Cosmos/source/Cosmos.System/FileSystem/FAT/Listing/FatDiretoryEntry.cs
2015-11-20 23:52:08 -06:00

425 lines
No EOL
17 KiB
C#

using Cosmos.Common.Extensions;
using Cosmos.System.FileSystem.Listing;
using global::System;
using global::System.Collections.Generic;
namespace Cosmos.System.FileSystem.FAT.Listing
{
using global::System.IO;
internal class FatDirectoryEntry : DirectoryEntry
{
private readonly uint mEntryHeaderDataOffset;
private new readonly FatFileSystem mFileSystem;
private readonly ulong mFirstClusterNum;
private new readonly FatDirectoryEntry mParent;
// Size is UInt32 because FAT doesn't support bigger.
// Don't change to UInt64
public FatDirectoryEntry(
FatFileSystem aFileSystem,
FatDirectoryEntry aParent,
string aName,
uint aSize,
ulong aFirstCluster,
uint aEntryHeaderDataOffset,
DirectoryEntryTypeEnum aEntryType)
: base(aFileSystem, aParent, aName, aSize, aEntryType)
{
if (aFileSystem == null)
{
throw new ArgumentNullException("aFileSystem");
}
if (aName == null)
{
throw new ArgumentNullException("aName");
}
if (aFirstCluster < 2)
{
throw new ArgumentOutOfRangeException("aFirstCluster");
}
mFileSystem = aFileSystem;
mParent = aParent;
mFirstClusterNum = aFirstCluster;
mEntryHeaderDataOffset = aEntryHeaderDataOffset;
//FatHelpers.Debug(
// "-- FatDirectoryEntry.ctor : " + "aParent.Name = " + aParent?.mName + ", aName = " + aName + ", aSize = "
// + aSize + ", aFirstCluster = " + aFirstCluster + ", aEntryHeaderDataOffset = " + aEntryHeaderDataOffset
// + " --");
}
public FatDirectoryEntry(
FatFileSystem aFileSystem,
FatDirectoryEntry aParent,
string aName,
ulong aFirstCluster)
: base(aFileSystem, aParent, aName, 0, DirectoryEntryTypeEnum.Directory)
{
if (aFileSystem == null)
{
throw new ArgumentNullException("aFileSystem");
}
if (aName == null)
{
throw new ArgumentNullException("aName");
}
if (aFirstCluster < 2)
{
throw new ArgumentOutOfRangeException("aFirstCluster");
}
mFileSystem = aFileSystem;
mParent = aParent;
mFirstClusterNum = aFirstCluster;
mEntryHeaderDataOffset = 0;
//FatHelpers.Debug(
// "-- FatDirectoryEntry.ctor : " + "aParent.Name = " + aParent?.mName + ", aName = " + aName
// + ", aFirstCluster = " + aFirstCluster + " --");
}
public ulong[] GetFatTable()
{
return null;
}
public FatFileSystem GetFileSystem()
{
return mFileSystem;
}
public override Stream GetFileStream()
{
if (mEntryType == DirectoryEntryTypeEnum.File)
{
return new FatStream(this);
}
return null;
}
public override void SetName(string aName)
{
SetDirectoryEntryMetadataValue(FatDirectoryEntryMetadata.ShortName, aName);
}
public override void SetSize(long aSize)
{
SetDirectoryEntryMetadataValue(FatDirectoryEntryMetadata.Size, (uint)aSize);
}
private void AllocateDirectoryEntry()
{
// TODO: Deal with short and long name.
