vpool.h

/*
 * Copyright (c) 2006, 2008 Alexey Vatchenko <av@bsdua.org>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * VPool: implementation of pool of data with a variable size.
 */
#ifndef _VPOOL_H_
#define _VPOOL_H_

#include <sys/types.h>
#include <limits.h>

struct vpool {
    void    *v_basebuf; /* pointer returned by (re|m)alloc() */
    void    *v_buf;     /* actual data starts here */
    size_t  v_off;
    size_t  v_size;

    size_t  v_blksize;
    size_t  v_limit;
    int v_lasterr;
};

enum vpool_trunc {VPOOL_EXCLUDE, VPOOL_INCLUDE};
#define VPOOL_TAIL  UINT_MAX

void    vpool_init(struct vpool *pool, size_t blksize, size_t limit);
void    vpool_final(struct vpool *pool);

void    vpool_reset(struct vpool *pool);
void    vpool_wipe(struct vpool *pool);

void *  vpool_insert(struct vpool *pool,
    size_t where, void *data, size_t datsize);
void *  vpool_expand(struct vpool *pool, size_t where, size_t size);

int vpool_truncate(struct vpool *pool,
    size_t where, size_t size, enum vpool_trunc how);

#define vpool_is_empty(pool)        ((pool)->v_off == 0)
#define vpool_get_buf(pool)     ((pool)->v_buf)
#define vpool_get_length(pool)      ((pool)->v_off)
#define vpool_get_error(pool)       ((pool)->v_lasterr)

void    vpool_export(struct vpool *pool, void **buf, size_t *size);

#endif /* !_VPOOL_H_ */