fix recursive polling logic

* update links

* update example app to show podcast, soundbite, and radio

Example/SwiftAudioPlayer/Base.lproj/Main.storyboard

@@ -72,8 +72,8 @@
                                 <rect key="frame" x="16" y="60" width="343" height="32"/>
                                 <segments>
                                     <segment title="Soundbite"/>
-                                    <segment title="Acquired"/>
-                                    <segment title="Y Combinator"/>
+                                    <segment title="Podcast"/>
+                                    <segment title="Radio"/>
                                 </segments>
                                 <connections>
                                     <action selector="audioSelected:" destination="vXZ-lx-hvc" eventType="valueChanged" id="oYE-yq-348"/>

Example/SwiftAudioPlayer/Model.swift

@@ -13,18 +13,18 @@ struct AudioInfo: Hashable {
     
     var urls: [URL] = [URL(string: "https://www.fesliyanstudios.com/musicfiles/2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com/15SecVersion2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com.mp3")!,
                        URL(string: "https://chtbl.com/track/18338/traffic.libsyn.com/secure/acquired/acquired_-_armrev_2.mp3?dest-id=376122")!,
-                       URL(string: "https://backtracks.fm/ycombinator/pr/0f685f72-29b1-11e9-9bcf-0ece7a7d2472/111---jake-klamka-and-kevin-hale---y-combinator.mp3?s=1&sd=1&u=1549423185")!]
+                       URL(string: "https://ice6.somafm.com/groovesalad-256-mp3")!]
     
     var url: URL {
         switch index {
         case 0:
-            return URL(string: "https://www.fesliyanstudios.com/musicfiles/2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com/15SecVersion2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com.mp3")!
+            return urls[0]
         case 1:
-            return URL(string: "https://chtbl.com/track/18338/traffic.libsyn.com/secure/acquired/acquired_-_armrev_2.mp3?dest-id=376122")!
+            return urls[1]
         case 2:
-            return URL(string: "https://backtracks.fm/ycombinator/pr/0f685f72-29b1-11e9-9bcf-0ece7a7d2472/111---jake-klamka-and-kevin-hale---y-combinator.mp3?s=1&sd=1&u=1549423185")!
+            return urls[2]
         default:
-            return URL(string: "https://www.fesliyanstudios.com/musicfiles/2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com/15SecVersion2019-04-23_-_Trusted_Advertising_-_www.fesliyanstudios.com.mp3")!
+            return urls[0]
         }
     }
     
@@ -33,9 +33,9 @@ struct AudioInfo: Hashable {
         case 0:
             return "Soundbite"
         case 1:
-            return "Acquired"
+            return "Podcast"
         case 2:
-            return "Y Combinator"
+            return "Radio"
         default:
             return "Soundbite"
         }

Source/Engine/AudioEngine.swift

@@ -173,6 +173,7 @@ class AudioEngine: AudioEngineProtocol {
         Timer.scheduledTimer(withTimeInterval: timeInterval, repeats: false) { [weak self] (timer: Timer) in
             guard let self = self else { return }
             guard self.playingStatus != .ended else {
+//                Log.test("END TIMER")
                 self.delegate = nil
                 return
             }

Source/Engine/AudioStreamEngine.swift

@@ -71,6 +71,7 @@ class AudioStreamEngine: AudioEngine {
     
     private var numberOfBuffersScheduledInTotal = 0 {
         didSet {
+//            Log.test(numberOfBuffersScheduledInTotal)
             Log.debug("number of buffers scheduled in total: \(numberOfBuffersScheduledInTotal)")
             if numberOfBuffersScheduledInTotal == 0 {
                 pause()
@@ -86,6 +87,7 @@ class AudioStreamEngine: AudioEngine {
     private var numberOfBuffersScheduledFromPoll = 0 {
         didSet {
             if numberOfBuffersScheduledFromPoll > MAX_POLL_BUFFER_COUNT {
+//                Log.test("🛑  🛑   STOP POLLING")
                 shouldPollForNextBuffer = false
             }
             
@@ -149,7 +151,7 @@ class AudioStreamEngine: AudioEngine {
             guard let self = self else { return }
             guard self.playingStatus != .ended else { return }
             
-            self.pollForNextBufferRecursive()
+            self.pollForNextBuffer()
             self.updateNetworkBufferRange()
             self.updateNeedle()
             self.updateIsPlaying()
@@ -162,9 +164,16 @@ class AudioStreamEngine: AudioEngine {
     //Called when
     //1. First time audio is finally parsed
     //2. When we run to the end of the network buffer and we're waiting again
-    private func pollForNextBufferRecursive() {
+    private func pollForNextBuffer() {
         guard shouldPollForNextBuffer else { return }
         
+//        Log.test("POLL INIT")
+        pollForNextBufferRecursive()
+    }
+    
+    private func pollForNextBufferRecursive() {
+//        Log.test("POLL")
+        
         do {
             var nextScheduledBuffer: AVAudioPCMBuffer! = try converter.pullBuffer()
             numberOfBuffersScheduledFromPoll += 1
@@ -174,15 +183,17 @@ class AudioStreamEngine: AudioEngine {
             queue.async { [weak self] in
                 if #available(iOS 11.0, *) {
                     // to make sure the pcm buffers are properly free'd from memory we need to nil them after the player has used them
-                    self?.playerNode.scheduleBuffer(nextScheduledBuffer, completionCallbackType: .dataRendered, completionHandler: { (_) in
+                    self?.playerNode.scheduleBuffer(nextScheduledBuffer, completionCallbackType: .dataConsumed, completionHandler: { (_) in
                         nextScheduledBuffer = nil
                         self?.numberOfBuffersScheduledInTotal -= 1
+//                        Log.test("POLL DATA RENDERED")
                         self?.pollForNextBufferRecursive()
                     })
                 } else {
                     self?.playerNode.scheduleBuffer(nextScheduledBuffer) {
                         nextScheduledBuffer = nil
                         self?.numberOfBuffersScheduledInTotal -= 1
+//                        Log.test("POLL OLD")
                         self?.pollForNextBufferRecursive()
                     }
                 }