output/*: use std::span instead of ConstBuffer

src/output/Source.cxx

@@ -24,7 +24,6 @@
 #include "filter/plugins/ReplayGainFilterPlugin.hxx"
 #include "pcm/Mix.hxx"
 #include "thread/Mutex.hxx"
-#include "util/ConstBuffer.hxx"
 #include "util/RuntimeError.hxx"
 
 #include <string.h>
@@ -130,7 +129,7 @@ AudioOutputSource::CloseFilter() noexcept
 	filter.reset();
 }
 
-ConstBuffer<void>
+std::span<const std::byte>
 AudioOutputSource::GetChunkData(const MusicChunk &chunk,
 				Filter *current_replay_gain_filter,
 				unsigned *replay_gain_serial_p)
@@ -138,9 +137,9 @@ AudioOutputSource::GetChunkData(const MusicChunk &chunk,
 	assert(!chunk.IsEmpty());
 	assert(chunk.CheckFormat(in_audio_format));
 
-	ConstBuffer<void> data(chunk.data, chunk.length);
+	std::span<const std::byte> data(chunk.data, chunk.length);
 
-	assert(data.size % in_audio_format.GetFrameSize() == 0);
+	assert(data.size() % in_audio_format.GetFrameSize() == 0);
 
 	if (!data.empty() && current_replay_gain_filter != nullptr) {
 		replay_gain_filter_set_mode(*current_replay_gain_filter,
@@ -160,7 +159,7 @@ AudioOutputSource::GetChunkData(const MusicChunk &chunk,
 	return data;
 }
 
-ConstBuffer<void>
+std::span<const std::byte>
 AudioOutputSource::FilterChunk(const MusicChunk &chunk)
 {
 	auto data = GetChunkData(chunk, replay_gain_filter.get(),
@@ -182,8 +181,8 @@ AudioOutputSource::FilterChunk(const MusicChunk &chunk)
 		   "next" song being faded in, and if there's a rest,
 		   it means cross-fading ends here */
 
-		if (data.size > other_data.size)
+		if (data.size() > other_data.size())
-			data.size = other_data.size;
+			data = data.first(other_data.size());
 
 		float mix_ratio = chunk.mix_ratio;
 		if (mix_ratio >= 0)
@@ -194,16 +193,15 @@ AudioOutputSource::FilterChunk(const MusicChunk &chunk)
 			   case */
 			mix_ratio = 1.0f - mix_ratio;
 
-		void *dest = cross_fade_buffer.Get(other_data.size);
+		void *dest = cross_fade_buffer.Get(other_data.size());
-		memcpy(dest, other_data.data, other_data.size);
+		memcpy(dest, other_data.data(), other_data.size());
-		if (!pcm_mix(cross_fade_dither, dest, data.data, data.size,
+		if (!pcm_mix(cross_fade_dither, dest, data.data(), data.size(),
 			     in_audio_format.format,
 			     mix_ratio))
 			throw FormatRuntimeError("Cannot cross-fade format %s",
 						 sample_format_to_string(in_audio_format.format));
 
-		data.data = dest;
+		data = {(const std::byte *)dest, other_data.size()};
-		data.size = other_data.size;
 	}
 
 	/* apply filter chain */
@@ -232,7 +230,7 @@ AudioOutputSource::Fill(Mutex &mutex)
 		   that may take a while */
 		const ScopeUnlock unlock(mutex);
 
-		pending_data = pending_data.FromVoid(FilterChunk(*current_chunk));
+		pending_data = FilterChunk(*current_chunk);
 	} catch (...) {
 		current_chunk = nullptr;
 		throw;
@@ -244,13 +242,13 @@ AudioOutputSource::Fill(Mutex &mutex)
 void
 AudioOutputSource::ConsumeData(size_t nbytes) noexcept
 {
-	pending_data.skip_front(nbytes);
+	pending_data = pending_data.subspan(nbytes);
 
 	if (pending_data.empty())
 		DropCurrentChunk();
 }
 
-ConstBuffer<void>
+std::span<const std::byte>
 AudioOutputSource::Flush()
 {
 	return filter

src/output/Source.hxx

@@ -26,11 +26,11 @@
 #include "pcm/Buffer.hxx"
 #include "pcm/Dither.hxx"
 #include "thread/Mutex.hxx"
-#include "util/ConstBuffer.hxx"
 
