| Rasqal RDF Query Library Manual | ||||
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| Top | Description | ||||
rasqal_data_graph; rasqal_data_graph * rasqal_new_data_graph_from_data_graph (rasqal_data_graph *dg); rasqal_data_graph * rasqal_new_data_graph_from_iostream (rasqal_world *world,raptor_iostream *iostr,raptor_uri *base_uri,raptor_uri *name_uri,int flags,const char *format_type,const char *format_name,raptor_uri *format_uri); rasqal_data_graph * rasqal_new_data_graph_from_uri (rasqal_world *world,raptor_uri *uri,raptor_uri *name_uri,int flags,const char *format_type,const char *format_name,raptor_uri *format_uri); void rasqal_free_data_graph (rasqal_data_graph *dg); enum rasqal_data_graph_flags; int rasqal_data_graph_print (rasqal_data_graph *dg,FILE *fh);
Data graphs are used in the query to describe RDF graphs that can be used to query against. The graphs can be used either with raptor_uri to name the graph, or without a name. The query language determines which graphs are used in the query.
typedef struct {
rasqal_world* world;
raptor_uri* uri;
raptor_uri* name_uri;
int flags;
char* format_type;
char* format_name;
raptor_uri* format_uri;
raptor_iostream* iostr;
raptor_uri* base_uri;
int usage;
} rasqal_data_graph;
A source of RDF data for querying.
If iostr is present, the graph can be constructed by parsing the
iostream and using base_uri as a base uri. Otherwise the graph
can be constructed from the graph at URI uri.
In either case the name_uri is the graph name as long as flags
is RASQAL_DATA_GRAPH_NAMED
rasqal_world * |
rasqal_world object |
raptor_uri * |
source URI |
raptor_uri * |
name of graph for RASQAL_DATA_GRAPH_NAMED
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RASQAL_DATA_GRAPH_NAMED or RASQAL_DATA_GRAPH_BACKGROUND
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MIME Type of data format at uri (or NULL) |
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Raptor parser Name of data format at uri (or NULL) |
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raptor_uri * |
URI of data format at uri (or NULL) |
raptor_iostream * |
Raptor iostream for content, overriding uri if present (or NULL) |
raptor_uri * |
base URI for reading from iostream |
| usage count of this object |
rasqal_data_graph * rasqal_new_data_graph_from_data_graph
(rasqal_data_graph *dg);
Copy Constructor - create a new rasqal_data_graph object from an existing rasqal_data_graph object.
|
rasqal_data_graph object to copy or NULL |
Returns : |
a new rasqal_data_graph object or NULL if dg was NULL. |
rasqal_data_graph * rasqal_new_data_graph_from_iostream (rasqal_world *world,raptor_iostream *iostr,raptor_uri *base_uri,raptor_uri *name_uri,int flags,const char *format_type,const char *format_name,raptor_uri *format_uri);
Constructor - create a new rasqal_data_graph from iostream content
The name_uri is used when the flags are RASQAL_DATA_GRAPH_NAMED.
The base_uri is used to provide the Raptor parser a base URI. If
a base URI is required but none is given, the parsing will fail
and the query that uses this data source will fail.
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rasqal_world object |
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source graph format iostream |
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base URI for iostream content |
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name of graph (or NULL) |
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RASQAL_DATA_GRAPH_NAMED or RASQAL_DATA_GRAPH_BACKGROUND
|
|
MIME Type of data format at uri (or NULL) |
|
Raptor parser Name of data format at uri (or NULL) |
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URI of data format at uri (or NULL) |
Returns : |
a new rasqal_data_graph or NULL on failure. |
rasqal_data_graph * rasqal_new_data_graph_from_uri (rasqal_world *world,raptor_uri *uri,raptor_uri *name_uri,int flags,const char *format_type,const char *format_name,raptor_uri *format_uri);
Constructor - create a new rasqal_data_graph.
The name_uri is only used when the flags are RASQAL_DATA_GRAPH_NAMED.
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rasqal_world object |
|
source URI |
|
name of graph (or NULL) |
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RASQAL_DATA_GRAPH_NAMED or RASQAL_DATA_GRAPH_BACKGROUND
|
|
MIME Type of data format at uri (or NULL) |
|
Raptor parser Name of data format at uri (or NULL) |
|
URI of data format at uri (or NULL) |
Returns : |
a new rasqal_data_graph or NULL on failure. |
void rasqal_free_data_graph (rasqal_data_graph *dg);
Destructor - destroy a rasqal_data_graph object.
|
rasqal_data_graph object |
typedef enum {
RASQAL_DATA_GRAPH_NONE = 0,
RASQAL_DATA_GRAPH_NAMED = 1,
RASQAL_DATA_GRAPH_BACKGROUND = 2,
} rasqal_data_graph_flags;
Flags for the type of rasqal_data_graph.
These are used by rasqal_new_data_graph_from_uri() and
rasqal_new_data_graph_from_iostream(). See rasqal_data_graph.
int rasqal_data_graph_print (rasqal_data_graph *dg,FILE *fh);
Print a Rasqal data graph in a debug format.
The print debug format may change in any release.
|
rasqal_data_graph object |
|
the FILE* handle to print to |
Returns : |
non-0 on failure |