Files
deepdrft/DeepDrftPublic.Client/Services/StreamingAudioPlayerService.cs
T

544 lines
21 KiB
C#

using DeepDrftModels.DTOs;
using DeepDrftPublic.Client.Clients;
using System.Buffers;
using Microsoft.Extensions.Logging;
namespace DeepDrftPublic.Client.Services;
public class StreamingAudioPlayerService : AudioPlayerService, IStreamingPlayerService
{
// Configuration constants
private const int DefaultBufferSize = 32 * 1024; // 32KB chunks
private const int NotificationThrottleMs = 100; // Throttle UI updates to max 10 per second
// Adaptive chunk sizing
private const int MinBufferSize = 16 * 1024; // 16KB minimum
private const int MaxBufferSize = 64 * 1024; // 64KB maximum
private int _currentBufferSize = DefaultBufferSize;
private int _consecutiveSlowReads = 0;
// Streaming state properties
public bool IsStreamingMode { get; private set; } = false;
public bool CanStartStreaming { get; private set; } = false;
public bool HeaderParsed { get; private set; } = false;
public int BufferedChunks { get; private set; } = 0;
public bool IsSeekingBeyondBuffer { get; private set; } = false;
private bool _streamingPlaybackStarted = false;
private CancellationTokenSource? _streamingCancellation;
private Task? _activeStreamingTask;
private DateTime _lastNotification = DateTime.MinValue;
private readonly ILogger<StreamingAudioPlayerService> _logger;
private string? _currentTrackId;
public StreamingAudioPlayerService(
AudioInteropService audioInterop,
TrackMediaClient trackMediaClient,
ILogger<StreamingAudioPlayerService> logger)
: base(audioInterop, trackMediaClient)
{
_logger = logger;
}
public override async Task SelectTrack(TrackDto track)
{
await SelectTrackStreaming(track);
}
public async Task SelectTrackStreaming(TrackDto track)
{
await EnsureInitializedAsync();
// Resume AudioContext immediately on track selection (user interaction) to avoid clicks later
await _audioInterop.EnsureAudioContextReady(PlayerId);
await NotifyTrackSelected();
await LoadTrackStreaming(track);
await NotifyStateChanged();
}
private async Task LoadTrackStreaming(TrackDto track)
{
// Always reset to clean state before loading new track. ResetToIdle
// both cancels and awaits any in-flight streaming loop, so by the time
// we return from it the previous loop is guaranteed to have exited and
// there is no risk of interleaved ProcessStreamingChunk calls against
// the single-instance JS StreamDecoder.
await ResetToIdle();
// Save track ID for seek operations
_currentTrackId = track.EntryKey;
// Expose to UI immediately — Now-Playing surfaces should reflect the selected
// track while it's still loading, not only after playback starts.
CurrentTrack = track;
// Create new cancellation token for this streaming operation
_streamingCancellation = new CancellationTokenSource();
try
{
// Set state to indicate loading has started
ErrorMessage = null;
LoadProgress = 0;
IsLoading = true;
IsStreamingMode = true;
// Reset adaptive buffer sizing
_currentBufferSize = DefaultBufferSize;
_consecutiveSlowReads = 0;
await NotifyStateChanged();
// Pass the streaming token to the HTTP layer so a navigation/track switch
// aborts the server connection instead of leaving it draining bytes.
