src/liblzma/common/stream_flags_common.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       stream_flags_common.c
   4 /// \brief      Common stuff for Stream flags coders
   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 "stream_flags_common.h"
  14
  15
  16 const uint8_t lzma_header_magic[6] = { 0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00 };
  17 const uint8_t lzma_footer_magic[2] = { 0x59, 0x5A };
  18
  19
  20 extern LZMA_API(lzma_ret)
  21 lzma_stream_flags_compare(
  22                 const lzma_stream_flags *a, const lzma_stream_flags *b)
  23 {
  24         // We can compare only version 0 structures.
  25         if (a->version != 0 || b->version != 0)
  26                 return LZMA_OPTIONS_ERROR;
  27
  28         // Check type
  29         if ((unsigned int)(a->check) > LZMA_CHECK_ID_MAX
  30                         || (unsigned int)(b->check) > LZMA_CHECK_ID_MAX)
  31                 return LZMA_PROG_ERROR;
  32
  33         if (a->check != b->check)
  34                 return LZMA_DATA_ERROR;
  35
  36         // Backward Sizes are compared only if they are known in both.
  37         if (a->backward_size != LZMA_VLI_UNKNOWN
  38                         && b->backward_size != LZMA_VLI_UNKNOWN) {
  39                 if (!is_backward_size_valid(a) || !is_backward_size_valid(b))
  40                         return LZMA_PROG_ERROR;
  41
  42                 if (a->backward_size != b->backward_size)
  43                         return LZMA_DATA_ERROR;
  44         }
  45
  46         return LZMA_OK;
  47 }