source: mainline/uspace/lib/c/include/adt/generic_field.h@ 9f3864a

/*
 * Copyright (c) 2009 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 *  @{
 */

/** @file
 *  Generic type field.
 */

#ifndef LIBC_GENERIC_FIELD_H_
#define LIBC_GENERIC_FIELD_H_

#include <errno.h>
#include <malloc.h>
#include <mem.h>
#include <unistd.h>

/** Internal magic value for a&nbsp;field consistency check. */
#define GENERIC_FIELD_MAGIC_VALUE               0x55667788

/** Generic type field declaration.
 *
 * @param[in] name      Name of the field.
 * @param[in] type      Inner object type.
 */
#define GENERIC_FIELD_DECLARE(name, type) \
        typedef struct name name##_t; \
        \
        struct  name { \
                int size; \
                int next; \
                type **items; \
                int magic; \
        }; \
        \
        int name##_add(name##_t *, type *); \
        int name##_count(name##_t *); \
        void name##_destroy(name##_t *); \
        void name##_exclude_index(name##_t *, int); \
        type **name##_get_field(name##_t *); \
        type *name##_get_index(name##_t *, int); \
        int name##_initialize(name##_t *); \
        int name##_is_valid(name##_t *);

/** Generic type field implementation.
 *
 * Should follow declaration with the same parameters.
 *
 * @param[in] name      Name of the field.
 * @param[in] type      Inner object type.
 */
#define GENERIC_FIELD_IMPLEMENT(name, type) \
        int name##_add(name##_t *field, type *value) \
        { \
                if (name##_is_valid(field)) { \
                        if (field->next == (field->size - 1)) { \
                                type **tmp; \
                                tmp = (type **) realloc(field->items, \
                                    sizeof(type *) * 2 * field->size); \
                                if (!tmp) \
                                        return ENOMEM; \
                                field->size *= 2; \
                                field->items = tmp; \
                        } \
                        field->items[field->next] = value; \
                        field->next++; \
                        field->items[field->next] = NULL; \
                        return field->next - 1; \
                } \
                return EINVAL; \
        } \
        \
        int name##_count(name##_t *field) \
        { \
                return name##_is_valid(field) ? field->next : -1; \
        } \
        \
        void name##_destroy(name##_t *field) \
        { \
                if (name##_is_valid(field)) { \
                        int index; \
                        field->magic = 0; \
                        for (index = 0; index < field->next; index++) { \
                                if (field->items[index]) \
                                        free(field->items[index]); \
                        } \
                        free(field->items); \
                } \
        } \
         \
        void name##_exclude_index(name##_t *field, int index) \
        { \
                if (name##_is_valid(field) && (index >= 0) && \
                    (index < field->next) && (field->items[index])) { \
                        free(field->items[index]); \
                        field->items[index] = NULL; \
                } \
        } \
         \
        type *name##_get_index(name##_t *field, int index) \
        { \
                if (name##_is_valid(field) && (index >= 0) && \
                    (index < field->next) && (field->items[index])) \
                        return field->items[index]; \
                return NULL; \
        } \
        \
        type **name##_get_field(name##_t *field) \
        { \
                return name##_is_valid(field) ? field->items : NULL; \
        } \
        \
        int name##_initialize(name##_t *field) \
        { \
                if (!field) \
                        return EINVAL; \
                field->size = 2; \
                field->next = 0; \
                field->items = (type **) malloc(sizeof(type *) * field->size); \
                if (!field->items) \
                        return ENOMEM; \
                field->items[field->next] = NULL; \
                field->magic = GENERIC_FIELD_MAGIC_VALUE; \
                return EOK; \
        } \
        \
        int name##_is_valid(name##_t *field) \
        { \
                return field && (field->magic == GENERIC_FIELD_MAGIC_VALUE); \
        }

#endif

/** @}
 */