ClickHouse/base/poco/Util/include/Poco/Util/ConfigurationView.h

86 lines
2.4 KiB
C++

//
// ConfigurationView.h
//
// Library: Util
// Package: Configuration
// Module: ConfigurationView
//
// Definition of the ConfigurationView class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Util_ConfigurationView_INCLUDED
#define Util_ConfigurationView_INCLUDED
#include "Poco/Util/AbstractConfiguration.h"
#include "Poco/Util/Util.h"
namespace Poco
{
namespace Util
{
class Util_API ConfigurationView : public AbstractConfiguration
/// This configuration implements a "view" into a sub-hierarchy
/// of another configuration.
///
/// For example, given a configuration with the following properties:
/// config.value1
/// config.value2
/// config.sub.value1
/// config.sub.value2
/// and a ConfigurationView with the prefix "config", then
/// the above properties will be available via the view as
/// value1
/// value2
/// sub.value1
/// sub.value2
///
/// A ConfigurationView is most useful in combination with a
/// LayeredConfiguration.
///
/// If a property is not found in the view, it is searched in
/// the original configuration. Given the above example configuration,
/// the property named "config.value1" will still be found in the view.
///
/// The main reason for this is that placeholder expansion (${property})
/// still works as expected given a ConfigurationView.
{
public:
ConfigurationView(const std::string & prefix, AbstractConfiguration * pConfig);
/// Creates the ConfigurationView. The ConfigurationView does not take
/// ownership of the passed configuration.
protected:
bool getRaw(const std::string & key, std::string & value) const;
void setRaw(const std::string & key, const std::string & value);
void enumerate(const std::string & key, Keys & range) const;
void removeRaw(const std::string & key);
std::string translateKey(const std::string & key) const;
~ConfigurationView();
private:
ConfigurationView(const ConfigurationView &);
ConfigurationView & operator=(const ConfigurationView &);
std::string _prefix;
AbstractConfiguration * _pConfig;
};
}
} // namespace Poco::Util
#endif // Util_ConfigurationView_INCLUDED