archive_read_data_into_fd.c revision 229592 
1/*-
2 * Copyright (c) 2003-2007 Tim Kientzle
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "archive_platform.h"
27__FBSDID("$FreeBSD: stable/9/contrib/libarchive/libarchive/archive_read_data_into_fd.c 229592 2012-01-05 12:06:54Z mm $");
28
29#ifdef HAVE_SYS_TYPES_H
30#include <sys/types.h>
31#endif
32#ifdef HAVE_ERRNO_H
33#include <errno.h>
34#endif
35#ifdef HAVE_UNISTD_H
36#include <unistd.h>
37#endif
38
39#include "archive.h"
40#include "archive_private.h"
41
42/* Maximum amount of data to write at one time. */
43#define	MAX_WRITE	(1024 * 1024)
44
45/*
46 * This implementation minimizes copying of data and is sparse-file aware.
47 */
48int
49archive_read_data_into_fd(struct archive *a, int fd)
50{
51	int r;
52	const void *buff;
53	size_t size, bytes_to_write;
54	ssize_t bytes_written, total_written;
55	off_t offset;
56	off_t output_offset;
57
58	__archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA, "archive_read_data_into_fd");
59
60	total_written = 0;
61	output_offset = 0;
62
63	while ((r = archive_read_data_block(a, &buff, &size, &offset)) ==
64	    ARCHIVE_OK) {
65		const char *p = buff;
66		if (offset > output_offset) {
67			output_offset = lseek(fd,
68			    offset - output_offset, SEEK_CUR);
69			if (output_offset != offset) {
70				archive_set_error(a, errno, "Seek error");
71				return (ARCHIVE_FATAL);
72			}
73		}
74		while (size > 0) {
75			bytes_to_write = size;
76			if (bytes_to_write > MAX_WRITE)
77				bytes_to_write = MAX_WRITE;
78			bytes_written = write(fd, p, bytes_to_write);
79			if (bytes_written < 0) {
80				archive_set_error(a, errno, "Write error");
81				return (ARCHIVE_FATAL);
82			}
83			output_offset += bytes_written;
84			total_written += bytes_written;
85			p += bytes_written;
86			size -= bytes_written;
87		}
88	}
89
90	if (r != ARCHIVE_EOF)
91		return (r);
92	return (ARCHIVE_OK);
93}
94