RDF graph module

Collaboration diagram for RDF graph module:

Macros
#define	VOLK_graph_add(...)
	Non-transactional version of VOLK_graph_add_txn.
#define	VOLK_graph_add_init(...)
	Non-transactional version of VOLK_graph_add_init_txn().
#define	VOLK_graph_bool_op(...)
	Non-transactional version of VOLK_graph_bool_op_txn.
#define	VOLK_graph_connections(...)
	Non-transactional version of VOLK_graph_connections_txn.
#define	VOLK_graph_contains(...)
	Non-transactional version of VOLK_graph_contains_txn().
#define	VOLK_graph_copy(src, dest)
#define	VOLK_graph_copy_contents(...)
#define	VOLK_graph_equals(...)
	Non-transactional version of VOLK_graph_equals_txn.
#define	VOLK_graph_get(...)
	Non-transactional version of VOLK_graph_get_txn().
#define	VOLK_graph_lookup(...)
	Non-transactional version of VOLK_graph_lookup_txn.
#define	VOLK_graph_remove(...)
	Non-transactional version of VOLK_graph_remove_txn.
#define	VOLK_graph_set_uri(...)
	Non-transactional version of VOLK_graph_set_uri_txn().
#define	VOLK_graph_size(...)
	Non-transactional version of VOLK_graph_size_txn().
#define	VOLK_graph_term_set(...)
	Non-transactional version of VOLK_graph_term_set_txn.
#define	VOLK_graph_unique_terms(...)
	Non-transactional version of VOLK_graph_unique_terms_txn.

Functions
VOLK_Term *	VOLK_bnode_add_collection (VOLK_GraphIterator *it, VOLK_TermSet *ts)
	Add triples for an anonymous collection to a graph.
VOLK_GraphIterator *	VOLK_graph_add_init_txn (void *txn, VOLK_Graph *gr)
	Initialize an iterator to add triples.
VOLK_rc	VOLK_graph_add_iter (VOLK_GraphIterator *it, const VOLK_Triple *spo)
	Add a single triple to the store.
size_t	VOLK_graph_add_link_map (VOLK_GraphIterator *it, VOLK_LinkMap *lm)
	Add triples for a term and related link map to a graph.
VOLK_rc	VOLK_graph_add_txn (void *txn, VOLK_Graph *gr, VOLK_Triple *const *trp, size_t *ct)
	Add triples to a graph.
VOLK_rc	VOLK_graph_bool_op_txn (void *txn, const VOLK_bool_op op, const VOLK_Graph *gr1, const VOLK_Graph *gr2, VOLK_Graph *res)
VOLK_LinkMap *	VOLK_graph_connections_txn (void *txn, const VOLK_Graph *gr, const VOLK_Term *t, const VOLK_LinkType type)
	Get term pairs connected to a term in a graph.
bool	VOLK_graph_contains_txn (void *txn, const VOLK_Graph *gr, const VOLK_Triple *spo)
	Whether a graph contains a triple.
VOLK_rc	VOLK_graph_copy_contents_txn (void *txn, const VOLK_Graph *src, VOLK_Graph *dest, const VOLK_Term *s, const VOLK_Term *p, const VOLK_Term *o)
	Copy triples from a source graph into a destination one.
bool	VOLK_graph_equals_txn (void *txn, const VOLK_Graph *gr1, const VOLK_Graph *gr2)
	Compare two graphs.
void	VOLK_graph_free (VOLK_Graph *gr)
	Free a graph.
VOLK_Graph *	VOLK_graph_get_txn (void *txn, VOLK_Store *store, const VOLK_Term *uri, size_t *ct)
	Create a temp graph from stored triples.
void	VOLK_graph_iter_free (VOLK_GraphIterator *it)
	Free a graph iterator.
const VOLK_Graph *	VOLK_graph_iter_graph (VOLK_GraphIterator *it)
	Return the graph related to an iterator.
VOLK_rc	VOLK_graph_iter_next (VOLK_GraphIterator *it, VOLK_Triple **spo)
	Advance a cursor obtained by a lookup and return a matching triple.
VOLK_GraphIterator *	VOLK_graph_lookup_txn (void *txn, const VOLK_Graph *gr, const VOLK_Term *s, const VOLK_Term *p, const VOLK_Term *o, size_t *ct)
	Look up triples by a matching pattern and yield an iterator.
VOLK_Graph *	VOLK_graph_new (VOLK_Store *store, const char *uri_str)
	Create new graph.
VOLK_Graph *	VOLK_graph_new_ns (VOLK_Store *store, const char *ns_str)
	Create an empty graph using a namespace-prefixed string for its URI.
void	VOLK_graph_print (const VOLK_Graph *gr)
	Print graph information and triples to stdout.
VOLK_rc	VOLK_graph_remove_txn (void *txn, VOLK_Graph *gr, const VOLK_Term *s, const VOLK_Term *p, const VOLK_Term *o, size_t *ct)
	Delete triples by a matching pattern.
VOLK_rc	VOLK_graph_set_uri_txn (void *txn, VOLK_Graph *gr, const char *uri_str)
size_t	VOLK_graph_size_txn (void *txn, const VOLK_Graph *gr)
	Number of triples in a graph.
VOLK_Store *	VOLK_graph_store (const VOLK_Graph *gr)
	Underlying graph store handle.
VOLK_TermSet *	VOLK_graph_term_set_txn (void *txn, const VOLK_Graph *gr, const VOLK_Term *t1, const VOLK_TriplePos t1_pos, const VOLK_Term *t2, const VOLK_TriplePos t2_pos)
	Get a list of terms related to a term pair in a graph.
VOLK_TermSet *	VOLK_graph_unique_terms_txn (void *txn, const VOLK_Graph *gr, VOLK_TriplePos pos)
	Get all unique subjcts, predicates, or objects in a graph.
const VOLK_Term *	VOLK_graph_uri (const VOLK_Graph *gr)
	Read-only graph URI.

