public byte ReadByte(long index, out bool isChanged)
{
long startIndex = 0;
isChanged = false;
BytePart bytePart = BytePartGetInfo(index, out startIndex);
FileBytePart fileBytePart = bytePart as FileBytePart;
MemoryBytePart memoryBytePart = bytePart as MemoryBytePart;
if (fileBytePart != null)
{
if (_fileDataStream.Position != fileBytePart.FilePartIndex + index - startIndex)
{
_fileDataStream.Position = fileBytePart.FilePartIndex + index - startIndex;
}
return((byte)_fileDataStream.ReadByte());
}
if (memoryBytePart != null)
{
isChanged = true;
return(memoryBytePart.Bytes[index - startIndex]);
}
else
{
throw new ArgumentNullException("index", "FileByteData.ReadByte: The internal BytePartList is corrupt.");
}
}
public bool IsChanged()
{
if (ReadOnly)
{
return(false);
}
if (Length != _fileDataStream.Length)
{
return(true);
}
long index = 0;
for (LinkedListNode <BytePart> bp = _bytePartList.First; bp != null; bp = bp.Next)
{
FileBytePart fileBytePart = bp.Value as FileBytePart;
if (fileBytePart == null || fileBytePart.FilePartIndex != index)
{
return(true);
}
index += fileBytePart.Length;
}
return(index != _fileDataStream.Length);
}
public void CommitChanges()
{
if (ReadOnly)
{
throw new OperationCanceledException("FileByteData.CommitChanges: The data cannot be saved when the file is in read only mode.");
}
if (Length > _fileDataStream.Length)
{
_fileDataStream.SetLength(Length);
}
long index = 0;
// run through the whole bytePart list
for (LinkedListNode <BytePart> bp = _bytePartList.First; bp != null; bp = bp.Next)
{
// try to convert it to a FileBytePart
FileBytePart fileBytePart = bp.Value as FileBytePart;
// if it's a FileBytePart and the orig file position is different, move the FileBytePart to the new (expected) position
if (fileBytePart != null && fileBytePart.FilePartIndex != index)
{
RearrangeFileBytePart(fileBytePart, index);
}
// increment the index to the next expected BytePart position for file - and memory parts
index += bp.Value.Length;
}
index = 0;
// run through the whole bytePart list again, now look at the memory parts
for (LinkedListNode <BytePart> bp = _bytePartList.First; bp != null; bp = bp.Next)
{
// try to convert it to a MemoryBytePart
MemoryBytePart memoryBytePart = bp.Value as MemoryBytePart;
// if it's a MemoryBytePart
if (memoryBytePart != null)
{
_fileDataStream.Position = index;
// write the MemoryBytePart into the stream
for (int memoryIndex = 0; memoryIndex < memoryBytePart.Length; memoryIndex += BLOCK_SIZE)
{
_fileDataStream.Write(memoryBytePart.Bytes, memoryIndex, (int)Math.Min(BLOCK_SIZE, memoryBytePart.Length - memoryIndex));
}
}
// increment the index to the next expected BytePart position for file - and memory parts
index += bp.Value.Length;
}
_fileDataStream.Flush();
InitFileByteData();
}
void RearrangeFileBytePart(FileBytePart bytePart, long index)
{
long nextIndex = 0;
byte[] buffer = new byte[BLOCK_SIZE];
FileBytePart nextFileBlock = GetNextFileBytePart(bytePart, index, out nextIndex);
if (nextFileBlock != null && index + bytePart.Length > nextFileBlock.FilePartIndex)
{
RearrangeFileBytePart(nextFileBlock, nextIndex);
}
if (bytePart.FilePartIndex > index)
{
Array.Clear(buffer, 0, buffer.Length);
for (long relIndex = 0; relIndex < bytePart.Length; relIndex += buffer.Length)
{
int bytesToRead = (int)Math.Min(buffer.Length, bytePart.Length - relIndex);
_fileDataStream.Position = bytePart.FilePartIndex + relIndex;
_fileDataStream.Read(buffer, 0, bytesToRead);
_fileDataStream.Position = index + relIndex;
_fileDataStream.Write(buffer, 0, bytesToRead);
}
}
else
{
Array.Clear(buffer, 0, buffer.Length);
for (long relIndex = 0; relIndex < bytePart.Length; relIndex += buffer.Length)
{
int bytesToRead = (int)Math.Min(buffer.Length, bytePart.Length - relIndex);
long readOffset = bytePart.FilePartIndex + bytePart.Length - relIndex - bytesToRead;
_fileDataStream.Position = readOffset;
_fileDataStream.Read(buffer, 0, bytesToRead);
long writeOffset = index + bytePart.Length - relIndex - bytesToRead;
_fileDataStream.Position = writeOffset;
_fileDataStream.Write(buffer, 0, bytesToRead);
}
}
bytePart.SetFilePartIndex(index);
}
FileBytePart GetNextFileBytePart(BytePart bytePart, long index, out long nextIndex)
{
FileBytePart nextFileBytePart = null;
nextIndex = index + bytePart.Length;
LinkedListNode <BytePart> bp = _bytePartList.Find(bytePart);
// run through the whole bytePart list from the current position + 1, to find the next FileBytePart
for (LinkedListNode <BytePart> bp1 = bp.Next; bp1 != null; bp1 = bp1.Next)
