Add native Fletcher-16.

This commit is contained in:
2021-10-14 00:11:16 +01:00
parent 7dc57e77a0
commit 64a2c9f9fb
4 changed files with 101 additions and 48 deletions

View File

@@ -32,7 +32,9 @@
// Disabled because the speed is abnormally slow
using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;
@@ -315,20 +317,29 @@ namespace Aaru6.Checksums
{
const byte FLETCHER_MODULE = 0xFF;
const byte NMAX = 22;
readonly IntPtr _nativeContext;
byte _sum1, _sum2;
readonly bool _useNative;
/// <summary>Initializes the Fletcher-16 sums</summary>
public Fletcher16Context()
{
_sum1 = 0xFF;
_sum2 = 0xFF;
if(!Native.IsSupported)
return;
_nativeContext = fletcher16_init();
_useNative = _nativeContext != IntPtr.Zero;
}
/// <inheritdoc />
/// <summary>Updates the hash with data.</summary>
/// <param name="data">Data buffer.</param>
/// <param name="len">Length of buffer to hash.</param>
public void Update(byte[] data, uint len) => Step(ref _sum1, ref _sum2, data, len);
public void Update(byte[] data, uint len) => Step(ref _sum1, ref _sum2, data, len, _useNative, _nativeContext);
/// <inheritdoc />
/// <summary>Updates the hash with data.</summary>
@@ -341,6 +352,12 @@ namespace Aaru6.Checksums
{
ushort finalSum = (ushort)((_sum2 << 8) | _sum1);
if(!_useNative)
return BigEndianBitConverter.GetBytes(finalSum);
fletcher16_final(_nativeContext, ref finalSum);
fletcher16_free(_nativeContext);
return BigEndianBitConverter.GetBytes(finalSum);
}
@@ -349,6 +366,13 @@ namespace Aaru6.Checksums
public string End()
{
ushort finalSum = (ushort)((_sum2 << 8) | _sum1);
if(_useNative)
{
fletcher16_final(_nativeContext, ref finalSum);
fletcher16_free(_nativeContext);
}
var fletcherOutput = new StringBuilder();
for(int i = 0; i < BigEndianBitConverter.GetBytes(finalSum).Length; i++)
@@ -357,8 +381,28 @@ namespace Aaru6.Checksums
return fletcherOutput.ToString();
}
static void Step(ref byte previousSum1, ref byte previousSum2, byte[] data, uint len)
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern IntPtr fletcher16_init();
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern int fletcher16_update(IntPtr ctx, byte[] data, uint len);
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern int fletcher16_final(IntPtr ctx, ref ushort checksum);
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern void fletcher16_free(IntPtr ctx);
static void Step(ref byte previousSum1, ref byte previousSum2, byte[] data, uint len, bool useNative,
IntPtr nativeContext)
{
if(useNative)
{
fletcher16_update(nativeContext, data, len);
return;
}
uint sum1 = previousSum1;
uint sum2 = previousSum2;
uint n;
@@ -502,6 +546,17 @@ namespace Aaru6.Checksums
/// <param name="hash">Byte array of the hash value.</param>
public static string File(string filename, out byte[] hash)
{
bool useNative = Native.IsSupported;
IntPtr nativeContext = IntPtr.Zero;
if(useNative)
{
nativeContext = fletcher16_init();
if(nativeContext == IntPtr.Zero)
useNative = false;
}
var fileStream = new FileStream(filename, FileMode.Open);
byte localSum1 = 0xFF;
@@ -512,13 +567,19 @@ namespace Aaru6.Checksums
while(read > 0)
{
Step(ref localSum1, ref localSum2, buffer, (uint)read);
Step(ref localSum1, ref localSum2, buffer, (uint)read, useNative, nativeContext);
read = fileStream.Read(buffer, 0, 65536);
}
ushort finalSum = (ushort)((localSum2 << 8) | localSum1);
if(useNative)
{
fletcher16_final(nativeContext, ref finalSum);
fletcher16_free(nativeContext);
}
hash = BigEndianBitConverter.GetBytes(finalSum);
var fletcherOutput = new StringBuilder();
@@ -537,13 +598,30 @@ namespace Aaru6.Checksums
/// <param name="hash">Byte array of the hash value.</param>
public static string Data(byte[] data, uint len, out byte[] hash)
{
bool useNative = Native.IsSupported;
IntPtr nativeContext = IntPtr.Zero;
if(useNative)
{
nativeContext = fletcher16_init();
if(nativeContext == IntPtr.Zero)
useNative = false;
}
byte localSum1 = 0xFF;
byte localSum2 = 0xFF;
Step(ref localSum1, ref localSum2, data, len);
Step(ref localSum1, ref localSum2, data, len, useNative, nativeContext);
ushort finalSum = (ushort)((localSum2 << 8) | localSum1);
if(useNative)
{
fletcher16_final(nativeContext, ref finalSum);
fletcher16_free(nativeContext);
}
hash = BigEndianBitConverter.GetBytes(finalSum);
var adlerOutput = new StringBuilder();

