src/liblzma/common/index.h

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