simple_private.h revision 292588 
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
19typedef struct lzma_simple_s lzma_simple;
20
21struct 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
68extern 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
77