View File

@@ -148,12 +148,12 @@ namespace AaruBenchmark.Checksums
IChecksum ctx = new CRC16CCITTContext();
ctx.Update(data);
byte[] result = ctx.Final();
/*
if(result?.Length != _expectedRandomCrc16Ccitt.Length)
throw new Exception("Invalid hash length");
if(result.Where((t, i) => t != _expectedRandomCrc16Ccitt[i]).Any())
throw new Exception("Invalid hash value");*/
throw new Exception("Invalid hash value");
}
public static void Crc16()

View File

@@ -77,6 +77,8 @@ namespace AaruBenchmark.Checksums
public static void Fletcher16()
{
Native.ForceManaged = true;
byte[] data = new byte[1048576];
var fs = new FileStream(Path.Combine(Program.Folder, "random"), FileMode.Open, FileAccess.Read);

View File

@@ -76,18 +76,6 @@ namespace AaruBenchmark.Checksums
0xb5, 0xf2, 0x8c, 0xbb, 0x4a, 0xa5, 0x1b, 0x40, 0x7c, 0xb6
};
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern IntPtr fletcher16_init();
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern int fletcher16_update(IntPtr ctx, byte[] data, uint len);
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern int fletcher16_final(IntPtr ctx, ref ushort crc);
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern void fletcher16_free(IntPtr ctx);
[DllImport("libAaru.Checksums.Native", SetLastError = true)]
static extern IntPtr fletcher32_init();
@@ -114,38 +102,23 @@ namespace AaruBenchmark.Checksums
public static void Fletcher16()
{
Native.ForceManaged = false;
byte[] data = new byte[1048576];
ushort fletcher16 = 0;
byte[] hash;
var fs = new FileStream(Path.Combine(Program.Folder, "random"), FileMode.Open, FileAccess.Read);
fs.Read(data, 0, 1048576);
fs.Close();
fs.Dispose();
IChecksum ctx = new Fletcher16Context();
ctx.Update(data);
byte[] result = ctx.Final();
IntPtr ctx = fletcher16_init();
if(result?.Length != _expectedRandomFletcher16.Length)
throw new Exception("Invalid hash length");
if(ctx == IntPtr.Zero)
throw new Exception("Could not initialize digest");
int ret = fletcher16_update(ctx, data, (uint)data.Length);
if(ret != 0)
throw new Exception("Could not digest block");
ret = fletcher16_final(ctx, ref fletcher16);
if(ret != 0)
throw new Exception("Could not finalize hash");
fletcher16_free(ctx);
fletcher16 = (ushort)((fletcher16 << 8) | (fletcher16 >> 8));
hash = BitConverter.GetBytes(fletcher16);
if(hash.Where((t, i) => t != _expectedRandomFletcher16[i]).Any())
if(result.Where((t, i) => t != _expectedRandomFletcher16[i]).Any())
throw new Exception("Invalid hash value");
}