File: [local] / src / usr.bin / cvs / buf.c (download)
Revision 1.17, Fri Jul 29 17:04:42 2005 UTC (18 years, 10 months ago) by xsa
Branch: MAIN
Changes since 1.16: +3 -3 lines
minor KNF;
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/* $OpenBSD: buf.c,v 1.17 2005/07/29 17:04:42 xsa Exp $ */
/*
* Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
* All rights reserved.
*
* 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. 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 ``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.
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "buf.h"
#include "log.h"
#define BUF_INCR 128
struct cvs_buf {
u_int cb_flags;
/* buffer handle and size */
u_char *cb_buf;
size_t cb_size;
/* start and length of valid data in buffer */
u_char *cb_cur;
size_t cb_len;
};
#define SIZE_LEFT(b) (b->cb_size - (size_t)(b->cb_cur - b->cb_buf) \
- b->cb_len)
static ssize_t cvs_buf_grow(BUF *, size_t);
/*
* cvs_buf_alloc()
*
* Create a new buffer structure and return a pointer to it. This structure
* uses dynamically-allocated memory and must be freed with cvs_buf_free(),
* once the buffer is no longer needed.
*/
BUF *
cvs_buf_alloc(size_t len, u_int flags)
{
BUF *b;
b = (BUF *)malloc(sizeof(*b));
if (b == NULL) {
cvs_log(LP_ERRNO, "failed to allocate buffer");
return (NULL);
}
b->cb_buf = malloc(len);
if (b->cb_buf == NULL) {
cvs_log(LP_ERRNO, "failed to allocate buffer");
free(b);
return (NULL);
}
memset(b->cb_buf, 0, len);
b->cb_flags = flags;
b->cb_size = len;
b->cb_cur = b->cb_buf;
b->cb_len = 0;
return (b);
}
/*
* cvs_buf_load()
*
* Open the file specified by <path> and load all of its contents into a
* buffer.
* Returns the loaded buffer on success, or NULL on failure.
*/
BUF *
cvs_buf_load(const char *path, u_int flags)
{
int fd;
ssize_t ret;
size_t len;
u_char *bp;
struct stat st;
BUF *buf;
fd = open(path, O_RDONLY, 0600);
if (fd == -1) {
cvs_log(LP_ERRNO, "failed to open buffer source");
return (NULL);
}
if (fstat(fd, &st) == -1) {
cvs_log(LP_ERRNO, "failed to stat buffer source");
(void)close(fd);
return (NULL);
}
buf = cvs_buf_alloc((size_t)st.st_size, flags);
if (buf == NULL) {
(void)close(fd);
return (NULL);
}
for (bp = buf->cb_cur; ; bp += (size_t)ret) {
len = SIZE_LEFT(buf);
ret = read(fd, bp, len);
if (ret == -1) {
cvs_log(LP_ERRNO, "read failed from buffer source");
(void)close(fd);
cvs_buf_free(buf);
return (NULL);
} else if (ret == 0)
break;
buf->cb_len += (size_t)ret;
}
(void)close(fd);
return (buf);
}
/*
* cvs_buf_free()
*
* Free the buffer <b> and all associated data.
*/
void
cvs_buf_free(BUF *b)
{
free(b->cb_buf);
free(b);
}
/*
* cvs_buf_release()
*
* Free the buffer <b>'s structural information but do not free the contents
* of the buffer. Instead, they are returned and should be freed later using
* free().
*/
void *
cvs_buf_release(BUF *b)
{
u_char *tmp;
tmp = b->cb_buf;
free(b);
return (tmp);
}
/*
* cvs_buf_empty()
*
* Empty the contents of the buffer <b> and reset pointers.
*/
void
cvs_buf_empty(BUF *b)
{
memset(b->cb_buf, 0, b->cb_size);
b->cb_cur = b->cb_buf;
b->cb_len = 0;
}
/*
* cvs_buf_copy()
*
* Copy the first <len> bytes of data in the buffer <b> starting at offset
* <off> in the destination buffer <dst>, which can accept up to <len> bytes.
* Returns the number of bytes successfully copied, or -1 on failure.
*/
ssize_t
cvs_buf_copy(BUF *b, size_t off, void *dst, size_t len)
{
size_t rc;
if (off > b->cb_len)
return (-1);
rc = MIN(len, (b->cb_len - off));
memcpy(dst, b->cb_buf + off, rc);
return (ssize_t)rc;
}
/*
* cvs_buf_set()
*
* Set the contents of the buffer <b> at offset <off> to the first <len>
* bytes of data found at <src>. If the buffer was not created with
* BUF_AUTOEXT, as many bytes as possible will be copied in the buffer.
*/
ssize_t
cvs_buf_set(BUF *b, const void *src, size_t len, size_t off)
{
size_t rlen;
if (b->cb_size < (len + off)) {
if ((b->cb_flags & BUF_AUTOEXT) && (cvs_buf_grow(b,
len + off - b->cb_size) < 0))
return (-1);
else
rlen = b->cb_size - off;
} else
rlen = len;
memcpy((b->cb_buf + off), src, rlen);
if (b->cb_len == 0) {
b->cb_cur = b->cb_buf + off;
b->cb_len = rlen;
}
return (rlen);
}
/*
* cvs_buf_putc()
*
* Append a single character <c> to the end of the buffer <b>.
