contrib/libarchive-2/libarchive/archive_read_data_into_fd.c

   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: src/lib/libarchive/archive_read_data_into_fd.c,v 1.16 2008/05/23 05:01:29 cperciva Exp $");
  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  */
  48 int
  49 archive_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 }