SetDirectoryEntryMetadataValue(FatDirectoryEntryMetadata.ShortName, mName);
SetDirectoryEntryMetadataValue(FatDirectoryEntryMetadata.Attributes, FatDirectoryEntryAttributeConsts.Directory);
SetDirectoryEntryMetadataValue(FatDirectoryEntryMetadata.FirstClusterHigh, (uint)(mFirstClusterNum >> 16));
SetDirectoryEntryMetadataValue(FatDirectoryEntryMetadata.FirstClusterLow, (uint)(mFirstClusterNum & 0xFFFF));
byte[] xData = GetDirectoryEntryData();
SetDirectoryEntryData(xData);
}
public FatDirectoryEntry AddDirectoryEntry(string aName, DirectoryEntryTypeEnum aType)
{
if (aType == DirectoryEntryTypeEnum.Directory)
{
uint xFirstCluster = mFileSystem.GetFat(0).GetNextUnallocatedFatEntry();
uint xEntryHeaderDataOffset = GetNextUnallocatedEntry();
var xNewEntry = new FatDirectoryEntry(
mFileSystem,
this,
aName,
0,
xFirstCluster,
xEntryHeaderDataOffset,
aType);
xNewEntry.AllocateDirectoryEntry();
return xNewEntry;
}
if (aType == DirectoryEntryTypeEnum.File)
{
throw new NotImplementedException("Creating new files is currently not implemented.");
}
throw new ArgumentOutOfRangeException("aType", "Unknown directory entry type.");
}
public List<FatDirectoryEntry> ReadDirectoryContents()
{
var xData = GetDirectoryEntryData();
FatDirectoryEntry xParent = mParent;
var xResult = new List<FatDirectoryEntry>();
//TODO: Change xLongName to StringBuilder
string xLongName = "";
string xName = "";
for (uint i = 0; i < xData.Length; i = i + 32)
{
//FatHelpers.Debug("-------------------------------------------------");
byte xAttrib = xData[i + 11];
byte xStatus = xData[i];
//FatHelpers.Debug("Attrib = " + xAttrib + ", Status = " + xStatus);
if (xAttrib == FatDirectoryEntryAttributeConsts.LongName)
{
byte xType = xData[i + 12];
byte xOrd = xData[i];
//FatHelpers.Debug("Reading LFN with Seqnr " + xOrd + ", Type = " + xType);
if (xOrd == 0xE5)
{
FatHelpers.Debug("<DELETED>");
continue;
}
if (xType == 0)
{
if ((xOrd & 0x40) > 0)
{
xLongName = "";
}
//TODO: Check LDIR_Ord for ordering and throw exception
// if entries are found out of order.
// Also save buffer and only copy name if a end Ord marker is found.
string xLongPart = xData.GetUtf16String(i + 1, 5);
// We have to check the length because 0xFFFF is a valid Unicode codepoint.
// So we only want to stop if the 0xFFFF is AFTER a 0x0000. We can determin
// this by also looking at the length. Since we short circuit the or, the length
// is rarely evaluated.
if (xData.ToUInt16(i + 14) != 0xFFFF || xLongPart.Length == 5)
{
xLongPart = xLongPart + xData.GetUtf16String(i + 14, 6);
if (xData.ToUInt16(i + 28) != 0xFFFF || xLongPart.Length == 11)
{
xLongPart = xLongPart + xData.GetUtf16String(i + 28, 2);
}
}
xLongName = xLongPart + xLongName;
xLongPart = null;
//TODO: LDIR_Chksum
}
}
else
{
xName = xLongName;
if (xStatus == 0x00)
{
FatHelpers.Debug("<EOF>");
break;
}
switch (xStatus)
{
case 0x05:
// Japanese characters - We dont handle these
break;
case 0xE5:
// Empty slot, skip it
break;
default:
if (xStatus >= 0x20)
{
if (xLongName.Length > 0)
{
// Leading and trailing spaces are to be ignored according to spec.
// Many programs (including Windows) pad trailing spaces although it
// it is not required for long names.
// As per spec, ignore trailing periods
xName = xLongName.Trim();
//If there are trailing periods
int nameIndex = xName.Length - 1;
if (xName[nameIndex] == '.')
{
//Search backwards till we find the first non-period character
for (; nameIndex > 0; nameIndex--)
{
if (xName[nameIndex] != '.')
{
break;
}
}
//Substring to remove the periods
xName = xName.Substring(0, nameIndex + 1);
}
xLongName = "";
}
else
{
string xEntry = xData.GetAsciiString(i, 11);
xName = xEntry.Substring(0, 8).TrimEnd();
string xExt = xEntry.Substring(8, 3).TrimEnd();
if (xExt.Length > 0)
{
xName = xName + "." + xExt;
}
}
}
break;
}
}
uint xFirstCluster = (uint)(xData.ToUInt16(i + 20) << 16 | xData.ToUInt16(i + 26));
int xTest = xAttrib & (FatDirectoryEntryAttributeConsts.Directory | FatDirectoryEntryAttributeConsts.VolumeID);
if (xAttrib == FatDirectoryEntryAttributeConsts.LongName)
{
// skip adding, as it's a LongFileName entry, meaning the next normal entry is the item with the name.
