public static byte[] CreatePatchFor(string filename1, string filename2)
{
// Compute hashes
HashBlock[] hashBlocksFromReceiver;
using (FileStream sourceStream = File.Open(filename1, FileMode.Open))
{
hashBlocksFromReceiver = new HashBlockGenerator(new RollingChecksum(),
new HashAlgorithmWrapper<MD5>(MD5.Create()),
blockSize).ProcessStream(sourceStream).ToArray();
}
// Compute deltas
MemoryStream deltaStream = new MemoryStream();
using (FileStream fileStream = File.Open(filename2, FileMode.Open))
{
DeltaGenerator deltaGen = new DeltaGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()));
deltaGen.Initialize(blockSize, hashBlocksFromReceiver);
IEnumerable<IDelta> deltas = deltaGen.GetDeltas(fileStream);
deltaGen.Statistics.Dump();
fileStream.Seek(0, SeekOrigin.Begin);
DeltaStreamer streamer = new DeltaStreamer();
streamer.Send(deltas, fileStream, deltaStream);
}
return deltaStream.ToArray();
}
public void ProcessStream_returns_correct_block_count()
{
MemoryStream stream = GetOriginalFileStream();
var gen = new HashBlockGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()), BLOCK_SIZE);
Assert.AreEqual(
Math.Ceiling(originalFile.Length/(float) BLOCK_SIZE),
gen.ProcessStream(stream).Count());
}
static void Main(string[] args)
{
int blockSize = 512;
// Compute hashes
IEnumerable<HashBlock> hashBlocksFromReceiver;
using (FileStream sourceStream = File.Open("../../dest.bmp", FileMode.Open))
{
hashBlocksFromReceiver = new HashBlockGenerator(new RollingChecksum(),
new HashAlgorithmWrapper<MD5>(MD5.Create()),
blockSize).ProcessStream(sourceStream).ToArray();
}
// Stream the hash blocks
var hashBlockStream = new MemoryStream();
HashBlockStreamer.Stream(hashBlocksFromReceiver, hashBlockStream);
// Receive the hash block stream
hashBlockStream.Seek(0, SeekOrigin.Begin);
Console.Out.WriteLine("Hash block stream length: {0}", hashBlockStream.Length);
hashBlocksFromReceiver = HashBlockStreamer.Destream(hashBlockStream);
// Compute deltas
var deltaStream = new MemoryStream();
using (FileStream fileStream = File.Open("../../source.bmp", FileMode.Open))
{
var deltaGen = new DeltaGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()));
deltaGen.Initialize(blockSize, hashBlocksFromReceiver);
IEnumerable<IDelta> deltas = deltaGen.GetDeltas(fileStream);
deltaGen.Statistics.Dump();
fileStream.Seek(0, SeekOrigin.Begin);
var streamer = new DeltaStreamer();
streamer.Send(deltas, fileStream, deltaStream);
Console.Out.WriteLine("Delta stream length: {0}", deltaStream.Length);
}
// Rewind the delta stream (obviously wouldn't apply from a network pipe)
deltaStream.Seek(0, SeekOrigin.Begin);
// Reconstruct file
using (FileStream sourceStream = File.Open("../../dest.bmp", FileMode.Open))
{
using (FileStream outStream = File.Open("../../reconstructed.bmp", FileMode.Create))
{
var streamer = new DeltaStreamer();
streamer.Receive(deltaStream, sourceStream, outStream);
outStream.Close();
}
}
}
public void ProcessStream_returns_hashes_with_correct_md5_sums()
{
MemoryStream stream = GetOriginalFileStream();
var gen = new HashBlockGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()), BLOCK_SIZE);
int i = 0;
Assert.IsTrue(gen.ProcessStream(stream).All(x =>
BitConverter.ToString(x.Hash)
.Replace("-", "")
.ToLower()
.Equals(md5sums[i++].ToLower())
));
}
public void ProcessStream_returns_hashes_with_correct_length()
{
MemoryStream stream = GetOriginalFileStream();
var gen = new HashBlockGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()), BLOCK_SIZE);
int i = 0;
Assert.IsTrue(gen.ProcessStream(stream).All(x =>
x.Length ==
Math.Min(BLOCK_SIZE, originalFile.Length - i++*BLOCK_SIZE)));
}
public void ProcessStream_throws_for_null_stream()
{
var gen = new HashBlockGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()), BLOCK_SIZE);
gen.ProcessStream(null).Count();
}
public void ProcessStream_returns_hashes_with_correct_rolling_sums()
{
MemoryStream stream = GetOriginalFileStream();
var gen = new HashBlockGenerator(new RollingChecksum(), new HashAlgorithmWrapper<MD5>(MD5.Create()), BLOCK_SIZE);
int i = 0;
Assert.IsTrue(gen.ProcessStream(stream).All(x => x.Checksum == checkSums[i++]));
}
