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#pragma once
#include <cstddef>
#include <cstdint>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include "esp32/himem.h"
#include "ff.h"
#include "span.hpp"
#include "sys/_stdint.h"
namespace database {
// Types used for indexing into files on disk. These should, at minimum, match
// the size of the types that the underlying filesystem uses to address within
// files. FAT32 uses 32 bit address. If we drop this and just support exFAT, we
// can change these to 64 bit types.
typedef uint32_t Index_t;
typedef Index_t IndexOffset_t;
// The amount of memory that will be used to page database columns in from disk.
// Currently we only use a single 'page' in PSRAM per column, but with some
// refactoring we could easily page more.
// Keep this value 32KiB-aligned for himem compatibility.
extern const std::size_t kRamBlockSize;
struct DatabaseHeader {
uint32_t magic_number;
uint16_t db_version;
Index_t num_indices;
};
struct DatabaseEntry {
uint8_t type;
std::string path;
std::string title;
std::string album;
std::string artist;
std::string album_artist;
};
struct IndexEntry {
uint8_t type;
IndexOffset_t path;
IndexOffset_t title;
IndexOffset_t album;
IndexOffset_t artist;
IndexOffset_t album_artist;
};
struct RowData {
std::unique_ptr<std::byte[]> arr;
std::size_t length;
};
// Representation of a single column of data. Each column is simply a tightly
// packed list of [size, [bytes, ...]] pairs. Callers are responsible for
// parsing and encoding the actual bytes themselves.
class Column {
public:
static auto Open(std::string) -> std::optional<Column>;
Column(FIL file, std::size_t file_size);
~Column();
auto ReadDataAtOffset(esp_himem_rangehandle_t, IndexOffset_t) -> RowData;
auto AppendRow(cpp::span<std::byte> row) -> bool;
auto FlushChanges() -> void;
private:
FIL file_;
IndexOffset_t length_;
esp_himem_handle_t block_;
std::pair<IndexOffset_t, IndexOffset_t> loaded_range_;
auto IsOffsetLoaded(IndexOffset_t offset) -> bool;
auto LoadOffsetFromDisk(cpp::span<std::byte> dest, IndexOffset_t offset)
-> bool;
};
} // namespace database
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