opencog-atomspace-storage / opencog / persist / flow / FetchValueOfLink.h

/*
 * opencog/persist/flow/FetchValueOfLink.h
 *
 * Copyright (C) 2015, 2022 Linas Vepstas
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License v3 as
 * published by the Free Software Foundation and including the exceptions
 * at http://opencog.org/wiki/Licenses
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, write to:
 * Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef _OPENCOG_FETCH_VALUE_OF_LINK_H
#define _OPENCOG_FETCH_VALUE_OF_LINK_H

#include <opencog/persist/storage/storage_types.h>
#include <opencog/atoms/flow/ValueOfLink.h>

namespace opencog
{
/** \addtogroup grp_atomspace
 *  @{
 */

/// The FetchValueOfLink gets a Value from an open StorageNode,
/// sets it at the key, and then returns that Value.
///
class FetchValueOfLink : public ValueOfLink
{
private:
	void init(void);

public:
	FetchValueOfLink(const HandleSeq&&, Type = FETCH_VALUE_OF_LINK);
	FetchValueOfLink(const FetchValueOfLink&) = delete;
	FetchValueOfLink& operator=(const FetchValueOfLink&) = delete;

	// Return a pointer to the Value being updated.
	virtual ValuePtr execute(AtomSpace*, bool);

	static Handle factory(const Handle&);
};

LINK_PTR_DECL(FetchValueOfLink)
#define createFetchValueOfLink CREATE_DECL(FetchValueOfLink)

/** @}*/
}

extern "C" {
void opencog_persist_flow_init(void);
};

#endif // _OPENCOG_FETCH_VALUE_OF_LINK_H