#include <BackingStore.h>

Inheritance diagram for opencog::BackingStore:

Public Member Functions
virtual	~BackingStore ()

virtual LinkPtr	getLink (Type, const HandleSeq &) const =0

virtual NodePtr	getNode (Type, const char *) const =0

virtual AtomPtr	getAtom (Handle) const =0

virtual HandleSeq	getIncomingSet (Handle) const =0

virtual void	storeAtom (Handle)=0

virtual void	loadType (AtomTable &, Type)=0

virtual void	barrier ()=0

virtual bool	ignoreType (Type t) const

virtual bool	ignoreAtom (Handle) const

Public Attributes
std::set< Type >	_ignored_types

Detailed Description

This class provides a simple, generic interface for dynamically storing/retreiving atoms from disk or other remote location or process. This class focuses on "on-demand" atom retreival, rather than on bulk-save/restore (although perhaps that should be provided as well.)

Definition at line 46 of file BackingStore.h.

Constructor & Destructor Documentation

virtual opencog::BackingStore::~BackingStore ( )

inlinevirtual

Definition at line 49 of file BackingStore.h.

Member Function Documentation

virtual void opencog::BackingStore::barrier ( )

pure virtual

Read-write synchronization barrier. All writes will be completed before this routine returns. This allows the backend to implement asynchronous writes, while still providing some control to those who need it. (Mostly the unit tests, at this time.)

Implemented in opencog::SQLBackingStore.

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virtual AtomPtr opencog::BackingStore::getAtom ( Handle ) const

pure virtual

Return a pointer to an Atom associated with the given handle, if it exists; else return NULL.

Implemented in opencog::AtomspaceHTabler, and opencog::SQLBackingStore.

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virtual HandleSeq opencog::BackingStore::getIncomingSet ( Handle ) const

pure virtual

Return a vector containing the handles of the entire incoming set of the indicated handle.

Implemented in opencog::AtomspaceHTabler, and opencog::SQLBackingStore.

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virtual LinkPtr opencog::BackingStore::getLink	(	Type	,
		const HandleSeq &
	)		const

pure virtual

Return a pointer to a link of the indicated type and outset, if it exists; else return NULL.

Implemented in opencog::SQLBackingStore.

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virtual NodePtr opencog::BackingStore::getNode	(	Type	,
		const char *
	)		const

pure virtual

Return a pointer to a node of the indicated type and name, if it exists; else return NULL.

Implemented in opencog::AtomspaceHTabler, and opencog::SQLBackingStore.

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bool BackingStore::ignoreAtom ( Handle h ) const

virtual

Returns true if the backing store will ignore this atom, either because it is of an ignorable type, or is a link which contains an atom that is of an ignorable type.

Definition at line 30 of file BackingStore.cc.

References python.create_atoms_by_type::a, ignoreType(), and opencog::LinkCast().

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virtual bool opencog::BackingStore::ignoreType ( Type t ) const

inlinevirtual

Returns true if the backing store will ignore this type. This is used for performance optimization, as asking the backend to retreive an atom can take a long time. If an atom is of this given type, it will not be fetched.

Definition at line 105 of file BackingStore.h.

References _ignored_types.

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virtual void opencog::BackingStore::loadType	(	AtomTable &	,
		Type
	)

pure virtual

Load all atoms of the given type, but only if they are not already in the AtomTable. (This avoids truth value merges between truth values stored in the backend, and truth values in the atomspace.)

Implemented in opencog::SQLBackingStore.

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