cetus/src/chassis-plugin.h

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 Copyright (c) 2007, 2012, Oracle and/or its affiliates. All rights reserved.

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License as
 published by the Free Software Foundation; version 2 of the
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 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU General Public License for more details.

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#ifndef _CHASSIS_PLUGIN_H_
#define _CHASSIS_PLUGIN_H_

#include <glib.h>
#include <gmodule.h>

#include "chassis-mainloop.h"
#include "chassis-exports.h"

/* current magic is 0.8.0-1 */
#define CHASSIS_PLUGIN_MAGIC 0x00080001L

/**
 * The private stats structure of a plugin. This is opaque to the rest of the code,
 * we can only get a copy of it in a hash.
 * @see chassis_plugin_stats.get_stats()
 */
typedef struct chassis_plugin_stats chassis_plugin_stats_t;
typedef struct chassis_plugin_config chassis_plugin_config;

typedef struct chassis_plugin {
    /**< a magic token to verify that the plugin API matches */
    long magic;

    /**< name of the option group (used in --help-<option-grp> */
    gchar *option_grp_name;

    /**< user visible name of this plugin */
    gchar *name;

    /**< the plugin's version number */
    gchar *version;

    /**< the plugin handle when loaded */
    GModule *module;

    /**< contains the plugin-specific statistics */
    chassis_plugin_stats_t *stats;

    /**< handler function to initialize the plugin-specific stats */
    chassis_plugin_stats_t *(*new_stats) (void);

    /**< handler function to dealloc the plugin-specific stats */
    void (*free_stats) (chassis_plugin_stats_t *user_data);

    /**< handler function to retrieve the plugin-specific stats */
    GHashTable *(*get_stats) (chassis_plugin_stats_t *user_data);

    /**< contains the plugin-specific config data */
    chassis_plugin_config *config;

    /**< handler function to allocate/initialize a chassis_plugin_config struct */
    chassis_plugin_config *(*init) (void);

    /**< handler function used to deallocate the chassis_plugin_config */
    void (*destroy) (chassis *chas, chassis_plugin_config *user_data);

    /**< handler function to obtain the command line argument information */
    GList *(*get_options) (chassis_plugin_config *user_data);

    /**< handler function to set the argument values in the plugin's config */
    int (*apply_config) (chassis *chas, chassis_plugin_config *user_data);

    void (*stop_listening) (chassis *chas, chassis_plugin_config *user_data);

    /**< handler function to retrieve the plugin's global state */
    void *(*get_global_state) (chassis_plugin_config *user_data, const char *member);

} chassis_plugin;

CHASSIS_API chassis_plugin *chassis_plugin_new(void);
CHASSIS_API chassis_plugin *chassis_plugin_load(const gchar *name);
CHASSIS_API void chassis_plugin_free(chassis_plugin *p);
CHASSIS_API GList *chassis_plugin_get_options(chassis_plugin *p);

/**
 * Retrieve the chassis plugin for a particular name.
 *
 * @param chas        a pointer to the chassis
 * @param plugin_name The name of the plugin to look up.
 * @return A pointer to a chassis_plugin structure
 * @retval NULL if there is no loaded chassis with this name
 */
CHASSIS_API chassis_plugin *chassis_plugin_for_name(chassis *chas, gchar *plugin_name);

#endif