contrib/libarchive-1.3.1/libarchive/archive_write_open_memory.c

   1 /*-
   2  * Copyright (c) 2003-2006 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  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "archive_platform.h"
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <errno.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #include "archive.h"
  35 #include "archive_private.h"
  36
  37 /*
  38  * This is a little tricky.  I used to allow the
  39  * compression handling layer to fork the compressor,
  40  * which means this write function gets invoked in
  41  * a separate process.  That would, of course, make it impossible
  42  * to actually use the data stored into memory here.
  43  * Fortunately, none of the compressors fork today and
  44  * I'm reluctant to use that route in the future but, if
  45  * forking compressors ever do reappear, this will have
  46  * to get a lot more complicated.
  47  */
  48
  49 struct write_memory_data {
  50         size_t  used;
  51         size_t  size;
  52         size_t * client_size;
  53         unsigned char * buff;
  54 };
  55
  56 static int      memory_write_close(struct archive *, void *);
  57 static int      memory_write_open(struct archive *, void *);
  58 static ssize_t  memory_write(struct archive *, void *, void *buff, size_t);
  59
  60 /*
  61  * Client provides a pointer to a block of memory to receive
  62  * the data.  The 'size' param both tells us the size of the
  63  * client buffer and lets us tell the client the final size.
  64  */
  65 int
  66 archive_write_open_memory(struct archive *a, void *buff, size_t buffSize, size_t *used)
  67 {
  68         struct write_memory_data *mine;
  69
  70         mine = malloc(sizeof(*mine));
  71         if (mine == NULL) {
  72                 archive_set_error(a, ENOMEM, "No memory");
  73                 return (ARCHIVE_FATAL);
  74         }
  75         memset(mine, 0, sizeof(*mine));
  76         mine->buff = buff;
  77         mine->size = buffSize;
  78         mine->client_size = used;
  79         return (archive_write_open(a, mine,
  80                     memory_write_open, memory_write, memory_write_close));
  81 }
  82
  83 static int
  84 memory_write_open(struct archive *a, void *client_data)
  85 {
  86         struct write_memory_data *mine;
  87         mine = client_data;
  88         mine->used = 0;
  89         if (mine->client_size != NULL)
  90                 *mine->client_size = mine->used;
  91         /* Disable padding if it hasn't been set explicitly. */
  92         if (-1 == archive_write_get_bytes_in_last_block(a))
  93                 archive_write_set_bytes_in_last_block(a, 1);
  94         return (ARCHIVE_OK);
  95 }
  96
  97 /*
  98  * Copy the data into the client buffer.
  99  * Note that we update mine->client_size on every write.
 100  * In particular, this means the client can follow exactly
 101  * how much has been written into their buffer at any time.
 102  */
 103 static ssize_t
 104 memory_write(struct archive *a, void *client_data, void *buff, size_t length)
 105 {
 106         struct write_memory_data *mine;
 107         mine = client_data;
 108
 109         if (mine->used + length > mine->size) {
 110                 archive_set_error(a, ENOMEM, "Buffer exhausted");
 111                 return (ARCHIVE_FATAL);
 112         }
 113         memcpy(mine->buff + mine->used, buff, length);
 114         mine->used += length;
 115         if (mine->client_size != NULL)
 116                 *mine->client_size = mine->used;
 117         return (length);
 118 }
 119
 120 static int
 121 memory_write_close(struct archive *a, void *client_data)
 122 {
 123         struct write_memory_data *mine;
 124         (void)a; /* UNUSED */
 125         mine = client_data;
 126         free(mine);
 127         return (ARCHIVE_OK);
 128 }