Sord

A lightweight RDF model library. More...


World
SORD_API SordWorld *	sord_world_new (void)
SORD_API void	sord_world_free (SordWorld *world)
SORD_API void	sord_world_set_error_sink (SordWorld world, SerdErrorSink error_sink, void handle)
Node
SORD_API SordNode *	sord_new_uri (SordWorld world, const uint8_t uri)
SORD_API SordNode *	sord_new_relative_uri (SordWorld world, const uint8_t str, const uint8_t *base_uri)
SORD_API SordNode *	sord_new_blank (SordWorld world, const uint8_t str)
SORD_API SordNode *	sord_new_literal (SordWorld world, SordNode datatype, const uint8_t str, const char lang)
SORD_API SordNode *	sord_node_copy (const SordNode *node)
SORD_API void	sord_node_free (SordWorld world, SordNode node)
SORD_API SordNodeType	sord_node_get_type (const SordNode *node)
SORD_API const uint8_t *	sord_node_get_string (const SordNode *node)
SORD_API const uint8_t *	sord_node_get_string_counted (const SordNode node, size_t len)
SORD_API const char *	sord_node_get_language (const SordNode *node)
SORD_API SordNode *	sord_node_get_datatype (const SordNode *node)
SORD_API SerdNodeFlags	sord_node_get_flags (const SordNode *node)
SORD_API bool	sord_node_is_inline_object (const SordNode *node)
SORD_API bool	sord_node_equals (const SordNode a, const SordNode b)
SORD_API const SerdNode *	sord_node_to_serd_node (const SordNode *node)
SORD_API SordNode *	sord_node_from_serd_node (SordWorld world, SerdEnv env, const SerdNode node, const SerdNode datatype, const SerdNode *lang)
Model
SORD_API SordModel *	sord_new (SordWorld *world, unsigned indices, bool graphs)
SORD_API void	sord_free (SordModel *model)
SORD_API SordWorld *	sord_get_world (SordModel *model)
SORD_API size_t	sord_num_nodes (const SordWorld *world)
SORD_API size_t	sord_num_quads (const SordModel *model)
SORD_API SordIter *	sord_begin (const SordModel *model)
SORD_API SordIter *	sord_find (SordModel *model, const SordQuad pat)
SORD_API SordIter *	sord_search (SordModel model, const SordNode s, const SordNode p, const SordNode o, const SordNode *g)
SORD_API SordNode *	sord_get (SordModel model, const SordNode s, const SordNode p, const SordNode o, const SordNode *g)
SORD_API bool	sord_ask (SordModel model, const SordNode s, const SordNode p, const SordNode o, const SordNode *g)
SORD_API uint64_t	sord_count (SordModel model, const SordNode s, const SordNode p, const SordNode o, const SordNode *g)
SORD_API bool	sord_contains (SordModel *model, const SordQuad pat)
SORD_API bool	sord_add (SordModel *model, const SordQuad quad)
SORD_API void	sord_remove (SordModel *model, const SordQuad quad)
SORD_API SerdStatus	sord_erase (SordModel model, SordIter iter)
Inserter
SORD_API SordInserter *	sord_inserter_new (SordModel model, SerdEnv env)
SORD_API void	sord_inserter_free (SordInserter *inserter)
SORD_API SerdStatus	sord_inserter_set_base_uri (SordInserter inserter, const SerdNode uri)
SORD_API SerdStatus	sord_inserter_set_prefix (SordInserter inserter, const SerdNode name, const SerdNode *uri)
SORD_API SerdStatus	sord_inserter_write_statement (SordInserter inserter, SerdStatementFlags flags, const SerdNode graph, const SerdNode subject, const SerdNode predicate, const SerdNode object, const SerdNode object_datatype, const SerdNode *object_lang)
Iteration
SORD_API void	sord_iter_get (const SordIter *iter, SordQuad quad)
SORD_API const SordNode *	sord_iter_get_node (const SordIter *iter, SordQuadIndex index)
SORD_API const SordModel *	sord_iter_get_model (SordIter *iter)
SORD_API bool	sord_iter_next (SordIter *iter)
SORD_API bool	sord_iter_end (const SordIter *iter)
SORD_API void	sord_iter_free (SordIter *iter)
Utilities
SORD_API bool	sord_quad_match (const SordQuad x, const SordQuad y)
Serialisation
SORD_API SerdReader *	sord_new_reader (SordModel model, SerdEnv env, SerdSyntax syntax, SordNode *graph)
SORD_API bool	sord_write (SordModel model, SerdWriter writer, SordNode *graph)
SORD_API bool	sord_write_iter (SordIter iter, SerdWriter writer)
Typedefs
typedef struct SordWorldImpl	SordWorld
typedef struct SordModelImpl	SordModel
typedef struct SordInserterImpl	SordInserter
typedef struct SordIterImpl	SordIter
typedef struct SordNodeImpl	SordNode
typedef const SordNode *	SordQuad [4]
Enumerations
enum	SordQuadIndex { SORD_SUBJECT = 0, SORD_PREDICATE = 1, SORD_OBJECT = 2, SORD_GRAPH = 3 }
enum	SordNodeType { SORD_URI = 1, SORD_BLANK = 2, SORD_LITERAL = 3 }
enum	SordIndexOption { SORD_SPO = 1, SORD_SOP = 1 << 1, SORD_OPS = 1 << 2, SORD_OSP = 1 << 3, SORD_PSO = 1 << 4, SORD_POS = 1 << 5 }

