UA-.NETStandard/SampleApplications/Samples/Opc.Ua.Sample/TestData/HistoryArchive.cs

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 *
 * OPC Foundation MIT License 1.00
 * 
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 * obtaining a copy of this software and associated documentation
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using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Xml;
using System.IO;
using Opc.Ua;

namespace TestData
{
    /// <summary>
    /// A class that provides access to archived data.
    /// </summary>
    internal class HistoryArchive : IDisposable
    {
        #region IDisposable Members
        /// <summary>
        /// Frees any unmanaged resources.
        /// </summary>
        public void Dispose()
        {
            Dispose(true);
        }

        /// <summary>
        /// An overrideable version of the Dispose.
        /// </summary>
        protected virtual void Dispose(bool disposing)
        {  
            if (disposing)
            {
                if (m_updateTimer != null)
                {
                    m_updateTimer.Dispose();
                    m_updateTimer = null;
                }
            }
        }
        #endregion
        
        #region Public Interface
        /// <summary>
        /// Returns an object that can be used to browse the archive.
        /// </summary>
        public HistoryFile GetHistoryFile(NodeId nodeId)
        {
            lock (m_lock)
            {
                if (m_records == null)
                {
                    return null;
                }

                HistoryRecord record = null;

                if (!m_records.TryGetValue(nodeId, out record))
                {
                    return null;
                }
                
                return new HistoryFile(m_lock, record.RawData);
            }
        }

        /// <summary>
        /// Creates a new record in the archive.
        /// </summary>
        public void CreateRecord(NodeId nodeId, BuiltInType dataType)
        {
            lock (m_lock)
            {
                HistoryRecord record = new HistoryRecord();
                
                record.RawData = new List<HistoryEntry>();
                record.Historizing = true;
                record.DataType = dataType;

                DateTime now = DateTime.UtcNow;

                for (int ii = 1000; ii >= 0; ii--)
                {
                    HistoryEntry entry = new HistoryEntry();

                    entry.Value = new DataValue();
                    entry.Value.ServerTimestamp = now.AddSeconds(-(ii*10));
                    entry.Value.SourceTimestamp = entry.Value.ServerTimestamp.AddMilliseconds(1234);
                    entry.IsModified = false;

                    switch (dataType)
                    {
                        case BuiltInType.Int32:
                        {
                            entry.Value.Value = ii;
                            break;
                        }
                    }

                    record.RawData.Add(entry);
                }

                if (m_records == null)
                {
                    m_records = new Dictionary<NodeId,HistoryRecord>();
                }

                m_records[nodeId] = record;

                if (m_updateTimer == null)
                {
                    m_updateTimer = new Timer(OnUpdate, null, 10000, 10000);
                }
            }
        }        
        #endregion
        
        #region Private Methods
        /// <summary>
        /// Periodically adds new values into the archive.
        /// </summary>
        private void OnUpdate(object state)
        {
            try
            {
                DateTime now = DateTime.UtcNow;

                lock (m_lock)
                {
                    foreach (HistoryRecord record in m_records.Values)
                    {
                        if (!record.Historizing || record.RawData.Count >= 2000)
                        {
                            continue;
                        }
                            
                        HistoryEntry entry = new HistoryEntry();

                        entry.Value = new DataValue();
                        entry.Value.ServerTimestamp = now;
                        entry.Value.SourceTimestamp = entry.Value.ServerTimestamp.AddMilliseconds(-4567);
                        entry.IsModified = false;

                        switch (record.DataType)
                        {
                            case BuiltInType.Int32:
                            {
                                int lastValue = (int)record.RawData[record.RawData.Count-1].Value.Value;
                                entry.Value.Value = lastValue+1;
                                break;
                            }
                        }

                        record.RawData.Add(entry);
                    }
                }
            }
            catch (Exception e)
            {
                Utils.Trace(e, "Unexpected error updating history.");
            }
        }
        #endregion

        #region Private Fields
        private object m_lock = new object();
        private Timer m_updateTimer;
        private Dictionary<NodeId,HistoryRecord> m_records;
        #endregion
    }
        
    #region HistoryEntry Class
    /// <summary>
    /// A single entry in the archive.
    /// </summary>
    internal class HistoryEntry
    {
        public DataValue Value;
        public bool IsModified;
    }
    #endregion
    
    #region HistoryRecord Class
    /// <summary>
    /// A record in the archive.
    /// </summary>
    internal class HistoryRecord
    {
        public List<HistoryEntry> RawData;
        public bool Historizing;
        public BuiltInType DataType;
    }
    #endregion
}