public override int ReadSamples(double[] buffer, int count)
{
if (BufferingTask.Status == TaskStatus.Created)
{
BufferingTask.Start();
}
var targetRange = new IntRange(SamplePosition, Math.Min(SamplePosition + count, SampleCount - 1));
while (!Disposed)
{
var exists = false;
lock (BufferedRange)
{
exists = BufferedRange.Exists((r) => r.IsInclude(targetRange));
}
if (exists)
{
break;
}
else
{
if (Stream.SamplePosition > SamplePosition || Stream.SamplePosition + BufferingSampleCount < SamplePosition)
{
lock (Stream)
{
Stream.SamplePosition = SamplePosition;
}
}
Thread.Sleep(10);
}
}
var copyCount = Math.Min(count, SampleCount - SamplePosition);
Buffer.BlockCopy(Samples, SamplePosition * sizeof(double), buffer, 0, copyCount * sizeof(double));
Position += copyCount * sizeof(double);
return(copyCount);
}
public WaveCacheStream(WaveDataStream stream)
{
Stream = stream;
Samples = new double[stream.SampleCount];
BufferingTaskCancellationToken = new CancellationTokenSource();
var token = BufferingTaskCancellationToken.Token;
BufferingTask = new Task(() =>
{
var totalRange = new IntRange(0, Samples.Length - 1);
while (!BufferedRange.Any(r => r.IsInclude(totalRange)))
{
if (token.IsCancellationRequested)
{
token.ThrowIfCancellationRequested();
}
var currentSamplePosition = 0;
var nextSamplePosition = 0;
var sampleCount = 0;
var buffer = new double[BufferingSampleCount];
lock (Stream)
{
currentSamplePosition = Stream.SamplePosition;
var alreadyProcessedRange = BufferedRange.Find(r => r.IsInclude(currentSamplePosition));
if (alreadyProcessedRange != null)
{
Stream.SamplePosition = alreadyProcessedRange.End;
continue;
}
sampleCount = Stream.ReadSamples(buffer, BufferingSampleCount);
nextSamplePosition = Stream.SamplePosition;
}
if (sampleCount == 0 || Samples.Length <= currentSamplePosition)
{
Stream.SamplePosition = 0;
continue;
}
var copyCount = Math.Min(sampleCount, Samples.Length - currentSamplePosition);
Buffer.BlockCopy(buffer, 0, Samples, currentSamplePosition * sizeof(double), copyCount * sizeof(double));
var processedRange = new IntRange(currentSamplePosition, nextSamplePosition);
var nearRange = BufferedRange.Where((r) => r.IsInclude(currentSamplePosition) || r.IsInclude(nextSamplePosition) || r.End == currentSamplePosition).ToArray();
lock (BufferedRange)
{
if (nearRange.Length > 0)
{
var newRange = nearRange.Aggregate(processedRange, (r, m) => m.Union(r));
BufferedRange.Add(newRange);
BufferedRange.RemoveAll(r => nearRange.Any(br => ReferenceEquals(br, r)));
}
else
{
BufferedRange.Add(processedRange);
}
}
}
}, token);
}
