external/public-domain/xz/dist/src/liblzma/simple/simple_private.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       simple_private.h
   4 /// \brief      Private definitions for so called 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 #ifndef LZMA_SIMPLE_PRIVATE_H
  14 #define LZMA_SIMPLE_PRIVATE_H
  15
  16 #include "simple_coder.h"
  17
  18
  19 typedef struct lzma_simple_s lzma_simple;
  20
  21 struct lzma_coder_s {
  22         /// Next filter in the chain
  23         lzma_next_coder next;
  24
  25         /// True if the next coder in the chain has returned LZMA_STREAM_END.
  26         bool end_was_reached;
  27
  28         /// True if filter() should encode the data; false to decode.
  29         /// Currently all simple filters use the same function for encoding
  30         /// and decoding, because the difference between encoders and decoders
  31         /// is very small.
  32         bool is_encoder;
  33
  34         /// Pointer to filter-specific function, which does
  35         /// the actual filtering.
  36         size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
  37                         bool is_encoder, uint8_t *buffer, size_t size);
  38
  39         /// Pointer to filter-specific data, or NULL if filter doesn't need
  40         /// any extra data.
  41         lzma_simple *simple;
  42
  43         /// The lowest 32 bits of the current position in the data. Most
  44         /// filters need this to do conversions between absolute and relative
  45         /// addresses.
  46         uint32_t now_pos;
  47
  48         /// Size of the memory allocated for the buffer.
  49         size_t allocated;
  50
  51         /// Flushing position in the temporary buffer. buffer[pos] is the
  52         /// next byte to be copied to out[].
  53         size_t pos;
  54
  55         /// buffer[filtered] is the first unfiltered byte. When pos is smaller
  56         /// than filtered, there is unflushed filtered data in the buffer.
  57         size_t filtered;
  58
  59         /// Total number of bytes (both filtered and unfiltered) currently
  60         /// in the temporary buffer.
  61         size_t size;
  62
  63         /// Temporary buffer
  64         uint8_t buffer[];
  65 };
  66
  67
  68 extern lzma_ret lzma_simple_coder_init(lzma_next_coder *next,
  69                 const lzma_allocator *allocator,
  70                 const lzma_filter_info *filters,
  71                 size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
  72                         bool is_encoder, uint8_t *buffer, size_t size),
  73                 size_t simple_size, size_t unfiltered_max,
  74                 uint32_t alignment, bool is_encoder);
  75
  76 #endif