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/*
* Copyright (C) 2016 DENSO CORPORATION
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include <libweston/libweston.h>
#include <libweston/plugin-registry.h>
struct weston_plugin_api {
struct wl_list link; /**< in weston_compositor::plugin_api_list */
char *api_name; /**< The search key */
const void *vtable; /**< The function table */
size_t vtable_size; /**< Size of the function table in bytes */
};
/** Register an implementation of an API
*
* \param compositor The compositor instance.
* \param api_name The API name which other plugins use to find the
* implementation.
* \param vtable Pointer to the function table of the API.
* \param vtable_size Size of the function table in bytes.
* \return 0 on success, -1 on error, -2 if api_name already registered
*
* This call makes the given vtable to be reachable via
* weston_plugin_api_get(). Calls through the vtable may start happening
* as soon as the caller returns after success. Argument vtable must not be
* NULL. Argument api_name must be non-NULL and non-zero length.
*
* You can increase the function table size without breaking the ABI.
* To cater for ABI breaks, it is recommended to have api_name include a
* version number.
*
* A registered API cannot be unregistered. However, calls through a
* registered API must not be made from the compositor destroy signal handlers.
*/
WL_EXPORT int
weston_plugin_api_register(struct weston_compositor *compositor,
const char *api_name,
const void *vtable,
size_t vtable_size)
{
struct weston_plugin_api *wpa;
assert(api_name);
assert(strlen(api_name) > 0);
assert(vtable);
if (!api_name || !vtable || strlen(api_name) == 0)
return -1;
wl_list_for_each(wpa, &compositor->plugin_api_list, link)
if (strcmp(wpa->api_name, api_name) == 0)
return -2;
wpa = zalloc(sizeof(*wpa));
if (!wpa)
return -1;
wpa->api_name = strdup(api_name);
wpa->vtable = vtable;
wpa->vtable_size = vtable_size;
if (!wpa->api_name) {
free(wpa);
return -1;
}
wl_list_insert(&compositor->plugin_api_list, &wpa->link);
weston_log("Registered plugin API '%s' of size %zd\n",
wpa->api_name, wpa->vtable_size);
return 0;
}
/** Internal function to free registered APIs
*
* \param compositor The compositor instance.
*/
void
weston_plugin_api_destroy_list(struct weston_compositor *compositor)
{
struct weston_plugin_api *wpa, *tmp;
wl_list_for_each_safe(wpa, tmp, &compositor->plugin_api_list, link) {
free(wpa->api_name);
wl_list_remove(&wpa->link);
free(wpa);
}
}
/** Fetch the implementation of an API
*
* \param compositor The compositor instance.
* \param api_name The name of the API to search for.
* \param vtable_size The expected function table size in bytes.
* \return Pointer to the function table, or NULL on error.
*
* Find the function table corresponding to api_name. The vtable_size here
* must be less or equal to the vtable_size given in the corresponding
* weston_plugin_api_register() call made by the implementing plugin.
*
* Calls can be made through the function table immediately. However, calls
* must not be made from or after the compositor destroy signal handler.
*/
WL_EXPORT const void *
weston_plugin_api_get(struct weston_compositor *compositor,
const char *api_name,
size_t vtable_size)
{
struct weston_plugin_api *wpa;
assert(api_name);
if (!api_name)
return NULL;
wl_list_for_each(wpa, &compositor->plugin_api_list, link) {
if (strcmp(wpa->api_name, api_name) != 0)
continue;
if (vtable_size <= wpa->vtable_size)
return wpa->vtable;
return NULL;
}
return NULL;
}
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