public void TestHeadAndBodyFitInBlockMargin()
{
var repo = new MockRepository();
var diskAccessMock = repo.DynamicMock<IDirectDiskAccess>();
var data = new byte[8192];
ulong addr1 = 0;
ulong addr2 = 4096;
diskAccessMock.WriteBytes(ref addr1, data, 0, 4096);
diskAccessMock.WriteBytes(ref addr2, data, 4096, 4096);
repo.ReplayAll();
var writer = new SparseWriter(diskAccessMock);
Assert.AreEqual(2, SparseWriter.GetNumberOfBlocksRequired(8192, 0));
var dest = new[] { new Address(0), new Address(4096) };
writer.WriteData(data, dest, 0);
repo.VerifyAll();
}
public void TestHeadBodyAndTailTakeOneBlockEach()
{
var repo = new MockRepository();
var diskAccessMock = repo.DynamicMock<IDirectDiskAccess>();
var data = new byte[4096 * 3];
ulong addr1 = 0;
ulong addr2 = 4096;
ulong addr3 = 8192;
diskAccessMock.WriteBytes(ref addr1, data, 0, 4096);
diskAccessMock.WriteBytes(ref addr2, data, 4096, 4096);
diskAccessMock.WriteBytes(ref addr3, data, 8192, 4096);
repo.ReplayAll();
var writer = new SparseWriter(diskAccessMock);
Assert.AreEqual(3, SparseWriter.GetNumberOfBlocksRequired(4096 * 3, 0));
var dest = new[] { new Address(0), new Address(4096), new Address(8192) };
writer.WriteData(data, dest, 0);
repo.VerifyAll();
}
public void TestHeadAndTailNoBody()
{
// test case when there is no body, just head and tail in two blocks.
var repo = new MockRepository();
var diskAccessMock = repo.StrictMock<IDirectDiskAccess>();
const uint size = 15;
var data = new byte[size];
ulong addr1 = 4095;
ulong addr2 = 4096;
diskAccessMock.WriteBytes(ref addr1, data, 0, 1);
diskAccessMock.WriteBytes(ref addr2, data, 1, size - 1);
repo.ReplayAll();
var writer = new SparseWriter(diskAccessMock);
Assert.AreEqual(2, SparseWriter.GetNumberOfBlocksRequired(size, 4095));
var dest = new[] { new Address(0), new Address(4096) };
writer.WriteData(data, dest, 4095);
repo.VerifyAll();
}
public void TestTailFitsIntoBody()
{
// test case when tail completely fits into last block
var repo = new MockRepository();
var diskAccessMock = repo.DynamicMock<IDirectDiskAccess>();
var data = new byte[10000];
uint delta = 4096 - 2288;
ulong addr1 = 2288;
ulong addr2 = 4096;
ulong addr3 = 8192;
diskAccessMock.WriteBytes(ref addr1, data, 0, delta);
diskAccessMock.WriteBytes(ref addr2, data, delta, 4096);
diskAccessMock.WriteBytes(ref addr3, data, delta + 4096, 4096);
repo.ReplayAll();
var writer = new SparseWriter(diskAccessMock);
Assert.AreEqual(3, SparseWriter.GetNumberOfBlocksRequired(10000, 2288));
var dest = new [] { new Address(0), new Address(4096), new Address(8192) };
writer.WriteData(data, dest, 2288);
repo.VerifyAll();
}
/// <summary>
/// Writes the data into file, resizing as needed.
/// </summary>
public ulong WriteData(ulong position, [NotNull] byte[] data)
{
Validate.ArgumentNotNull(data, "data");
ulong newSize = position + (uint)data.Length;
if (newSize > FileSize)
{
SetFileSize(newSize); // force allocation of new space. will throw if not enough memory.
}
var startBlockIndex = (uint)(position / Constants.BlockSizeBytes);
var offset = (uint)(position % Constants.BlockSizeBytes);
var sparseWriter = new SparseWriter(DiskAccess);
var requiredNumberOfBlocks = SparseWriter.GetNumberOfBlocksRequired((uint)data.Length, offset);
var blocks = new List<Address>();
for (uint i = 0; i < requiredNumberOfBlocks; ++i)
{
blocks.Add(Storage.GetBlockStartAddress(startBlockIndex + i));
}
sparseWriter.WriteData(data, blocks.ToArray(), offset);
UpdateModifiedDate();
return newSize;
}