/// <summary>
/// 向LruDictionary中添加一个元素，用户需要把组成元素的Key和Value值传入。
/// </summary>
/// <param name="key">向LruDictionary中填入元素的Key值</param>
/// <param name="data">向LruDictionary中填入元素的Value值</param>
/// <remarks>向LruDictionary中添加一个元素时，该元素是由Key和Value值组成。按照LRU原则，经常使用的元素放在LruDictionary的前面。
/// <code source="..\Framework\TestProjects\DeluxeWorks.Library.Test\Core\LruDictionaryTest.cs" region="AddTest" lang="cs" title="向LruDictionary中添加一个元素"/>
/// <seealso cref="Framework.Core.EnumItemDescriptionAttribute"/>
///</remarks>
public void Add(TKey key, TValue data)
{
ExceptionHelper.TrueThrow <ArgumentNullException>(key == null, "LruDictionary-Add-key");//add by yuanyong 20071227
//如果已经存在，抛出异常
ExceptionHelper.TrueThrow <ArgumentException>(this.innerDictionary.ContainsKey(key),
Resource.DuplicateKey, key);
LinkedListNode <KeyValuePair <TKey, TValue> > node =
new LinkedListNode <KeyValuePair <TKey, TValue> >(new KeyValuePair <TKey, TValue>(key, data));
lock (syncRoot)
{
this.innerDictionary.Add(key, node);
this.innerLinkedList.AddFirst(node);
if (this.innerLinkedList.Count >= MaxLength)
{
for (int i = 0; i < this.innerLinkedList.Count - MaxLength + 1; i++)
{
LinkedListNode <KeyValuePair <TKey, TValue> > lastNode = this.innerLinkedList.Last;
if (this.innerDictionary.ContainsKey(lastNode.Value.Key))
{
this.innerDictionary.Remove(lastNode.Value.Key);
this.innerLinkedList.Remove(lastNode);
}
}
}
}
}
/// <summary>
/// 获取或设置LruDictionary中元素键值为key值的Value值
/// </summary>
/// <param name="key">要获得的元素的键值</param>
/// <returns>LruDictionary中键值key的Value值</returns>
/// <remarks>该属性是可读可写的。
/// <code source="..\Framework\TestProjects\DeluxeWorks.Library.Test\Core\LruDictionaryTest.cs" lang="cs" title="读取或设置LruDictionary中键值为Key值的Value值"/>
/// <seealso cref="Framework.Core.EnumItemDescriptionAttribute"/>
/// </remarks>
public TValue this[TKey key]
{
get
{
ExceptionHelper.TrueThrow <ArgumentNullException>(key == null, "LruDictionary-get-key");//add by yuanyong 20071227
LinkedListNode <KeyValuePair <TKey, TValue> > node = this.innerDictionary[key];
//没有找到，会自动抛出异常
lock (syncRoot)
{
MoveNodeToFirst(node);
}
return(node.Value.Value);
}
set
{
ExceptionHelper.TrueThrow <ArgumentNullException>(key == null, "LruDictionary-set-key");//add by yuanyong 20071227
LinkedListNode <KeyValuePair <TKey, TValue> > node;
lock (syncRoot)
{
if (this.innerDictionary.TryGetValue(key, out node))
{
MoveNodeToFirst(node);
node.Value = new KeyValuePair <TKey, TValue>(key, value);
}
else
{
Add(key, value);
}
}
}
}
/// <summary>
/// 删除LruDictionary中键值为Key值的元素
/// </summary>
/// <param name="key">键值Key</param>
/// <remarks>若LruDictionary中不包含键值为Key的元素，则系统自动的抛出异常。
/// <code source="..\Framework\TestProjects\DeluxeWorks.Library.Test\Core\LruDictionaryTest.cs" region="RemoveTest" lang="cs" title="从LruDictionary中删除键值为Key的元素"/>
/// <seealso cref="Framework.Core.EnumItemDescriptionAttribute"/>
/// </remarks>
public void Remove(TKey key)
{
ExceptionHelper.TrueThrow <ArgumentNullException>(key == null, "LruDictionary-Remove-key");//add by yuanyong 20071227
LinkedListNode <KeyValuePair <TKey, TValue> > node = null;
lock (syncRoot)
{
if (this.innerDictionary.TryGetValue(key, out node))
{
this.innerDictionary.Remove(key);
this.innerLinkedList.Remove(node);
}
}
}
/// <summary>
/// 判断LruDictionary中是否包含键值为Key值的元素。若包含，则返回值是true，可以从data中取出该值，否则返回false。
/// </summary>
/// <param name="key">键值key</param>
/// <param name="data">键值key的Value值</param>
/// <returns>返回true或false</returns>
/// <remarks>若返回值为true，由于该Key值的元素刚使用过，则把该元素放在LruDictionary的最前面。
/// <code source="..\Framework\TestProjects\DeluxeWorks.Library.Test\Core\LruDictionaryTest.cs" region="TryGetValueTest" lang="cs" title="试图从LruDictionary中取出键值为key的元素"/>
/// <seealso cref="Framework.Core.EnumItemDescriptionAttribute"/>
/// </remarks>
public bool TryGetValue(TKey key, out TValue data)
{
ExceptionHelper.TrueThrow <ArgumentNullException>(key == null, "LruDictionary-TryGetValue-key");//add by yuanyong 20071227
LinkedListNode <KeyValuePair <TKey, TValue> > node;
data = default(TValue);
lock (syncRoot)
{
bool result = this.innerDictionary.TryGetValue(key, out node);
if (result)
{
MoveNodeToFirst(node);
data = node.Value.Value;
}
return(result);
}
}
/// <summary>
/// 定制最大长度为maxLength的LruDictionary。
/// </summary>
/// <param name="maxLruLength">需要设置的LruDictionary的最大长度。</param>
/// <remarks>在默认情况下，LruDictionary的最大长度为100。此构造方法适用于构造指定最大长度的LruDictionary。
/// <code source="..\Framework\TestProjects\DeluxeWorks.Library.Test\Core\LruDictionaryTest.cs" region="LruDictionaryTest" lang="cs" title="获取最大长度为maxLength的LruDictionary"/>
/// <seealso cref="Framework.Core.EnumItemDescriptionAttribute"/>
/// </remarks>
public LruDictionary(int maxLruLength)
{
ExceptionHelper.TrueThrow <InvalidOperationException>(maxLruLength < 0, "maxLruLength must >= 0");
this.maxLength = maxLruLength;
}
/// <summary>
/// 判断LruDictionary中是否包含键值为Key值的元素
/// </summary>
/// <param name="key">键值Key</param>
/// <returns>若LruDictionary中包含键值为key值的元素,则返回true，否则返回false</returns>
/// <remarks>若返回值为true，由于该Key值的元素刚使用过，则把该元素放在LruDictionary的最前面。
/// <code source="..\Framework\TestProjects\DeluxeWorks.Library.Test\Core\LruDictionaryTest.cs" region ="ContainsKeyTest" lang="cs" title="判断LruDictionary中是否包含键值为key的元素"/>
/// <seealso cref="Framework.Core.EnumItemDescriptionAttribute"/>
/// </remarks>
public bool ContainsKey(TKey key)
{
ExceptionHelper.TrueThrow <ArgumentNullException>(key == null, "LruDictionary-ContainsKey-key");//add by yuanyong 20071227
return(this.innerDictionary.ContainsKey(key));
}
