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 		lzma_allocator *allocator, const lzma_filter_info *filters,
70 		size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
71 			bool is_encoder, uint8_t *buffer, size_t size),
72 		size_t simple_size, size_t unfiltered_max,
73 		uint32_t alignment, bool is_encoder);
74 
75 #endif
76