var mediaResult = await _trackMediaClient.GetTrackMedia(
track.EntryKey,
byteOffset: 0,
cancellationToken: _streamingCancellation.Token);
if (!mediaResult.Success)
{
var technicalError = mediaResult.GetMessage();
_logger.LogError("Failed to get track media for {TrackId}: {Error}",
track.EntryKey, technicalError);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(technicalError);
return;
}
if (mediaResult.Value == null)
{
const string technicalError = "No audio returned from server";
_logger.LogError("No audio data returned for track {TrackId}", track.EntryKey);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(technicalError);
return;
}
using var audio = mediaResult.Value;
// Initialize streaming mode with content length
var streamingResult = await _audioInterop.InitializeStreaming(PlayerId, audio.ContentLength);
if (!streamingResult.Success)
{
var technicalError = $"Failed to initialize streaming: {streamingResult.Error}";
_logger.LogError("Streaming initialization failed for track {TrackId}: {Error}",
track.EntryKey, technicalError);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(technicalError);
return;
}
_activeStreamingTask = StreamAudioWithEarlyPlayback(audio, _streamingCancellation.Token);
await _activeStreamingTask;
}
catch (OperationCanceledException)
{
// Cancellation is expected, reset state
_logger.LogDebug("Audio streaming cancelled for track {TrackId}", track.EntryKey);
IsLoaded = false;
IsStreamingMode = false;
}
catch (Exception ex)
{
StreamingErrorHandler.LogError(_logger, ex, "LoadTrackStreaming", track.EntryKey);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(ex.Message);
LoadProgress = 0;
IsLoaded = false;
IsStreamingMode = false;
}
finally
{
IsLoading = false;
await NotifyStateChanged();
}
}
private async Task StreamAudioWithEarlyPlayback(TrackMediaResponse audio, CancellationToken cancellationToken)
{
byte[]? buffer = null;
try
{
long totalBytesRead = 0;
buffer = ArrayPool<byte>.Shared.Rent(MaxBufferSize); // Rent larger buffer to accommodate adaptive sizing
int currentBytes;
var readTimer = System.Diagnostics.Stopwatch.StartNew();
do
{
readTimer.Restart();
currentBytes = await audio.Stream.ReadAsync(buffer, 0, _currentBufferSize, cancellationToken);
readTimer.Stop();
// Adapt buffer size based on read performance
AdaptBufferSize(currentBytes, readTimer.ElapsedMilliseconds);
if (currentBytes > 0)
{
totalBytesRead += currentBytes;
// Always slice to the exact number of bytes read. The pooled buffer
// is rented at MaxBufferSize and may carry stale bytes past
// currentBytes from a prior rental — handing the full array to JS
// interop would serialise that garbage into the audio stream.
var actualBuffer = buffer.AsSpan(0, currentBytes).ToArray();
// Process chunk for streaming
var chunkResult = await _audioInterop.ProcessStreamingChunk(PlayerId, actualBuffer);
if (!chunkResult.Success)
{
var error = $"Failed to process streaming chunk: {chunkResult.Error}";
_logger.LogWarning("Chunk processing failed: {Error}", error);
throw new Exception(error);
}
// Update streaming state
CanStartStreaming = chunkResult.CanStartStreaming;
HeaderParsed = chunkResult.HeaderParsed;
BufferedChunks = chunkResult.BufferCount;
// Set duration from WAV header when available (only set once)
if (chunkResult.Duration.HasValue && Duration == null)
{
Duration = chunkResult.Duration.Value;
_logger.LogInformation("Duration set from WAV header: {Duration:F2} seconds", Duration);
}
// Start playback as soon as we can
if (!_streamingPlaybackStarted && CanStartStreaming)
{
var playbackResult = await _audioInterop.StartStreamingPlayback(PlayerId);
if (playbackResult.Success)
{
_streamingPlaybackStarted = true;
IsPlaying = true;
IsPaused = false;
IsLoaded = true; // Track is loaded and ready to play (even if still downloading)
ErrorMessage = null;
await NotifyStateChanged(); // Immediate notification for critical state change
}
else
{
var technicalError = $"Failed to start streaming playback: {playbackResult.Error}";
_logger.LogError("Failed to start playback: {Error}", technicalError);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(technicalError);
}
}
// Update progress
if (audio.ContentLength > 0)
{
LoadProgress = Math.Min(1.0, (double)totalBytesRead / audio.ContentLength);
}
await ThrottledNotifyStateChanged();
}
} while (currentBytes > 0);
// Notify the JS decoder that the stream is finished. When the server omits
// Content-Length the StreamDecoder cannot determine completion via byte counting
// alone; this explicit signal ensures the tail-decoding path (streamComplete=true)
// fires regardless of whether Content-Length was present.
await _audioInterop.MarkStreamCompleteAsync(PlayerId);
// Mark as fully loaded
LoadProgress = 1.0;
await NotifyStateChanged();
}
catch (Exception ex)
{
StreamingErrorHandler.LogError(_logger, ex, "StreamAudioWithEarlyPlayback");
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(ex.Message);
LoadProgress = 0;
IsLoaded = false;
IsStreamingMode = false;
await NotifyStateChanged();
throw;
}
finally
{
if (buffer != null)
{
ArrayPool<byte>.Shared.Return(buffer);
}
}
}
/// <summary>
/// In streaming mode, Stop fully resets to Idle state since audio data is consumed.
