public static string GetChecksum(this TypeDefinition type, TextualRepresentationOptions options)
{
uint lastHash = 0;
StringBuilder checksumBuilder = new StringBuilder(2 * ChecksumThreshold);
Action <string> appendAction = (s) =>
{
checksumBuilder.Append(s);
if (checksumBuilder.Length > ChecksumThreshold)
{
byte[] bytes = Encoding.ASCII.GetBytes(checksumBuilder.ToString());
lastHash = Crc32CAlgorithm.Append(lastHash, bytes);
checksumBuilder.Clear();
}
};
type.GetTextualRepresentation(appendAction, options);
// clear if something left in StringBuilder
if (checksumBuilder.Length > 0)
{
byte[] bytes = Encoding.ASCII.GetBytes(checksumBuilder.ToString());
lastHash = Crc32CAlgorithm.Append(lastHash, bytes);
checksumBuilder.Clear();
}
return(lastHash.ToString());
}
public void MethodConsistency(string text, int offset, int tail, int split)
{
var checksums = new List <uint>();
var array = Encoding.ASCII.GetBytes(text);
var padded = Enumerable.Repeat <byte>(17, offset).Concat(array).Concat(Enumerable.Repeat <byte>(93, tail)).ToArray();
var half1 = array.Take(split).ToArray();
var half2 = array.Skip(split).ToArray();
checksums.Add(Crc32CAlgorithm.Compute(array));
checksums.Add(Crc32CAlgorithm.Compute(padded, offset, array.Length));
checksums.Add(Crc32CAlgorithm.Append(0, array));
checksums.Add(Crc32CAlgorithm.Append(0, padded, offset, array.Length));
checksums.Add(Crc32CAlgorithm.Append(Crc32CAlgorithm.Append(0, half1), half2));
checksums.Add(Crc32CAlgorithm.Append(Crc32CAlgorithm.Append(0, padded, offset, split), padded, offset + split, array.Length - split));
using (var hash = new Crc32CAlgorithm())
checksums.Add(BitConverter.ToUInt32(hash.ComputeHash(array), 0));
using (var hash = new Crc32CAlgorithm())
checksums.Add(BitConverter.ToUInt32(hash.ComputeHash(padded, offset, array.Length), 0));
using (var stream = new MemoryStream(array))
using (var hash = new Crc32CAlgorithm())
checksums.Add(BitConverter.ToUInt32(hash.ComputeHash(stream), 0));
if (text.Length == 0)
{
Assert.AreEqual(0, checksums[0]);
}
foreach (var checksum in checksums)
{
Assert.AreEqual(checksums[0], checksum);
}
}
public static uint GetCrc32FromFile(string fileName)
{
try
{
using (FileStream file = new FileStream(fileName, FileMode.Open))
{
const int NumBytes = 10000;
var bytes = new byte[NumBytes];
var numRead = file.Read(bytes, 0, NumBytes);
if (numRead == 0)
{
return(0);
}
var crc = 0u;
while (numRead > 0)
{
Crc32CAlgorithm.Append(crc, bytes, 0, numRead);
numRead = file.Read(bytes, 0, NumBytes);
}
return(crc);
}
}
catch (Exception ex) when(ex is UnauthorizedAccessException || ex is IOException)
{
return(0);
}
}
/// <summary>
/// Write a single record.