Detailed Description

A lightweight RDF model library.

Sord stores RDF (subject object predicate context) quads, where the context may be omitted (to represent triples in the default graph).

Typedef Documentation

typedef struct SordWorldImpl SordWorld

Sord World.

The World represents all library state, including interned strings.

typedef struct SordModelImpl SordModel

Sord Model.

A model is an indexed set of Quads (i.e. it can contain several RDF graphs). It may be searched using various patterns depending on which indices are enabled.

typedef struct SordInserterImpl SordInserter

Model Inserter.

An inserter is used for writing statements to a model using the Serd sink interface. This makes it simple to write to a model directly using a SerdReader, or any other code that writes statements to a SerdStatementSink.

typedef struct SordIterImpl SordIter

Model Iterator.

typedef struct SordNodeImpl SordNode

RDF Node.

A Node is a component of a Quad. Nodes may be URIs, blank nodes, or (in the case of quad objects only) string literals. Literal nodes may have an associate language or datatype (but not both).

typedef const SordNode* SordQuad[4]

Quad of nodes (a statement), or a quad pattern.

Nodes are ordered (S P O G). The ID of the default graph is 0.

Enumeration Type Documentation

enum SordQuadIndex

Index into a SordQuad.

Enumerator:

SORD_SUBJECT	Subject.
SORD_PREDICATE	Predicate (a.k.a. "key")
SORD_OBJECT	Object (a.k.a. "value")
SORD_GRAPH	Graph (a.k.a. "context")

enum SordNodeType

Type of a node.

Enumerator:

SORD_URI	URI.
SORD_BLANK	Blank node identifier.
SORD_LITERAL	Literal (string with optional lang or datatype).

enum SordIndexOption

Indexing option.

Enumerator:

SORD_SPO	Subject, Predicate, Object.
SORD_SOP	Subject, Object, Predicate.
SORD_OPS	Object, Predicate, Subject.
SORD_OSP	Object, Subject, Predicate.
SORD_PSO	Predicate, Subject, Object.
SORD_POS	Predicate, Object, Subject.

Function Documentation

SORD_API SordWorld* sord_world_new ( void )

Create a new Sord World.

It is safe to use multiple worlds in one process, though no data (e.g. nodes) can be shared between worlds, and this should be avoided if possible for performance reasons.

SORD_API void sord_world_free ( SordWorld * world )

Free `world`.

SORD_API void sord_world_set_error_sink	(	SordWorld *	world,
		SerdErrorSink	error_sink,
		void *	handle
	)

Set a function to be called when errors occur.

The `error_sink` will be called with `handle` as its first argument. If no error function is set, errors are printed to stderr.

SORD_API SordNode* sord_new_uri	(	SordWorld *	world,
		const uint8_t *	uri
	)

Get a URI node from a string.

Note this function measures `str`, which is a common bottleneck. Use sord_node_from_serd_node instead if `str` is already measured.

SORD_API SordNode* sord_new_relative_uri	(	SordWorld *	world,
		const uint8_t *	str,
		const uint8_t *	base_uri
	)

Get a URI node from a relative URI string.

SORD_API SordNode* sord_new_blank	(	SordWorld *	world,
		const uint8_t *	str
	)

Get a blank node from a string.

