Tidy up pipeline and use arena capacity to test for overruns

1 files changed, 5 insertions, 43 deletions

diff --git a/src/audio/include/audio_element.hpp b/src/audio/include/audio_element.hpp
index b881404c..91036348 100644
--- a/src/audio/include/audio_element.hpp
+++ b/src/audio/include/audio_element.hpp
@@ -20,25 +20,6 @@
 
 namespace audio {
 
-enum ElementState {
-  STATE_RUN,
-  STATE_PAUSE,
-  STATE_QUIT,
-};
-
-/*
- * Errors that may be returned by any of the Process* methods of an audio
- * element.
- */
-enum AudioProcessingError {
-  // Indicates that this element is unable to handle the upcoming chunks.
-  UNSUPPORTED_STREAM,
-  // Indicates an error with reading or writing stream data.
-  IO_ERROR,
-  // Indicates that the element has run out of data to process.
-  OUT_OF_DATA,
-};
-
 static const size_t kEventQueueSize = 8;
 
 /*
@@ -66,35 +47,24 @@ class IAudioElement {
    */
   virtual auto StackSizeBytes() const -> std::size_t { return 4096; };
 
-  virtual auto InputMinChunkSize() const -> std::size_t { return 0; }
-
   /* Returns this element's input buffer. */
   auto InputEventQueue() const -> QueueHandle_t { return input_events_; }
-
   /* Returns this element's output buffer. */
   auto OutputEventQueue() const -> QueueHandle_t { return output_events_; }
-
   auto OutputEventQueue(const QueueHandle_t q) -> void { output_events_ = q; }
 
-  auto HasUnflushedOutput() -> bool { return !buffered_output_.empty(); }
-
   virtual auto HasUnprocessedInput() -> bool = 0;
 
-  auto IsOverBuffered() -> bool { return unprocessed_output_chunks_ > 4; }
+  virtual auto IsOverBuffered() -> bool { return false; }
 
+  auto HasUnflushedOutput() -> bool { return !buffered_output_.empty(); }
   auto FlushBufferedOutput() -> bool;
 
-  auto ElementState() const -> ElementState { return current_state_; }
-  auto ElementState(enum ElementState e) -> void { current_state_ = e; }
-
-  virtual auto OnChunkProcessed() -> void { unprocessed_output_chunks_--; }
-
   /*
    * Called when a StreamInfo message is received. Used to configure this
    * element in preperation for incoming chunks.
    */
-  virtual auto ProcessStreamInfo(const StreamInfo& info)
-      -> cpp::result<void, AudioProcessingError> = 0;
+  virtual auto ProcessStreamInfo(const StreamInfo& info) -> void = 0;
 
   /*
    * Called when a ChunkHeader message is received. Includes the data associated
@@ -102,8 +72,7 @@ class IAudioElement {
    * bytes in this chunk that were actually used; leftover bytes will be
    * prepended to the next call.
    */
-  virtual auto ProcessChunk(const cpp::span<std::byte>& chunk)
-      -> cpp::result<std::size_t, AudioProcessingError> = 0;
+  virtual auto ProcessChunk(const cpp::span<std::byte>& chunk) -> void = 0;
 
   virtual auto ProcessEndOfStream() -> void = 0;
 
@@ -114,7 +83,7 @@ class IAudioElement {
    * time. This could be used to synthesize output, or to save memory by
    * releasing unused resources.
    */
-  virtual auto Process() -> cpp::result<void, AudioProcessingError> = 0;
+  virtual auto Process() -> void = 0;
 
  protected:
   auto SendOrBufferEvent(std::unique_ptr<StreamEvent> event) -> bool;
@@ -125,15 +94,8 @@ class IAudioElement {
   // if we're not yet in a pipeline.
   // FIXME: it would be nicer if this was non-nullable.
   QueueHandle_t output_events_;
-
-  // The number of output chunks that we have generated, but have not yet been
-  // processed by the next element in the pipeline. This includes any chunks
-  // that are currently help in buffered_output_.
-  int unprocessed_output_chunks_;
   // Output events that have been generated, but are yet to be sent downstream.
   std::deque<std::unique_ptr<StreamEvent>> buffered_output_;
-
-  enum ElementState current_state_;
 };
 
 }  // namespace audio