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102 lines
2.7 KiB
C++
102 lines
2.7 KiB
C++
//
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// Subsystem.h
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//
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// Library: Util
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// Package: Application
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// Module: Subsystem
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//
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// Definition of the Subsystem class.
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//
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// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
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// and Contributors.
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//
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// SPDX-License-Identifier: BSL-1.0
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//
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#ifndef Util_Subsystem_INCLUDED
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#define Util_Subsystem_INCLUDED
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#include "Poco/RefCountedObject.h"
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#include "Poco/Util/Util.h"
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namespace Poco
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{
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namespace Util
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{
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class Application;
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class OptionSet;
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class Util_API Subsystem : public Poco::RefCountedObject
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/// Subsystems extend an application in a modular way.
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///
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/// The Subsystem class provides a common interface
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/// for subsystems so that subsystems can be automatically
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/// initialized at startup and uninitialized at shutdown.
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///
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/// Subsystems should also support dynamic reconfiguration,
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/// so that they can be reconfigured anytime during the
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/// life of a running application.
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///
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/// The degree to which dynamic reconfiguration is supported
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/// is up to the actual subsystem implementation. It can
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/// range from ignoring the reconfiguration request (not
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/// recommended), to changing certain settings that affect
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/// the performance, to a complete reinitialization.
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{
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public:
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Subsystem();
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/// Creates the Subsystem.
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virtual const char * name() const = 0;
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/// Returns the name of the subsystem.
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/// Must be implemented by subclasses.
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protected:
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virtual void initialize(Application & app) = 0;
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/// Initializes the subsystem.
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virtual void uninitialize() = 0;
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/// Uninitializes the subsystem.
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virtual void reinitialize(Application & app);
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/// Re-initializes the subsystem.
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///
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/// The default implementation just calls
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/// uninitialize() followed by initialize().
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/// Actual implementations might want to use a
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/// less radical and possibly more performant
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/// approach.
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virtual void defineOptions(OptionSet & options);
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/// Called before the Application's command line processing begins.
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/// If a subsystem wants to support command line arguments,
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/// it must override this method.
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/// The default implementation does not define any options.
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///
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/// To effectively handle options, a subsystem should either bind
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/// the option to a configuration property or specify a callback
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/// to handle the option.
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virtual ~Subsystem();
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/// Destroys the Subsystem.
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friend class Application;
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private:
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Subsystem(const Subsystem &);
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Subsystem & operator=(const Subsystem &);
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};
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}
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} // namespace Poco::Util
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#endif // Util_Subsystem_INCLUDED
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