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#pragma once
#include <cstdint>
#include <future>
#include <memory>
#include <optional>
#include <string>
#include <utility>
#include <vector>
#include "leveldb/cache.h"
#include "leveldb/db.h"
#include "leveldb/iterator.h"
#include "leveldb/slice.h"
#include "result.hpp"
namespace database {
struct Artist {
std::string name;
};
struct Album {
std::string name;
};
typedef uint64_t SongId_t;
struct Song {
std::string title;
uint64_t id;
};
struct SongMetadata {};
template <typename T>
class DbResult {
public:
DbResult(const std::vector<T>& values, std::unique_ptr<leveldb::Iterator> it)
: values_(values), it_(std::move(it)) {}
auto values() -> std::vector<T> { return values_; }
auto it() -> leveldb::Iterator* { return it_.release(); };
private:
std::vector<T> values_;
std::unique_ptr<leveldb::Iterator> it_;
};
class Database {
public:
enum DatabaseError {
ALREADY_OPEN,
FAILED_TO_OPEN,
};
static auto Open() -> cpp::result<Database*, DatabaseError>;
~Database();
auto Populate() -> std::future<void>;
auto GetArtists(std::size_t page_size) -> std::future<DbResult<Artist>>;
auto GetMoreArtists(std::size_t page_size, DbResult<Artist> continuation)
-> std::future<DbResult<Artist>>;
auto GetAlbums(std::size_t page_size, std::optional<Artist> artist)
-> std::future<DbResult<Album>>;
auto GetMoreAlbums(std::size_t page_size, DbResult<Album> continuation)
-> std::future<DbResult<Album>>;
auto GetSongs(std::size_t page_size) -> std::future<DbResult<Song>>;
auto GetSongs(std::size_t page_size, std::optional<Artist> artist)
-> std::future<DbResult<Song>>;
auto GetSongs(std::size_t page_size,
std::optional<Artist> artist,
std::optional<Album> album) -> std::future<DbResult<Song>>;
auto GetMoreSongs(std::size_t page_size, DbResult<Song> continuation)
-> std::future<DbResult<Song>>;
auto GetSongIds(std::optional<Artist> artist, std::optional<Album> album)
-> std::future<std::vector<SongId_t>>;
auto GetSongFilePath(SongId_t id) -> std::future<std::optional<std::string>>;
auto GetSongMetadata(SongId_t id) -> std::future<std::optional<SongMetadata>>;
Database(const Database&) = delete;
Database& operator=(const Database&) = delete;
private:
std::unique_ptr<leveldb::DB> db_;
std::unique_ptr<leveldb::Cache> cache_;
Database(leveldb::DB* db, leveldb::Cache* cache);
};
} // namespace database
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