public void GetDeltas_returns_two_CopyDelta_objects_and_a_middle_ByteDelta_for_interspaced_new_data()
{
var checksumMock = new Mock<IRollingChecksum>();
int checksumCallNumber = 0;
// Returns "1" for calls number 2 through 11 inclusive.
checksumMock.Setup(x => x.Value)
.Returns(() => (uint) (++checksumCallNumber > 1 && checksumCallNumber <= 11 ? 1 : 0));
var hashMock = new Mock<IHashAlgorithm>();
byte[] dummyBytes = InitializeDummyMD5Hash(hashMock);
var gen = new DeltaGenerator(checksumMock.Object, hashMock.Object);
int blockSize = 10;
var magicHashBlock = new HashBlock {Checksum = 0, Hash = dummyBytes, Offset = 42, Length = 43};
gen.Initialize(blockSize, new[] {magicHashBlock});
var bytes = new byte[blockSize*3];
for (int i = 0; i < bytes.Length; ++i) bytes[i] = 0;
// Should immediately get a match for an entire block.
// Then upon trying to match a new one get a mismatch for the next
// 10 bytes
IEnumerable<IDelta> deltas = gen.GetDeltas(new MemoryStream(bytes));
Assert.AreEqual(3, deltas.Count());
Assert.IsTrue(
deltas.ElementAt(0) is CopyDelta &&
deltas.ElementAt(1) is ByteDelta &&
deltas.ElementAt(2) is CopyDelta);
Assert.AreEqual(10, (deltas.ElementAt(1) as ByteDelta).Offset);
Assert.AreEqual(10, (deltas.ElementAt(1) as ByteDelta).Length);
}
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();
}
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 GetDeltas_returns_three_CopyDeltas_object_when_matching_hash_is_provided_for_triple_repeat()
{
var checksumMock = new Mock<IRollingChecksum>();
checksumMock.Setup(x => x.Value).Returns(0);
var hashMock = new Mock<IHashAlgorithm>();
byte[] dummyBytes = InitializeDummyMD5Hash(hashMock);
var gen = new DeltaGenerator(checksumMock.Object, hashMock.Object);
int blockSize = 10;
var magicHashBlock = new HashBlock {Checksum = 0, Hash = dummyBytes, Offset = 42, Length = 43};
gen.Initialize(blockSize, new[] {magicHashBlock});
var bytes = new byte[blockSize*3];
for (int i = 0; i < bytes.Length; ++i) bytes[i] = 0;
IEnumerable<IDelta> deltas = gen.GetDeltas(new MemoryStream(bytes));
Assert.AreEqual(3, deltas.Count());
Assert.IsTrue(deltas.All(d => d is CopyDelta));
Assert.IsTrue(deltas.All(d => (d as CopyDelta).Offset == magicHashBlock.Offset));
}
