dlite-mapping

Map instances of one metadata to another.

Mappings are used to map one or more instances of certain metadata to an instance of another metadata.

Mappings can be registered as plugins and invoked transparently by DLite. For this to work, DLite search all paths listed in the DLITE_MAPPING_PLUGIN_DIRS environment variable for plugins.

Typedefs

typedef struct _DLiteMapping DLiteMapping

Struct describing mapping.

For each input, either the corresponding element in inputs_maps (if the element is the result of a sub-mapping) or input_uris (if the input is a provided input instance) is not NULL.

Functions

DLiteInstance *dlite_mapping(const char *output_uri, const DLiteInstance **instances, int n)

Returns a new instance of metadata output_uri by mapping the n input instances in the array instances.

This is the main function in the mapping api.

DLiteMapping *dlite_mapping_create(const char *ouput_uri, const char **input_uris, int n)

Returns a new nested mapping structure describing how n input instances of metadata input_uris can be mapped to output_uri.

Note

In the trivial case where one of the input URIs equals output_uri, will the “output_uri” field in the returned mapping point to output_uri. Hence, do not free output_uri as long as the returned mapping is in use.

void dlite_mapping_free(DLiteMapping *m)

Free’s a mapping created with mapping_create().

char *dlite_mapping_string(const DLiteMapping *m)

Returns a malloc’ed string displaying mapping m.

DLiteInstance *dlite_mapping_map(const DLiteMapping *m, const DLiteInstance **instances, int n)

Applies the mapping m on instances (array of length n of instance pointers) and returns a new instance.

struct _DLiteMapping

#include <dlite-mapping.h>

Struct describing mapping.

For each input, either the corresponding element in inputs_maps (if the element is the result of a sub-mapping) or input_uris (if the input is a provided input instance) is not NULL.

Public Members

const char *name

Name of mapping. NULL corresponds to the trivial case where one of the input URIs is output_uri.

const char *output_uri

Output metadata URI

int ninput

Number of inputs

const struct _DLiteMapping **input_maps

Array of input sub-trees. Length: ninput

const char **input_uris

Array of input metadata URIs. Length: ninput

DLiteMappingPlugin *api

Mapping that performs this mapping.

int cost

The total cost of this mapping.