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <span>
 #include <utility>
 
 struct MusicChunk;
@@ -115,7 +115,7 @@ class AudioOutputSource {
 	 * Filtered #MusicChunk PCM data to be processed by the
 	 * #AudioOutput.
 	 */
-	ConstBuffer<uint8_t> pending_data;
+	std::span<const std::byte> pending_data;
 
 public:
 	AudioOutputSource() noexcept;
@@ -174,8 +174,8 @@ public:
 	 * Be sure to call Fill() successfully before calling this
 	 * metohd.
 	 */
-	ConstBuffer<void> PeekData() const noexcept {
+	std::span<const std::byte> PeekData() const noexcept {
-		return pending_data.ToVoid();
+		return pending_data;
 	}
 
 	/**
@@ -196,7 +196,7 @@ public:
 	/**
 	 * Wrapper for Filter::Flush().
 	 */
-	ConstBuffer<void> Flush();
+	std::span<const std::byte> Flush();
 
 private:
 	void OpenFilter(AudioFormat audio_format,
@@ -206,11 +206,11 @@ private:
 
 	void CloseFilter() noexcept;
 
-	ConstBuffer<void> GetChunkData(const MusicChunk &chunk,
+	std::span<const std::byte> GetChunkData(const MusicChunk &chunk,
 				       Filter *replay_gain_filter,
 				       unsigned *replay_gain_serial_p);
 
-	ConstBuffer<void> FilterChunk(const MusicChunk &chunk);
+	std::span<const std::byte> FilterChunk(const MusicChunk &chunk);
 
 	void DropCurrentChunk() noexcept {
 		assert(current_chunk != nullptr);

src/output/Thread.cxx

@@ -265,9 +265,9 @@ AudioOutputControl::PlayChunk(std::unique_lock<Mutex> &lock) noexcept
 
 		try {
 			const ScopeUnlock unlock(mutex);
-			nbytes = output->Play(data.data, data.size);
+			nbytes = output->Play(data.data(), data.size());
 			assert(nbytes > 0);
-			assert(nbytes <= data.size);
+			assert(nbytes <= data.size());
 		} catch (AudioOutputInterrupted) {
 			caught_interrupted = true;
 			return false;
@@ -377,15 +377,13 @@ AudioOutputControl::InternalPause(std::unique_lock<Mutex> &lock) noexcept
 }
 
 static void
-PlayFull(FilteredAudioOutput &output, ConstBuffer<void> _buffer)
+PlayFull(FilteredAudioOutput &output, std::span<const std::byte> buffer)
 {
-	auto buffer = ConstBuffer<uint8_t>::FromVoid(_buffer);
-
 	while (!buffer.empty()) {
-		size_t nbytes = output.Play(buffer.data, buffer.size);
+		size_t nbytes = output.Play(buffer.data(), buffer.size());
 		assert(nbytes > 0);
 
-		buffer.skip_front(nbytes);
+		buffer = buffer.subspan(nbytes);
 	}
 
 }
@@ -404,7 +402,7 @@ AudioOutputControl::InternalDrain() noexcept
 
 		while (true) {
 			auto buffer = source.Flush();
-			if (buffer.IsNull())
+			if (buffer.data() == nullptr)
 				break;
 
 			PlayFull(*output, buffer);

src/output/plugins/AlsaOutputPlugin.cxx

@@ -35,7 +35,6 @@
 #include "util/Manual.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
-#include "util/ConstBuffer.hxx"
 #include "event/MultiSocketMonitor.hxx"
 #include "event/InjectEvent.hxx"
 #include "event/FineTimerEvent.hxx"

src/output/plugins/JackOutputPlugin.cxx

@@ -24,7 +24,6 @@
 #include "output/Features.h"
 #include "thread/Mutex.hxx"
 #include "util/ScopeExit.hxx"
-#include "util/ConstBuffer.hxx"
 #include "util/IterableSplitString.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
@@ -32,6 +31,7 @@
 
 #include <atomic>
 #include <cassert>
+#include <span>
 
 #include <jack/jack.h>
 #include <jack/types.h>
@@ -287,7 +287,7 @@ JackOutput::GetAvailable() const noexcept
  * Call jack_ringbuffer_read_advance() on all buffers in the list.
  */
 static void
-MultiReadAdvance(ConstBuffer<jack_ringbuffer_t *> buffers,
+MultiReadAdvance(std::span<jack_ringbuffer_t *const> buffers,
 		 size_t size)
 {
 	for (auto *i : buffers)
@@ -316,7 +316,7 @@ WriteSilence(jack_port_t &port, jack_nframes_t nframes)
  * Write a specific amount of "silence" to all ports in the list.
  */
 static void
-MultiWriteSilence(ConstBuffer<jack_port_t *> ports, jack_nframes_t nframes)
+MultiWriteSilence(std::span<jack_port_t *const> ports, jack_nframes_t nframes)
 {
 	for (auto *i : ports)
 		WriteSilence(*i, nframes);

src/output/plugins/OSXOutputPlugin.cxx

@@ -28,7 +28,6 @@
 #include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
 #include "util/Manual.hxx"
-#include "util/ConstBuffer.hxx"
 #include "pcm/Export.hxx"
 #include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
@@ -46,6 +45,7 @@
 #include <boost/lockfree/spsc_queue.hpp>
 
