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/*
* 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.
*/
#include <sys/types.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "vpool.h"
static void vpool_shift(struct vpool *pool);
static int vpool_new_size(struct vpool *pool, size_t datsize,
size_t *size);
static int vpool_resize(struct vpool *pool, size_t datsize);
static void
vpool_shift(struct vpool *pool)
{
if (pool->v_buf != pool->v_basebuf) {
memmove(pool->v_basebuf, pool->v_buf, pool->v_off);
pool->v_buf = pool->v_basebuf;
}
}
static int
vpool_new_size(struct vpool *pool, size_t datsize, size_t *size)
{
size_t need;
size_t rem;
if (datsize <= pool->v_size - pool->v_off) {
*size = pool->v_size;
return (0);
}
/* Check limit of new requested size */
if (pool->v_limit - pool->v_off < datsize)
return (EFBIG);
need = pool->v_off + datsize;
/* Check limit of new size aligned to block size */
rem = need % pool->v_blksize;
if (rem != 0) {
if (pool->v_limit - pool->v_off >=
datsize + (pool->v_blksize - rem))
need += pool->v_blksize - rem;
else
need = pool->v_limit;
}
*size = need;
return (0);
}
static int
vpool_resize(struct vpool *pool, size_t datsize)
{
char *ret;
size_t size;
int error;
error = vpool_new_size(pool, datsize, &size);
if (error != 0)
return (error);
if (size > pool->v_size) {
ret = (char *) malloc(size);
if (ret == NULL)
return (ENOMEM);
memcpy(ret, pool->v_buf, pool->v_off);
free(pool->v_basebuf);
pool->v_basebuf = pool->v_buf = ret;
pool->v_size = size;
} else if ((pool->v_size - pool->v_off) -
(size_t)((char*)pool->v_buf - (char*)pool->v_basebuf) < datsize)
vpool_shift(pool);
return (0);
}
void
vpool_init(struct vpool *pool, size_t blksize, size_t limit)
{
pool->v_basebuf = pool->v_buf = NULL;
pool->v_off = pool->v_size = 0;
pool->v_blksize = (blksize == 0) ? 4096 : blksize; /* XXX */
pool->v_limit = (limit == 0) ? SIZE_MAX : limit;
pool->v_lasterr = 0;
}
void
vpool_final(struct vpool *pool)
{
free(pool->v_basebuf);
}
void
vpool_reset(struct vpool *pool)
{
free(pool->v_basebuf);
pool->v_basebuf = pool->v_buf = NULL;
pool->v_off = pool->v_size = 0;
pool->v_lasterr = 0;
}
void
vpool_wipe(struct vpool *pool)
{
pool->v_off = 0;
pool->v_lasterr = 0;
}
void *
vpool_insert(struct vpool *pool, size_t where, void *data, size_t datsize)
{
char *ret;
int error;
error = vpool_resize(pool, datsize);
if (error != 0) {
pool->v_lasterr = error;
return (NULL);
}
/*
* If ``where'' is greater than or equal to offset then
* we are appending data to the end of the buffer.
*/
if (where > pool->v_off)
where = pool->v_off;
ret = (char *)pool->v_buf + where;
if (pool->v_off - where > 0)
memmove(ret + datsize, ret, pool->v_off - where);
memcpy(ret, data, datsize);
pool->v_off += datsize;
pool->v_lasterr = 0;
return (ret);
}
void *
vpool_expand(struct vpool *pool, size_t where, size_t size)
{
char *ret;
int error;
error = vpool_resize(pool, size);
if (error != 0) {
pool->v_lasterr = error;
return (NULL);
}
/*
* If ``where'' is greater than or equal to offset then
* we are appending data to the end of the buffer.
*/
if (where > pool->v_off)
where = pool->v_off;
ret = (char *)pool->v_buf + where;
if (pool->v_off - where > 0)
memmove(ret + size, ret, pool->v_off - where);
pool->v_off += size;
pool->v_lasterr = 0;
return (ret);
}
int
vpool_truncate(struct vpool *pool,
size_t where, size_t size, enum vpool_trunc how)
{
/* Check if caller wants to remove more data than we have */
if (where >= pool->v_off ||
size > pool->v_off || pool->v_off - size < where) {
pool->v_lasterr = ERANGE;
return (pool->v_lasterr);
}
if (how == VPOOL_EXCLUDE) {
if (where == 0) {
/*
* Optimization.
* Don't move data, just adjust pointer.
*/
pool->v_buf = (char *)pool->v_buf + size;
} else {
memmove((char *)pool->v_buf + where,
(char *)pool->v_buf + where + size,
pool->v_off - size - where);
}
pool->v_off -= size;
} else {
pool->v_buf = (char*)(pool->v_buf) + where;
pool->v_off = size;
}
pool->v_lasterr = 0;
return (0);
}
void
vpool_export(struct vpool *pool, void **buf, size_t *size)
{
vpool_shift(pool);
*buf = pool->v_buf;
*size = pool->v_off;
pool->v_basebuf = pool->v_buf = NULL;
pool->v_off = pool->v_size = 0;
pool->v_lasterr = 0;
}
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