internal static LogRowData CreateData(Stream stream, LogRowIndex index)
{
byte[] buffer = new byte[index.RowLength + 2];
char[] chars = new char[index.RowLength];
if (stream.Position != index.RowStart)
{
stream.Seek(index.RowStart, SeekOrigin.Begin);
}
stream.Read(buffer, 0, index.RowLength);
int length = buffer.IndexOf((byte)'\r', 0);
if (length == -1)
{
length = buffer.IndexOf((byte)'\n', 0);
}
for (int i = 0; i < length; i++)
{
chars[i] = (char)buffer[i];
}
index.GetValues(out int timeStampIndex, out int nameIndex, out int userIndex, out int cycleIndex, out int valueIndex);
var itemId = new string(chars, nameIndex, index.NameLength);
var timeStamp = LogRowDataFactory.ParseDate(chars, 0, LogRowIndex.TimeStampLength);
var user = new string(chars, userIndex, index.UserLength);
var cycleIndexValue = long.Parse(new string(chars, cycleIndex, index.CycleLength), NumberStyles.None);
var value = new string(chars, valueIndex, length - valueIndex);
return(new LogRowData(timeStamp, itemId, user, cycleIndexValue, value));
}
public IEnumerable <LogRowDataPoint> GetDataPoints(IEnumerable <LogRowIndex> indexes)
{
foreach (LogRowIndex logRowIndex in indexes)
{
if (!m_DataPointCache.TryGetValue(logRowIndex.RowStart, out var reference))
{
LogRowDataPoint point = LogRowDataFactory.CreateDataPoint(m_PagedReader, logRowIndex);
reference = new WeakReference(point);
m_DataPointCache.Add(logRowIndex.RowStart, reference);
}
LogRowDataPoint dataPoint = reference.Target as LogRowDataPoint;
//Reload data point
if (dataPoint == null)
{
dataPoint = LogRowDataFactory.CreateDataPoint(m_PagedReader, logRowIndex);
reference.Target = dataPoint;
}
yield return(dataPoint);
}
}
public IEnumerable <LogRowData> GetData(IEnumerable <LogRowIndex> indexes)
{
foreach (LogRowIndex logRowIndex in indexes)
{
WeakReference reference;
if (!m_DataCache.TryGetValue(logRowIndex.RowStart, out reference))
{
reference = new WeakReference(null);
m_DataCache.Add(logRowIndex.RowStart, reference);
}
LogRowData data = reference.Target as LogRowData;
//Reload data point
if (data == null)
{
data = LogRowDataFactory.CreateData(m_Stream, logRowIndex);
reference.Target = data;
}
yield return(data);
}
}
private void OnQueuedReadThreadExecute()
{
try
{
Trace.TraceInformation("QueuedReadThread started: {0}", m_DatabaseInstanceID);
using (var stream = new BufferedStream(new FileStream(m_Filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, 4096, FileOptions.RandomAccess), 1024 * 1024))
{
//int handle;
WaitHandle[] handles = new WaitHandle[] { m_Quit, m_Event };
var pagedReader = new PagedStreamReader(stream, 4096);
while (WaitHandle.WaitAny(handles) == 1) // (handle = WaitHandle.WaitAny(handles)) == 0)
{
Thread.Sleep(200); //Wait to consolidate if more requests are coming in.
QueuedReadRequest[] requests = null;
lock (m_SyncObject)
{
if (m_Queue.Count > 0)
{
requests = m_Queue.ToArray();
m_Queue.Clear();
}
else
{
m_Event.Reset();
}
}
if (requests == null)
{
continue;
}
LinkedList <LogRowIndex> indicesList = new LinkedList <LogRowIndex>();
Dictionary <LogRowIndex, List <RequestPoints> > indexToRequestPoints = new Dictionary <LogRowIndex, List <RequestPoints> >();
foreach (var readRequest in requests)
{
var indices = m_Indexes.GetItemRows(readRequest.ItemID, readRequest.StartIndex, readRequest.Count);
var requestPoints = new RequestPoints(readRequest);
foreach (var logRowIndex in indices)
{
if (!indexToRequestPoints.TryGetValue(logRowIndex, out var list))
{
list = new List <RequestPoints>();
indexToRequestPoints.Add(logRowIndex, list);
}
list.Add(requestPoints);
}
indicesList.AddSorted(indices);
}
foreach (var logRowIndex in indicesList)
{
var point = LogRowDataFactory.CreateDataPoint(pagedReader, logRowIndex);
var list = indexToRequestPoints[logRowIndex];
foreach (var rp in list)
{
if (rp.Add(point))
{
rp.Send(m_DatabaseInstanceID);
}
}
}
foreach (var index in indexToRequestPoints)
{
index.Value.ForEach(points => points.Send(m_DatabaseInstanceID));
}
}
}
Trace.TraceInformation("QueuedReadThread ended: {0}", m_DatabaseInstanceID);
}
catch (Exception ex)
{
m_Log.Fatal(ex.Message, ex);
throw;
}
}
