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#pragma once
#include <stdint.h>
#include <string>
#include "leveldb/db.h"
#include "leveldb/slice.h"
#include "song.hpp"
namespace database {
/*
* Helper class for creating leveldb Slices bundled with the data they point to.
* Slices are otherwise non-owning, which can make handling them post-creation
* difficult.
*/
class OwningSlice {
public:
std::string data;
leveldb::Slice slice;
explicit OwningSlice(std::string d);
};
/*
* Returns the prefix added to every SongData key. This can be used to iterate
* over every data record in the database.
*/
auto CreateDataPrefix() -> OwningSlice;
/* Creates a data key for a song with the specified id. */
auto CreateDataKey(const SongId& id) -> OwningSlice;
/*
* Encodes a SongData instance into bytes, in preparation for storing it within
* the database. This encoding is consistent, and will remain stable over time.
*/
auto CreateDataValue(const SongData& song) -> OwningSlice;
/*
* Parses bytes previously encoded via CreateDataValue back into a SongData. May
* return nullopt if parsing fails.
*/
auto ParseDataValue(const leveldb::Slice& slice) -> std::optional<SongData>;
/* Creates a hash key for the specified hash. */
auto CreateHashKey(const uint64_t& hash) -> OwningSlice;
/*
* Encodes a hash value (at this point just a song id) into bytes, in
* preparation for storing within the database. This encoding is consistent, and
* will remain stable over time.
*/
auto CreateHashValue(SongId id) -> OwningSlice;
/*
* Parses bytes previously encoded via CreateHashValue back into a song id. May
* return nullopt if parsing fails.
*/
auto ParseHashValue(const leveldb::Slice&) -> std::optional<SongId>;
/* Encodes a SongId as bytes. */
auto SongIdToBytes(SongId id) -> OwningSlice;
/*
* Converts a song id encoded via SongIdToBytes back into a SongId. May return
* nullopt if parsing fails.
*/
auto BytesToSongId(const std::string& bytes) -> std::optional<SongId>;
} // namespace database
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