Detailed Description

Macro Definition Documentation

VOLK_graph_add

#define VOLK_graph_add

(

...

)

Value:

VOLK_graph_add_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_add_txn.

Definition at line 365 of file graph.h.

VOLK_graph_add_init

#define VOLK_graph_add_init

(

...

)

Value:

VOLK_graph_add_init_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_add_init_txn().

Definition at line 328 of file graph.h.

VOLK_graph_bool_op

#define VOLK_graph_bool_op

(

...

)

Value:

VOLK_graph_bool_op_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_bool_op_txn.

Definition at line 208 of file graph.h.

VOLK_graph_connections

#define VOLK_graph_connections

(

...

)

Value:

VOLK_graph_connections_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_connections_txn.

Definition at line 483 of file graph.h.

VOLK_graph_contains

#define VOLK_graph_contains

(

...

)

Value:

VOLK_graph_contains_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_contains_txn().

Definition at line 309 of file graph.h.

VOLK_graph_copy

#define VOLK_graph_copy	(		src,
			dest )

Value:

VOLK_graph_copy_contents_txn (NULL, src, dest, NULL, NULL, NULL)

Definition at line 173 of file graph.h.

VOLK_graph_copy_contents

#define VOLK_graph_copy_contents

(

...

)

Value:

VOLK_graph_copy_contents_txn (NULL, __VA_ARGS__)

Definition at line 157 of file graph.h.

VOLK_graph_equals

#define VOLK_graph_equals

(

...

)

Value:

VOLK_graph_equals_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_equals_txn.

Definition at line 234 of file graph.h.

VOLK_graph_get

#define VOLK_graph_get

(

...

)

Value:

VOLK_graph_get_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_get_txn().

Definition at line 114 of file graph.h.

VOLK_graph_lookup

#define VOLK_graph_lookup

(

...

)

Value:

VOLK_graph_lookup_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_lookup_txn.

