MemoryMappedStream.cs

MemoryMappedStream.cs

public class MemoryMappedStream : IDisposable
    {
        private bool disposedValue;

        private readonly MemoryMappedFile _memoryMappedFile;

        private MemoryMappedViewAccessor MemoryMappedViewAccessor { get; set; }

        public bool IsMemoryNew
        {
            get
            {
                return _isMemoryNew;
            }
        }

        private readonly bool _isMemoryNew;

        private readonly byte[] _buffer;

        public MemoryMappedStream(string memoryName, object data)
        {
            this._buffer = this.ObjectToByteArray(data);
            try
            {
                this._memoryMappedFile = MemoryMappedFile.OpenExisting(memoryName);
                this._isMemoryNew = false;
            }
            catch
            {
                this._memoryMappedFile = MemoryMappedFile.CreateNew(memoryName, this._buffer.Length);
                this._isMemoryNew = true;
                this.WriteObjectToMemoryMappedStream();
            }
        }

        public object ReadObjectFromMemoryMappedStream()
        {
            if (this._isMemoryNew)
            {
                return null;
            }
            this.MemoryMappedViewAccessor = this._memoryMappedFile.CreateViewAccessor();
            byte[] buffer = new byte[this.MemoryMappedViewAccessor.Capacity];
            this.MemoryMappedViewAccessor.ReadArray<byte>(0, buffer, 0, buffer.Length);
            return this.ByteArrayToObject(buffer);
        }

        public void WriteObjectToMemoryMappedStream()
        {
            this.MemoryMappedViewAccessor = this._memoryMappedFile.CreateViewAccessor(0, this._buffer.Length);
            this.MemoryMappedViewAccessor.WriteArray<byte>(0, this._buffer, 0, this._buffer.Length);
        }

        private object ByteArrayToObject(byte[] buffer)
        {
            BinaryFormatter binaryFormatter = new BinaryFormatter();
            using (MemoryStream memoryStream = new MemoryStream(buffer))
            {
                return binaryFormatter.Deserialize(memoryStream);
            }
        }

        private byte[] ObjectToByteArray(object inputObject)
        {
            BinaryFormatter binaryFormatter = new BinaryFormatter();
            using (MemoryStream memoryStream = new MemoryStream())
            {
                binaryFormatter.Serialize(memoryStream, inputObject);
                return memoryStream.ToArray();
            }
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                if (disposing)
                {
                    if(null != this.MemoryMappedViewAccessor)
                    {
                        this.MemoryMappedViewAccessor.Dispose();
                    }
                    if(null != this._memoryMappedFile)
                    {
                        this._memoryMappedFile.Dispose();
                    }
                }

                // TODO: free unmanaged resources (unmanaged objects) and override finalizer
                // TODO: set large fields to null
                disposedValue = true;
            }
        }

        // // TODO: override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
        ~MemoryMappedStream()
        {
            // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
            Dispose(disposing: false);
        }

        public void Dispose()
        {
            // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
            Dispose(disposing: true);
            GC.SuppressFinalize(this);
        }
    }