Tests/MathCore.Tests/IO/HashStream.cs - dev - shmachilin/MathCore

Tests/MathCore.Tests/IO/HashStream.cs

79 строк2 KB

Infarh

0.0.85 - Добавлены методы-расширения для Task - OnSuccess,OnCancelled,OnFailure

12 дек 2022, 14:29

12 дек 2022, 14:2934322a7

using System.Security.Cryptography;

namespace MathCore.Tests.IO;

public class HashStream : Stream
{
    protected readonly Stream _Source;
    protected readonly HashAlgorithm _Hasher;

    public byte[] Hash => _Hasher.Hash;

    public override bool CanRead => _Source.CanRead;

    public override bool CanSeek => _Source.CanSeek;

    public override bool CanWrite => _Source.CanWrite;

    public override long Length => _Source.Length;

    public override long Position
    {
        get => _Source.Position;
        set => _Source.Position = value;
    }

    public HashStream(Stream Source, HashAlgorithm Hasher)
    {
        _Source = Source;
        Hasher.Initialize();
        _Hasher = Hasher;
    }

    public override long Seek(long offset, SeekOrigin origin) => _Source.Seek(offset, origin);

    public override void SetLength(long value) => _Source.SetLength(value);

    public override int Read(byte[] buffer, int offset, int count)
    {
        var ret = _Source.Read(buffer, offset, count);
        _Hasher.TransformBlock(buffer, offset, ret, buffer, offset);
        return ret;
    }

    public override void Write(byte[] buffer, int offset, int count)
    {
        _Source.Write(buffer, offset, count);
        _Hasher.TransformBlock(buffer, offset, count, buffer, offset);
    }

    public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken Cancel)
    {
        var readed = await _Source.ReadAsync(buffer, offset, count, Cancel);
        if(readed > 0)
            _Hasher.TransformBlock(buffer, offset, readed, buffer, offset);
        return readed;
    }

    public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken Cancel)
    {
        Cancel.ThrowIfCancellationRequested();
        var write_task = _Source.WriteAsync(buffer, offset, count, Cancel);
        _Hasher.TransformBlock(buffer, offset, count, buffer, offset);
        await write_task.ConfigureAwait(false);
    }

    #region Overrides of Stream

    public override async Task CopyToAsync(Stream destination, int BufferSize, CancellationToken Cancel)
    {
        await base.CopyToAsync(destination, BufferSize, Cancel);
    }

    #endregion

    public override void Flush()
    {
        _Source.Flush();
    }
}