/// <summary>
/// Compress data from a stream.
/// </summary>
/// <param name="source">The stream to read from.</param>
/// <param name="destination">The stream to write to.</param>
public override void Compress(Stream source, Stream destination)
{
long destinationStart = destination.Position;
// Get the source length, and read it in to an array
int sourceLength = (int)(source.Length - source.Position);
byte[] sourceArray = new byte[sourceLength];
source.Read(sourceArray, 0, sourceLength);
// Get the encryption key
uint key = (uint)(DateTime.Now - new DateTime(1970, 1, 1)).TotalSeconds;
// Set the source and destination pointers
int sourcePointer = 0x0;
int destinationPointer = 0x40;
// Initalize the LZ dictionary
LzBufferDictionary dictionary = new LzBufferDictionary();
dictionary.SetBufferSize(0x1000);
dictionary.SetBufferStart(0xFEE);
dictionary.SetMaxMatchAmount(0xF + 3);
// Write out the header
// Magic code
destination.WriteByte((byte)'L');
destination.WriteByte((byte)'Z');
destination.WriteByte((byte)'0');
destination.WriteByte((byte)'0');
PTStream.WriteInt32(destination, 0); // Compressed length (will be filled in later)
PTStream.WriteInt32(destination, 0);
PTStream.WriteInt32(destination, 0);
PTStream.WriteCString(destination, Path.GetFileName(DestinationPath), 32, Encoding.GetEncoding("Shift_JIS")); // File name
PTStream.WriteInt32(destination, sourceLength); // Decompressed length
PTStream.WriteUInt32(destination, key); // Encryption key
PTStream.WriteInt32(destination, 0);
PTStream.WriteInt32(destination, 0);
// Start compression
while (sourcePointer < sourceLength)
{
using (MemoryStream buffer = new MemoryStream())
{
byte flag = 0;
for (int i = 0; i < 8; i++)
{
// Search for a match
int[] match = dictionary.Search(sourceArray, (uint)sourcePointer, (uint)sourceLength);
if (match[1] > 0) // There is a match
{
buffer.WriteByte((byte)(match[0] & 0xFF));
buffer.WriteByte((byte)(((match[0] & 0xF00) >> 4) | ((match[1] - 3) & 0xF)));
dictionary.AddEntryRange(sourceArray, sourcePointer, match[1]);
sourcePointer += match[1];
}
else // There is not a match
{
flag |= (byte)(1 << i);
buffer.WriteByte(sourceArray[sourcePointer]);
dictionary.AddEntry(sourceArray, sourcePointer);
sourcePointer++;
}
// Check to see if we reached the end of the file
if (sourcePointer >= sourceLength)
{
break;
}
}
// Flush the buffer and write it to the destination stream
WriteByte(destination, flag, ref key);
buffer.Position = 0;
while (buffer.Position < buffer.Length)
{
byte value = PTStream.ReadByte(buffer);
WriteByte(destination, value, ref key);
}
destinationPointer += (int)buffer.Length + 1;
}
}
// Go back to the beginning of the file and write out the compressed length
long currentPosition = destination.Position;
destination.Position = destinationStart + 4;
PTStream.WriteInt32(destination, destinationPointer);
destination.Position = currentPosition;
}
/// <summary>
/// Compress data from a stream.
/// </summary>
/// <param name="source">The stream to read from.</param>
/// <param name="destination">The stream to write to.</param>
public override void Compress(Stream source, Stream destination)
{
long destinationStart = destination.Position;
// Get the source length, and read it in to an array
int sourceLength = (int)(source.Length - source.Position);
byte[] sourceArray = new byte[sourceLength];
source.Read(sourceArray, 0, sourceLength);
// Set the source and destination pointers
int sourcePointer = 0x0;
int destinationPointer = 0x10;
// Initalize the LZ dictionary
LzBufferDictionary dictionary = new LzBufferDictionary();
dictionary.SetBufferSize(0x1000);
dictionary.SetBufferStart(0xFEE);
dictionary.SetMaxMatchAmount(0xF + 3);
// Write out the header
// Magic code
destination.WriteByte((byte)'L');
destination.WriteByte((byte)'Z');
destination.WriteByte((byte)'0');
destination.WriteByte((byte)'1');
PTStream.WriteInt32(destination, 0); // Compressed length (will be filled in later)
PTStream.WriteInt32(destination, sourceLength); // Decompressed length
PTStream.WriteInt32(destination, 0);
// Start compression
while (sourcePointer < sourceLength)
{
using (MemoryStream buffer = new MemoryStream())
{
byte flag = 0;
for (int i = 0; i < 8; i++)
{
// Search for a match
int[] match = dictionary.Search(sourceArray, (uint)sourcePointer, (uint)sourceLength);
if (match[1] > 0) // There is a match
{
buffer.WriteByte((byte)(match[0] & 0xFF));
buffer.WriteByte((byte)(((match[0] & 0xF00) >> 4) | ((match[1] - 3) & 0xF)));
dictionary.AddEntryRange(sourceArray, sourcePointer, match[1]);
sourcePointer += match[1];
}
else // There is not a match
{
flag |= (byte)(1 << i);
buffer.WriteByte(sourceArray[sourcePointer]);
dictionary.AddEntry(sourceArray, sourcePointer);
sourcePointer++;
}
// Check to see if we reached the end of the file
if (sourcePointer >= sourceLength)
break;
}
// Flush the buffer and write it to the destination stream
destination.WriteByte(flag);
buffer.Position = 0;
while (buffer.Position < buffer.Length)
{
byte value = PTStream.ReadByte(buffer);
destination.WriteByte(value);
}
destinationPointer += (int)buffer.Length + 1;
}
}
// Go back to the beginning of the file and write out the compressed length
long currentPosition = destination.Position;
destination.Position = destinationStart + 4;
PTStream.WriteInt32(destination, destinationPointer);
destination.Position = currentPosition;
}
