Opc.Ua.Com.Server.ComDaGroup.UpdateCache C# (CSharp) Method

        private void UpdateCache(ComDaGroupItem item, DaValue value, bool isInitialRefresh)
        {
            lock (m_lock)
            {
                
                // get sampling rate.
                long now = HiResClock.UtcNow.Ticks;
                int samplingRate = item.ActualSamplingRate;

                if (item.SamplingRate == -1)
                {
                    samplingRate = m_actualUpdateRate;
                }

                // check existing cache contents.
                DaValue oldValue = null;
                DaCacheValue entry = null;

                if (item.CacheEntry != null)
                {
                    // do not update cache if a newer value exists.
                    if (item.CacheEntry.Timestamp >= value.Timestamp)
                    {
                        /*
                        TraceState(
                            "UpdateCache OLD VALUE RECEIVED", 
                            this.m_serverHandle, 
                            item.ServerHandle, 
                            new Variant(item.CacheEntry.Value),
                            item.CacheEntry.Timestamp.ToString("HH:mm:ss.fff"),
                            new Variant(value.Value),
                            value.Timestamp.ToString("HH:mm:ss.fff"));
                        */

                        return;
                    }

                    oldValue = item.CacheEntry;

                    // replace the newest value if sampling interval has not elasped.

                    if (!item.BufferEnabled || item.NextUpdateTime > now)
                    {
                        // TraceState("UpdateCache ENTRY REPLACED", this.m_serverHandle, item.ServerHandle, samplingRate);
                        entry = item.CacheEntry;
                    }
                }

                // create a new cache entry.
                if (entry == null)
                {
                    entry = new DaCacheValue();
                    entry.CacheTimestamp =  DateTime.UtcNow;

                    if (item.BufferEnabled)
                    {
                        entry.NextEntry = item.CacheEntry;
                        item.NextUpdateTime += samplingRate*TimeSpan.TicksPerMillisecond;

                        if (entry.NextEntry != null)
                        {
                            // TraceState("UpdateCache ENTRY BUFFERED", this.m_serverHandle, item.ServerHandle, samplingRate);
                        }
                    }

                    item.CacheEntry = entry;
                }

                // check if the value has changed.
                bool changed = !isInitialRefresh;

                if (oldValue != null)
                {
                    if (oldValue.Error == value.Error)
                    {
                        if (oldValue.Quality == value.Quality)
                        {
                            if (Utils.IsEqual(oldValue.Value, value.Value))
                            {
                                changed = false;
                            }
                        }
                    }
                }

                // save values.
                item.CacheEntry.Value = value.Value;
                item.CacheEntry.Quality = value.Quality;
                item.CacheEntry.Timestamp = value.Timestamp;
                item.CacheEntry.Error = value.Error;
                item.CacheEntry.Changed = changed;

                TraceState(
                    "UpdateCache COMPLETE",
                    this.m_serverHandle,
                    item.ServerHandle,
                    item.ClientHandle,
                    new Variant(value.Value),
                    value.Timestamp.ToString("HH:mm:ss.fff"),
                    item.CacheEntry.Changed);
            }
        }