//******************************************************************************************************//  PIConnection.cs - Gbtc////  Copyright © 2010, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may//  not use this file except in compliance with the License. You may obtain a copy of the License at:////      http://www.opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  06/17/2014 - J. Ritchie Carroll//       Generated original version of source code.//  12/17/2014 - J. Ritchie Carroll//       Updated to use AF-SDK////****************************************************************************************************** using System;using System.Collections.Generic;using System.Net;using OSIsoft.AF.PI; namespace PIAdapters{    /// <summary>    /// Represents a connection to a PI server that handles open, close and executes operations.    /// </summary>    // ReSharper disable SuspiciousTypeConversion.Global    public class PIConnection : IComparable<PIConnection>, IComparable, IDisposable    {        #region [ Members ]         // Constants         /// <summary>        /// Default value for <see cref="ConnectTimeout"/>.        /// </summary>        public const int DefaultConnectTimeout = 30000;         // Events         /// <summary>        /// Raised when <see cref="PIConnection"/> has been disconnected from server.        /// </summary>        public event EventHandler Disconnected;         private volatile bool m_connected;                          // Flag that determines connectivity        private readonly Guid m_instanceID;                         // Unique instance ID for this connection        private bool m_disposed;         // Connection pool access count        internal volatile int AccessCount;         #endregion         #region [ Constructors ]         /// <summary>        /// Creates a new OSI-PI connection.        /// </summary>        public PIConnection()        {            ConnectTimeout = DefaultConnectTimeout;            m_instanceID = Guid.NewGuid();        }         #endregion         #region [ Properties ]         /// <summary>        /// Gets PI server object for this PI connection.        /// </summary>        public PIServer Server { get; private set; }         /// <summary>        /// Gets or sets the name of the PI server for the adapter's PI connection.        /// </summary>        public string ServerName { get; set; }         /// <summary>        /// Gets or sets the name of the PI user ID for the adapter's PI connection.        /// </summary>        public string UserName { get; set; }         /// <summary>        /// Gets or sets the password used for the adapter's PI connection.        /// </summary>        public string Password { get; set; }         /// <summary>        /// Gets or sets the timeout interval (in milliseconds) for the adapter's connection.        /// </summary>        public int ConnectTimeout { get; set; }         /// <summary>        /// Gets flag that determines if <see cref="PIConnection"/> is currently connected to <see cref="ServerName"/>.        /// </summary>        public bool Connected => m_connected;         #endregion         #region [ Methods ]         /// <summary>        /// Releases all the resources used by the <see cref="PIConnection"/> object.        /// </summary>        public void Dispose()        {            Dispose(true);            GC.SuppressFinalize(this);   // In case any future subclass has a finalizer        }         /// <summary>        /// Releases the unmanaged resources used by the <see cref="PIConnection"/> object and optionally releases the managed resources.        /// </summary>        /// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.</param>        protected virtual void Dispose(bool disposing)        {            if (m_disposed)                return;             try            {                Close();            }            finally            {                m_disposed = true;  // Prevent duplicate dispose.            }        }         /// <summary>        /// Attempts to open <see cref="PIConnection"/>.        /// </summary>        public void Open()        {            if (m_connected || (Server is not null && Server.ConnectionInfo.IsConnected))                throw new InvalidOperationException("OSI-PI server connection is already open.");             if (string.IsNullOrWhiteSpace(ServerName))                throw new InvalidOperationException("Cannot open OSI-PI server connection without a defined server name.");             m_connected = false;             try            {                // Locate configured PI server                PIServers servers = new();                Server = servers[ServerName];                 if (Server is null)                    throw new InvalidOperationException("Server not found in the PI servers collection.");                 Server.ConnectChanged += PIConnection_ConnectChanged;            }            catch (Exception ex)            {                throw new InvalidOperationException(string.Format("Failed to connect to PI server \"{0}\": {1}", ServerName, ex.Message));            }             if (!Server.ConnectionInfo.IsConnected)            {                // Attempt to open OSI-PI connection                if (!string.IsNullOrEmpty(UserName) && !string.IsNullOrEmpty(Password))                    Server.Connect(new NetworkCredential(UserName, Password));                else                    Server.Connect(true);            }             m_connected = true;        }         /// <summary>        /// Closes <see cref="PIConnection"/>.        /// </summary>        public void Close()        {            m_connected = false;             // Attempt to close OSI-PI connection            if (Server is not null)            {                if (Server.ConnectionInfo.IsConnected)                    Server.Disconnect();                 // Detach from server disconnected event                Server.ConnectChanged -= PIConnection_ConnectChanged;            }        }         private void PIConnection_ConnectChanged(object sender, EventArgs e)        {            if (Server is null || !m_connected)                return;             Disconnected?.Invoke(this, EventArgs.Empty);             Close();        }         /// <summary>        /// Compares the current object with another object of the same type.        /// </summary>        /// <returns>        /// A value that indicates the relative order of the objects being compared. The return value has the following meanings:         /// Value Meaning Less than zero This object is less than the <paramref name="other"/> parameter.        /// Zero This object is equal to <paramref name="other"/>.        /// Greater than zero This object is greater than <paramref name="other"/>.         /// </returns>        /// <param name="other">An object to compare with this object.</param>        public int CompareTo(PIConnection other)        {            if (other is null)                return 1;             return Comparer<Guid>.Default.Compare(m_instanceID, other.m_instanceID);        }         int IComparable.CompareTo(object obj)        {            PIConnection other = obj as PIConnection;             if (other is not null)                return CompareTo(other);             throw new ArgumentException();        }         #endregion    }}