hook.h

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/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */

#ifndef SPA_HOOK_H
#define SPA_HOOK_H

#ifdef __cplusplus
extern "C" {
#endif

#include <spa/utils/defs.h>
#include <spa/utils/list.h>

#ifndef SPA_API_HOOK
 #ifdef SPA_API_IMPL
  #define SPA_API_HOOK SPA_API_IMPL
 #else
  #define SPA_API_HOOK static inline
 #endif
#endif

struct spa_callbacks {
        const void *funcs;
        void *data;
};

#define SPA_CALLBACK_VERSION_MIN(c,v) ((c) && ((v) == 0 || (c)->version > (v)-1))

#define SPA_CALLBACK_CHECK(c,m,v) (SPA_CALLBACK_VERSION_MIN(c,v) && (c)->m)

#define SPA_CALLBACKS_INIT(_funcs,_data) ((struct spa_callbacks){ (_funcs), (_data), })

struct spa_interface {
        const char *type;
        uint32_t version;
        struct spa_callbacks cb;
};

#define SPA_INTERFACE_INIT(_type,_version,_funcs,_data) \
        ((struct spa_interface){ (_type), (_version), SPA_CALLBACKS_INIT(_funcs,_data), })

#define spa_callbacks_call(callbacks,type,method,vers,...)                      \
({                                                                              \
        const type *_f = (const type *) (callbacks)->funcs;                     \
        bool _res = SPA_CALLBACK_CHECK(_f,method,vers);                         \
        if (SPA_LIKELY(_res))                                                   \
                (_f->method)((callbacks)->data, ## __VA_ARGS__);                \
        _res;                                                                   \
})

#define spa_callbacks_call_fast(callbacks,type,method,vers,...)                 \
({                                                                              \
        const type *_f = (const type *) (callbacks)->funcs;                     \
        (_f->method)((callbacks)->data, ## __VA_ARGS__);                        \
        true;                                                                   \
})


#define spa_callback_version_min(callbacks,type,vers)                           \
({                                                                              \
        const type *_f = (const type *) (callbacks)->funcs;                     \
        SPA_CALLBACK_VERSION_MIN(_f,vers);                                      \
})

#define spa_callback_check(callbacks,type,method,vers)                          \
({                                                                              \
        const type *_f = (const type *) (callbacks)->funcs;                     \
        SPA_CALLBACK_CHECK(_f,method,vers);                                     \
})

#define spa_callbacks_call_res(callbacks,type,res,method,vers,...)              \
({                                                                              \
        const type *_f = (const type *) (callbacks)->funcs;                     \
        if (SPA_LIKELY(SPA_CALLBACK_CHECK(_f,method,vers)))                     \
                res = (_f->method)((callbacks)->data, ## __VA_ARGS__);          \
        res;                                                                    \
})
#define spa_callbacks_call_fast_res(callbacks,type,res,method,vers,...)         \
({                                                                              \
        const type *_f = (const type *) (callbacks)->funcs;                     \
        res = (_f->method)((callbacks)->data, ## __VA_ARGS__);                  \
})

#define spa_interface_callback_version_min(iface,method_type,vers)              \
   spa_callback_version_min(&(iface)->cb, method_type, vers)

#define spa_interface_callback_check(iface,method_type,method,vers)             \
   spa_callback_check(&(iface)->cb, method_type, method, vers)

#define spa_interface_call(iface,method_type,method,vers,...)                   \
        spa_callbacks_call(&(iface)->cb,method_type,method,vers,##__VA_ARGS__)

#define spa_interface_call_fast(iface,method_type,method,vers,...)              \
        spa_callbacks_call_fast(&(iface)->cb,method_type,method,vers,##__VA_ARGS__)

#define spa_interface_call_res(iface,method_type,res,method,vers,...)                   \
        spa_callbacks_call_res(&(iface)->cb,method_type,res,method,vers,##__VA_ARGS__)

#define spa_interface_call_fast_res(iface,method_type,res,method,vers,...)              \
        spa_callbacks_call_fast_res(&(iface)->cb,method_type,res,method,vers,##__VA_ARGS__)


#define spa_api_func_v(o,method,version,...)                            \
({                                                                      \
        if (SPA_LIKELY(SPA_CALLBACK_CHECK(o,method,version)))           \
                ((o)->method)(o, ##__VA_ARGS__);                        \
})
#define spa_api_func_r(rtype,def,o,method,version,...)                  \
({                                                                      \
        rtype _res = def;                                               \
        if (SPA_LIKELY(SPA_CALLBACK_CHECK(o,method,version)))           \
                _res = ((o)->method)(o, ##__VA_ARGS__);                 \
        _res;                                                           \
})
#define spa_api_func_fast(o,method,...)                                 \
({                                                                      \
        ((o)->method)(o, ##__VA_ARGS__);                                \
})