 #include <memory>
+#include <span>
 
 static constexpr unsigned MPD_OSX_BUFFER_TIME_MS = 100;
 
@@ -96,7 +96,7 @@ struct OSXOutput final : AudioOutput {
 	AudioComponentInstance au;
 	AudioStreamBasicDescription asbd;
 
-	boost::lockfree::spsc_queue<uint8_t> *ring_buffer;
+	boost::lockfree::spsc_queue<std::byte> *ring_buffer;
 
 	OSXOutput(const ConfigBlock &block);
 
@@ -620,7 +620,7 @@ osx_render(void *vdata,
 
 	int count = in_number_frames * od->asbd.mBytesPerFrame;
 	buffer_list->mBuffers[0].mDataByteSize =
-		od->ring_buffer->pop((uint8_t *)buffer_list->mBuffers[0].mData,
+		od->ring_buffer->pop((std::byte *)buffer_list->mBuffers[0].mData,
 				     count);
 	return noErr;
 }
@@ -764,7 +764,7 @@ OSXOutput::Open(AudioFormat &audio_format)
 						   MPD_OSX_BUFFER_TIME_MS * pcm_export->GetOutputFrameSize() * asbd.mSampleRate / 1000);
 	}
 #endif
-	ring_buffer = new boost::lockfree::spsc_queue<uint8_t>(ring_buffer_size);
+	ring_buffer = new boost::lockfree::spsc_queue<std::byte>(ring_buffer_size);
 
 	pause = false;
 	started = false;
@@ -777,17 +777,17 @@ OSXOutput::Play(const void *chunk, size_t size)
 
 	pause = false;
 
-	ConstBuffer<uint8_t> input((const uint8_t *)chunk, size);
+	std::span<const std::byte> input((const std::byte *)chunk, size);
 
 #ifdef ENABLE_DSD
 	if (dop_enabled) {
-		input = ConstBuffer<uint8_t>::FromVoid(pcm_export->Export(input.ToVoid()));
+		input = pcm_export->Export(input);
 		if (input.empty())
 			return size;
 	}
 #endif
 
-	size_t bytes_written = ring_buffer->push(input.data, input.size);
+	size_t bytes_written = ring_buffer->push(input.data(), input.size());
 
 	if (!started) {
 		OSStatus status = AudioOutputUnitStart(au);

src/output/plugins/OssOutputPlugin.cxx

@@ -23,7 +23,6 @@
 #include "pcm/Export.hxx"
 #include "io/UniqueFileDescriptor.hxx"
 #include "system/Error.hxx"
-#include "util/ConstBuffer.hxx"
 #include "util/Domain.hxx"
 #include "util/ByteOrder.hxx"
 #include "util/Manual.hxx"

src/output/plugins/wasapi/WasapiOutputPlugin.cxx

@@ -35,7 +35,6 @@
 #include "thread/Name.hxx"
 #include "thread/Thread.hxx"
 #include "util/AllocatedString.hxx"
-#include "util/ConstBuffer.hxx"
 #include "util/Domain.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/ScopeExit.hxx"
@@ -228,12 +227,12 @@ public:
 		SetStatus(Status::PAUSE);
 	}
 
-	std::size_t Push(ConstBuffer<void> input) noexcept {
+	std::size_t Push(std::span<const std::byte> input) noexcept {
 		empty.store(false);
 
 		std::size_t consumed =
-			spsc_buffer.push(static_cast<const BYTE *>(input.data),
+			spsc_buffer.push((const BYTE *)input.data(),
-					 input.size);
+					 input.size());
 
 		if (!playing) {
 			playing = true;
@@ -717,7 +716,7 @@ WasapiOutput::Play(const void *chunk, size_t size)
 
 	not_interrupted.test_and_set();
 
-	ConstBuffer<void> input(chunk, size);
+	std::span<const std::byte> input{(const std::byte*)chunk, size};
 	if (pcm_export) {
 		input = pcm_export->Export(input);
 	}
@@ -725,7 +724,7 @@ WasapiOutput::Play(const void *chunk, size_t size)
 		return size;
 
 	do {
-		const size_t consumed_size = thread->Push({input.data, input.size});
+		const size_t consumed_size = thread->Push(input);
 
 		if (consumed_size == 0) {
 			thread->Wait();