/// <summary>
/// 根据指定初始需缓存的数据集合创建缓存值集
/// </summary>
/// <param name="datas"></param>
/// <returns></returns>
public static CacheItemInfoCollection <TParam, TKey, TValue> CreateDatas(Dictionary <TKey, TValue> datas)
{
CacheItemInfoCollection <TParam, TKey, TValue> items = new CacheItemInfoCollection <TParam, TKey, TValue>();
if (datas.IsNotNull())
{
foreach (TKey key in datas.Keys)
{
items[key] = new CacheItemInfo <TParam, TKey, TValue>(datas[key], DateTime.Now, items);
}
}
return(items);
}
public void InsertItem(TKey key, TValue value)
{
if (ContainsKey(key))
{
CacheItemInfo <TParam, TKey, TValue> item = this[key];
this[key].CacheItemValue = value;
item.UpdateTime = DateTime.Now;
if (Owner.EliminateMethod != null) //本项缓存有淘汰算法
{
Owner.EliminateMethod.UpdateWeight(key);
}
}
else
{
this[key] = new CacheItemInfo <TParam, TKey, TValue>(value, DateTime.Now, this);
}
}
/// <summary>
/// 更新指定键的缓存
/// </summary>
/// <param name="key"></param>
/// <param name="method"></param>
/// <returns></returns>
public void SetItem(TKey key, TValue newValue, Func <TParam, TValue> method, TParam obj)
{
TValue v = method.IsNotNull() ? method(obj) : newValue;
if (v == null || v.Equals(default(TValue))) //表示移除
{
lock (this)
{
Remove(key);
if (Owner.EliminateMethod != null) //本项缓存有淘汰算法
{
Owner.EliminateMethod.DelWeight(key);
}
}
}
else
{
lock (this)
{
this[key] = new CacheItemInfo <TParam, TKey, TValue>(v, DateTime.Now, this);
}
}
}
/// <summary>
/// 获取指定键值的缓存对象，如没有，则从指定委托及参数中获取
/// </summary>
/// <param name="key"></param>
/// <param name="method"></param>
/// <returns></returns>
public TValue GetItem(TKey key, Func <TParam, TValue> method, TParam obj)
{
CacheItemInfo <TParam, TKey, TValue> item = null;
if (this.ContainsKey(key)) //有该值
{
//为了线程安全，在取值时，增加防异常处理
try {
item = this[key];
}
catch {
//有异常，表示该项此时已被其它用户移除了集合
}
}
if (item != null) //该项在缓存中
{
if (item.IsOverdue) //该缓存值已过期
{
item.CacheItemValue = method(obj); //则直接从数据源中更新该缓存值
item.UpdateTime = DateTime.Now;
if (Owner.EliminateMethod != null) //本项缓存有淘汰算法
{
Owner.EliminateMethod.UpdateWeight(key);
}
}
return(item.CacheItemValue);
}
else
{
if (method == null)
{
return(default(TValue));
}
TValue o = method(obj);
if (o == null)
{
return(o);
}
lock (this)
{
if (Owner.MaxSize > 0)
{
if (Owner.EliminateMethod != null)
{
int i = this.Count;
if (i >= Owner.MaxSize)
{
Owner.DelCacheValue();
Owner.EliminateMethod.DelPoorWeight();
}
}
this[key] = new CacheItemInfo <TParam, TKey, TValue>(o, DateTime.Now, this);
if (Owner.EliminateMethod != null)
{
Owner.EliminateMethod.InsertWeight(key);
}
}
}
return(o);
}
}
