5.13.3 Model

enum SerdStatementOrder

Statement ordering.

Statements themselves always have the same fields in the same order (subject, predicate, object, graph), but a model can keep indices for different orderings to provide good performance for different kinds of queries.

enumerator SERD_ORDER_SPO

Subject, Predicate, Object.

enumerator SERD_ORDER_SOP

Subject, Object, Predicate.

enumerator SERD_ORDER_OPS

Object, Predicate, Subject.

enumerator SERD_ORDER_OSP

Object, Subject, Predicate.

enumerator SERD_ORDER_PSO

Predicate, Subject, Object.

enumerator SERD_ORDER_POS

Predicate, Object, Subject.

enumerator SERD_ORDER_GSPO

Graph, Subject, Predicate, Object.

enumerator SERD_ORDER_GSOP

Graph, Subject, Object, Predicate.

enumerator SERD_ORDER_GOPS

Graph, Object, Predicate, Subject.

enumerator SERD_ORDER_GOSP

Graph, Object, Subject, Predicate.

enumerator SERD_ORDER_GPSO

Graph, Predicate, Subject, Object.

enumerator SERD_ORDER_GPOS

Graph, Predicate, Object, Subject.

enum SerdModelFlag

Flags that control model storage and indexing.

enumerator SERD_STORE_GRAPHS

Store and index the graph of statements.

enumerator SERD_STORE_CARETS

Store original caret of statements.

typedef struct SerdModelImpl SerdModel

An indexed set of statements.

typedef uint32_t SerdModelFlags

Bitwise OR of SerdModelFlag values.

SerdModel *serd_model_new(SerdWorld *world, SerdStatementOrder default_order, SerdModelFlags flags)

Create a new model.

Parameters

  • world – The world in which to make this model.

  • default_order – The order for the default index, which is always present and responsible for owning all the statements in the model. This should almost always be SerdStatementOrder.SERD_ORDER_SPO or SerdStatementOrder.SERD_ORDER_GSPO (which support writing pretty documents), but advanced applications that do not want either of these indices can use a different order. Additional indices can be added with serd_model_add_index().

  • flags – Options that control what data is stored in the model.

SerdModel *serd_model_copy(SerdAllocator *allocator, const SerdModel *model)

Return a deep copy of model

bool serd_model_equals(const SerdModel *a, const SerdModel *b)

Return true iff a is equal to b, ignoring statement cursor metadata.

void serd_model_free(SerdModel *model)

Close and free model

SerdStatus serd_model_add_index(SerdModel *model, SerdStatementOrder order)

Add an index for a particular statement order to the model.

Returns

Failure if this index already exists.

SerdStatus serd_model_drop_index(SerdModel *model, SerdStatementOrder order)

Add an index for a particular statement order to the model.

Returns

Failure if this index does not exist.

SerdWorld *serd_model_world(SerdModel *model)

Get the world associated with model

const SerdNodes *serd_model_nodes(const SerdModel *model)

Get all nodes interned in model

SerdStatementOrder serd_model_default_order(const SerdModel *model)

Get the default statement order of model

SerdModelFlags serd_model_flags(const SerdModel *model)

Get the flags enabled on model

size_t serd_model_size(const SerdModel *model)

Return the number of statements stored in model

bool serd_model_empty(const SerdModel *model)

Return true iff there are no statements stored in model

SerdCursor *serd_model_begin(const SerdModel *model)

Return a cursor at the start of every statement in the model.

The returned cursor will advance over every statement in the model’s default order.

const SerdCursor *serd_model_end(const SerdModel *model)

Return a cursor past the end of the model.

This returns the “universal” end cursor, which is equivalent to any cursor for this model that has reached its end.

SerdCursor *serd_model_begin_ordered(const SerdModel *model, SerdStatementOrder order)

Return a cursor over all statements in the model in a specific order.

SerdCursor *serd_model_find(const SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *g)

Search for statements that match a pattern.

Returns

An iterator to the first match, or NULL if no matches found.

const SerdNode *serd_model_get(const SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *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.

Returns

The first matching node, or NULL if no matches are found.

const SerdStatement *serd_model_get_statement(const SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *g)

Search for a single statement that matches a pattern.

This function is mainly useful for predicates that only have one value.

Returns

The first matching statement, or NULL if none are found.

bool serd_model_ask(const SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *g)

Return true iff a statement exists.

size_t serd_model_count(const SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *g)

Return the number of matching statements.

SerdStatus serd_model_add(SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *g)

Add a statement to a model from nodes.

This function fails if there are any active iterators on model.

SerdStatus serd_model_add_with_caret(SerdModel *model, const SerdNode *s, const SerdNode *p, const SerdNode *o, const SerdNode *g, const SerdCaret *caret)

Add a statement to a model from nodes with a caret.

This function fails if there are any active iterators on model.

SerdStatus serd_model_insert(SerdModel *model, const SerdStatement *statement)

Add a statement to a model.

This function fails if there are any active iterators on model. If statement is null, then SERD_FAILURE is returned.

SerdStatus serd_model_insert_statements(SerdModel *model, SerdCursor *range)

Add a range of statements to a model.

This function fails if there are any active iterators on model.

SerdStatus serd_model_erase(SerdModel *model, SerdCursor *cursor)

Remove a statement from a model via an iterator.

Calling this function invalidates all other iterators on this model.

Parameters

  • model – The model which iter points to.

  • cursor – Cursor pointing to the element to erase. This cursor is advanced to the next statement on return.

SerdStatus serd_model_erase_statements(SerdModel *model, SerdCursor *range)

Remove a range of statements from a model.

This can be used with serd_model_find() to erase all statements in a model that match a pattern.

Calling this function invalidates all iterators on model.

Parameters

  • model – The model which range points to.

  • range – Range to erase, which will be empty on return.

SerdStatus serd_model_clear(SerdModel *model)

Remove everything from a model.

Calling this function invalidates all iterators on model.

Parameters

  • model – The model to clear.