From 6d9dd1dc6dacbba9907e7c4e92e2d9d111ef44f4 Mon Sep 17 00:00:00 2001
From: MerryMage <MerryMage@users.noreply.github.com>
Date: Sat, 8 Sep 2018 14:55:11 +0100
Subject: [PATCH] cubeb_sink: Use RingBuffer

---
 src/audio_core/cubeb_sink.cpp | 66 ++++++++++++++---------------------
 1 file changed, 26 insertions(+), 40 deletions(-)

diff --git a/src/audio_core/cubeb_sink.cpp b/src/audio_core/cubeb_sink.cpp
index 0f77fd1628..552bcd051d 100644
--- a/src/audio_core/cubeb_sink.cpp
+++ b/src/audio_core/cubeb_sink.cpp
@@ -4,18 +4,17 @@
 
 #include <algorithm>
 #include <cstring>
-#include <mutex>
-
 #include "audio_core/cubeb_sink.h"
 #include "audio_core/stream.h"
 #include "common/logging/log.h"
+#include "common/ring_buffer.h"
 
 namespace AudioCore {
 
-class SinkStreamImpl final : public SinkStream {
+class CubebSinkStream final : public SinkStream {
 public:
-    SinkStreamImpl(cubeb* ctx, u32 sample_rate, u32 num_channels_, cubeb_devid output_device,
-                   const std::string& name)
+    CubebSinkStream(cubeb* ctx, u32 sample_rate, u32 num_channels_, cubeb_devid output_device,
+                    const std::string& name)
         : ctx{ctx}, num_channels{num_channels_} {
 
         if (num_channels == 6) {
@@ -38,7 +37,7 @@ public:
 
         if (cubeb_stream_init(ctx, &stream_backend, name.c_str(), nullptr, nullptr, output_device,
                               &params, std::max(512u, minimum_latency),
-                              &SinkStreamImpl::DataCallback, &SinkStreamImpl::StateCallback,
+                              &CubebSinkStream::DataCallback, &CubebSinkStream::StateCallback,
                               this) != CUBEB_OK) {
             LOG_CRITICAL(Audio_Sink, "Error initializing cubeb stream");
             return;
@@ -50,7 +49,7 @@ public:
         }
     }
 
-    ~SinkStreamImpl() {
+    ~CubebSinkStream() {
         if (!ctx) {
             return;
         }
@@ -63,33 +62,27 @@ public:
     }
 
     void EnqueueSamples(u32 num_channels, const std::vector<s16>& samples) override {
-        if (!ctx) {
-            return;
-        }
-
-        std::lock_guard lock{queue_mutex};
-
-        queue.reserve(queue.size() + samples.size() * GetNumChannels());
-
         if (is_6_channel) {
             // Downsample 6 channels to 2
             const size_t sample_count_copy_size = samples.size() * 2;
-            queue.reserve(sample_count_copy_size);
+            std::vector<s16> buf;
+            buf.reserve(sample_count_copy_size);
             for (size_t i = 0; i < samples.size(); i += num_channels) {
-                queue.push_back(samples[i]);
-                queue.push_back(samples[i + 1]);
+                buf.push_back(samples[i]);
+                buf.push_back(samples[i + 1]);
             }
-        } else {
-            // Copy as-is
-            std::copy(samples.begin(), samples.end(), std::back_inserter(queue));
+            queue.Push(buf);
+            return;
         }
+
+        queue.Push(samples);
     }
 
-    size_t SamplesInQueue(u32 num_channels) const {
+    size_t SamplesInQueue(u32 num_channels) const override {
         if (!ctx)
             return 0;
 
-        return queue.size() / num_channels;
+        return queue.Size() / num_channels;
     }
 
     u32 GetNumChannels() const {
@@ -104,8 +97,7 @@ private:
     u32 num_channels{};
     bool is_6_channel{};
 
-    std::mutex queue_mutex;
-    std::vector<s16> queue;
+    Common::RingBuffer<s16, 0x10000> queue;
 
     static long DataCallback(cubeb_stream* stream, void* user_data, const void* input_buffer,
                              void* output_buffer, long num_frames);
@@ -151,38 +143,32 @@ CubebSink::~CubebSink() {
 SinkStream& CubebSink::AcquireSinkStream(u32 sample_rate, u32 num_channels,
                                          const std::string& name) {
     sink_streams.push_back(
-        std::make_unique<SinkStreamImpl>(ctx, sample_rate, num_channels, output_device, name));
+        std::make_unique<CubebSinkStream>(ctx, sample_rate, num_channels, output_device, name));
     return *sink_streams.back();
 }
 
-long SinkStreamImpl::DataCallback(cubeb_stream* stream, void* user_data, const void* input_buffer,
+long CubebSinkStream::DataCallback(cubeb_stream* stream, void* user_data, const void* input_buffer,
                                   void* output_buffer, long num_frames) {
-    SinkStreamImpl* impl = static_cast<SinkStreamImpl*>(user_data);
+    CubebSinkStream* impl = static_cast<CubebSinkStream*>(user_data);
     u8* buffer = reinterpret_cast<u8*>(output_buffer);
 
     if (!impl) {
         return {};
     }
 
-    std::lock_guard lock{impl->queue_mutex};
+    const size_t max_samples_to_write = impl->GetNumChannels() * num_frames;
+    const size_t samples_written = impl->queue.Pop(buffer, max_samples_to_write);
 
-    const size_t frames_to_write{
-        std::min(impl->queue.size() / impl->GetNumChannels(), static_cast<size_t>(num_frames))};
-
-    memcpy(buffer, impl->queue.data(), frames_to_write * sizeof(s16) * impl->GetNumChannels());
-    impl->queue.erase(impl->queue.begin(),
-                      impl->queue.begin() + frames_to_write * impl->GetNumChannels());
-
-    if (frames_to_write < num_frames) {
+    if (samples_written < max_samples_to_write) {
         // Fill the rest of the frames with silence
-        memset(buffer + frames_to_write * sizeof(s16) * impl->GetNumChannels(), 0,
-               (num_frames - frames_to_write) * sizeof(s16) * impl->GetNumChannels());
+        std::memset(buffer + samples_written * sizeof(s16), 0,
+                    (max_samples_to_write - samples_written) * sizeof(s16));
     }
 
     return num_frames;
 }
 
-void SinkStreamImpl::StateCallback(cubeb_stream* stream, void* user_data, cubeb_state state) {}
+void CubebSinkStream::StateCallback(cubeb_stream* stream, void* user_data, cubeb_state state) {}
 
 std::vector<std::string> ListCubebSinkDevices() {
     std::vector<std::string> device_list;