/// <summary>
/// 删除实体文件
/// </summary>
/// <param name="drivename"></param>
/// <param name="volumeinfo"></param>
/// <param name="fat"></param>
/// <returns></returns>
public static ErrorCode DeleteFile(string drivename, VolumeInfo volumeinfo, FileInfo fat)
{
var content = GetList(drivename, fat.Location, volumeinfo);
UInt32 clustercount = (UInt32)((volumeinfo.SectorCount - 1) / (volumeinfo.Cluster >> 9)); //簇总数
UInt32 UseBytes = (clustercount >> 3) + 1; //用多少个字节存储
UInt32 UseCluster = UseBytes / volumeinfo.Cluster + 1; //表大小(簇)
//读取空闲表内容
byte[] freetable = DiskRW.ReadA(drivename, volumeinfo.FreeTableStart, UseCluster * (UInt32)(volumeinfo.Cluster >> 9));
//将位置写回空闲表
foreach (UInt32 block in content)
{
Set(block, false, freetable);
}
//fat簇写回空闲表;
Set(TransferInverse(volumeinfo.SectorStart, fat.Location, volumeinfo.Cluster), false, freetable);
//保存空闲表
var res = SetFreeBlock(drivename, ref volumeinfo, freetable);
if (res == ErrorCode.Fail)
{
return(ErrorCode.WriteFreeTableFail);
}
return(ErrorCode.Success);
}
/// <summary>
/// 删除目录中某项
/// </summary>
/// <param name="drivename">驱动器名</param>
/// <param name="volumeinfo">卷信息结构体</param>
/// <param name="cluster">要删的扇区</param>
/// <param name="dirinfo">目录</param>
/// <returns></returns>
public static ErrorCode DeleteInDir(string drivename, VolumeInfo volumeinfo, UInt32 sector, DirectInfo dirinfo)
{
var cluster = TransferInverse(volumeinfo.SectorStart, sector, volumeinfo.Cluster);
byte[] content = DiskRW.ReadA(drivename, dirinfo.Location, (uint)(volumeinfo.Cluster >> 9));
UInt32 next = mergeByte(content[160], content[161], content[162], content[163]);
for (UInt16 i = 164; i < content.Length; i += 4)
{
UInt32 s1 = mergeByte(content[i], content[i + 1], content[i + 2], content[i + 3]);
if (s1 == cluster)
{
content[i] = 0;
content[i + 1] = 0;
content[i + 2] = 0;
content[i + 3] = 0;
DiskRW.write(drivename, dirinfo.Location, content);
return(ErrorCode.Success);
}
}
//没有下一个索引块,找不到该目录
if (next == 0)
{
return(ErrorCode.NoSuchFile);
}
//读取索引表
content = DiskRW.ReadA(drivename, transfer(volumeinfo.SectorStart, next, volumeinfo.Cluster), (uint)(volumeinfo.Cluster >> 9));
while (true)
{
for (UInt16 i = 4; i < content.Length; i += 4)
{
UInt32 s1 = mergeByte(content[i], content[i + 1], content[i + 2], content[i + 3]);
if (s1 == cluster)
{
content[i] = 0;
content[i + 1] = 0;
content[i + 2] = 0;
content[i + 3] = 0;
DiskRW.write(drivename, next, content);
return(ErrorCode.Success);
}
}
next = mergeByte(content[0], content[1], content[2], content[3]);
//下簇号 为零表示没有下一簇
if (next == 0)
{
return(ErrorCode.NoSuchFile);
}
content = ReadOut(drivename, volumeinfo, next);
}
}
/// <summary>
/// 获取文件内容具体位置(簇号)
/// </summary>
/// <param name="drivename"></param>
/// <param name="Location">扇区号</param>
/// <param name="fileUnit"></param>
/// <returns>位置表(簇号)</returns>
public static List <UInt32> GetList(string drivename, UInt32 location, VolumeInfo volumeinfo)
{
