private TEntity GetItem(TKey key)
{
// 为空的key，直接返回null，不进行缓存查找
if (key == null)
{
return(null);
}
if (Type.GetTypeCode(typeof(TKey)) == TypeCode.String)
{
String value = key as String;
if (String.IsNullOrEmpty(value))
{
return(null);
}
}
// 更新统计信息
XCache.CheckShowStatics(ref NextShow, ref Total, ShowStatics);
// 如果找到项，返回
CacheItem item = null;
if (Entities.TryGetValue(key, out item) && item != null)
{
Interlocked.Increment(ref Shoot1);
return(GetItem(item, key));
}
// 加锁
lock (Entities)
{
// 如果找到项，返回
if (Entities.TryGetValue(key, out item) && item != null)
{
Interlocked.Increment(ref Shoot2);
return(GetItem(item, key));
}
item = new CacheItem();
item.Key = key;
//队列满时，移除最老的一个
if (Entities.Count >= MaxEntity)
{
TKey keyFirst = GetFirstKey();
if (keyFirst != null && (Type.GetTypeCode(typeof(TKey)) != TypeCode.String || String.IsNullOrEmpty(keyFirst as String)))
{
CacheItem item2 = null;
if (Entities.TryGetValue(keyFirst, out item2) && item2 != null)
{
if (Debug)
{
DAL.WriteLog("单实体缓存{0}超过最大数量限制{1}，准备移除第一项{2}", typeof(TEntity).FullName, MaxEntity, keyFirst);
}
Entities.Remove(keyFirst);
//自动保存
if (AutoSave && item2.Entity != null)
{
InvokeFill(delegate { item2.Entity.Update(); });
}
}
}
}
//查找数据
//TEntity entity = FindKeyMethod(key);
TEntity entity = null;
InvokeFill(delegate { entity = FindKeyMethod(key); });
if (entity != null || AllowNull)
{
item.Entity = entity;
item.ExpireTime = DateTime.Now.AddSeconds(Expriod);
if (!Entities.ContainsKey(key))
{
Entities.Add(key, item);
}
}
else
{
Interlocked.Increment(ref Invalid);
}
return(entity);
}
}
