Add ModbusDevice as preparation for server implementations.

AMWD.Protocols.Modbus.Common/Models/ModbusDevice.cs

@@ -0,0 +1,220 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+
+namespace AMWD.Protocols.Modbus.Common.Models
+{
+	/// <summary>
+	/// Represents a Modbus device used in a Modbus server implementation.
+	/// </summary>
+	/// <remarks>
+	/// Initializes a new instance of the <see cref="ModbusDevice"/> class.
+	/// </remarks>
+	/// <param name="id">The <see cref="ModbusDevice"/> ID.</param>
+	public class ModbusDevice(byte id) : IDisposable
+	{
+		private readonly ReaderWriterLockSlim _rwLockCoils = new();
+		private readonly ReaderWriterLockSlim _rwLockDiscreteInputs = new();
+		private readonly ReaderWriterLockSlim _rwLockHoldingRegisters = new();
+		private readonly ReaderWriterLockSlim _rwLockInputRegisters = new();
+
+		private readonly HashSet<ushort> _coils = [];
+		private readonly HashSet<ushort> _discreteInputs = [];
+		private readonly Dictionary<ushort, ushort> _holdingRegisters = [];
+		private readonly Dictionary<ushort, ushort> _inputRegisters = [];
+
+		private bool _isDisposed;
+
+		/// <summary>
+		/// Gets the ID of the <see cref="ModbusDevice"/>.
+		/// </summary>
+		public byte Id { get; } = id;
+
+		/// <summary>
+		/// Releases the unmanaged resources used by the <see cref="ModbusDevice"/>
+		/// and optionally also discards the managed resources.
+		/// </summary>
+		public void Dispose()
+		{
+			if (_isDisposed)
+				return;
+
+			_isDisposed = true;
+
+			_rwLockCoils.Dispose();
+			_rwLockDiscreteInputs.Dispose();
+			_rwLockHoldingRegisters.Dispose();
+			_rwLockInputRegisters.Dispose();
+
+			_coils.Clear();
+			_discreteInputs.Clear();
+			_holdingRegisters.Clear();
+			_inputRegisters.Clear();
+		}
+
+		/// <summary>
+		/// Gets a <see cref="Coil"/> from the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="address">The address of the <see cref="Coil"/>.</param>
+		public Coil GetCoil(ushort address)
+		{
+			Assertions();
+			using (_rwLockCoils.GetReadLock())
+			{
+				return new Coil
+				{
+					Address = address,
+					HighByte = (byte)(_coils.Contains(address) ? 0xFF : 0x00)
+				};
+			}
+		}
+
+		/// <summary>
+		/// Sets a <see cref="Coil"/> to the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="coil">The <see cref="Coil"/> to set.</param>
+		public void SetCoil(Coil coil)
+		{
+			Assertions();
+			using (_rwLockCoils.GetWriteLock())
+			{
+				if (coil.Value)
+					_coils.Add(coil.Address);
+				else
+					_coils.Remove(coil.Address);
+			}
+		}
+
+		/// <summary>
+		/// Gets a <see cref="DiscreteInput"/> from the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="address">The address of the <see cref="DiscreteInput"/>.</param>
+		public DiscreteInput GetDiscreteInput(ushort address)
+		{
+			Assertions();
+			using (_rwLockDiscreteInputs.GetReadLock())
+			{
+				return new DiscreteInput
+				{
+					Address = address,
+					HighByte = (byte)(_discreteInputs.Contains(address) ? 0xFF : 0x00)
+				};
+			}
+		}
+
+		/// <summary>
+		/// Sets a <see cref="DiscreteInput"/> to the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="input">The <see cref="DiscreteInput"/> to set.</param>
+		public void SetDiscreteInput(DiscreteInput input)
+		{
+			using (_rwLockDiscreteInputs.GetWriteLock())
+			{
+				if (input.Value)
+					_discreteInputs.Add(input.Address);
+				else
+					_discreteInputs.Remove(input.Address);
+			}
+		}
+
+		/// <summary>
+		/// Gets a <see cref="HoldingRegister"/> from the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="address">The address of the <see cref="HoldingRegister"/>.</param>
+		public HoldingRegister GetHoldingRegister(ushort address)
+		{
+			Assertions();
+			using (_rwLockHoldingRegisters.GetReadLock())
+			{
+				if (!_holdingRegisters.TryGetValue(address, out ushort value))
+					value = 0x0000;
+
+				byte[] blob = BitConverter.GetBytes(value);
+				blob.SwapNetworkOrder();
+
+				return new HoldingRegister
+				{
+					Address = address,
+					HighByte = blob[0],
+					LowByte = blob[1]
+				};
+			}
+		}
+
+		/// <summary>
+		/// Sets a <see cref="HoldingRegister"/> to the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="register">The <see cref="HoldingRegister"/> to set.</param>
+		public void SetHoldingRegister(HoldingRegister register)
+		{
+			Assertions();
+			using (_rwLockHoldingRegisters.GetWriteLock())
+			{
+				if (register.Value == 0)
+				{
+					_holdingRegisters.Remove(register.Address);
+					return;
+				}
+
+				byte[] blob = [register.HighByte, register.LowByte];
+				blob.SwapNetworkOrder();
+				_holdingRegisters[register.Address] = BitConverter.ToUInt16(blob, 0);
+			}
+		}
+
+		/// <summary>
+		/// Gets a <see cref="InputRegister"/> from the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="address">The address of the <see cref="InputRegister"/>.</param>
+		public InputRegister GetInputRegister(ushort address)
+		{
+			Assertions();
+			using (_rwLockInputRegisters.GetReadLock())
+			{
+				if (!_inputRegisters.TryGetValue(address, out ushort value))
+					value = 0x0000;
+
+				byte[] blob = BitConverter.GetBytes(value);
+				blob.SwapNetworkOrder();
+
+				return new InputRegister
+				{
+					Address = address,
+					HighByte = blob[0],
+					LowByte = blob[1]
+				};
+			}
+		}
+
+		/// <summary>
+		/// Sets a <see cref="InputRegister"/> to the <see cref="ModbusDevice"/>.
+		/// </summary>
+		/// <param name="register">The <see cref="InputRegister"/> to set.</param>
+		public void SetInputRegister(InputRegister register)
+		{
+			Assertions();
+			using (_rwLockInputRegisters.GetWriteLock())
+			{
+				if (register.Value == 0)
+				{
+					_inputRegisters.Remove(register.Address);
+					return;
+				}
+
+				byte[] blob = [register.HighByte, register.LowByte];
+				blob.SwapNetworkOrder();
+				_inputRegisters[register.Address] = BitConverter.ToUInt16(blob, 0);
+			}
+		}
+
+		private void Assertions()
+		{
+#if NET8_0_OR_GREATER
+			ObjectDisposedException.ThrowIf(_isDisposed, this);
+#else
+			if (_isDisposed)
+				throw new ObjectDisposedException(GetType().FullName);
+#endif
+		}
+	}
+}