src/liblzma/common/index.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       index.h
   4 /// \brief      Handling of Index
   5 /// \note       This header file does not include common.h or lzma.h because
   6 ///             this file is needed by both liblzma internally and by the
   7 ///             tests. Including common.h will include and define many things
   8 ///             the tests do not need and prevents issues with header file
   9 ///             include order. This way, if lzma.h or common.h are not
  10 ///             included before this file it will break on every OS instead
  11 ///             of causing more subtle errors.
  12 //
  13 //  Author:     Lasse Collin
  14 //
  15 //  This file has been put into the public domain.
  16 //  You can do whatever you want with this file.
  17 //
  18 ///////////////////////////////////////////////////////////////////////////////
  19
  20 #ifndef LZMA_INDEX_H
  21 #define LZMA_INDEX_H
  22
  23
  24 /// Minimum Unpadded Size
  25 #define UNPADDED_SIZE_MIN LZMA_VLI_C(5)
  26
  27 /// Maximum Unpadded Size
  28 #define UNPADDED_SIZE_MAX (LZMA_VLI_MAX & ~LZMA_VLI_C(3))
  29
  30 /// Index Indicator based on xz specification
  31 #define INDEX_INDICATOR 0
  32
  33
  34 /// Get the size of the Index Padding field. This is needed by Index encoder
  35 /// and decoder, but applications should have no use for this.
  36 extern uint32_t lzma_index_padding_size(const lzma_index *i);
  37
  38
  39 /// Set for how many Records to allocate memory the next time
  40 /// lzma_index_append() needs to allocate space for a new Record.
  41 /// This is used only by the Index decoder.
  42 extern void lzma_index_prealloc(lzma_index *i, lzma_vli records);
  43
  44
  45 /// Round the variable-length integer to the next multiple of four.
  46 static inline lzma_vli
  47 vli_ceil4(lzma_vli vli)
  48 {
  49         assert(vli <= LZMA_VLI_MAX);
  50         return (vli + 3) & ~LZMA_VLI_C(3);
  51 }
  52
  53
  54 /// Calculate the size of the Index field excluding Index Padding
  55 static inline lzma_vli
  56 index_size_unpadded(lzma_vli count, lzma_vli index_list_size)
  57 {
  58         // Index Indicator + Number of Records + List of Records + CRC32
  59         return 1 + lzma_vli_size(count) + index_list_size + 4;
  60 }
  61
  62
  63 /// Calculate the size of the Index field including Index Padding
  64 static inline lzma_vli
  65 index_size(lzma_vli count, lzma_vli index_list_size)
  66 {
  67         return vli_ceil4(index_size_unpadded(count, index_list_size));
  68 }
  69
  70
  71 /// Calculate the total size of the Stream
  72 static inline lzma_vli
  73 index_stream_size(lzma_vli blocks_size,
  74                 lzma_vli count, lzma_vli index_list_size)
  75 {
  76         return LZMA_STREAM_HEADER_SIZE + blocks_size
  77                         + index_size(count, index_list_size)
  78                         + LZMA_STREAM_HEADER_SIZE;
  79 }
  80
  81 #endif