Note this function measures `str`, which is a common bottleneck. Use sord_node_from_serd_node instead if `str` is already measured.

SORD_API SordNode* sord_new_literal	(	SordWorld *	world,
		SordNode *	datatype,
		const uint8_t *	str,
		const char *	lang
	)

Get a literal node from a string.

Note this function measures `str`, which is a common bottleneck. Use sord_node_from_serd_node instead if `str` is already measured.

SORD_API SordNode* sord_node_copy ( const SordNode * node )

Copy a node (obtain a reference).

Node that since nodes are interned and reference counted, this does not actually create a deep copy of `node`.

SORD_API void sord_node_free	(	SordWorld *	world,
		SordNode *	node
	)

Free a node (drop a reference).

SORD_API SordNodeType sord_node_get_type ( const SordNode * node )

Return the type of a node (SORD_URI, SORD_BLANK, or SORD_LITERAL).

SORD_API const uint8_t* sord_node_get_string ( const SordNode * node )

Return the string value of a node.

SORD_API const uint8_t* sord_node_get_string_counted	(	const SordNode *	node,
		size_t *	len
	)

Return the string value of a node, and set `len` to its length.

SORD_API const char* sord_node_get_language ( const SordNode * node )

Return the language of a literal node (or NULL).

SORD_API SordNode* sord_node_get_datatype ( const SordNode * node )

Return the datatype URI of a literal node (or NULL).

SORD_API SerdNodeFlags sord_node_get_flags ( const SordNode * node )

Return the flags (string attributes) of a node.

SORD_API bool sord_node_is_inline_object ( const SordNode * node )

Return true iff node can be serialised as an inline object.

More specifically, this returns true iff the node is the object field of exactly one statement, and therefore can be inlined since it needn't be referred to by name.

SORD_API bool sord_node_equals	(	const SordNode *	a,
		const SordNode *	b
	)

Return true iff `a` is equal to `b`.

Note this is much faster than comparing the node's strings.

SORD_API const SerdNode* sord_node_to_serd_node ( const SordNode * node )

Return a SordNode as a SerdNode.

The returned node is shared and must not be freed or modified.

SORD_API SordNode* sord_node_from_serd_node	(	SordWorld *	world,
		SerdEnv *	env,
		const SerdNode *	node,
		const SerdNode *	datatype,
		const SerdNode *	lang
	)

Create a new SordNode from a SerdNode.

The returned node must be freed using sord_node_free.

SORD_API SordModel* sord_new	(	SordWorld *	world,
		unsigned	indices,
		bool	graphs
	)

Create a new model.

Parameters:

	world	The world in which to make this model.
	indices	SordIndexOption flags (e.g. SORD_SPO\|SORD_OPS). Be sure to enable an index where the most significant node(s) are not variables in your queries (e.g. to make (? P O) queries, enable either SORD_OPS or SORD_POS).
	graphs	If true, store (and index) graph contexts.

SORD_API void sord_free ( SordModel * model )

Close and free `model`.

SORD_API SordWorld* sord_get_world ( SordModel * model )

Get the world associated with `model`.

SORD_API size_t sord_num_nodes ( const SordWorld * world )

Return the number of nodes stored in `world`.

Nodes are included in this count iff they are a part of a quad in `world`.

SORD_API size_t sord_num_quads ( const SordModel * model )

Return the number of quads stored in `model`.

SORD_API SordIter* sord_begin ( const SordModel * model )

Return an iterator to the start of `model`.

SORD_API SordIter* sord_find	(	SordModel *	model,
		const SordQuad	pat
	)

Search for statements by a quad pattern.

Returns:: an iterator to the first match, or NULL if no matches found.

SORD_API SordIter* sord_search	(	SordModel *	model,
		const SordNode *	s,
		const SordNode *	p,
		const SordNode *	o,
		const SordNode *	g
	)

Search for statements by nodes.

Returns:: an iterator to the first match, or NULL if no matches found.

SORD_API SordNode* sord_get	(	SordModel *	model,
		const SordNode *	s,
		const SordNode *	p,
		const SordNode *	o,
		const SordNode *	g
	)

Search for a single node that matches a pattern.

Exactly one of `s`, `p`, `o` must be NULL. This function is mainly useful for predicates that only have one value. The returned node must be freed using sord_node_free.