* Returns 0 on success, or -1 on failure.
*/
int
cvs_buf_putc(BUF *b, int c)
{
u_char *bp;
bp = b->cb_cur + b->cb_len;
if (bp == (b->cb_buf + b->cb_size)) {
/* extend */
if (!(b->cb_flags & BUF_AUTOEXT) ||
(cvs_buf_grow(b, BUF_INCR) < 0))
return (-1);
/* the buffer might have been moved */
bp = b->cb_cur + b->cb_len;
}
*bp = (u_char)c;
b->cb_len++;
return (0);
}
/*
* cvs_buf_append()
*
* Append <len> bytes of data pointed to by <data> to the buffer <b>. If the
* buffer is too small to accept all data, it will attempt to append as much
* data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
* will get resized to an appropriate size to accept all data.
* Returns the number of bytes successfully appended to the buffer, or -1
* on failure.
*/
ssize_t
cvs_buf_append(BUF *b, const void *data, size_t len)
{
size_t left, rlen;
u_char *bp, *bep;
bp = b->cb_cur + b->cb_len;
bep = b->cb_buf + b->cb_size;
left = bep - bp;
rlen = len;
if (left < len) {
if (b->cb_flags & BUF_AUTOEXT) {
if (cvs_buf_grow(b, len - left) < 0)
return (-1);
bp = b->cb_cur + b->cb_len;
} else
rlen = bep - bp;
}
memcpy(bp, data, rlen);
b->cb_len += rlen;
return (rlen);
}
/*
* cvs_buf_fappend()
*
*/
int
cvs_buf_fappend(BUF *b, const char *fmt, ...)
{
int ret;
char *str;
va_list vap;
va_start(vap, fmt);
ret = vasprintf(&str, fmt, vap);
va_end(vap);
if (ret == -1) {
cvs_log(LP_ERRNO, "failed to format data");
return (-1);
}
ret = cvs_buf_append(b, str, ret);
free(str);
return (ret);
}
/*
* cvs_buf_len()
*
* Returns the size of the buffer that is being used.
*/
size_t
cvs_buf_len(BUF *b)
{
return (b->cb_len);
}
/*
* cvs_buf_peek()
*
* Peek at the contents of the buffer <b> at offset <off>.
*/
const void *
cvs_buf_peek(BUF *b, size_t off)
{
if (off >= b->cb_len)
return (NULL);
return (b->cb_buf + off);
}
/*
* cvs_buf_write_fd()
*
* Write the contents of the buffer <b> to the specified <fd>
*/
int
cvs_buf_write_fd(BUF *b, int fd)
{
u_char *bp;
size_t len;
ssize_t ret;
len = b->cb_len;
bp = b->cb_cur;
do {
ret = write(fd, bp, len);
if (ret == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
return (-1);
}
len -= (size_t)ret;
bp += (size_t)ret;
} while (len > 0);
return (0);
}
/*
* cvs_buf_write()
*
* Write the contents of the buffer <b> to the file whose path is given in
* <path>. If the file does not exist, it is created with mode <mode>.
*/
int
cvs_buf_write(BUF *b, const char *path, mode_t mode)
{
int ret, fd;
fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode);
if (fd == -1) {
cvs_log(LP_ERRNO, "failed to open file `%s'", path);
return (-1);
}
ret = cvs_buf_write_fd(b, fd);
if (ret == -1) {
cvs_log(LP_ERRNO, "failed to write to file `%s'", path);
(void)unlink(path);
}
(void)close(fd);
return (ret);
}
/*
* cvs_buf_write_stmp()
*
* Write the contents of the buffer <b> to a temporary file whose path is
* specified using <template> (see mkstemp.3). NB. This function will modify
* <template>, as per mkstemp
*/
int
cvs_buf_write_stmp(BUF *b, char *template, mode_t mode)
{
int ret, fd;
fd = mkstemp(template);
if (fd == -1) {
cvs_log(LP_ERRNO, "failed to mkstemp file `%s'", template);
return (-1);
}
ret = cvs_buf_write_fd(b, fd);
if (ret == -1) {
cvs_log(LP_ERRNO, "failed to write to temp file `%s'",
template);
(void)unlink(template);
}
(void)close(fd);
return (ret);
}
/*
* cvs_buf_grow()
*
* Grow the buffer <b> by <len> bytes. The contents are unchanged by this
* operation regardless of the result.
* Returns the new size on success, or -1 on failure.
*/
static ssize_t
cvs_buf_grow(BUF *b, size_t len)
{
void *tmp;
size_t diff;
diff = b->cb_cur - b->cb_buf;
tmp = realloc(b->cb_buf, b->cb_size + len);
if (tmp == NULL) {
cvs_log(LP_ERRNO, "failed to grow buffer");
return (-1);
}
b->cb_buf = (u_char *)tmp;
b->cb_size += len;
/* readjust pointers in case the buffer moved in memory */
b->cb_cur = b->cb_buf + diff;
return (ssize_t)b->cb_size;
}