array.h

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/* PipeWire
 * Copyright (C) 2016 Wim Taymans <wim.taymans@gmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __PIPEWIRE_ARRAY_H__
#define __PIPEWIRE_ARRAY_H__

#ifdef __cplusplus
extern "C" {
#endif

#include <spa/defs.h>

struct pw_array {
        void *data;             
        size_t size;            
        size_t alloc;           
        size_t extend;          
};

#define PW_ARRAY_INIT(extend) (struct pw_array) { NULL, 0, 0, extend }

#define pw_array_get_len_s(a,s)                 ((a)->size / (s))
#define pw_array_get_unchecked_s(a,idx,s,t)     SPA_MEMBER((a)->data,(idx)*(s),t)
#define pw_array_check_index_s(a,idx,s)         ((idx) < pw_array_get_len_s(a,s))

#define pw_array_get_len(a,t)                   pw_array_get_len_s(a,sizeof(t))

#define pw_array_get_unchecked(a,idx,t)         pw_array_get_unchecked_s(a,idx,sizeof(t),t)

#define pw_array_check_index(a,idx,t)           pw_array_check_index_s(a,idx,sizeof(t))

#define pw_array_for_each(pos, array)                                                   \
        for (pos = (array)->data;                                                       \
             (const uint8_t *) pos < ((const uint8_t *) (array)->data + (array)->size); \
             (pos)++)

static inline void pw_array_init(struct pw_array *arr, size_t extend)
{
        arr->data = NULL;
        arr->size = arr->alloc = 0;
        arr->extend = extend;
}

static inline void pw_array_clear(struct pw_array *arr)
{
        free(arr->data);
}

static inline bool pw_array_ensure_size(struct pw_array *arr, size_t size)
{
        size_t alloc, need;

        alloc = arr->alloc;
        need = arr->size + size;

        if (SPA_UNLIKELY(alloc < need)) {
                void *data;
                alloc = SPA_MAX(alloc, arr->extend);
                while (alloc < need)
                        alloc *= 2;
                if (SPA_UNLIKELY((data = realloc(arr->data, alloc)) == NULL))
                        return false;
                arr->data = data;
                arr->alloc = alloc;
        }
        return true;
}

static inline void *pw_array_add(struct pw_array *arr, size_t size)
{
        void *p;

        if (!pw_array_ensure_size(arr, size))
                return NULL;

        p = arr->data + arr->size;
        arr->size += size;

        return p;
}

static inline void *pw_array_add_fixed(struct pw_array *arr, size_t size)
{
        void *p;

        if (SPA_UNLIKELY(arr->alloc < arr->size + size))
                return NULL;

        p = arr->data + arr->size;
        arr->size += size;

        return p;
}

#define pw_array_add_ptr(a,p)                                   \
        *((void**) pw_array_add(a, sizeof(void*))) = (p)

#ifdef __cplusplus
}  /* extern "C" */
#endif

#endif /* __PIPEWIRE_ARRAY_H__ */