freebsd-dev/lib/libarchive/archive_read_open_memory.c
Tim Kientzle ab16ac785a New "version stamp" simplifies determining the exact version
of libarchive being used.  I've been taking advantage of this
with a recent round of updates to libarchive_test so that it
can test older and newer versions of the library.

Approved by: re (Ken Smith)
2007-07-06 15:36:38 +00:00

157 lines
4.7 KiB
C

/*-
* Copyright (c) 2003-2007 Tim Kientzle
* 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. 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 AUTHOR(S) ``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(S) 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 "archive_platform.h"
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "archive.h"
/*
* Glue to read an archive from a block of memory.
*
* This is mostly a huge help in building test harnesses;
* test programs can build archives in memory and read them
* back again without having to mess with files on disk.
*/
struct read_memory_data {
unsigned char *buffer;
unsigned char *end;
ssize_t read_size;
};
static int memory_read_close(struct archive *, void *);
static int memory_read_open(struct archive *, void *);
#if ARCHIVE_API_VERSION < 2
static ssize_t memory_read_skip(struct archive *, void *, size_t request);
#else
static off_t memory_read_skip(struct archive *, void *, off_t request);
#endif
static ssize_t memory_read(struct archive *, void *, const void **buff);
int
archive_read_open_memory(struct archive *a, void *buff, size_t size)
{
return archive_read_open_memory2(a, buff, size, size);
}
/*
* Don't use _open_memory2() in production code; the archive_read_open_memory()
* version is the one you really want. This is just here so that
* test harnesses can exercise block operations inside the library.
*/
int
archive_read_open_memory2(struct archive *a, void *buff,
size_t size, size_t read_size)
{
struct read_memory_data *mine;
mine = (struct read_memory_data *)malloc(sizeof(*mine));
if (mine == NULL) {
archive_set_error(a, ENOMEM, "No memory");
return (ARCHIVE_FATAL);
}
memset(mine, 0, sizeof(*mine));
mine->buffer = (unsigned char *)buff;
mine->end = mine->buffer + size;
mine->read_size = read_size;
return (archive_read_open2(a, mine, memory_read_open,
memory_read, memory_read_skip, memory_read_close));
}
/*
* There's nothing to open.
*/
static int
memory_read_open(struct archive *a, void *client_data)
{
(void)a; /* UNUSED */
(void)client_data; /* UNUSED */
return (ARCHIVE_OK);
}
/*
* This is scary simple: Just advance a pointer. Limiting
* to read_size is not technically necessary, but it exercises
* more of the internal logic when used with a small block size
* in a test harness. Production use should not specify a block
* size; then this is much faster.
*/
static ssize_t
memory_read(struct archive *a, void *client_data, const void **buff)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
ssize_t size;
(void)a; /* UNUSED */
*buff = mine->buffer;
size = mine->end - mine->buffer;
if (size > mine->read_size)
size = mine->read_size;
mine->buffer += size;
return (size);
}
/*
* Advancing is just as simple. Again, this is doing more than
* necessary in order to better exercise internal code when used
* as a test harness.
*/
#if ARCHIVE_API_VERSION < 2
static ssize_t
memory_read_skip(struct archive *a, void *client_data, size_t skip)
#else
static off_t
memory_read_skip(struct archive *a, void *client_data, off_t skip)
#endif
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
(void)a; /* UNUSED */
if ((off_t)skip > (off_t)(mine->end - mine->buffer))
skip = mine->end - mine->buffer;
/* Round down to block size. */
skip /= mine->read_size;
skip *= mine->read_size;
mine->buffer += skip;
return (skip);
}
/*
* Close is just cleaning up our one small bit of data.
*/
static int
memory_read_close(struct archive *a, void *client_data)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
(void)a; /* UNUSED */
free(mine);
return (ARCHIVE_OK);
}