/// </summary>
/// <param name="stream">Stream containing record in binary form</param>
public void Write(Stream stream)
{
ulong length = (ulong)stream.Length;
uint crcLength = Crc32CAlgorithm.Compute(BitConverter.GetBytes(length));
uint maskLength = MaskCrc32(crcLength);
_fileStream.Write(BitConverter.GetBytes(length), 0, 8); // uint64 length
_fileStream.Write(BitConverter.GetBytes(maskLength), 0, 4); // uint32 masked_crc32_of_length
stream.Seek(0, SeekOrigin.Begin); // Read from head
byte[] buffer = new byte[BufferSize];
int count = 0;
int readSize = stream.Read(buffer, 0, buffer.Length);
uint crcData = Crc32CAlgorithm.Compute(buffer, 0, readSize);
for (bool firstRun = true; readSize > 0;
count += readSize, readSize = stream.Read(buffer, 0, buffer.Length), firstRun = false)
{
if (!firstRun)
{
crcData = Crc32CAlgorithm.Append(crcData, buffer, 0, readSize);
}
_fileStream.Write(buffer, 0, readSize); // byte data[length]
}
if (count != (int)length)
{
throw new Exception("Stream length does not equal to read length.");
}
uint maskCrcData = MaskCrc32(crcData);
_fileStream.Write(BitConverter.GetBytes(maskCrcData), 0, 4); // uint32 masked_crc32_of_data
}
public void ResultConsistency(string text, int offset)
{
var bytes = Encoding.ASCII.GetBytes(text);
var crc1 = Crc32CAlgorithm.Append(123456789, bytes, offset, bytes.Length - offset);
CoreSwitchHelper.SetCoreAlgType("Crc32C.SafeProxy");
var crc2 = Crc32CAlgorithm.Append(123456789, bytes, offset, bytes.Length - offset);
Assert.That(crc2, Is.EqualTo(crc1));
}
public void ResultConsistencyLong()
{
var bytes = new byte[30000];
new Random().NextBytes(bytes);
var crc1 = Crc32CAlgorithm.Append(123456789, bytes, 0, bytes.Length);
CoreSwitchHelper.SetCoreAlgType("Crc32C.SafeProxy");
var crc2 = Crc32CAlgorithm.Append(123456789, bytes, 0, bytes.Length);
Assert.That(crc2, Is.EqualTo(crc1));
}
public static uint Append(BytesView bv, uint initial)
{
uint crc = initial;
while (bv != null)
{
if (bv.len > 0)
{
crc = Crc32CAlgorithm.Append(crc, bv.bytes, bv.offset, bv.len);
}
bv = bv.nextNode;
}
return(crc);
}
public void Exceptions()
{
Assert.Throws <ArgumentNullException>(() => Crc32CAlgorithm.Compute(null));
Assert.Throws <ArgumentNullException>(() => Crc32CAlgorithm.Compute(null, 0, 0));
Assert.Throws <ArgumentNullException>(() => Crc32CAlgorithm.Append(0, null));
Assert.Throws <ArgumentNullException>(() => Crc32CAlgorithm.Append(0, null, 0, 0));
var buffer = new byte[10];
Assert.Throws <ArgumentOutOfRangeException>(() => Crc32CAlgorithm.Compute(buffer, -1, 5));
Assert.Throws <ArgumentOutOfRangeException>(() => Crc32CAlgorithm.Compute(buffer, 0, -1));
Assert.Throws <ArgumentOutOfRangeException>(() => Crc32CAlgorithm.Compute(buffer, 5, 6));
Assert.Throws <ArgumentOutOfRangeException>(() => Crc32CAlgorithm.Append(0, buffer, -1, 5));
Assert.Throws <ArgumentOutOfRangeException>(() => Crc32CAlgorithm.Append(0, buffer, 0, -1));
Assert.Throws <ArgumentOutOfRangeException>(() => Crc32CAlgorithm.Append(0, buffer, 5, 6));
}
internal bool VerifyChecksum()
{
uint crc = 0;
using (Stream source = GetStream())
{
byte[] buffer = new byte[PPeXCore.Settings.BufferSize];
int length = 0;
while ((length = source.Read(buffer, 0, (int)PPeXCore.Settings.BufferSize)) > 0)
{
crc = Crc32CAlgorithm.Append(crc, buffer, 0, length);
}
}
return(crc == Crc);
}
private void CalculateCrc32(PhotoModel item)
{
var crc = Crc32CAlgorithm.Compute(Encoding.Default.GetBytes(item.LocalPath.ToLowerInvariant()));
var buffer = new byte[8096];
using (var stream = File.OpenRead(item.LocalPath))
{
while (true)
{
var read = stream.Read(buffer, 0, 8096);
crc = Crc32CAlgorithm.Append(crc, buffer, 0, read);
if (read < 8096)
{
item.Crc32 = crc.ToString();
return;
}
}
}
}
public uint Process()
{
if (Complete)
{
throw new InvalidOperationException($"{typeof(T)} has already been mapped.");
}
uint crc32C = 0;
stopwatch.Start();
foreach (T result in Map())
{
crc32C = Crc32CAlgorithm.Append(crc32C, Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
results.Add(result);
}
stopwatch.Stop();
Complete = true;
return(crc32C);
}
public void Throughput()
{
var data = new byte[65536];
var random = new Random();
random.NextBytes(data);
long total = 0;
var stopwatch = new Stopwatch();
uint crc = 0;
stopwatch.Start();
while (stopwatch.Elapsed < TimeSpan.FromSeconds(3))
{
var length = random.Next(data.Length + 1);
var offset = random.Next(data.Length - length);
crc = Crc32CAlgorithm.Append(crc, data, offset, length);
total += length;
}
stopwatch.Stop();
Console.WriteLine("Throughput: {0:0.0} GB/s", total / stopwatch.Elapsed.TotalSeconds / 1024 / 1024 / 1024);
}
public static uint Append(byte[] bytes, uint initial)
{
return(Crc32CAlgorithm.Append(initial, bytes));
}