From 01be69eca1fa89c047fc29f5cb0ea8ba0898dad1 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Wed, 7 Dec 2022 15:36:47 +1100
Subject: better handling of chunk buffer

---
 src/audio/chunk.cpp | 50 +++++++++++++++++---------------------------------
 1 file changed, 17 insertions(+), 33 deletions(-)

(limited to 'src/audio/chunk.cpp')

diff --git a/src/audio/chunk.cpp b/src/audio/chunk.cpp
index eb28d5a9..fbd795d9 100644
--- a/src/audio/chunk.cpp
+++ b/src/audio/chunk.cpp
@@ -8,31 +8,19 @@
 
 #include "cbor.h"
 
+#include "stream_buffer.hpp"
 #include "stream_message.hpp"
 
 namespace audio {
 
-/*
- * The maximum size of a single chunk of stream data. This should be comfortably
- * larger than the largest size of a frame of audio we should expect to handle.
- *
- * 128 kbps MPEG-1 @ 44.1 kHz is approx. 418 bytes according to the internet.
- *
- * TODO(jacqueline): tune as more codecs are added.
- */
-const std::size_t kMaxChunkSize = 2048;
-
-// TODO: tune
-static const std::size_t kWorkingBufferSize = kMaxChunkSize * 1.5;
-
-auto WriteChunksToStream(MessageBufferHandle_t* stream,
-                         cpp::span<std::byte> working_buffer,
+auto WriteChunksToStream(StreamBuffer* stream,
                          std::function<size_t(cpp::span<std::byte>)> callback,
                          TickType_t max_wait) -> ChunkWriteResult {
+  cpp::span<std::byte> write_buffer = stream->WriteBuffer();
   while (1) {
     // First, write out our chunk header so we know how much space to give to
     // the callback.
-    auto header_size = WriteTypeOnlyMessage(TYPE_CHUNK_HEADER, working_buffer);
+    auto header_size = WriteTypeOnlyMessage(TYPE_CHUNK_HEADER, write_buffer);
     if (header_size.has_error()) {
       return CHUNK_ENCODING_ERROR;
     }
@@ -40,8 +28,8 @@ auto WriteChunksToStream(MessageBufferHandle_t* stream,
     // Now we can ask the callback to fill the remaining space.
     size_t chunk_size = std::invoke(
         callback,
-        working_buffer.subspan(header_size.value(),
-                               working_buffer.size() - header_size.value()));
+        write_buffer.subspan(header_size.value(),
+                             write_buffer.size() - header_size.value()));
 
     if (chunk_size == 0) {
       // They had nothing for us, so bail out.
@@ -51,7 +39,7 @@ auto WriteChunksToStream(MessageBufferHandle_t* stream,
     // Try to write to the buffer. Note the return type here will be either 0 or
     // header_size + chunk_size, as MessageBuffer doesn't allow partial writes.
     size_t actual_write_size =
-        xMessageBufferSend(*stream, working_buffer.data(),
+        xMessageBufferSend(stream->Handle(), write_buffer.data(),
                            header_size.value() + chunk_size, max_wait);
 
     if (actual_write_size == 0) {
@@ -63,15 +51,9 @@ auto WriteChunksToStream(MessageBufferHandle_t* stream,
   }
 }
 
-ChunkReader::ChunkReader(MessageBufferHandle_t* stream)
-    : stream_(stream),
-      raw_working_buffer_(static_cast<std::byte*>(
-          heap_caps_malloc(kWorkingBufferSize, MALLOC_CAP_SPIRAM))),
-      working_buffer_(raw_working_buffer_, kWorkingBufferSize) {}
+ChunkReader::ChunkReader(StreamBuffer* stream) : stream_(stream) {}
 
-ChunkReader::~ChunkReader() {
-  free(raw_working_buffer_);
-}
+ChunkReader::~ChunkReader() {}
 
 auto ChunkReader::Reset() -> void {
   leftover_bytes_ = 0;
@@ -79,16 +61,17 @@ auto ChunkReader::Reset() -> void {
 }
 
 auto ChunkReader::GetLastMessage() -> cpp::span<std::byte> {
-  return working_buffer_.subspan(leftover_bytes_, last_message_size_);
+  return stream_->ReadBuffer().subspan(leftover_bytes_, last_message_size_);
 }
 
 auto ChunkReader::ReadChunkFromStream(
     std::function<std::optional<size_t>(cpp::span<std::byte>)> callback,
     TickType_t max_wait) -> ChunkReadResult {
   // First, wait for a message to arrive over the buffer.
-  last_message_size_ =
-      xMessageBufferReceive(*stream_, raw_working_buffer_ + leftover_bytes_,
-                            working_buffer_.size() - leftover_bytes_, max_wait);
+  cpp::span<std::byte> new_data_dest = stream_->ReadBuffer().last(
+      stream_->ReadBuffer().size() - leftover_bytes_);
+  last_message_size_ = xMessageBufferReceive(
+      stream_->Handle(), new_data_dest.data(), new_data_dest.size(), max_wait);
 
   if (last_message_size_ == 0) {
     return CHUNK_READ_TIMEOUT;
@@ -109,7 +92,8 @@ auto ChunkReader::ReadChunkFromStream(
   // Now we need to stick the end of the last chunk (if it exists) onto the
   // front of the new chunk. Do it this way around bc we assume the old chunk
   // is shorter, and therefore faster to move.
-  cpp::span<std::byte> leftover_data = working_buffer_.first(leftover_bytes_);
+  cpp::span<std::byte> leftover_data =
+      stream_->ReadBuffer().first(leftover_bytes_);
   cpp::span<std::byte> combined_data(chunk_data.data() - leftover_data.size(),
                                      leftover_data.size() + chunk_data.size());
   if (leftover_bytes_ > 0) {
@@ -127,7 +111,7 @@ auto ChunkReader::ReadChunkFromStream(
   leftover_bytes_ = combined_data.size() - amount_processed.value();
   if (leftover_bytes_ > 0) {
     std::copy(combined_data.begin() + amount_processed.value(),
-              combined_data.end(), working_buffer_.begin());
+              combined_data.end(), stream_->ReadBuffer().begin());
     return CHUNK_LEFTOVER_DATA;
   }
 
-- 
cgit v1.2.3