discord-bot/libs/sqlite_orm-1.8.2/dev/backup.h

74 lines
2.5 KiB
C++

#pragma once
#include <sqlite3.h>
#include <system_error> // std::system_error
#include <string> // std::string
#include <memory>
#include <utility> // std::move, std::exchange
#include "error_code.h"
#include "connection_holder.h"
namespace sqlite_orm {
namespace internal {
/**
* A backup class. Don't construct it as is, call storage.make_backup_from or storage.make_backup_to instead.
* An instance of this class represents a wrapper around sqlite3_backup pointer. Use this class
* to have maximum control on a backup operation. In case you need a single backup in one line you
* can skip creating a backup_t instance and just call storage.backup_from or storage.backup_to function.
*/
struct backup_t {
backup_t(connection_ref to_,
const std::string& zDestName,
connection_ref from_,
const std::string& zSourceName,
std::unique_ptr<connection_holder> holder_) :
handle(sqlite3_backup_init(to_.get(), zDestName.c_str(), from_.get(), zSourceName.c_str())),
holder(std::move(holder_)), to(to_), from(from_) {
if(!this->handle) {
throw std::system_error{orm_error_code::failed_to_init_a_backup};
}
}
backup_t(backup_t&& other) :
handle(std::exchange(other.handle, nullptr)), holder(std::move(other.holder)), to(other.to),
from(other.from) {}
~backup_t() {
if(this->handle) {
(void)sqlite3_backup_finish(this->handle);
}
}
/**
* Calls sqlite3_backup_step with pages argument
*/
int step(int pages) {
return sqlite3_backup_step(this->handle, pages);
}
/**
* Returns sqlite3_backup_remaining result
*/
int remaining() const {
return sqlite3_backup_remaining(this->handle);
}
/**
* Returns sqlite3_backup_pagecount result
*/
int pagecount() const {
return sqlite3_backup_pagecount(this->handle);
}
protected:
sqlite3_backup* handle = nullptr;
std::unique_ptr<connection_holder> holder;
connection_ref to;
connection_ref from;
};
}
}