/// <summary>
/// 读取内存中的数据
/// </summary>
/// <param name="segment">段地址</param>
/// <param name="page">页地址</param>
/// <param name="size">数据长度</param>
/// <returns>返回数据包</returns>
public override byte[] Get(long segment, long page, int size)
{
bool find = false;
long address = segment + page;
byte[] vs = null;
for (int i = 0; i < CacheTable.Count; i++)
{
if (CacheTable[i].Start <= address && CacheTable[i].End > address)
{
find = true;
if (address + size <= CacheTable[i].End)
{
vs = new byte[size];
for (long j = 0, k = address - CacheTable[i].Start; j < size; j++, k++)
{
vs[j] = CacheTable[i].Data[k];
}
CacheTable[i].AgeCount++;
}
else
{
Interrput.Interrupt(MemoryCache_Type.Out_Bounds, address, size);
}
}
}
if (!find)
{
LRU(address);
vs = Get(segment, page, size);
}
return(vs);
}
public override void Set(long segment, long page, byte[] data)
{
bool find = false;
long address = segment + page;
for (int i = 0; i < CacheTable.Count; i++)
{
if (CacheTable[i].Start <= address && CacheTable[i].End > address)
{
find = true;
if (address + data.LongLength <= CacheTable[i].End)
{
for (long j = 0, k = address - CacheTable[i].Start; j < data.LongLength; j++, k++)
{
CacheTable[i].Data[k] = data[j];
}
CacheTable[i].AgeCount++;
}
else
{
Interrput.Interrupt(MemoryCache_Type.Out_Bounds, address, data.Length);
}
}
}
if (!find)
{
LRU(address);
Set(segment, page, data);
}
}
/// <summary>
/// 缓存替换（最近最少使用算法）
/// </summary>
/// <param name="address">替换地址块</param>
private void LRU(long address)
{
MemoryBlock memory = Interrput.PageMissingInterrupt(address, out long realize);
if (-1 != realize)
{
if (3 == CacheTable.Count)
{
int index = 0;
for (int i = 1; i < CacheTable.Count; i++)
{
if (CacheTable[index].AgeCount <= CacheTable[i].AgeCount)
{
index = i;
}
}
CacheTable.RemoveAt(index);
}
CacheTable.Add(new Node
{
Data = memory,
Address = realize,
AgeCount = 0
});
}
else
{
Interrput.Interrupt(MemoryCache_Type.Over_Flow, address, -1);
}
}