/// This is equivalent to Unload for streaming playback.
/// </summary>
public override async Task Stop()
{
// In streaming mode, Stop = Unload (data is consumed, can't replay)
await ResetToIdle();
}
/// <summary>
/// Fully resets the player to Idle state, ready for a new track.
/// </summary>
public override async Task Unload()
{
await ResetToIdle();
}
/// <summary>
/// Override Seek to handle seek-beyond-buffer for streaming mode.
/// </summary>
public override async Task Seek(double position)
{
if (!IsLoaded || !IsStreamingMode) return;
try
{
var result = await _audioInterop.SeekAsync(PlayerId, position);
if (result.Success)
{
if (result.SeekBeyondBuffer && result.ByteOffset > 0)
{
// Need to load new stream from offset
_logger.LogInformation("Seeking beyond buffer to {Position:F2}s, byte offset: {ByteOffset}",
position, result.ByteOffset);
await SeekBeyondBuffer(position, result.ByteOffset);
}
else
{
// Seek within buffer succeeded
CurrentTime = position;
ErrorMessage = null;
await NotifyStateChanged();
}
}
else
{
ErrorMessage = $"Seek error: {result.Error}";
await NotifyStateChanged();
}
}
catch (Exception ex)
{
_logger.LogError(ex, "Error seeking to position {Position}", position);
ErrorMessage = $"Error seeking: {ex.Message}";
await NotifyStateChanged();
}
}
/// <summary>
/// Handle seeking beyond the currently buffered content by requesting a new stream from offset.
/// </summary>
private async Task SeekBeyondBuffer(double seekPosition, long byteOffset)
{
if (string.IsNullOrEmpty(_currentTrackId))
{
ErrorMessage = "Cannot seek - no track loaded";
return;
}
IsSeekingBeyondBuffer = true;
// Cancel the current streaming loop AND wait for it to fully exit before
// starting a new one. The previous loop's pending ReadAsync will throw
// OperationCanceledException asynchronously; if we kick off a new loop
// immediately, both can race against the single-instance JS StreamDecoder
// and corrupt decode state. Draining here is the load-bearing guarantee.
_streamingCancellation?.Cancel();
await DrainActiveStreamingTaskAsync();
_streamingCancellation?.Dispose();
_streamingCancellation = new CancellationTokenSource();
try
{
// Update UI immediately
CurrentTime = seekPosition;
await NotifyStateChanged();
// Request new stream from offset
var mediaResult = await _trackMediaClient.GetTrackMedia(
_currentTrackId,
byteOffset,
cancellationToken: _streamingCancellation.Token);
if (!mediaResult.Success || mediaResult.Value == null)
{
var technicalError = mediaResult.GetMessage() ?? "Failed to load audio from position";
_logger.LogError("Failed to get track media from offset {Offset}: {Error}", byteOffset, technicalError);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(technicalError);
IsSeekingBeyondBuffer = false;
return;
}
using var audio = mediaResult.Value;
// Reinitialize JS player for offset streaming
var reinitResult = await _audioInterop.ReinitializeFromOffset(PlayerId, audio.ContentLength, seekPosition);
if (!reinitResult.Success)
{
_logger.LogError("Failed to reinitialize for offset streaming: {Error}", reinitResult.Error);
ErrorMessage = "Failed to seek to position";
IsSeekingBeyondBuffer = false;
return;
}
// Reset streaming state for new stream
_streamingPlaybackStarted = false;
CanStartStreaming = false;
HeaderParsed = false;
BufferedChunks = 0;
// Stream audio from offset
_activeStreamingTask = StreamAudioWithEarlyPlayback(audio, _streamingCancellation.Token);
await _activeStreamingTask;
IsSeekingBeyondBuffer = false;
}
catch (OperationCanceledException)
{
// Another seek or stop interrupted this one
_logger.LogDebug("Seek beyond buffer cancelled");
IsSeekingBeyondBuffer = false;
}
catch (Exception ex)
{
_logger.LogError(ex, "Error during seek beyond buffer to position {Position}", seekPosition);
ErrorMessage = StreamingErrorHandler.GetUserFriendlyMessage(ex.Message);
IsSeekingBeyondBuffer = false;
await NotifyStateChanged();
}
}
/// <summary>
/// Single method to reset all state - called by both Stop and Unload.
