dlite-mapping-plugins

dlite-mapping-plugins#

Common API for all mapping plugins (internal).

A DPite mapping plugin should be a shared library that defines the function

const DLiteMappingPlugin *
get_dlite_mapping_api(const char *name);

that returns a pointer to a struct with pointers to all functions provided by the plugin. The name is just a hint that plugins are free to ignore. It is used by mapping plugins that supports several different drivers, to select which api that should be returned.

The mapping plugin search path is initialised from the environment variable DLITE_MAPPING_PLUGIN_DIRS.

Signatures of functions defined by the plugins.

typedef DLiteInstance *(*Mapper)(const DLiteMappingPlugin *api, const DLiteInstance **instances, int n)#: Returns a new instance obtained by mapping instances. Returns NULL on error.

typedef void (*Freer)(DLiteMappingPlugin *api)#: Releases internal resources associated with api.

Plugin frontend

const DLiteMappingPlugin *dlite_mapping_plugin_get(const char *name)#

Returns a mapping plugin with the given name, or NULL if it cannot be found.

If a plugin with the given name is registered, it is returned.

Otherwise the plugin search path is checked for shared libraries matching name.EXT where EXT is the extension for shared library on the current platform (“dll” on Windows and “so” on Unix/Linux). If a plugin with the provided name is found, it is loaded, registered and returned.

Otherwise the plugin search path is checked again, but this time for any shared library. If a plugin with the provided name is found, it is loaded, registered and returned.

Otherwise NULL is returned.

int dlite_mapping_plugin_init_iter(DLiteMappingPluginIter *iter)#: Initiates a mapping plugin iterator. Returns non-zero on error.

const DLiteMappingPlugin *dlite_mapping_plugin_next(DLiteMappingPluginIter *iter)#

Returns the next registered mapping plugin or NULL if all plugins has been visited.

Used for iterating over plugins. Plugins should not be registered or removed while iterating.

int dlite_mapping_plugin_unload(const char *name)#

Unloads and unregisters mapping plugin with the given name.

If name is NULL, dlite_mapping_plugin_unload_all() is called.

Returns non-zero on error.

int dlite_mapping_plugin_unload_all(void)#: Unloads and unregisters all mappings. Returns non-zero on error.

FUPaths *dlite_mapping_plugin_paths_get(void)#: Returns a pointer to the underlying FUPaths object for storage plugins or NULL on error.

const char **dlite_mapping_plugin_paths(void)#

Returns a pointer to the current mapping plugin search path. It is initialised from the environment variable DLITE_MAPPING_PLUGIN_DIRS.

Use dlite_mapping_plugin_path_insert(), dlite_mapping_plugin_path_append() and dlite_mapping_plugin_path_remove() to modify it.

char *dlite_mapping_plugin_path_string(void)#

Returns an allocated string with the content of paths formatted according to the current platform. See dlite_set_platform().

Returns NULL on error.

int dlite_mapping_plugin_path_insert(int n, const char *path)#

Inserts path into the current search path at index n. If n is negative, it counts from the end of the search path (like Python).

If n is out of range, it is clipped.

Returns non-zero on error.

int dlite_mapping_plugin_path_append(const char *path)#

Appends path into the current search path.

Returns non-zero on error.

int dlite_mapping_plugin_path_appendn(const char *path, size_t n)#

Like dlite_mapping_plugin_path_append(), but appends at most the first n bytes of path to the current search path.

Returns non-zero on error.

int dlite_mapping_plugin_path_remove_index(int index)#

Removes path number n from current search path.

Returns non-zero on error.

Typedefs

typedef struct _DLiteMappingPlugin DLiteMappingPlugin#: A struct with data and function pointers provided by a plugin.

typedef struct _DLiteMappingPluginIter DLiteMappingPluginIter#: An iterator over all registered mapping plugins.

typedef const DLiteMappingPlugin *(*GetDLiteMappingAPI)(int *iter)#

Prototype for function returning a pointer to a DLiteMappingPlugin or NULL on error.

The iter argument is normally ignored. It is provided to support plugins exposing several APIs. If the plugin has more APIs to expose, it should increase the integer pointed to by iter by one.

struct _DLiteMappingPluginIter#

#include <dlite-mapping-plugins.h>

An iterator over all registered mapping plugins.

Public Members

PluginIter iter#: plugin iterator

int n#: counter for python mappings

int stop#: set to non-zero if no more python mappings are available

struct _DLiteMappingPlugin#

#include <dlite-mapping-plugins.h>

Struct with the name and pointers to function for a plugin. All plugins should define themselves by defining an intance of DLiteMappingPlugin.

The cost of a mapping is an integer greater than (or equal to) zero. Mappings with low costs are preferred in front of mappings with high costs. The default cost for a mapping is 20, while the cost for the trivial mapping to an existing input is zero.

Public Members

const char *output_uri#: Output metedata URI

int ninput#: Number of inputs

const char **input_uris#: Array of input metedata URIs

Mapper mapper#: Pointer to mapping function

int cost#: Cost of this mapping. Default: 20

void *data#: Internal data used by the mapper

dlite-mapping-plugins

Contents

dlite-mapping-plugins#