{
FileBytePart fileBytePart = bp1.Value as FileBytePart;
if (fileBytePart != null)
{
nextFileBytePart = fileBytePart;
break;
}
nextIndex += bp1.Value.Length;
}
return(nextFileBytePart);
}
public void InsertBytes(long index, byte[] value, bool track_Change = true)
{
if (track_Change)
{
_undoList.Add(new UndoAction(value, index, mod_type.mod_insert));
}
BytePart bytePart = BytePartGetInfo(index, out long startIndex);
FileBytePart fileBytePart = bytePart as FileBytePart;
MemoryBytePart memoryBytePart = bytePart as MemoryBytePart;
if (memoryBytePart != null)
{
memoryBytePart.InsertBytes(index - startIndex, value);
Length += value.Length;
OnDataLengthChanged(EventArgs.Empty);
OnDataChanged(EventArgs.Empty);
return;
}
LinkedListNode <BytePart> bp = _bytePartList.Find(bytePart);
if (startIndex == index && bp.Previous != null)
{
MemoryBytePart prevMemoryBytePart = bp.Previous.Value as MemoryBytePart;
if (prevMemoryBytePart != null)
{
prevMemoryBytePart.InsertBytes(prevMemoryBytePart.Length, value);
Length += value.Length;
OnDataLengthChanged(EventArgs.Empty);
OnDataChanged(EventArgs.Empty);
return;
}
}
if (fileBytePart != null)
{
FileBytePart newPrevFileBytePart = null;
FileBytePart newNextFileBytePart = null;
if (index > startIndex)
{
newPrevFileBytePart = new FileBytePart(fileBytePart.FilePartIndex, index - startIndex);
}
if (index < startIndex + fileBytePart.Length)
{
newNextFileBytePart = new FileBytePart(
fileBytePart.FilePartIndex + index - startIndex,
fileBytePart.Length - (index - startIndex));
}
BytePart newBP = new MemoryBytePart(value);
_bytePartList.Find(bytePart).Value = newBP;
bytePart = newBP;
if (newPrevFileBytePart != null)
{
LinkedListNode <BytePart> bp1 = _bytePartList.Find(bytePart);
_bytePartList.AddBefore(bp1, newPrevFileBytePart);
}
if (newNextFileBytePart != null)
{
LinkedListNode <BytePart> bp2 = _bytePartList.Find(bytePart);
_bytePartList.AddAfter(bp2, newNextFileBytePart);
}
Length += value.Length;
OnDataLengthChanged(EventArgs.Empty);
OnDataChanged(EventArgs.Empty);
}
else
{
throw new ArgumentNullException("index", "FileByteData.InsertBytes: The internal BytePartList is corrupt.");
}
}
public void WriteByte(long index, byte value, bool track_Change = true)
{
long startIndex = 0;
byte oldValue = ReadByte(index);
if (track_Change)
{
_undoList.Add(new UndoAction(new byte[] { oldValue }, index, mod_type.mod_replace));
}
BytePart bytePart = BytePartGetInfo(index, out startIndex);
FileBytePart fileBytePart = bytePart as FileBytePart;
MemoryBytePart memoryBytePart = bytePart as MemoryBytePart;
if (memoryBytePart != null)
{
memoryBytePart.Bytes[index - startIndex] = value;
OnDataChanged(EventArgs.Empty);
return;
}
if (fileBytePart != null)
{
LinkedListNode <BytePart> bp = _bytePartList.Find(bytePart);
if (index == startIndex && bp.Previous != null)
{
MemoryBytePart prevMemoryBytePart = bp.Previous.Value as MemoryBytePart;
if (prevMemoryBytePart != null)
{
prevMemoryBytePart.AddByteToEnd(value);
fileBytePart.RemoveBytesFromStart(1);
if (fileBytePart.Length == 0)
{
_bytePartList.Remove(fileBytePart);
}
OnDataChanged(EventArgs.Empty);
return;
}
}
if (index == startIndex + fileBytePart.Length - 1 && bp.Next != null)
{
MemoryBytePart nextMemoryBytePart = bp.Next.Value as MemoryBytePart;
if (nextMemoryBytePart != null)
{
nextMemoryBytePart.AddByteToStart(value);
fileBytePart.RemoveBytesFromEnd(1);
if (fileBytePart.Length == 0)
{
_bytePartList.Remove(fileBytePart);
}
OnDataChanged(EventArgs.Empty);
return;
}
}
FileBytePart newPrevFileBytePart = null;
FileBytePart newNextFileBytePart = null;
if (index > startIndex)
{
newPrevFileBytePart = new FileBytePart(fileBytePart.FilePartIndex, index - startIndex);
}
if (index < startIndex + fileBytePart.Length - 1)
{
newNextFileBytePart = new FileBytePart(
fileBytePart.FilePartIndex + index - startIndex + 1,
fileBytePart.Length - (index - startIndex + 1));
}
BytePart newMemoryBP = new MemoryBytePart(value);
_bytePartList.Find(bytePart).Value = newMemoryBP;
bytePart = newMemoryBP;
if (newPrevFileBytePart != null)
{
LinkedListNode <BytePart> bp1 = _bytePartList.Find(bytePart);
_bytePartList.AddBefore(bp1, newPrevFileBytePart);
}
if (newNextFileBytePart != null)
{
LinkedListNode <BytePart> bp2 = _bytePartList.Find(bytePart);
_bytePartList.AddAfter(bp2, newNextFileBytePart);
}
OnDataChanged(EventArgs.Empty);
}
else
{
throw new ArgumentNullException("index", "FileByteData.WriteByte: The internal BytePartList is corrupt.");
}
}
