/*-

 * 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);

}