Fork of Tangara with customizations
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
tangara-fw/src/audio/include/readahead_source.hpp

60 lines
1.2 KiB

/*
* Copyright 2023 jacqueline <me@jacqueline.id.au>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#pragma once
#include <cstddef>
#include <cstdint>
#include <memory>
#include "freertos/FreeRTOS.h"
#include "ff.h"
#include "freertos/stream_buffer.h"
#include "audio_source.hpp"
#include "codec.hpp"
#include "tasks.hpp"
namespace audio {
/*
* Wraps another stream, proactively buffering large chunks of it into memory
* at a time.
*/
class ReadaheadSource : public codecs::IStream {
public:
ReadaheadSource(tasks::Worker&, std::unique_ptr<codecs::IStream>);
~ReadaheadSource();
auto Read(cpp::span<std::byte> dest) -> ssize_t override;
auto CanSeek() -> bool override;
auto SeekTo(int64_t destination, SeekFrom from) -> void override;
auto CurrentPosition() -> int64_t override;
auto Size() -> std::optional<int64_t> override;
auto SetPreambleFinished() -> void override;
ReadaheadSource(const ReadaheadSource&) = delete;
ReadaheadSource& operator=(const ReadaheadSource&) = delete;
private:
auto BeginReadahead() -> void;
tasks::Worker& worker_;
std::unique_ptr<codecs::IStream> wrapped_;
bool readahead_enabled_;
std::atomic<bool> is_refilling_;
StreamBufferHandle_t buffer_;
int64_t tell_;
};
} // namespace audio