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