/// <summary>
/// 从内部缓存获取一个内存表
/// </summary>
/// <param name="key">key</param>
/// <returns>table</returns>
internal TMemoryTable Get(TKey key)
{
GetByKey <TKey, TMemoryTable> getByKey = GetMemoryTableByKey;
TMemoryTable memoryTable = cache.GetWithAdd(key, getByKey);
return(memoryTable);
}
/// <summary>
/// 根据key获取value，当获取不到时，通过getBykey方法获取value，并插入缓存，
/// 同时返回给调用者
/// </summary>
/// <param name="key">key</param>
/// <param name="getByKey">GetByKey类型的方法委托</param>
/// <returns>value</returns>
public V GetWithAdd(K key, GetByKey <K, V> getByKey)
{
cacheLock.EnterUpgradeableReadLock();
V result;
try
{
if (innerCache.ContainsKey(key))
{
result = innerCache[key];
}
else
{
result = getByKey(key);
if (result != null)
{
cacheLock.EnterWriteLock();
try
{
innerCache[key] = result;
}
finally
{
cacheLock.ExitWriteLock();
}
}
}
}
finally
{
cacheLock.ExitUpgradeableReadLock();
}
return(result);
}