var res = new List <UInt32>();
byte[] content = DiskRW.ReadA(drivename, location, (uint)(volumeinfo.Cluster >> 9));
UInt32 next = mergeByte(content[160], content[161], content[162], content[163]);
for (UInt16 i = 164; i < content.Length; i += 4)
{
UInt32 s1 = mergeByte(content[i], content[i + 1], content[i + 2], content[i + 3]);
if (s1 == 0)
{
continue;
}
res.Add(s1);
}
//没有下一个索引块
if (next == 0)
{
return(res);
}
//读取索引表
content = DiskRW.ReadA(drivename, transfer(volumeinfo.SectorStart, next, volumeinfo.Cluster), (uint)(volumeinfo.Cluster >> 9));
while (true)
{
for (UInt16 i = 4; i < content.Length; i += 4)
{
UInt32 s1 = mergeByte(content[i], content[i + 1], content[i + 2], content[i + 3]);
if (s1 == 0)
{
continue;
}
res.Add(s1);
}
next = mergeByte(content[0], content[1], content[2], content[3]);
//下簇号 为零表示没有下一簇
if (next == 0)
{
return(res);
}
content = ReadOut(drivename, volumeinfo, next);
}
}
/// <summary>
/// 获取实体文件信息
/// </summary>
/// <param name="drivename"></param>
/// <param name="location"></param>
/// <param name="fileUnit"></param>
/// <returns></returns>
public static FileInfo GetFileInfoA(string drivename, UInt32 location, UInt16 fileUnit)
{
byte[] content = DiskRW.ReadA(drivename, location, (uint)(fileUnit >> 9));
var file = new FileInfo();
byte[] tmp = new byte[64];
Array.Copy(content, tmp, 64);
file.Name = Encoding.Unicode.GetString(tmp).Replace("\0", "");
//后缀名
tmp = new byte[13];
Array.Copy(content, 64, tmp, 0, 13);
file.Extension = Encoding.ASCII.GetString(tmp).Replace("\0", "");
//类型
file.Type = content[77];
//权限号
file.AccessCode = content[78];
//权限标记
file.AccessMode = content[79];
//作者
tmp = new byte[32];
Array.Copy(content, 80, tmp, 0, 32);
file.Author = Encoding.Unicode.GetString(tmp);
//最后修改人
tmp = new byte[32];
Array.Copy(content, 112, tmp, 0, 32);
file.LastEditor = Encoding.Unicode.GetString(tmp);
//创建时间
file.CreateTime = mergeByte(content[144], content[145], content[146], content[147]);
//最后修改时间
file.LastEditTime = mergeByte(content[148], content[149], content[150], content[151]);
//尾字节
UInt16 s5 = content[152];
UInt16 s6 = content[153];
file.Rest = (UInt16)((s6 << 8) + s5);
file.Location = location;
return(file);
}
/// <summary>
/// 获取空闲块 位示图
/// </summary>
/// <param name="drivename"></param>
/// <param name="volumeInfo">卷信息的引用</param>
/// <param name="count">所需空闲块个数</param>
/// <returns>空闲簇列表</returns>
public static List <UInt32> GetFreeBlock(string drivename, ref VolumeInfo volumeInfo, UInt32 count)
{
UInt32 clustercount = (UInt32)((volumeInfo.SectorCount - 1) / (volumeInfo.Cluster >> 9)); //簇总数
UInt32 UseBytes = (clustercount >> 3) + 1; //用多少个字节存储
UInt32 UseCluster = UseBytes / volumeInfo.Cluster + 1; //表大小(簇)
//读取空闲表内容
byte[] content = DiskRW.ReadA(drivename, volumeInfo.FreeTableStart, UseCluster * (UInt32)(volumeInfo.Cluster >> 9));
//返回的空闲块号
List <UInt32> ls = new List <uint>();
//i为计数,j为簇索引值
UInt32 i = 0;
for (UInt32 j = 0; j < clustercount; j++)
{
