gwymoduleloader

gwymoduleloader — Basic module loader interface

Synopsis

#include <libgwymodule/gwymodule.h>

#define             GWY_MODULE_ABI_VERSION
#define             GWY_MODULE_QUERY                    (mod_info)
enum                GwyModuleError;
struct              GwyModuleInfo;
GwyModuleInfo *     (*GwyModuleQueryFunc)               (void);
gboolean            (*GwyModuleRegisterFunc)            (void);
GQuark              gwy_module_error_quark              (void);
void                gwy_module_foreach                  (GHFunc function,
                                                         gpointer data);
const gchar *       gwy_module_get_filename             (const gchar *name);
GSList *            gwy_module_get_functions            (const gchar *name);
const GwyModuleInfo * gwy_module_lookup                 (const gchar *name);
const GwyModuleInfo * gwy_module_register_module        (const gchar *name,
                                                         GError **error);
void                gwy_module_register_modules         (const gchar **paths);

Description

Details

GWY_MODULE_ABI_VERSION

#define GWY_MODULE_ABI_VERSION 2

Gwyddion module ABI version.

To be filled as abi_version in GwyModuleInfo.

GWY_MODULE_QUERY()

#define             GWY_MODULE_QUERY(mod_info)

The module query must be the ONLY exported symbol from a module.

This macro does The Right Thing necessary to export module info in a way Gwyddion understands it. Put GWY_MODULE_QUERY with the module info (GwyModuleInfo) of your module as its argument on a line (with NO semicolon after).

If you write a module in C++ note the module query must have C linkage. This is achieved by marking it extern "C":

1
2
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extern "C" {
GWY_MODULE_QUERY(module_info)
}

This has to be done manually in versions up to 2.24; since version 2.25 GWY_MODULE_QUERY() includes extern "C" automatically if it is compiled using a C++ compiler.

mod_info :

The GwyModuleInfo structure to return as module info.

enum GwyModuleError

typedef enum {
    GWY_MODULE_ERROR_NAME,
    GWY_MODULE_ERROR_DUPLICATE,
    GWY_MODULE_ERROR_OPEN,
    GWY_MODULE_ERROR_QUERY,
    GWY_MODULE_ERROR_ABI,
    GWY_MODULE_ERROR_INFO,
    GWY_MODULE_ERROR_REGISTER
} GwyModuleError;

struct GwyModuleInfo

struct GwyModuleInfo {
    guint32 abi_version;
    GwyModuleRegisterFunc register_func;
    const gchar *blurb;
    const gchar *author;
    const gchar *version;
    const gchar *copyright;
    const gchar *date;
};

Module information returned by GWY_MODULE_QUERY().

guint32 `abi_version`;	Gwyddion module ABI version, should be always GWY_MODULE_ABI_VERSION.
GwyModuleRegisterFunc `register_func`;	Module registration function (the function run by Gwyddion module system, actually registering particular module features).
const gchar *`blurb`;	Some module description.
const gchar *`author`;	Module author(s).
const gchar *`version`;	Module version.
const gchar *`copyright`;	Who has copyright on this module.
const gchar *`date`;	Date (year).

GwyModuleQueryFunc ()

GwyModuleInfo *     (*GwyModuleQueryFunc)               (void);

Module query function type.

The module query function should be simply declared as GWY_MODULE_QUERY(mod_info), where mod_info is module info struct for the module.

Returns :

The module info struct.

GwyModuleRegisterFunc ()

gboolean            (*GwyModuleRegisterFunc)            (void);

Module registration function type.

It actually runs particular featrue registration functions, like gwy_module_register_file_func() and gwy_module_register_process_func().

Returns :

Whether the registration succeeded. When it returns FALSE, the module and its features are unloaded (FIXME: maybe. Currenly only module is unloaded, features are NOT unregistered, this can lead to all kinds of disasters).

gwy_module_error_quark ()

GQuark              gwy_module_error_quark              (void);

Returns error domain for module loading.

See and use GWY_MODULE_ERROR.

Returns :

The error domain.

gwy_module_foreach ()

void                gwy_module_foreach                  (GHFunc function,
                                                         gpointer data);

Runs function on each registered module.

It passes module name as the key and pointer to module info (GwyModuleInfo) as the value. Neither should be modified.

`function` :	A GHFunc run for each module.
`data` :	User data.

gwy_module_get_filename ()

const gchar *       gwy_module_get_filename             (const gchar *name);

Returns full file name of a module.

`name` :	A module name.
Returns :	Module file name as a string that must be modified or freed.

gwy_module_get_functions ()

GSList *            gwy_module_get_functions            (const gchar *name);

Returns list of names of functions a module implements.

`name` :	A module name.
Returns :	List of module function names, as a GSList that is owned by module loader and must not be modified or freed.

gwy_module_lookup ()

const GwyModuleInfo * gwy_module_lookup                 (const gchar *name);

Returns information about one module.

`name` :	A module name.
Returns :	The module info, of `NULL` if not found. It must be considered constant and never modified or freed.

gwy_module_register_module ()

const GwyModuleInfo * gwy_module_register_module        (const gchar *name,
                                                         GError **error);

Loads a single module.

`name` :	Module file name to load, including full path and extension.
`error` :	Location to store error, or `NULL` to ignore them. Errors from GwyModuleError domain can occur.
Returns :	Module info on success, `NULL` on failure.

gwy_module_register_modules ()

void                gwy_module_register_modules         (const gchar **paths);

Registers all modules in given directories.

It can be called several times (on different directories). No errors are reported, register modules individually with gwy_module_register_module() to get registration errors.

paths :

A NULL-terminated list of directory names.

			Gwyddion Module Library Reference Manual
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