#define spa_api_method_v(type,o,method,version,...)                     \
({                                                                      \
        struct spa_interface *_i = o;                   \
        spa_interface_call(_i, struct type ##_methods,                  \
                        method, version, ##__VA_ARGS__);                \
})
#define spa_api_method_r(rtype,def,type,o,method,version,...)           \
({                                                                      \
        rtype _res = def;                                               \
        struct spa_interface *_i = o;                   \
        spa_interface_call_res(_i, struct type ##_methods,              \
                        _res, method, version, ##__VA_ARGS__);          \
        _res;                                                           \
})
#define spa_api_method_null_v(type,co,o,method,version,...)             \
({                                                                      \
        struct type *_co = co;                                          \
        if (SPA_LIKELY(_co != NULL)) {                                  \
                struct spa_interface *_i = o;                           \
                spa_interface_call(_i, struct type ##_methods,          \
                        method, version, ##__VA_ARGS__);                \
        }                                                               \
})
#define spa_api_method_null_r(rtype,def,type,co,o,method,version,...)   \
({                                                                      \
        rtype _res = def;                                               \
        struct type *_co = co;                                          \
        if (SPA_LIKELY(_co != NULL)) {                                  \
                struct spa_interface *_i = o;                           \
                spa_interface_call_res(_i, struct type ##_methods,      \
                                _res, method, version, ##__VA_ARGS__);  \
        }                                                               \
        _res;                                                           \
})
#define spa_api_method_fast_v(type,o,method,version,...)                \
({                                                                      \
        struct spa_interface *_i = o;                                   \
        spa_interface_call_fast(_i, struct type ##_methods,             \
                        method, version, ##__VA_ARGS__);                \
})
#define spa_api_method_fast_r(rtype,def,type,o,method,version,...)      \
({                                                                      \
        rtype _res = def;                                               \
        struct spa_interface *_i = o;                                   \
        spa_interface_call_fast_res(_i, struct type ##_methods,         \
                        _res, method, version, ##__VA_ARGS__);          \
        _res;                                                           \
})

struct spa_hook_list {
        struct spa_list list;
};


struct spa_hook {
        struct spa_list link;
        struct spa_callbacks cb;
        void (*removed) (struct spa_hook *hook);
        void *priv;
};

SPA_API_HOOK void spa_hook_list_init(struct spa_hook_list *list)
{
        spa_list_init(&list->list);
}

SPA_API_HOOK bool spa_hook_list_is_empty(struct spa_hook_list *list)
{
        return spa_list_is_empty(&list->list);
}

SPA_API_HOOK void spa_hook_list_append(struct spa_hook_list *list,
                                        struct spa_hook *hook,
                                        const void *funcs, void *data)
{
        spa_zero(*hook);
        hook->cb = SPA_CALLBACKS_INIT(funcs, data);
        spa_list_append(&list->list, &hook->link);
}

SPA_API_HOOK void spa_hook_list_prepend(struct spa_hook_list *list,
                                         struct spa_hook *hook,
                                         const void *funcs, void *data)
{
        spa_zero(*hook);
        hook->cb = SPA_CALLBACKS_INIT(funcs, data);
        spa_list_prepend(&list->list, &hook->link);
}

SPA_API_HOOK void spa_hook_remove(struct spa_hook *hook)
{
        if (spa_list_is_initialized(&hook->link))
                spa_list_remove(&hook->link);
        if (hook->removed)
                hook->removed(hook);
}

SPA_API_HOOK void spa_hook_list_clean(struct spa_hook_list *list)
{
        struct spa_hook *h;
        spa_list_consume(h, &list->list, link)
                spa_hook_remove(h);
}

SPA_API_HOOK void
spa_hook_list_isolate(struct spa_hook_list *list,
                struct spa_hook_list *save,
                struct spa_hook *hook,
                const void *funcs, void *data)
{
        /* init save list and move hooks to it */
        spa_hook_list_init(save);
        spa_list_insert_list(&save->list, &list->list);
        /* init hooks and add single hook */
        spa_hook_list_init(list);
        spa_hook_list_append(list, hook, funcs, data);
}

SPA_API_HOOK void
spa_hook_list_join(struct spa_hook_list *list,
                struct spa_hook_list *save)
{
        spa_list_insert_list(&list->list, &save->list);
}

#define spa_hook_list_call_simple(l,type,method,vers,...)                       \
({                                                                              \
        struct spa_hook_list *_l = l;                                           \
        struct spa_hook *_h, *_t;                                               \
        spa_list_for_each_safe(_h, _t, &_l->list, link)                         \
                spa_callbacks_call(&_h->cb,type,method,vers, ## __VA_ARGS__);   \
})

#define spa_hook_list_do_call(l,start,type,method,vers,once,...)                \
({                                                                              \
        struct spa_hook_list *_list = l;                                        \
        struct spa_list *_s = start ? (struct spa_list *)start : &_list->list;  \
        struct spa_hook _cursor = { 0 }, *_ci;                                  \
        int _count = 0;                                                         \
        spa_list_cursor_start(_cursor, _s, link);                               \
        spa_list_for_each_cursor(_ci, _cursor, &_list->list, link) {            \
                if (spa_callbacks_call(&_ci->cb,type,method,vers, ## __VA_ARGS__)) {            \
                        _count++;                                               \
                        if (once)                                               \
                                break;                                          \
                }                                                               \
        }                                                                       \
        spa_list_cursor_end(_cursor, link);                                     \
        _count;                                                                 \
})

#define spa_hook_list_call(l,t,m,v,...)                 spa_hook_list_do_call(l,NULL,t,m,v,false,##__VA_ARGS__)

#define spa_hook_list_call_once(l,t,m,v,...)            spa_hook_list_do_call(l,NULL,t,m,v,true,##__VA_ARGS__)

#define spa_hook_list_call_start(l,s,t,m,v,...)         spa_hook_list_do_call(l,s,t,m,v,false,##__VA_ARGS__)
#define spa_hook_list_call_once_start(l,s,t,m,v,...)    spa_hook_list_do_call(l,s,t,m,v,true,##__VA_ARGS__)

#ifdef __cplusplus
}
#endif

#endif /* SPA_HOOK_H */