Definition at line 414 of file graph.h.

VOLK_graph_remove

#define VOLK_graph_remove

(

...

)

Value:

VOLK_graph_remove_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_remove_txn.

Definition at line 385 of file graph.h.

VOLK_graph_set_uri

#define VOLK_graph_set_uri

(

...

)

Value:

VOLK_graph_set_uri_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_set_uri_txn().

Definition at line 276 of file graph.h.

VOLK_graph_size

#define VOLK_graph_size

(

...

)

Value:

VOLK_graph_size_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_size_txn().

Definition at line 291 of file graph.h.

VOLK_graph_term_set

#define VOLK_graph_term_set

(

...

)

Value:

VOLK_graph_term_set_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_term_set_txn.

Definition at line 510 of file graph.h.

VOLK_graph_unique_terms

#define VOLK_graph_unique_terms

(

...

)

Value:

VOLK_graph_unique_terms_txn (NULL, __VA_ARGS__)

Non-transactional version of VOLK_graph_unique_terms_txn.

Definition at line 526 of file graph.h.

Function Documentation

VOLK_bnode_add_collection()

VOLK_Term * VOLK_bnode_add_collection	(	VOLK_GraphIterator *	it,
		VOLK_TermSet *	ts )

Add triples for an anonymous collection to a graph.

The rdf:first, rdf:rest, etc. terms are automatically added and the term for the first item in the list is returned.

Parameters

[in]	it	Graph iterator to use for insertion.
[in]	ts	Source term set.

Returns

Blank node representing the first list item.

Definition at line 904 of file graph.c.

VOLK_graph_add_init_txn()

VOLK_GraphIterator * VOLK_graph_add_init_txn	(	void *	txn,
		VOLK_Graph *	gr )

Initialize an iterator to add triples.

Parameters

[in]	txn	Transaction handle. If provided, the handle MUST be a valid, open read/write transaction. If NULL, a new transaction is opened and will be closed with VOLK_graph_iter_free(). This is ignored by graphs with non-transactional back ends.
[in]	gr	Graph to add to. It is added to the iterator state.

Returns

Iterator handle. This should be passed to VOLK_graph_add_iter() and must be freed with VOLK_graph_iter_free().

Definition at line 410 of file graph.c.

VOLK_graph_add_iter()

VOLK_rc VOLK_graph_add_iter	(	VOLK_GraphIterator *	it,
		const VOLK_Triple *	spo )

Add a single triple to the store.

Parameters

[in]	it	Iterator obtained with VOLK_graph_add_init_txn().
[in]	spo	Triple to add. The terms are copied and the caller retains ownership.

Note

the triple subject and object, if IRIRefs, are stored as relative to the graph URI.

Definition at line 427 of file graph.c.

VOLK_graph_add_link_map()

size_t VOLK_graph_add_link_map	(	VOLK_GraphIterator *	it,
		VOLK_LinkMap *	lm )

Add triples for a term and related link map to a graph.

The link map can be of inbound, outbound, or edge type; depending on that, triples are added with the given term as the subject, the predicate, or the object.

Parameters

[in]	it	Graph iterator obtained with VOLK_graph_add_init_txn().
[in]	lm	Link map.

Returns

Number of triples parsed on success, or <0 (VOLK_*_ERR) on error.

Definition at line 885 of file graph.c.

VOLK_graph_add_txn()

VOLK_rc VOLK_graph_add_txn	(	void *	txn,
		VOLK_Graph *	gr,
		VOLK_Triple *const *	trp,
		size_t *	ct )

Add triples to a graph.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph to add triples to.
[in]	trp	NULL-terminated array of triple handles to add. The terms are copied and the caller retains ownership.
[out]	ct	This will be filled with the total number of triples inserted.

Note

the triple subject and object, if IRIRefs, are stored as relative to the graph URI.

Definition at line 484 of file graph.c.

