archive_read_open_memory.c [plain text]
#include "archive_platform.h"
__FBSDID("$FreeBSD: src/lib/libarchive/archive_read_open_memory.c,v 1.6 2007/07/06 15:51:59 kientzle Exp $");
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "archive.h"
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);
}
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));
}
static int
memory_read_open(struct archive *a, void *client_data)
{
(void)a;
(void)client_data;
return (ARCHIVE_OK);
}
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;
*buff = mine->buffer;
size = mine->end - mine->buffer;
if (size > mine->read_size)
size = mine->read_size;
mine->buffer += size;
return (size);
}
#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;
if ((off_t)skip > (off_t)(mine->end - mine->buffer))
skip = mine->end - mine->buffer;
skip /= mine->read_size;
skip *= mine->read_size;
mine->buffer += skip;
return (skip);
}
static int
memory_read_close(struct archive *a, void *client_data)
{
struct read_memory_data *mine = (struct read_memory_data *)client_data;
(void)a;
free(mine);
return (ARCHIVE_OK);
}