src/liblzma/simple/simple_decoder.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       simple_decoder.c
   4 /// \brief      Properties decoder for simple filters
   5 //
   6 //  Author:     Lasse Collin
   7 //
   8 //  This file has been put into the public domain.
   9 //  You can do whatever you want with this file.
  10 //
  11 ///////////////////////////////////////////////////////////////////////////////
  12
  13 #include "simple_decoder.h"
  14
  15
  16 extern lzma_ret
  17 lzma_simple_props_decode(void **options, const lzma_allocator *allocator,
  18                 const uint8_t *props, size_t props_size)
  19 {
  20         if (props_size == 0)
  21                 return LZMA_OK;
  22
  23         if (props_size != 4)
  24                 return LZMA_OPTIONS_ERROR;
  25
  26         lzma_options_bcj *opt = lzma_alloc(
  27                         sizeof(lzma_options_bcj), allocator);
  28         if (opt == NULL)
  29                 return LZMA_MEM_ERROR;
  30
  31         opt->start_offset = unaligned_read32le(props);
  32
  33         // Don't leave an options structure allocated if start_offset is zero.
  34         if (opt->start_offset == 0)
  35                 lzma_free(opt, allocator);
  36         else
  37                 *options = opt;
  38
  39         return LZMA_OK;
  40 }