VOLK_graph_bool_op_txn()

VOLK_rc VOLK_graph_bool_op_txn	(	void *	txn,
		const VOLK_bool_op	op,
		const VOLK_Graph *	gr1,
		const VOLK_Graph *	gr2,
		VOLK_Graph *	res )

Perform a boolean operation between two graphs.

This method populates an initialized graph with the result of the operation between two other graphs. The resulting graph may be of any store type and may be the result of graphs of different store types.

Parameters

[in]	txn	R/W transaction handle for the destination store. It may be NULL, or an open transaction within which the operation is performed. Read-only transactions are automatically opened for the source graphs if they are not in the same store as the destination.
[in]	op	Operation to perform. One of VOLK_bool_op.
[in]	gr1	First operand.
[in]	gr2	Second operand.
[out]	res	Result graph. The handle should be initialized via VOLK_graph_new() or equivalent. Any preexisting contents are not removed. If an unrecoverable error occurs, this graph is freed, and any preexisting triples are lost. Therefore, reusing a result graph handle should only be done in tightly controlled loops or sequences.

Returns

VOLK_OK on success; <0 on error.

Definition at line 111 of file graph.c.

VOLK_graph_connections_txn()

VOLK_LinkMap * VOLK_graph_connections_txn	(	void *	txn,
		const VOLK_Graph *	gr,
		const VOLK_Term *	t,
		const VOLK_LinkType	type )

Get term pairs connected to a term in a graph.

This returns a VOLK_LinkMap extracted from a graph for a given term. The map can generate triples using VOLK_link_map_triples().

Depending on the type requested (VOLK_CONN_*), the term can be leveraged as a subject, predicate, or object.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph to extract the connection list from.
[in]	t	Term to query for connections.
[in]	type	Type of connections to look up.

Returns

Link map for the requested term. It should be freed with VOLK_link_map_free().

Definition at line 763 of file graph.c.

VOLK_graph_contains_txn()

bool VOLK_graph_contains_txn	(	void *	txn,
		const VOLK_Graph *	gr,
		const VOLK_Triple *	spo )

Whether a graph contains a triple.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph to look up into.
[in]	spo	Triple to look up.

Returns

1 if the triple is found, 0 if not found.

Definition at line 717 of file graph.c.

VOLK_graph_copy_contents_txn()

VOLK_rc VOLK_graph_copy_contents_txn	(	void *	txn,
		const VOLK_Graph *	src,
		VOLK_Graph *	dest,
		const VOLK_Term *	s,
		const VOLK_Term *	p,
		const VOLK_Term *	o )

Copy triples from a source graph into a destination one.

The destination graph is not initialized here, so the copy is cumulative.

A 3-term pattern may be provided to filter triples to be extracted from the source graph. If all terms are NULL, all triples are copied.

Parameters

[in]	txn	Transaction handle. It may be NULL, or an open transaction handle, in which case the copy is done within the specified transaction.
[in]	src	Source graph.
[in]	dest	Destination graph.
[in]	s,p,o	Terms to look up for filtering. Any and all terms can be NULL, which indicate unbound terms.

Returns

VOLK_OK on success; VOLK_NOACTION if no triples were copied; <0 if an error occurred.

Definition at line 549 of file graph.c.

VOLK_graph_equals_txn()

bool VOLK_graph_equals_txn	(	void *	txn,
		const VOLK_Graph *	gr1,
		const VOLK_Graph *	gr2 )

Compare two graphs.

Note that if any of the two graphs has an open transaction, the function is performed in the first graph's transaction.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr1	First operand.
[in]	gr2	Second operand.

Returns

True if the graphs are topologically equal, false otherwise.

Definition at line 354 of file graph.c.

VOLK_graph_free()

void VOLK_graph_free

(

VOLK_Graph *

gr

)

Free a graph.

Definition at line 263 of file graph.c.

