/// <summary>
/// 流写入
/// </summary>
/// <param name="cin">待写入的流</param>
/// <param name="position">写入起始位置</param>
/// <param name="count">需写入的数量</param>
protected void WriteStream(byte[] cin, int itemNum, int count, InodeStr dinode)
{
int pos = _dire.BMap(dinode, itemNum / 512);
_diskFile.OpenFile();
_diskFile.SeekFilePosition(pos * 512 + itemNum % 512, System.IO.SeekOrigin.Begin);
_diskFile.WriteFile(ref cin, 0, count);
_diskFile.CloseFile();
}
/// <summary>
/// 初始化数据块
/// </summary>
public void InitDataBlock()
{
byte[] writeTo;
_initSuper._s_nfree = 0;
_initSuper._s_free[_initSuper._s_nfree++] = 0;
_diskFile.OpenFile();
//从最后一块往前走，每100块之前的一块为管理块
//其内容包括
//1：该管理块管理的块数
//2：该管理块管理的所有块号
for (int i = _dataBlkNum - 1; i >= 0; --i)
{
if (_initSuper._s_nfree >= 100)
{
//找到要写入的位置,将s_nfree和s_free写入i + datablkstart号磁盘块
_diskFile.SeekFilePosition(_diskFile.ConvertPosition(i + _dataBlkStart, 0), System.IO.SeekOrigin.Begin);
//转换成流，写入磁盘
writeTo = Helper.Struct2Bytes(_initSuper._s_nfree);
_diskFile.WriteFile(ref writeTo, 0, 4);
for (int j = 0; j < _initSuper._s_nfree; ++j)
{
//转换成流，写入磁盘
writeTo = Helper.Struct2Bytes(_initSuper._s_free[j]);
_diskFile.WriteFile(ref writeTo, 0, 4);
}
_initSuper._s_nfree = 0;
}
//数组元素初始化(数组元素用于管理空闲块号)
_initSuper._s_free[_initSuper._s_nfree++] = i + _dataBlkStart;
}
//关闭磁盘文件
_diskFile.CloseFile();
//将更新后的超级快信息写回
_initSuper.UpdateSuperBlockToDisk();
}
/// <summary>
/// 将编译好的启动文件boot.bin按规定写入磁盘
/// </summary>
public void WriteBootBlock()
{
int bootSize = MachinePara.Boot_Size * MachinePara.Block_Size;
byte[] writeTo = new byte[bootSize];
//读取boot.bin
_bootFile.OpenFile();
_bootFile.SeekFilePosition(0, System.IO.SeekOrigin.Begin);
_bootFile.ReadFile(ref writeTo, 0, 512);
_bootFile.CloseFile();
//写入c.img
_diskFile.OpenFile();
_diskFile.SeekFilePosition(0, System.IO.SeekOrigin.Begin);
_diskFile.WriteFile(ref writeTo, 0, bootSize);
_diskFile.CloseFile();
}
/// <summary>
/// 将编译好的内核kernel.bin文件按规定写入磁盘
/// </summary>
public void WriteKernelBlock()
{
_kernelFile.OpenFile();
int kernelFileLength = (int)_kernelFile.ReturnFileLength();
byte[] writeTo;
writeTo = new byte[kernelFileLength];
//读出kernel.bin文件的内容
_kernelFile.SeekFilePosition(0, System.IO.SeekOrigin.Begin);
_kernelFile.ReadFile(ref writeTo, 0, kernelFileLength);
_kernelFile.CloseFile();
//将kernel.bin的内容写入c.img
_diskFile.OpenFile();
_diskFile.SeekFilePosition(1 * 512, System.IO.SeekOrigin.Begin);
_diskFile.WriteFile(ref writeTo, 0, kernelFileLength);
_diskFile.CloseFile();
}
/// <summary>
/// 虚实地址转换
/// </summary>\
///
/// <param name="DirInode"></param>
/// <param name="no"></param>
/// <returns></returns>
public int BMap(InodeStr dirInode, int itemNum)
{
int blockNum;
byte[] blockNumBuf = new byte[4];
//直接索引0~5项，一次间接索引6~7项，二次间接索引8~9项
//直接索引所引用的逻辑块号为0~5块，一次间接引用索引项6~261块
//二次间接引用索引项128*2+6~128*128*2+128*2+6-1项
//直接索引
if (itemNum < 6)
{
blockNum = dirInode._i_addr[itemNum];
//如果该逻辑块还没有相应的物理块与之对应，则分配一个物理块
if (blockNum == 0)
{
try
{
blockNum = _dataBlock.GetFreeBlock();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
dirInode._i_addr[itemNum] = blockNum;
}
return(blockNum);
}
//间接引用bn>=6
else
{
int firstIndex;
//一次间接块
if (itemNum - 262 < 0)
{
firstIndex = ((itemNum - 6) / 128) + 6; //6或7
}
else //二次间接块
{
firstIndex = ((itemNum - 262) / (128 * 128)) + 8; //8或9
