public static void DecompressSparse(Stream input, Stream output)
{
SparseHeader sparseHeader = SparseHeader.Read(input);
if (sparseHeader == null)
{
throw new ArgumentException("Invalid Sparse Image Format");
}
output.Seek(0, SeekOrigin.Begin);
for (uint index = 0; index < sparseHeader.TotalChunks; index++)
{
ChunkHeader chunkHeader = ChunkHeader.Read(input);
long dataLength = (long)chunkHeader.ChunkSize * sparseHeader.BlockSize;
switch (chunkHeader.ChunkType)
{
case ChunkType.Raw:
{
byte[] data = ReadBytes(input, (int)dataLength);
ByteWriter.WriteBytes(output, data);
break;
}
case ChunkType.Fill:
{
byte[] fillBytes = ReadBytes(input, 4);
byte[] data = new byte[dataLength];
for (int offset = 0; offset < data.Length; offset += 4)
{
ByteWriter.WriteBytes(data, offset, fillBytes);
}
ByteWriter.WriteBytes(output, data);
break;
}
case ChunkType.DontCare:
{
output.Seek(dataLength, SeekOrigin.Current);
break;
}
case ChunkType.CRC:
{
byte[] crcBytes = ReadBytes(input, 4);
break;
}
default:
{
throw new ArgumentException("Error: Invalid Chunk Type");
}
}
}
input.Close();
}
/// <param name="sparseIndex">one-based index</param>
/// <returns>True if the write was complete (i.e. this was the last sparse)</returns>
public static bool WriteCompressedSparse(Stream input, Stream output, long maxSparseSize)
{
// We will write the header later
output.Seek(SparseHeader.Length, SeekOrigin.Begin);
long currentSparseSize = SparseHeader.Length;
uint chunkCount = 0;
if (input.Position != 0)
{
WriteDontCareChunk(output, (uint)(input.Position / BlockSize));
chunkCount++;
}
MemoryStream rawChunk = new MemoryStream();
byte[] fill = null;
int fillCount = 0;
// We keep reading as long as we have a room for an additional chunk
// (the largest chunk is a raw chunk)
while (currentSparseSize + ChunkHeader.Length + BlockSize <= maxSparseSize &&
input.Position < input.Length)
{
byte[] block = new byte[BlockSize];
input.Read(block, 0, BlockSize);
byte[] currentFill = SparseCompressionHelper.TryToCompressBlock(block);
if (fill != null)
{
if (currentFill != null)
{
if (ByteUtils.AreByteArraysEqual(fill, currentFill))
{
fillCount++;
}
else
{
WriteFillChunk(output, fill, (uint)fillCount);
chunkCount++;
fillCount = 1;
fill = currentFill;
currentSparseSize += ChunkHeader.Length + 4;
}
}
else
{
WriteFillChunk(output, fill, (uint)fillCount);
chunkCount++;
ByteWriter.WriteBytes(rawChunk, block);
fill = null;
fillCount = 0;
currentSparseSize += ChunkHeader.Length + BlockSize;
}
}
else // fill == null
{
if (currentFill != null)
{
WriteRawChunk(output, rawChunk);
chunkCount++;
rawChunk = new MemoryStream();
fillCount = 1;
fill = currentFill;
currentSparseSize += ChunkHeader.Length + 4;
}
else
{
ByteWriter.WriteBytes(rawChunk, block);
currentSparseSize += BlockSize;
}
}
}
if (rawChunk.Length > 0)
{
WriteRawChunk(output, rawChunk);
chunkCount++;
}
else
{
WriteFillChunk(output, fill, (uint)fillCount);
chunkCount++;
}
bool complete = (input.Position == input.Length);
if (!complete)
{
WriteDontCareChunk(output, (uint)((input.Length - input.Position) / BlockSize));
chunkCount++;
}
output.Seek(0, SeekOrigin.Begin);
SparseHeader sparseHeader = new SparseHeader();
sparseHeader.BlockSize = BlockSize;
sparseHeader.TotalBlocks = (uint)(input.Length / BlockSize);
sparseHeader.TotalChunks = chunkCount;
sparseHeader.WriteBytes(output);
output.Close();
return(complete);
}
private static void PrintSparseImageStatistics(string path)
{
FileStream stream;
try
{
stream = File.Open(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
}
catch (IOException)
{
Console.WriteLine("Cannot open " + path);
return;
}
catch (UnauthorizedAccessException)
{
Console.WriteLine("Cannot open {0} - Access Denied", path);
return;
}
SparseHeader sparseHeader = SparseHeader.Read(stream);
if (sparseHeader == null)
{
Console.WriteLine("Invalid Sparse Image Format");
return;
}
Console.WriteLine("Total Blocks: " + sparseHeader.TotalBlocks);
Console.WriteLine("Total Chunks: " + sparseHeader.TotalChunks);
long outputSize = 0;
for (uint index = 0; index < sparseHeader.TotalChunks; index++)
{
ChunkHeader chunkHeader = ChunkHeader.Read(stream);
Console.Write("Chunk type: {0}, size: {1}, total size: {2}", chunkHeader.ChunkType.ToString(), chunkHeader.ChunkSize, chunkHeader.TotalSize);
int dataLength = (int)(chunkHeader.ChunkSize * sparseHeader.BlockSize);
switch (chunkHeader.ChunkType)
{
case ChunkType.Raw:
{
SparseDecompressionHelper.ReadBytes(stream, dataLength);
Console.WriteLine();
outputSize += dataLength;
break;
}
case ChunkType.Fill:
{
byte[] fillBytes = SparseDecompressionHelper.ReadBytes(stream, 4);
uint fill = LittleEndianConverter.ToUInt32(fillBytes, 0);
Console.WriteLine(", value: 0x{0}", fill.ToString("X8"));
outputSize += dataLength;
break;
}
case ChunkType.DontCare:
{
Console.WriteLine();
break;
}
case ChunkType.CRC:
{
byte[] crcBytes = SparseDecompressionHelper.ReadBytes(stream, 4);
uint crc = LittleEndianConverter.ToUInt32(crcBytes, 0);
Console.WriteLine(", value: 0x{0}", crc.ToString("X8"));
break;
}
default:
{
Console.WriteLine();
Console.WriteLine("Error: Invalid Chunk Type");
return;
}
}
}
stream.Close();
Console.WriteLine("Output size: {0}", outputSize);
}
