contrib/libarchive-2/libarchive/archive_read_support_format_empty.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_support_format_empty.c,v 1.3 2007/05/29 01:00:19 kientzle Exp $");
  28
  29 #include "archive.h"
  30 #include "archive_entry.h"
  31 #include "archive_private.h"
  32 #include "archive_read_private.h"
  33
  34 static int      archive_read_format_empty_bid(struct archive_read *);
  35 static int      archive_read_format_empty_read_data(struct archive_read *,
  36                     const void **, size_t *, off_t *);
  37 static int      archive_read_format_empty_read_header(struct archive_read *,
  38                     struct archive_entry *);
  39 int
  40 archive_read_support_format_empty(struct archive *_a)
  41 {
  42         struct archive_read *a = (struct archive_read *)_a;
  43         int r;
  44
  45         r = __archive_read_register_format(a,
  46             NULL,
  47             archive_read_format_empty_bid,
  48             archive_read_format_empty_read_header,
  49             archive_read_format_empty_read_data,
  50             NULL,
  51             NULL);
  52
  53         return (r);
  54 }
  55
  56
  57 static int
  58 archive_read_format_empty_bid(struct archive_read *a)
  59 {
  60         int bytes_read;
  61         const void *h;
  62
  63         bytes_read = (a->decompressor->read_ahead)(a, &h, 1);
  64         if (bytes_read > 0)
  65                 return (-1);
  66         return (1);
  67 }
  68
  69 static int
  70 archive_read_format_empty_read_header(struct archive_read *a,
  71     struct archive_entry *entry)
  72 {
  73         (void)a; /* UNUSED */
  74         (void)entry; /* UNUSED */
  75
  76         a->archive.archive_format = ARCHIVE_FORMAT_EMPTY;
  77         a->archive.archive_format_name = "Empty file";
  78
  79         return (ARCHIVE_EOF);
  80 }
  81
  82 static int
  83 archive_read_format_empty_read_data(struct archive_read *a,
  84     const void **buff, size_t *size, off_t *offset)
  85 {
  86         (void)a; /* UNUSED */
  87         (void)buff; /* UNUSED */
  88         (void)size; /* UNUSED */
  89         (void)offset; /* UNUSED */
  90
  91         return (ARCHIVE_EOF);
  92 }