}
//该项为空,则到数据区分配一块空闲块
if (dirInode._i_addr[firstIndex] == 0)
{
try
{
dirInode._i_addr[firstIndex] = _dataBlock.GetFreeBlock();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
blockNum = dirInode._i_addr[firstIndex];
//如果是二次间接索引，则再获取二级索引块的块号
if (firstIndex >= 8)
{
int secondIndex = ((itemNum - 262) / 128) % 128; //0-128
_diskFile.OpenFile();
_diskFile.SeekFilePosition(dirInode._i_addr[firstIndex] * 512 + secondIndex * 4, System.IO.SeekOrigin.Begin);
_diskFile.ReadFile(ref blockNumBuf, 0, 4);
_diskFile.CloseFile();
blockNum = (int)Helper.Bytes2Struct(blockNumBuf, typeof(int));
if (blockNum == 0)
{
try
{
blockNum = _dataBlock.GetFreeBlock();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
blockNumBuf = Helper.Struct2Bytes(blockNum);
_diskFile.OpenFile();
_diskFile.SeekFilePosition(dirInode._i_addr[firstIndex] * 512 + secondIndex * 4, System.IO.SeekOrigin.Begin);
_diskFile.WriteFile(ref blockNumBuf, 0, 4);
_diskFile.CloseFile();
}
}
}
int directIndex;
//一次间接块
if (itemNum - 262 < 0)
{
directIndex = ((itemNum - 6) % 128);
}
else //二次间接块
{
directIndex = ((itemNum - 262) % 128);
}
_diskFile.OpenFile();
_diskFile.SeekFilePosition(512 * blockNum + 4 * directIndex, System.IO.SeekOrigin.Begin);
_diskFile.ReadFile(ref blockNumBuf, 0, 4);
_diskFile.CloseFile();
int tmpBlockNum = (int)Helper.Bytes2Struct(blockNumBuf, typeof(int));
//若该目录索引项为空，则分配
if (tmpBlockNum == 0)
{
try
{
tmpBlockNum = _dataBlock.GetFreeBlock();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
blockNumBuf = Helper.Struct2Bytes(tmpBlockNum);
_diskFile.OpenFile();
_diskFile.SeekFilePosition(512 * blockNum + 4 * directIndex, System.IO.SeekOrigin.Begin);
_diskFile.WriteFile(ref blockNumBuf, 0, 4);
_diskFile.CloseFile();
}
blockNum = tmpBlockNum;
return(blockNum);
}
/// <summary>
/// 将当前的超级快信息更新到磁盘
/// </summary>
public void UpdateSuperBlockToDisk()
{
byte[] writeTo;
//定位到超级块起始位置
_diskFile.OpenFile();
_diskFile.SeekFilePosition(MachinePara.BootAndKernelSize * 512, System.IO.SeekOrigin.Begin);
//inode区占据的磁盘块数
writeTo = Helper.Struct2Bytes(_s_isize);
_diskFile.WriteFile(ref writeTo, 0, 4);
//总的磁盘块数，为扇区数的一半
writeTo = Helper.Struct2Bytes(_s_fsize);
_diskFile.WriteFile(ref writeTo, 0, 4);
//得到直接管理块数
writeTo = Helper.Struct2Bytes(_s_nfree);
_diskFile.WriteFile(ref writeTo, 0, 4);
//得到空闲列表
for (int i = 0; i < 100; ++i)
{
writeTo = Helper.Struct2Bytes(_s_free[i]);
_diskFile.WriteFile(ref writeTo, 0, 4);
}
//得到直接管理的inodee数量
writeTo = Helper.Struct2Bytes(_s_ninode);
_diskFile.WriteFile(ref writeTo, 0, 4);
//得到空闲inode列表
for (int i = 0; i < 100; ++i)
{
writeTo = Helper.Struct2Bytes(_s_inode[i]);
_diskFile.WriteFile(ref writeTo, 0, 4);
}
//封锁标志
writeTo = Helper.Struct2Bytes(_s_flock);
_diskFile.WriteFile(ref writeTo, 0, 4);
//inode封锁标志
writeTo = Helper.Struct2Bytes(_s_ilock);
_diskFile.WriteFile(ref writeTo, 0, 4);
//已修改标志
writeTo = Helper.Struct2Bytes(_s_fmod);
_diskFile.WriteFile(ref writeTo, 0, 4);
//只读标志
writeTo = Helper.Struct2Bytes(_s_ronly);
_diskFile.WriteFile(ref writeTo, 0, 4);
//最后修改时间
writeTo = Helper.Struct2Bytes(_s_time);
_diskFile.WriteFile(ref writeTo, 0, 4);
//填充字段
if (_s_padding[0] == 1)
{
for (int i = 0; i < 47; i++)
{
writeTo = Helper.Struct2Bytes(_s_padding[i]);
_diskFile.WriteFile(ref writeTo, 0, 4);
}
_s_padding[0] = 0;
}
_diskFile.CloseFile();
}