experimenting with RemoteAudioSource

AudioStreaming/Core/Network/NetworkDataStream.swift

@@ -33,6 +33,7 @@ internal final class NetworkDataStream {
         let error: Error?
     }
 
+    private var lock = UnfairLock()
     private var streamCallback: StreamCompletion?
 
     /// The serial queue for all internal async actions.
@@ -66,6 +67,7 @@ internal final class NetworkDataStream {
 
     @discardableResult
     func responseStream(completion: @escaping StreamCompletion) -> Self {
+        lock.lock(); defer { lock.unlock() }
         streamCallback = completion
         return self
     }
@@ -79,6 +81,7 @@ internal final class NetworkDataStream {
     }
 
     func cancel() {
+        lock.lock(); defer { lock.unlock() }
         guard state.canBecome(.cancelled) else { return }
         state = .cancelled
         streamCallback = nil

AudioStreaming/Streaming/Audio Source/RemoteAudioSource.swift

@@ -44,7 +44,6 @@ public class RemoteAudioSource: AudioStreamSource {
     }
 
     internal let underlyingQueue: DispatchQueue
-    internal let streamOperationQueue: OperationQueue
     internal let netStatusService: NetStatusProvider
     internal var waitingForNetwork = false
     internal let retrierTimeout: Retrier
@@ -67,12 +66,7 @@ public class RemoteAudioSource: AudioStreamSource {
         supportsSeek = false
         netStatusService = netStatusProvider
         self.icycastHeadersProcessor = icycastHeadersProcessor
-        self.underlyingQueue = underlyingQueue
-        streamOperationQueue = OperationQueue()
-        streamOperationQueue.underlyingQueue = underlyingQueue
-        streamOperationQueue.maxConcurrentOperationCount = 1
-        streamOperationQueue.isSuspended = true
-        streamOperationQueue.name = "remote.audio.source.data.stream.queue"
+        self.underlyingQueue = DispatchQueue(label: "remote.audio.source.queue", target: underlyingQueue)
         retrierTimeout = retrier
         startNetworkService()
     }
@@ -110,7 +104,6 @@ public class RemoteAudioSource: AudioStreamSource {
     func close() {
         retrierTimeout.cancel()
         netStatusService.stop()
-        streamOperationQueue.cancelAllOperations()
         if let streamTask = streamRequest {
             streamTask.cancel()
             networkingClient.remove(task: streamTask)
@@ -138,12 +131,10 @@ public class RemoteAudioSource: AudioStreamSource {
 
     func suspend() {
         streamRequest?.suspend()
-        streamOperationQueue.isSuspended = true
     }
 
     func resume() {
         streamRequest?.resume()
-        streamOperationQueue.isSuspended = false
     }
 
     // MARK: Private
@@ -165,7 +156,9 @@ public class RemoteAudioSource: AudioStreamSource {
         let request = networkingClient.stream(request: urlRequest)
             .responseStream { [weak self] event in
                 guard let self = self else { return }
-                self.handleResponse(event: event)
+                self.underlyingQueue.sync {
+                    self.handleResponse(event: event)
+                }
             }
             .resume()
 
@@ -179,17 +172,13 @@ public class RemoteAudioSource: AudioStreamSource {
         switch event {
         case let .response(urlResponse):
             parseResponseHeader(response: urlResponse)
-            streamOperationQueue.isSuspended = false
         case let .stream(event):
             handleStreamEvent(event: event)
         case let .complete(event):
             if let error = event.error {
                 delegate?.errorOccured(source: self, error: error)
             } else {
-                addCompletionOperation { [weak self] in
-                    guard let self = self else { return }
-                    self.delegate?.endOfFileOccured(source: self)
-                }
+                delegate?.endOfFileOccured(source: self)
             }
         }
     }
@@ -198,26 +187,23 @@ public class RemoteAudioSource: AudioStreamSource {
         switch event {
         case let .success(value):
             if let audioData = value.data {
-                addStreamOperation { [weak self] in
-                    guard let self = self else { return }
-                    if self.shouldTryParsingIcycastHeaders {
-                        let (header, extractedAudio) = self.icycastHeadersProcessor.proccess(data: audioData)
-                        if let header = header {
-                            self.shouldTryParsingIcycastHeaders = false
-                            let parser = IcycastHeaderParser()
-                            self.parsedHeaderOutput = parser.parse(input: header)
-                            if let metadataStep = self.parsedHeaderOutput?.metadataStep {
-                                self.metadataStreamProcessor.metadataAvailable(step: metadataStep)
-                            }
-
-                            let audioCount = self.processAudio(data: extractedAudio)
-                            self.relativePosition += audioCount
-                            return
+                if shouldTryParsingIcycastHeaders {
+                    let (header, extractedAudio) = icycastHeadersProcessor.proccess(data: audioData)
+                    if let header = header {
+                        shouldTryParsingIcycastHeaders = false
+                        let parser = IcycastHeaderParser()
+                        parsedHeaderOutput = parser.parse(input: header)
+                        if let metadataStep = parsedHeaderOutput?.metadataStep {
+                            metadataStreamProcessor.metadataAvailable(step: metadataStep)
                         }
+
+                        let audioCount = processAudio(data: extractedAudio)
+                        relativePosition += audioCount
+                        return
                     }
-                    let audioCount = self.processAudio(data: audioData)
-                    self.relativePosition += audioCount
                 }
+                let audioCount = processAudio(data: audioData)
+                relativePosition += audioCount
             }
         case .failure:
             if !netStatusService.isConnected {
@@ -280,7 +266,7 @@ public class RemoteAudioSource: AudioStreamSource {
         var urlRequest = URLRequest(url: url)
         urlRequest.networkServiceType = .avStreaming
         urlRequest.cachePolicy = .reloadIgnoringLocalCacheData
-        urlRequest.timeoutInterval = 60
+        urlRequest.timeoutInterval = 240
 
         for header in additionalRequestHeaders {
             urlRequest.addValue(header.value, forHTTPHeaderField: header.key)
@@ -301,25 +287,6 @@ public class RemoteAudioSource: AudioStreamSource {
             self.seek(at: self.position)
         }
     }
-
-    // MARK: - Network Stream Operation Queue
-
-    /// Schedules the given block on the stream operation queue
-    ///
-    /// - Parameter block: A closure to be executed
-    private func addStreamOperation(_ block: @escaping () -> Void) {
-        let operation = BlockOperation(block: block)
-        streamOperationQueue.addOperation(operation)
-    }
-
-    /// Schedules the given block on the stream operation queue as a completion
-    ///
-    /// - Parameter block: A closure to be executed
-    private func addCompletionOperation(_ block: @escaping () -> Void) {
-        let operation = BlockOperation(block: block)
-        operation.queuePriority = .veryLow
-        streamOperationQueue.addOperation(operation)
-    }
 }
 
 extension RemoteAudioSource: MetadataStreamSourceDelegate {

AudioStreaming/Streaming/AudioPlayer/AudioPlayer.swift

@@ -535,10 +535,11 @@ open class AudioPlayer {
     /// This calls `processSource` method every `500 ms`
     private func startReadProcessFromSourceIfNeeded() {
         guard audioReadSource.state != .activated else { return }
-        audioReadSource.add { [weak self] in
-            self?.processSource()
-        }
-        audioReadSource.activate()
+        // TODO: this might be needed after all...
+//        audioReadSource.add { [weak self] in
+//            self?.processSource()
+//        }
+//        audioReadSource.activate()
     }
 
     /// Stops and removes the handler from the timer, @see `audioReadSource`