/// </summary>
private async Task ResetToIdle()
{
// 1. Cancel any ongoing streaming operation and wait for it to exit
// before tearing down JS state. Otherwise the loop's pending
// ProcessStreamingChunk call can land after StopAsync/UnloadAsync.
_streamingCancellation?.Cancel();
await DrainActiveStreamingTaskAsync();
_streamingCancellation?.Dispose();
_streamingCancellation = null;
// 2. Tell JS to stop and unload
try
{
await _audioInterop.StopAsync(PlayerId);
await _audioInterop.UnloadAsync(PlayerId);
}
catch
{
// Ignore JS errors during cleanup
}
// 3. Reset ALL state to Idle
IsPlaying = false;
IsPaused = false;
IsLoaded = false;
IsLoading = false;
CurrentTime = 0;
Duration = null;
LoadProgress = 0;
ErrorMessage = null;
CurrentTrack = null;
// 4. Reset streaming-specific state
IsStreamingMode = false;
CanStartStreaming = false;
HeaderParsed = false;
BufferedChunks = 0;
_streamingPlaybackStarted = false;
IsSeekingBeyondBuffer = false;
_currentTrackId = null;
await NotifyStateChanged();
}
/// <summary>
/// Wait for the previously-started streaming loop to fully exit. The caller
/// must have already cancelled <see cref="_streamingCancellation"/>. Swallows
/// the expected OperationCanceledException; any other exception was already
/// surfaced through the loop's own catch block, so we ignore it here too.
/// </summary>
private async Task DrainActiveStreamingTaskAsync()
{
var task = _activeStreamingTask;
if (task == null) return;
try
{
await task;
}
catch (OperationCanceledException)
{
// Expected when we cancelled the loop ourselves.
}
catch
{
// Any other failure was already logged inside the loop.
}
finally
{
// Only clear if we are still the active task — a concurrent caller
// may have started a new stream while we were draining the old one.
if (ReferenceEquals(_activeStreamingTask, task))
{
_activeStreamingTask = null;
}
}
}
private async Task ThrottledNotifyStateChanged()
{
var now = DateTime.UtcNow;
if ((now - _lastNotification).TotalMilliseconds >= NotificationThrottleMs)
{
_lastNotification = now;
await NotifyStateChanged();
}
}
/// <summary>
/// On component unmount we must cancel the in-flight streaming loop and tear
/// down JS callbacks before the JS side's setInterval fires again with a
/// stale DotNetObjectReference. ResetToIdle covers cancellation + JS stop
/// + state reset; the base then disposes the JS player and its callbacks.
/// </summary>
public override async ValueTask DisposeAsync()
{
try
{
await ResetToIdle();
}
catch
{
// Disposal must not throw; any failure here is best-effort cleanup.
}
await base.DisposeAsync();
}
private void AdaptBufferSize(int bytesRead, long readTimeMs)
{
// Adaptive buffer sizing based on network performance
if (readTimeMs > 100) // Slow read (>100ms)
{
_consecutiveSlowReads++;
if (_consecutiveSlowReads >= 3 && _currentBufferSize > MinBufferSize)
{
// Reduce buffer size for slow connections
_currentBufferSize = Math.Max(MinBufferSize, _currentBufferSize / 2);
_consecutiveSlowReads = 0;
}
}
else if (readTimeMs < 20 && bytesRead == _currentBufferSize) // Fast read, buffer fully utilized
{
_consecutiveSlowReads = 0;
if (_currentBufferSize < MaxBufferSize)
{
// Increase buffer size for fast connections
_currentBufferSize = Math.Min(MaxBufferSize, _currentBufferSize * 2);
}
}
else
{
_consecutiveSlowReads = 0;
}
}
}