VOLK_graph_get_txn()

VOLK_Graph * VOLK_graph_get_txn	(	void *	txn,
		VOLK_Store *	store,
		const VOLK_Term *	uri,
		size_t *	ct )

Create a temp graph from stored triples.

The new graph is stored in a hash map and is made up of all the triples found in the store with the given context URI. The new graph URI is the same as the given context.

Parameters

[in]	txn	Transaction handle. If not NULL, new child transaction will be opened under the one provided.
[in]	store	Back end store handle.
[in]	uri	URI of the graph to retrieve.
[out]	ct	If not NULL, it will be populated with the number of triples found. TODO deprecate. VOLK_graph_size() does the same.

Returns

New graph handle. It must be freed by the caller. If no matching context URI was found, NULL is returned.

Definition at line 67 of file graph.c.

VOLK_graph_iter_free()

void VOLK_graph_iter_free

(

VOLK_GraphIterator *

it

)

Free a graph iterator.

DO NOT USE with iterators obtained with VOLK_graph_add_init_txn(). Use VOLK_graph_iter_free() with those.

Parameters

[in]

it

Iterator to finalize.

Definition at line 688 of file graph.c.

VOLK_graph_iter_graph()

const VOLK_Graph * VOLK_graph_iter_graph

(

VOLK_GraphIterator *

it

)

Return the graph related to an iterator.

Definition at line 678 of file graph.c.

VOLK_graph_iter_next()

VOLK_rc VOLK_graph_iter_next	(	VOLK_GraphIterator *	it,
		VOLK_Triple **	spo )

Advance a cursor obtained by a lookup and return a matching triple.

Parameters

[in]	it	Iterator handle obtained through VOLK_graph_lookup_txn.
[out]	spo	Triple handle pointer to be populated with the next result. If not NULL, it will allocate a new triple and new terms, and should be freed with VOLK_triple_free().

Returns

VOLK_OK if a result was found; VOLK_END if the end of the match list was reached.

Definition at line 658 of file graph.c.

VOLK_graph_lookup_txn()

VOLK_GraphIterator * VOLK_graph_lookup_txn	(	void *	txn,
		const VOLK_Graph *	gr,
		const VOLK_Term *	s,
		const VOLK_Term *	p,
		const VOLK_Term *	o,
		size_t *	ct )

Look up triples by a matching pattern and yield an iterator.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph to look up.
[in]	s	Subject to look for. It can be NULL, which indicates an unbound term.
[in]	p	Predicate to look for. It can be NULL, which indicates an unbound term.
[in]	o	Object to look for. It can be NULL, which indicates an unbound term.
[out]	ct	If not NULL, this handle is populated with the number of entries found.

Returns

Pointer to a VOLK_GraphIterator to be generated. It must be freed with VOLK_graph_iter_free() after use.

Definition at line 599 of file graph.c.

VOLK_graph_new()

VOLK_Graph * VOLK_graph_new	(	VOLK_Store *	store,
		const char *	uri_str )

Create new graph.

This operation does not perform any access to the back end store (unless store is NULL, in which case a non-transactional store is created at this time), hence it is non-transactional.

Parameters

[in]	store	Back end store handle. It may be the result of VOLK_store_new(), or NULL; in the latter case, it defaults to a temporary HTable store that is freed together with the graph.
[in]	uri_str	URI string of the new graph. It MUST be a non-prefixed URI. For a namespace-prefixed URI, use VOLK_graph_new_ns(). If NULL, a UUID4 URN is generated.

Returns

New graph, or NULL on error. Must be freed with VOLK_graph_free().

Definition at line 45 of file graph.c.

VOLK_graph_new_ns()

VOLK_Graph * VOLK_graph_new_ns ( VOLK_Store * store, const char * ns_str )

inline

Create an empty graph using a namespace-prefixed string for its URI.

Parameters

[in]	store	Back end store handle. It may be the result of VOLK_store_new(), or NULL; in the latter case, it defaults to a temporary HTable store that is freed together with the graph.
[in]	ns_str	URI string of the new graph. It MUST be a namespace- prefixed URI registered in the global namespace map. It cannot be NULL.

