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freebsd/sbin/hastd/ebuf.c
Pedro F. Giffuni 1de7b4b805 various: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:37:16 +00:00

262 lines
6.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2009-2010 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``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 AUTHORS OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <strings.h>
#include <unistd.h>
#include <pjdlog.h>
#include "ebuf.h"
#ifndef PJDLOG_ASSERT
#include <assert.h>
#define PJDLOG_ASSERT(...) assert(__VA_ARGS__)
#endif
#define EBUF_MAGIC 0xeb0f41c
struct ebuf {
/* Magic to assert the caller uses valid structure. */
int eb_magic;
/* Address where we did the allocation. */
unsigned char *eb_start;
/* Allocation end address. */
unsigned char *eb_end;
/* Start of real data. */
unsigned char *eb_used;
/* Size of real data. */
size_t eb_size;
};
static int ebuf_head_extend(struct ebuf *eb, size_t size);
static int ebuf_tail_extend(struct ebuf *eb, size_t size);
struct ebuf *
ebuf_alloc(size_t size)
{
struct ebuf *eb;
int rerrno;
eb = malloc(sizeof(*eb));
if (eb == NULL)
return (NULL);
size += PAGE_SIZE;
eb->eb_start = malloc(size);
if (eb->eb_start == NULL) {
rerrno = errno;
free(eb);
errno = rerrno;
return (NULL);
}
eb->eb_end = eb->eb_start + size;
/*
* We set start address for real data not at the first entry, because
* we want to be able to add data at the front.
*/
eb->eb_used = eb->eb_start + PAGE_SIZE / 4;
eb->eb_size = 0;
eb->eb_magic = EBUF_MAGIC;
return (eb);
}
void
ebuf_free(struct ebuf *eb)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
eb->eb_magic = 0;
free(eb->eb_start);
free(eb);
}
int
ebuf_add_head(struct ebuf *eb, const void *data, size_t size)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
if (size > (size_t)(eb->eb_used - eb->eb_start)) {
/*
* We can't add more entries at the front, so we have to extend
* our buffer.
*/
if (ebuf_head_extend(eb, size) == -1)
return (-1);
}
PJDLOG_ASSERT(size <= (size_t)(eb->eb_used - eb->eb_start));
eb->eb_size += size;
eb->eb_used -= size;
/*
* If data is NULL the caller just wants to reserve place.
*/
if (data != NULL)
bcopy(data, eb->eb_used, size);
return (0);
}
int
ebuf_add_tail(struct ebuf *eb, const void *data, size_t size)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
if (size > (size_t)(eb->eb_end - (eb->eb_used + eb->eb_size))) {
/*
* We can't add more entries at the back, so we have to extend
* our buffer.
*/
if (ebuf_tail_extend(eb, size) == -1)
return (-1);
}
PJDLOG_ASSERT(size <=
(size_t)(eb->eb_end - (eb->eb_used + eb->eb_size)));
/*
* If data is NULL the caller just wants to reserve space.
*/
if (data != NULL)
bcopy(data, eb->eb_used + eb->eb_size, size);
eb->eb_size += size;
return (0);
}
void
ebuf_del_head(struct ebuf *eb, size_t size)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
PJDLOG_ASSERT(size <= eb->eb_size);
eb->eb_used += size;
eb->eb_size -= size;
}
void
ebuf_del_tail(struct ebuf *eb, size_t size)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
PJDLOG_ASSERT(size <= eb->eb_size);
eb->eb_size -= size;
}
/*
* Return pointer to the data and data size.
*/
void *
ebuf_data(struct ebuf *eb, size_t *sizep)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
if (sizep != NULL)
*sizep = eb->eb_size;
return (eb->eb_size > 0 ? eb->eb_used : NULL);
}
/*
* Return data size.
*/
size_t
ebuf_size(struct ebuf *eb)
{
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
return (eb->eb_size);
}
/*
* Function adds size + (PAGE_SIZE / 4) bytes at the front of the buffer..
*/
static int
ebuf_head_extend(struct ebuf *eb, size_t size)
{
unsigned char *newstart, *newused;
size_t newsize;
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
newsize = eb->eb_end - eb->eb_start + (PAGE_SIZE / 4) + size;
newstart = malloc(newsize);
if (newstart == NULL)
return (-1);
newused =
newstart + (PAGE_SIZE / 4) + size + (eb->eb_used - eb->eb_start);
bcopy(eb->eb_used, newused, eb->eb_size);
eb->eb_start = newstart;
eb->eb_used = newused;
eb->eb_end = newstart + newsize;
return (0);
}
/*
* Function adds size + ((3 * PAGE_SIZE) / 4) bytes at the back.
*/
static int
ebuf_tail_extend(struct ebuf *eb, size_t size)
{
unsigned char *newstart;
size_t newsize;
PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
newsize = eb->eb_end - eb->eb_start + size + ((3 * PAGE_SIZE) / 4);
newstart = realloc(eb->eb_start, newsize);
if (newstart == NULL)
return (-1);
eb->eb_used = newstart + (eb->eb_used - eb->eb_start);
eb->eb_start = newstart;
eb->eb_end = newstart + newsize;
return (0);
}