mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-27 10:02:01 +00:00
50 lines
1.4 KiB
C++
50 lines
1.4 KiB
C++
#pragma once
|
|
|
|
#include <string>
|
|
#include <memory>
|
|
#include <boost/noncopyable.hpp>
|
|
#include <pcg_random.hpp>
|
|
#include <base/types.h>
|
|
|
|
|
|
namespace Poco::Util
|
|
{
|
|
class AbstractConfiguration;
|
|
}
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
/// Min and max lifetimes for a loadable object or it's entry
|
|
struct ExternalLoadableLifetime
|
|
{
|
|
UInt64 min_sec = 0;
|
|
UInt64 max_sec = 0;
|
|
|
|
ExternalLoadableLifetime(const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix);
|
|
ExternalLoadableLifetime() = default;
|
|
};
|
|
|
|
/// Get delay before trying to load again after error.
|
|
UInt64 calculateDurationWithBackoff(pcg64 & rnd_engine, size_t error_count = 1);
|
|
|
|
/// Basic interface for external loadable objects. Is used in ExternalLoader.
|
|
class IExternalLoadable : public std::enable_shared_from_this<IExternalLoadable>, private boost::noncopyable
|
|
{
|
|
public:
|
|
virtual ~IExternalLoadable() = default;
|
|
|
|
virtual const ExternalLoadableLifetime & getLifetime() const = 0;
|
|
|
|
virtual std::string getLoadableName() const = 0;
|
|
/// True if object can be updated when lifetime exceeded.
|
|
virtual bool supportUpdates() const = 0;
|
|
/// If lifetime exceeded and isModified(), ExternalLoader replace current object with the result of clone().
|
|
virtual bool isModified() const = 0;
|
|
/// Returns new object with the same configuration. Is used to update modified object when lifetime exceeded.
|
|
virtual std::shared_ptr<IExternalLoadable> clone() const = 0;
|
|
};
|
|
|
|
}
|