simple_private.h revision 207842 
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	/// or if we have processed uncompressed_size bytes.
27	bool end_was_reached;
28
29	/// True if filter() should encode the data; false to decode.
30	/// Currently all simple filters use the same function for encoding
31	/// and decoding, because the difference between encoders and decoders
32	/// is very small.
33	bool is_encoder;
34
35	/// Pointer to filter-specific function, which does
36	/// the actual filtering.
37	size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
38			bool is_encoder, uint8_t *buffer, size_t size);
39
40	/// Pointer to filter-specific data, or NULL if filter doesn't need
41	/// any extra data.
42	lzma_simple *simple;
43
44	/// The lowest 32 bits of the current position in the data. Most
45	/// filters need this to do conversions between absolute and relative
46	/// addresses.
47	uint32_t now_pos;
48
49	/// Size of the memory allocated for the buffer.
50	size_t allocated;
51
52	/// Flushing position in the temporary buffer. buffer[pos] is the
53	/// next byte to be copied to out[].
54	size_t pos;
55
56	/// buffer[filtered] is the first unfiltered byte. When pos is smaller
57	/// than filtered, there is unflushed filtered data in the buffer.
58	size_t filtered;
59
60	/// Total number of bytes (both filtered and unfiltered) currently
61	/// in the temporary buffer.
62	size_t size;
63
64	/// Temporary buffer
65	uint8_t buffer[];
66};
67
68
69extern lzma_ret lzma_simple_coder_init(lzma_next_coder *next,
70		lzma_allocator *allocator, 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