// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <array>
#include <mutex>
#include <span>
#include <vector>
#include "audio_buffer.h"
#include "audio_core/device/device_session.h"
#include "core/core_timing.h"
namespace AudioCore {
constexpr s32 BufferAppendLimit = 4;
/**
* A ringbuffer of N audio buffers.
* The buffer contains 3 sections:
* Appended - Buffers added to the ring, but have yet to be sent to the audio backend.
* Registered - Buffers sent to the backend and queued for playback.
* Released - Buffers which have been played, and can now be recycled.
* Any others are free/untracked.
*
* @tparam N - Maximum number of buffers in the ring.
*/
template <size_t N>
class AudioBuffers {
public:
explicit AudioBuffers(size_t limit) : append_limit{static_cast<u32>(limit)} {}
/**
* Append a new audio buffer to the ring.
*
* @param buffer - The new buffer.
*/
void AppendBuffer(const AudioBuffer& buffer) {
std::scoped_lock l{lock};
buffers[appended_index] = buffer;
appended_count++;
appended_index = (appended_index + 1) % append_limit;
}
/**
* Register waiting buffers, up to a maximum of BufferAppendLimit.
*
* @param out_buffers - The buffers which were registered.
*/
void RegisterBuffers(std::vector<AudioBuffer>& out_buffers) {
std::scoped_lock l{lock};
const s32 to_register{std::min(std::min(appended_count, BufferAppendLimit),
BufferAppendLimit - registered_count)};
for (s32 i = 0; i < to_register; i++) {
s32 index{appended_index - appended_count};
if (index < 0) {
index += N;
}
out_buffers.push_back(buffers[index]);
registered_count++;
registered_index = (registered_index + 1) % append_limit;
appended_count--;
if (appended_count == 0) {
break;
}
}
}
/**
* Release a single buffer. Must be already registered.
*
* @param index - The buffer index to release.
* @param timestamp - The released timestamp for this buffer.
*/
void ReleaseBuffer(s32 index, s64 timestamp) {
std::scoped_lock l{lock};
buffers[index].played_timestamp = timestamp;
registered_count--;
released_count++;
released_index = (released_index + 1) % append_limit;
}
/**
* Release all registered buffers.
*
* @param core_timing - The CoreTiming instance
* @param session - The device session
*
* @return If any buffer was released.
*/
bool ReleaseBuffers(const Core::Timing::CoreTiming& core_timing, const DeviceSession& session,
bool force) {
std::scoped_lock l{lock};
bool buffer_released{false};
while (registered_count > 0) {
auto index{registered_index - registered_count};
if (index < 0) {
index += N;
}
// Check with the backend if this buffer can be released yet.
// If we're shutting down, we don't care if it's been played or not.
if (!force && !session.IsBufferConsumed(buffers[index])) {
break;
}
ReleaseBuffer(index, core_timing.GetGlobalTimeNs().count());
buffer_released = true;
}
return buffer_released || registered_count == 0;
}
/**
* Get all released buffers.
*
* @param tags - Container to be filled with the released buffers' tags.
* @return The number of buffers released.
*/
u32 GetReleasedBuffers(std::span<u64> tags) {
std::scoped_lock l{lock};
u32 released{0};
while (released_count > 0) {
auto index{released_index - released_count};
if (index < 0) {
index += N;
}
auto& buffer{buffers[index]};
released_count--;
auto tag{buffer.tag};
buffer.played_timestamp = 0;
buffer.samples = 0;
buffer.tag = 0;
buffer.size = 0;
if (tag == 0) {
break;
}
tags[released++] = tag;
if (released >= tags.size()) {
break;
}
}
return released;
}
/**
* Get all appended and registered buffers.
*
* @param buffers_flushed - Output vector for the buffers which are released.
* @param max_buffers - Maximum number of buffers to released.
* @return The number of buffers released.
*/
u32 GetRegisteredAppendedBuffers(std::vector<AudioBuffer>& buffers_flushed, u32 max_buffers) {
std::scoped_lock l{lock};
if (registered_count + appended_count == 0) {
return 0;
}
size_t buffers_to_flush{
std::min(static_cast<u32>(registered_count + appended_count), max_buffers)};
if (buffers_to_flush == 0) {
return 0;
}
while (registered_count > 0) {
auto index{registered_index - registered_count};
if (index < 0) {
index += N;
}
buffers_flushed.push_back(buffers[index]);
registered_count--;
released_count++;
released_index = (released_index + 1) % append_limit;
if (buffers_flushed.size() >= buffers_to_flush) {
break;
}
}
while (appended_count > 0) {
auto index{appended_index - appended_count};
if (index < 0) {
index += N;
}
buffers_flushed.push_back(buffers[index]);
appended_count--;
released_count++;
released_index = (released_index + 1) % append_limit;
if (buffers_flushed.size() >= buffers_to_flush) {
break;
}
}
return static_cast<u32>(buffers_flushed.size());
}
/**
* Check if the given tag is in the buffers.
*
* @param tag - Unique tag of the buffer to search for.
* @return True if the buffer is still in the ring, otherwise false.
*/
bool ContainsBuffer(const u64 tag) const {
std::scoped_lock l{lock};
const auto registered_buffers{appended_count + registered_count + released_count};
if (registered_buffers == 0) {
return false;
}
auto index{released_index - released_count};
if (index < 0) {
index += append_limit;
}
for (s32 i = 0; i < registered_buffers; i++) {
if (buffers[index].tag == tag) {
return true;
}
index = (index + 1) % append_limit;
}
return false;
}
/**
* Get the number of active buffers in the ring.
* That is, appended, registered and released buffers.
*
* @return Number of active buffers.
*/
u32 GetAppendedRegisteredCount() const {
std::scoped_lock l{lock};
return appended_count + registered_count;
}
/**
* Get the total number of active buffers in the ring.
* That is, appended, registered and released buffers.
*
* @return Number of active buffers.
*/
u32 GetTotalBufferCount() const {
std::scoped_lock l{lock};
return static_cast<u32>(appended_count + registered_count + released_count);
}
/**
* Flush all of the currently appended and registered buffers
*
* @param buffers_released - Output count for the number of buffers released.
* @return True if buffers were successfully flushed, otherwise false.
*/
bool FlushBuffers(u32& buffers_released) {
std::scoped_lock l{lock};
std::vector<AudioBuffer> buffers_flushed{};
buffers_released = GetRegisteredAppendedBuffers(buffers_flushed, append_limit);
if (registered_count > 0) {
return false;
}
if (static_cast<u32>(released_count + appended_count) > append_limit) {
return false;
}
return true;
}
u64 GetNextTimestamp() const {
// Iterate backwards through the buffer queue, and take the most recent buffer's end
std::scoped_lock l{lock};
auto index{appended_index - 1};
if (index < 0) {
index += append_limit;
}
return buffers[index].end_timestamp;
}
private:
/// Buffer lock
mutable std::recursive_mutex lock{};
/// The audio buffers
std::array<AudioBuffer, N> buffers{};
/// Current released index
s32 released_index{};
/// Number of released buffers
s32 released_count{};
/// Current registered index
s32 registered_index{};
/// Number of registered buffers
s32 registered_count{};
/// Current appended index
s32 appended_index{};
/// Number of appended buffers
s32 appended_count{};
/// Maximum number of buffers (default 32)
u32 append_limit{};
};
} // namespace AudioCore
