Synnefo » Pithos MS Client

using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

using System.Threading;

using System.Threading.Tasks;

using System.Threading.Tasks.Dataflow;

namespace Pithos.Network

{

    class MD5BlockCalculator:IDisposable

    {

        private HashAlgorithm _hasher = HashAlgorithm.Create("md5");

        private ActionBlock<Tuple<long, byte[],int>>  _actionBlock;

        private long _currentBlock = 0;

        public MD5BlockCalculator()

        {

            _actionBlock=new ActionBlock<Tuple<long, byte[],int>>(t=> ProcessBlock(t));

        }

        private void ProcessBlock(Tuple<long,byte[],int> tuple)

        {

            if (tuple.Item1 == _currentBlock)

            {

                _hasher.TransformBlock(tuple.Item2, 0, tuple.Item3, null, 0);

                Interlocked.Increment(ref _currentBlock);

            }

            else

            {

                _actionBlock.Post(tuple);

            }

        }

        public void PostBlock(long blockIndex,byte[] buffer,int size)

        {

            _actionBlock.Post(Tuple.Create(blockIndex, buffer, size));

        }

        public async Task<string> GetHash()

        {

            _actionBlock.Complete();

            await _actionBlock.Completion;

            Debug.Assert(_actionBlock.InputCount == 0);

            _hasher.TransformFinalBlock(new byte[0], 0, 0);

            var hash=_hasher.Hash.ToHashString();

            return hash;

        }

        public void Dispose()

        {

            Dispose(true);

            GC.SuppressFinalize(this);

        }

        protected virtual void Dispose(bool disposing)

        {

            if (disposing && _hasher!=null)

                _hasher.Dispose();

            _hasher = null;            

        }

    }

}