public void Destream_can_read_streamed_blocks()
{
var blocks = new HashBlock[5];
for (int index = 0; index < blocks.Length; index++)
{
blocks[index] = new HashBlock
{
Checksum = (uint) index,
Length = index * 2,
Offset = 9223372036854775807L,
Hash = new byte[16]
};
new Random().NextBytes(blocks[index].Hash);
}
var ms = new MemoryStream();
HashBlockStreamer.Stream(blocks, ms);
ms.Seek(0, SeekOrigin.Begin);
HashBlock[] newBlocks = HashBlockStreamer.Destream(ms);
Assert.AreEqual(blocks.Length, newBlocks.Length);
for (int index = 0; index < newBlocks.Length; index++)
{
HashBlock newBlock = newBlocks[index];
HashBlock oldBlock = blocks[index];
Assert.AreEqual(oldBlock.Checksum, newBlock.Checksum);
Assert.AreEqual(oldBlock.Length, newBlock.Length);
Assert.AreEqual(oldBlock.Offset, newBlock.Offset);
Assert.IsTrue(oldBlock.Hash.SequenceEqual(newBlock.Hash));
}
}
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 void Stream_writes_valid_byte_length()
{
var blocks = new HashBlock[5];
for (int index = 0; index < blocks.Length; index++)
{
blocks[index] = new HashBlock {Hash = new byte[16]};
}
var ms = new MemoryStream();
HashBlockStreamer.Stream(blocks, ms);
Assert.AreEqual(blocks.Length*32 + 4, ms.Length);
}
public static HashBlock[] Destream(Stream inputStream)
{
uint count = inputStream.ReadUInt();
var hashBlocks = new HashBlock[count];
for (int i = 0; i < count; ++i)
{
hashBlocks[i] = new HashBlock {Hash = new byte[16]};
inputStream.Read(hashBlocks[i].Hash, 0, 16);
hashBlocks[i].Length = inputStream.ReadInt();
hashBlocks[i].Offset = inputStream.ReadLong();
hashBlocks[i].Checksum = inputStream.ReadUInt();
}
return hashBlocks;
}
public void Stream_writes_valid_length()
{
var blocks = new HashBlock[5];
for (int index = 0; index < blocks.Length; index++)
{
blocks[index] = new HashBlock {Hash = new byte[16]};
}
var ms = new MemoryStream();
HashBlockStreamer.Stream(blocks, ms);
ms.Seek(0, SeekOrigin.Begin);
var buf = new byte[4];
ms.Read(buf, 0, 4);
Assert.AreEqual((uint) blocks.Length, BitConverter.ToUInt32(buf, 0));
}
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));
}
public static HashBlock[] Destream(Stream inputStream)
{
uint count = inputStream.ReadUInt();
var hashBlocks = new HashBlock[count];
for (int i = 0; i < count; ++i)
{
hashBlocks[i] = new HashBlock {
Hash = new byte[16]
};
inputStream.Read(hashBlocks[i].Hash, 0, 16);
hashBlocks[i].Length = inputStream.ReadInt();
hashBlocks[i].Offset = inputStream.ReadLong();
hashBlocks[i].Checksum = inputStream.ReadUInt();
}
return(hashBlocks);
}
public void GetDeltas_throws_for_null_stream()
{
var dummyBlock =
new HashBlock
{
Checksum = 0,
Length = 0,
Offset = 0,
Hash = new byte[] {1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8}
};
DeltaGenerator gen = GetValidDeltaGenerator();
gen.Initialize(10, new[] {dummyBlock});
gen.GetDeltas(null).Count();
}