if (!Test(j, content))
{
ls.Add(j);
i++;
}
if (i == count)
{
break;
}
}
//磁盘已满或没有空间返回null;
if (ls.Count < i)
{
return(null);
}
//写空闲表
foreach (UInt32 item in ls)
{
Set(item, true, content);
}
//写回磁盘
DiskRW.write(drivename, volumeInfo.FreeTableStart, content);
return(ls);
}
/// <summary>
/// 添加文件fat，文件为空
/// </summary>
/// <param name="current">当前目录信息</param>
/// <param name="drivename">驱动器名</param>
/// <param name="volumeinfo">当前卷信息</param>
/// <returns>新文件簇号</returns>
public static UInt32 AddDir(DirectInfo current, string drivename, VolumeInfo volumeinfo)
{
byte[] buffer = new byte[volumeinfo.Cluster];
var ls = GetFreeBlock(drivename, ref volumeinfo, 1);//获取存放fat的簇
//向现在目录加项
var currentDir = DiskRW.ReadA(drivename, current.Location, (UInt16)(volumeinfo.Cluster >> 9));
//检索当前的fat表
for (int i = 164; i < volumeinfo.Cluster; i += 4)
{
if (mergeByte(currentDir[i], currentDir[i + 1], currentDir[i + 2], currentDir[i + 3]) == 0)
{
currentDir[i] = (byte)ls[0];
currentDir[i + 1] = (byte)(ls[0] >> 8);
currentDir[i + 2] = (byte)(ls[0] >> 16);
currentDir[i + 3] = (byte)(ls[0] >> 24);
//写回磁盘
DiskRW.write(drivename, current.Location, currentDir);
return(ls[0]);
}
}
//fat满并且没有下个簇存放
if (mergeByte(currentDir[160], currentDir[161], currentDir[162], currentDir[163]) == 0)
{
//添加下一索引块
byte[] buffer2 = new byte[volumeinfo.Cluster];//写入内容缓存
var l2 = GetFreeBlock(drivename, ref volumeinfo, 1);
//写入上个的索引表
currentDir[160] = (byte)l2[0];
currentDir[161] = (byte)(l2[0] >> 8);
currentDir[162] = (byte)(l2[0] >> 16);
currentDir[163] = (byte)(l2[0] >> 24);
//下个
buffer2[4] = (byte)ls[0];
buffer2[5] = (byte)(ls[0] >> 8);
buffer2[6] = (byte)(ls[0] >> 16);
buffer2[7] = (byte)(ls[0] >> 24);
//写入磁盘
WriteIn(drivename, volumeinfo, l2[0], buffer2);
DiskRW.write(drivename, current.Location, currentDir);
return(ls[0]);
}
//寻找下一个索引表
currentDir = ReadOut(drivename, volumeinfo, mergeByte(currentDir[160], currentDir[161], currentDir[162], currentDir[163]));
while (true)
{
for (int i = 4; i < volumeinfo.Cluster; i += 4)
{
if (mergeByte(currentDir[i], currentDir[i + 1], currentDir[i + 2], currentDir[i + 3]) == 0)
{
currentDir[i] = (byte)ls[0];
currentDir[i + 1] = (byte)(ls[0] >> 8);
currentDir[i + 2] = (byte)(ls[0] >> 16);
currentDir[i + 3] = (byte)(ls[0] >> 24);
//写回磁盘
DiskRW.write(drivename, current.Location, currentDir);
return(ls[0]);
}
continue;
}
//索引表满并且没有下个簇存放
if (mergeByte(currentDir[0], currentDir[1], currentDir[2], currentDir[3]) == 0)
{
//添加下一索引块
byte[] buffer2 = new byte[volumeinfo.Cluster];//写入内容缓存
var l2 = GetFreeBlock(drivename, ref volumeinfo, 1);
//写入上个的索引表
currentDir[0] = (byte)l2[0];
currentDir[1] = (byte)(l2[0] >> 8);
currentDir[2] = (byte)(l2[0] >> 16);
currentDir[3] = (byte)(l2[0] >> 24);
//下个
buffer2[4] = (byte)ls[0];
buffer2[5] = (byte)(ls[0] >> 8);
buffer2[6] = (byte)(ls[0] >> 16);
buffer2[7] = (byte)(ls[0] >> 24);
//写入磁盘
WriteIn(drivename, volumeinfo, l2[0], buffer2);
DiskRW.write(drivename, current.Location, currentDir);
