/// <remarks>
/// <para>
/// This struct implements the <see cref="IDisposable"/> and is designed to be used
/// with the <see langword="using"/> pattern to remove the stack frame at the end of the scope.
/// </para>
/// </remarks>
private struct AutoPopStackFrame : IDisposable
{
#region Private Instance Fields
/// <summary>
/// The depth to trim the stack to when this instance is disposed
/// </summary>
private int m_frameDepth;
/// <summary>
/// The outer LogicalThreadContextStack.
/// </summary>
private LogicalThreadContextStack m_logicalThreadContextStack;
#endregion Private Instance Fields
#region Internal Instance Constructors
/// <summary>
/// Constructor
/// </summary>
/// <param name="logicalThreadContextStack">The internal stack used by the ThreadContextStack.</param>
/// <param name="frameDepth">The depth to return the stack to when this object is disposed.</param>
/// <remarks>
/// <para>
/// Initializes a new instance of the <see cref="AutoPopStackFrame" /> class with
/// the specified stack and return depth.
/// </para>
/// </remarks>
internal AutoPopStackFrame(LogicalThreadContextStack logicalThreadContextStack, int frameDepth)
{
m_frameDepth = frameDepth;
m_logicalThreadContextStack = logicalThreadContextStack;
}
#endregion Internal Instance Constructors
#region Implementation of IDisposable
/// <summary>
/// Returns the stack to the correct depth.
/// </summary>
/// <remarks>
/// <para>
/// Returns the stack to the correct depth.
/// </para>
/// </remarks>
public void Dispose()
{
if (m_frameDepth >= 0 && m_logicalThreadContextStack.m_stack != null)
{
Stack stack = new Stack(new Stack(m_logicalThreadContextStack.m_stack));
while (stack.Count > m_frameDepth)
{
stack.Pop();
}
LogicalThreadContextStack ltcs = new LogicalThreadContextStack(m_logicalThreadContextStack.m_propertyKey, m_logicalThreadContextStack.m_registerNew);
ltcs.m_stack = stack;
m_logicalThreadContextStack.m_registerNew(m_logicalThreadContextStack.m_propertyKey,
ltcs);
}
}
#endregion Implementation of IDisposable
}
}
}
#endif