//FatHelpers.Debug("Entry was a Long FileName entry. Current LongName = '" + xLongName + "'");
}
else if (xTest == 0)
{
uint xSize = xData.ToUInt32(i + 28);
if (xSize == 0 && xName.Length == 0)
{
continue;
}
var xEntry = new FatDirectoryEntry(mFileSystem, xParent, xName, xSize, xFirstCluster, i, DirectoryEntryTypeEnum.File);
xResult.Add(xEntry);
FatHelpers.Debug(xEntry.mName + " --- " + xEntry.mSize + " bytes");
}
else if (xTest == FatDirectoryEntryAttributeConsts.Directory)
{
uint xSize = xData.ToUInt32(i + 28);
var xEntry = new FatDirectoryEntry(mFileSystem, xParent, xName, xSize, xFirstCluster, i, DirectoryEntryTypeEnum.Directory);
FatHelpers.Debug(xEntry.mName + " <DIR> " + xEntry.mSize + " bytes");
xResult.Add(xEntry);
}
else if (xTest == FatDirectoryEntryAttributeConsts.VolumeID)
{
FatHelpers.Debug("<VOLUME ID>");
}
else
{
FatHelpers.Debug("<INVALID ENTRY>");
}
}
return xResult;
}
private uint GetNextUnallocatedEntry()
{
var xData = GetDirectoryEntryData();
FatHelpers.DebugNumber((uint)xData.Length);
for (uint i = 0; i < xData.Length; i += 32)
{
uint x1 = xData.ToUInt32(i);
uint x2 = xData.ToUInt32(i + 8);
uint x3 = xData.ToUInt32(i + 16);
uint x4 = xData.ToUInt32(i + 24);
if ((x1 == 0) && (x2 == 0) && (x3 == 0) && (x4 == 0))
{
//FatHelpers.Debug("Found unallocated Directory entry: " + i);
return i;
}
}
// TODO: What should we return if no available entry is found.
throw new Exception("Failed to find an unallocated directory entry.");
}
private byte[] GetDirectoryEntryData()
{
if (mEntryType != DirectoryEntryTypeEnum.Unknown)
{
byte[] xData;
mFileSystem.Read(mFirstClusterNum, out xData);
return xData;
}
throw new Exception("Invalid directory entry type");
}
private void SetDirectoryEntryData(byte[] aData)
{
if (aData == null)
{
throw new ArgumentNullException("aData");
}
if (aData.Length == 0)
{
//FatHelpers.Debug("SetDirectoryEntryData: No data to write.");
return;
}
//FatHelpers.Debug("SetDirectoryEntryData: Name = " + mName);
//FatHelpers.Debug("SetDirectoryEntryData: Size = " + mSize);
//FatHelpers.Debug("SetDirectoryEntryData: FirstClusterNum = " + mFirstClusterNum);
//FatHelpers.Debug("SetDirectoryEntryData: aData.Length = " + aData.Length);
if (mEntryType != DirectoryEntryTypeEnum.Unknown)
{
mFileSystem.Write(mFirstClusterNum, aData);
}
else
{
throw new Exception("Invalid directory entry type");
}
}
internal void SetDirectoryEntryMetadataValue(
FatDirectoryEntryMetadata aEntryMetadata,
uint aValue)
{
var xData = mParent.GetDirectoryEntryData();
if (xData.Length > 0)
{
var xValue = new byte[aEntryMetadata.DataLength];
xValue.SetUInt32(0, aValue);
uint offset = mEntryHeaderDataOffset + aEntryMetadata.DataOffset;
Array.Copy(xValue, 0, xData, offset, aEntryMetadata.DataLength);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: DataLength = " + aEntryMetadata.DataLength);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: DataOffset = " + aEntryMetadata.DataOffset);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: EntryHeaderDataOffset = " + mEntryHeaderDataOffset);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: TotalOffset = " + offset);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: aValue = " + aValue);
//for (int i = 0; i < xValue.Length; i++)
//{
// FatHelpers.DebugNumber(xValue[i]);
//}
}
mParent.SetDirectoryEntryData(xData);
}
internal void SetDirectoryEntryMetadataValue(
FatDirectoryEntryMetadata aEntryMetadata,
string aValue)
{
var xData = mParent.GetDirectoryEntryData();
if (xData.Length > 0)
{
var xValue = new byte[aEntryMetadata.DataLength];
xValue = aValue.GetUtf8Bytes(0, aEntryMetadata.DataLength);
uint offset = mEntryHeaderDataOffset + aEntryMetadata.DataOffset;
Array.Copy(xValue, 0, xData, offset, aEntryMetadata.DataLength);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: DataLength = " + aEntryMetadata.DataLength);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: DataOffset = " + aEntryMetadata.DataOffset);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: EntryHeaderDataOffset = " + mEntryHeaderDataOffset);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: TotalOffset = " + offset);
//FatHelpers.Debug("SetDirectoryEntryMetadataValue: aValue = " + aValue);
//for (int i = 0; i < xValue.Length; i++)
//{
// FatHelpers.DebugNumber(xValue[i]);
//}
mParent.SetDirectoryEntryData(xData);
}
}
}
}