return(ls[0]);
}
currentDir = ReadOut(drivename, volumeinfo, mergeByte(currentDir[0], currentDir[1], currentDir[2], currentDir[3]));
}
}
/// <summary>
/// 从某个FAT节点读取文件信息,返回值要转换方可使用
/// </summary>
/// <param name="drivename"></param>
/// <param name="location">扇区</param>
/// <param name="fileUnit"></param>
/// <returns>返回目录信息或者文件信息</returns>
public static FATInfo GetFileInfo(string drivename, UInt32 location, UInt16 fileUnit)
{
byte[] content = DiskRW.ReadA(drivename, location, (uint)(fileUnit >> 9));
if (content[77] == 0) //目录
{
var dir = new DirectInfo();
byte[] tmp = new byte[64];
Array.Copy(content, tmp, 64);
dir.Name = Encoding.Unicode.GetString(tmp).Replace("\0", "");
//类型
dir.Type = content[77];
//权限号
dir.AccessCode = content[78];
//权限标记
dir.AccessMode = content[79];
//作者
tmp = new byte[32];
Array.Copy(content, 80, tmp, 0, 32);
dir.Author = Encoding.Unicode.GetString(tmp);
//最后修改人
tmp = new byte[32];
Array.Copy(content, 112, tmp, 0, 32);
dir.LastEditor = Encoding.Unicode.GetString(tmp);
//创建时间
UInt32 s1 = content[144];
UInt32 s2 = content[145];
UInt32 s3 = content[146];
UInt32 s4 = content[147];
dir.CreateTime = (s4 << 24) + (s3 << 16) + (s2 << 8) + s1;
//最后修改时间
s1 = content[148];
s2 = content[149];
s3 = content[150];
s4 = content[151];
dir.LastEditTime = (s4 << 24) + (s3 << 16) + (s2 << 8) + s1;
dir.Location = location;
return(dir);
}
else if (content[77] != 0) //实体文件
{
var file = new FileInfo();
byte[] tmp = new byte[64];
Array.Copy(content, tmp, 64);
file.Name = Encoding.Unicode.GetString(tmp).Replace("\0", "");
//后缀名
tmp = new byte[13];
Array.Copy(content, 64, tmp, 0, 13);
file.Extension = Encoding.Unicode.GetString(tmp).Replace("\0", "");
//类型
file.Type = content[77];
//权限号
file.AccessCode = content[78];
//权限标记
file.AccessMode = content[79];
//作者
tmp = new byte[32];
Array.Copy(content, 80, tmp, 0, 32);
file.Author = Encoding.Unicode.GetString(tmp);
//最后修改人
tmp = new byte[32];
Array.Copy(content, 112, tmp, 0, 32);
file.LastEditor = Encoding.Unicode.GetString(tmp);
//创建时间
UInt32 s1 = content[144];
UInt32 s2 = content[145];
UInt32 s3 = content[146];
UInt32 s4 = content[147];
file.CreateTime = (s4 << 24) + (s3 << 16) + (s2 << 8) + s1;
//最后修改时间
s1 = content[148];
s2 = content[149];
s3 = content[150];
s4 = content[151];
file.LastEditTime = (s4 << 24) + (s3 << 16) + (s2 << 8) + s1;
//尾字节
UInt16 s5 = content[152];
UInt16 s6 = content[153];
file.Rest = (UInt16)((s6 << 8) + s5);
file.Location = location;
return(file);
}
return(null);
}
/// <summary>
/// 读取某簇内容
/// </summary>
/// <param name="drivename">驱动器</param>
/// <param name="volumeinfo">卷信息结构体</param>
/// <param name="cluster">要读取的簇号</param>
/// <returns>具体内容</returns>
public static byte[] ReadOut(string drivename, VolumeInfo volumeinfo, UInt32 cluster)
{
var res = DiskRW.ReadA(drivename, transfer(volumeinfo.SectorStart, cluster, volumeinfo.Cluster), (UInt32)(volumeinfo.Cluster >> 9));
return(res);
}