Returns

New graph, or NULL on error. Must be freed with VOLK_graph_free().

Definition at line 75 of file graph.h.

VOLK_graph_print()

void VOLK_graph_print

(

const VOLK_Graph *

gr

)

Print graph information and triples to stdout.

Parameters

[in]

gr

Graph handle to display.

Definition at line 733 of file graph.c.

VOLK_graph_remove_txn()

VOLK_rc VOLK_graph_remove_txn	(	void *	txn,
		VOLK_Graph *	gr,
		const VOLK_Term *	s,
		const VOLK_Term *	p,
		const VOLK_Term *	o,
		size_t *	ct )

Delete triples by a matching pattern.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph to delete triples from.
[in]	s,p,o	Matching pattern. Any and all of s, p, o can be NULL.
[out]	ct	If not NULL it is populated with the number of triples deleted.

Definition at line 518 of file graph.c.

VOLK_graph_set_uri_txn()

VOLK_rc VOLK_graph_set_uri_txn	(	void *	txn,
		VOLK_Graph *	gr,
		const char *	uri_str )

Set the URI of a graph.

Note that by changing the URI of a graph backed by a context-sensitive store (i.e. VOLK_STORE_MDB*) effectively changes the underlying context that the triples are bound to. Triples are looked up in, and added to, the context that the graph URI represents. A non-context graph retains the same triple set when a graph URI changes, and relative URI lookups are resolved in real-time against the current graph URI.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph handle.
[in]	uri_str	New URI string. If namespace-prefixed, it will be resolved according to the graph's namespace map.

Returns

VOLK_OK on success; <0 on error.

Definition at line 287 of file graph.c.

VOLK_graph_size_txn()

size_t VOLK_graph_size_txn	(	void *	txn,
		const VOLK_Graph *	gr )

Number of triples in a graph.

Parameters

[in]	txn	Transaction handle. It may be NULL.
	gr	Graph handle.

Returns

Number of triples, or a negative value on error.

Definition at line 328 of file graph.c.

VOLK_graph_store()

VOLK_Store * VOLK_graph_store

(

const VOLK_Graph *

gr

)

Underlying graph store handle.

Definition at line 282 of file graph.c.

VOLK_graph_term_set_txn()

VOLK_TermSet * VOLK_graph_term_set_txn	(	void *	txn,
		const VOLK_Graph *	gr,
		const VOLK_Term *	t1,
		const VOLK_TriplePos	t1_pos,
		const VOLK_Term *	t2,
		const VOLK_TriplePos	t2_pos )

Get a list of terms related to a term pair in a graph.

Parameters

[in]	txn	Transaction handle. It may be NULL.
[in]	gr	Graph to extract terms from.
[in]	t1	First term.
[in]	t1_pos	Position of the first term in the triples to look up.
[in]	t2	Second term.
[in]	t2_pos	Position of the second term in the triples to look up.

Returns

Term set of results.

Definition at line 829 of file graph.c.

VOLK_graph_unique_terms_txn()

VOLK_TermSet * VOLK_graph_unique_terms_txn	(	void *	txn,
		const VOLK_Graph *	gr,
		VOLK_TriplePos	pos )

Get all unique subjcts, predicates, or objects in a graph.

Parameters

[in]	txn	Transaction handle to work in. It may be NULL.
[in]	gr	Graph handle.
[in]	pos	Position in the triples of the terms to look for.

Definition at line 864 of file graph.c.

VOLK_graph_uri()

const VOLK_Term * VOLK_graph_uri

(

const VOLK_Graph *

gr

)

Read-only graph URI.

Note that, while VOLK_graph_new() and VOLK_graph_set_uri() expect a string, this function returns the complete VOLK_Term structure.

To change the graph URI, use VOLK_graph_set_uri.

Definition at line 278 of file graph.c.