Returns:: the first matching node, or NULL if no matches are found.

SORD_API bool sord_ask	(	SordModel *	model,
		const SordNode *	s,
		const SordNode *	p,
		const SordNode *	o,
		const SordNode *	g
	)

Return true iff a statement exists.

SORD_API uint64_t sord_count	(	SordModel *	model,
		const SordNode *	s,
		const SordNode *	p,
		const SordNode *	o,
		const SordNode *	g
	)

Return the number of matching statements.

SORD_API bool sord_contains	(	SordModel *	model,
		const SordQuad	pat
	)

Check if `model` contains a triple pattern.

Returns:: true if `model` contains a match for `pat`, otherwise false.

SORD_API bool sord_add	(	SordModel *	model,
		const SordQuad	quad
	)

Add a quad to a model.

Calling this function invalidates all iterators on `model`.

Returns:: true on success, false, on error.

SORD_API void sord_remove	(	SordModel *	model,
		const SordQuad	quad
	)

Remove a quad from a model.

Calling this function invalidates all iterators on `model`. To remove quads while iterating, use sord_erase() instead.

SORD_API SerdStatus sord_erase	(	SordModel *	model,
		SordIter *	iter
	)

Remove a quad from a model via an iterator.

Calling this function invalidates all iterators on `model` except `iter`.

Parameters:

iter

Iterator to the element to erase, which is incremented to the next value on return.

SORD_API SordInserter* sord_inserter_new	(	SordModel *	model,
		SerdEnv *	env
	)

Create an inserter for writing statements to a model.

SORD_API void sord_inserter_free ( SordInserter * inserter )

Free an inserter.

SORD_API SerdStatus sord_inserter_set_base_uri	(	SordInserter *	inserter,
		const SerdNode *	uri
	)

Set the current base URI for writing to the model.

Note this function can be safely casted to SerdBaseSink.

SORD_API SerdStatus sord_inserter_set_prefix	(	SordInserter *	inserter,
		const SerdNode *	name,
		const SerdNode *	uri
	)

Set a namespace prefix for writing to the model.

Note this function can be safely casted to SerdPrefixSink.

SORD_API SerdStatus sord_inserter_write_statement	(	SordInserter *	inserter,
		SerdStatementFlags	flags,
		const SerdNode *	graph,
		const SerdNode *	subject,
		const SerdNode *	predicate,
		const SerdNode *	object,
		const SerdNode *	object_datatype,
		const SerdNode *	object_lang
	)

Write a statement to the model.

Note this function can be safely casted to SerdStatementSink.

SORD_API void sord_iter_get	(	const SordIter *	iter,
		SordQuad	quad
	)

Set `quad` to the quad pointed to by `iter`.

SORD_API const SordNode* sord_iter_get_node	(	const SordIter *	iter,
		SordQuadIndex	index
	)

Return a field of the quad pointed to by `iter`.

SORD_API const SordModel* sord_iter_get_model ( SordIter * iter )

Return the store pointed to by `iter`.

SORD_API bool sord_iter_next ( SordIter * iter )

Increment `iter` to point to the next statement.

SORD_API bool sord_iter_end ( const SordIter * iter )

Return true iff `iter` is at the end of its range.

SORD_API void sord_iter_free ( SordIter * iter )

Free `iter`.

SORD_API bool sord_quad_match	(	const SordQuad	x,
		const SordQuad	y
	)

Match two quads (using ID comparison only).

This function is a straightforward and fast equivalence match with wildcard support (ID 0 is a wildcard). It does not actually read node data.

Returns:: true iff `x` and `y` match.

SORD_API SerdReader* sord_new_reader	(	SordModel *	model,
		SerdEnv *	env,
		SerdSyntax	syntax,
		SordNode *	graph
	)

Return a reader that will read into `model`.

SORD_API bool sord_write	(	SordModel *	model,
		SerdWriter *	writer,
		SordNode *	graph
	)

Write a model to a writer.

SORD_API bool sord_write_iter	(	SordIter *	iter,
		SerdWriter *	writer
	)

Write a range to a writer.

This increments `iter` to its end, then frees it.

Sord

World

Node

Model

Inserter

Iteration

Utilities

Serialisation

Typedefs

Enumerations

Detailed Description

Typedef Documentation

Enumeration Type Documentation

Function Documentation