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/*-
* 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: src/lib/libarchive/archive_read_data_into_fd.c,v 1.16 2008/05/23 05:01:29 cperciva Exp $");
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "archive.h"
#include "archive_private.h"
/* Maximum amount of data to write at one time. */
#define MAX_WRITE (1024 * 1024)
/*
* This implementation minimizes copying of data and is sparse-file aware.
*/
static int
pad_to(struct archive *a, int fd, int can_lseek,
size_t nulls_size, const char *nulls,
int64_t target_offset, int64_t actual_offset)
{
size_t to_write;
ssize_t bytes_written;
if (can_lseek) {
actual_offset = lseek(fd,
target_offset - actual_offset, SEEK_CUR);
if (actual_offset != target_offset) {
archive_set_error(a, errno, "Seek error");
return (ARCHIVE_FATAL);
}
return (ARCHIVE_OK);
}
while (target_offset > actual_offset) {
to_write = nulls_size;
if (target_offset < actual_offset + (int64_t)nulls_size)
to_write = (size_t)(target_offset - actual_offset);
bytes_written = write(fd, nulls, to_write);
if (bytes_written < 0) {
archive_set_error(a, errno, "Write error");
return (ARCHIVE_FATAL);
}
actual_offset += bytes_written;
}
return (ARCHIVE_OK);
}
int
archive_read_data_into_fd(struct archive *a, int fd)
{
struct stat st;
int r, r2;
const void *buff;
size_t size, bytes_to_write;
ssize_t bytes_written;
int64_t target_offset;
int64_t actual_offset = 0;
int can_lseek;
char *nulls = NULL;
size_t nulls_size = 16384;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA,
"archive_read_data_into_fd");
can_lseek = (fstat(fd, &st) == 0) && S_ISREG(st.st_mode);
if (!can_lseek)
nulls = calloc(1, nulls_size);
while ((r = archive_read_data_block(a, &buff, &size, &target_offset)) ==
ARCHIVE_OK) {
const char *p = buff;
if (target_offset > actual_offset) {
r = pad_to(a, fd, can_lseek, nulls_size, nulls,
target_offset, actual_offset);
if (r != ARCHIVE_OK)
break;
actual_offset = target_offset;
}
while (size > 0) {
bytes_to_write = size;
if (bytes_to_write > MAX_WRITE)
bytes_to_write = MAX_WRITE;
bytes_written = write(fd, p, bytes_to_write);
if (bytes_written < 0) {
archive_set_error(a, errno, "Write error");
r = ARCHIVE_FATAL;
goto cleanup;
}
actual_offset += bytes_written;
p += bytes_written;
size -= bytes_written;
}
}
if (r == ARCHIVE_EOF && target_offset > actual_offset) {
r2 = pad_to(a, fd, can_lseek, nulls_size, nulls,
target_offset, actual_offset);
if (r2 != ARCHIVE_OK)
r = r2;
}
cleanup:
free(nulls);
if (r != ARCHIVE_EOF)
return (r);
return (ARCHIVE_OK);
}
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