xref: /freebsd/contrib/xz/src/liblzma/common/index.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file       index.h
4 /// \brief      Handling of Index
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_INDEX_H
14 #define LZMA_INDEX_H
15 
16 #include "common.h"
17 
18 
19 /// Minimum Unpadded Size
20 #define UNPADDED_SIZE_MIN LZMA_VLI_C(5)
21 
22 /// Maximum Unpadded Size
23 #define UNPADDED_SIZE_MAX (LZMA_VLI_MAX & ~LZMA_VLI_C(3))
24 
25 
26 /// Get the size of the Index Padding field. This is needed by Index encoder
27 /// and decoder, but applications should have no use for this.
28 extern uint32_t lzma_index_padding_size(const lzma_index *i);
29 
30 
31 /// Set for how many Records to allocate memory the next time
32 /// lzma_index_append() needs to allocate space for a new Record.
33 /// This is used only by the Index decoder.
34 extern void lzma_index_prealloc(lzma_index *i, lzma_vli records);
35 
36 
37 /// Round the variable-length integer to the next multiple of four.
38 static inline lzma_vli
39 vli_ceil4(lzma_vli vli)
40 {
41 	assert(vli <= LZMA_VLI_MAX);
42 	return (vli + 3) & ~LZMA_VLI_C(3);
43 }
44 
45 
46 /// Calculate the size of the Index field excluding Index Padding
47 static inline lzma_vli
48 index_size_unpadded(lzma_vli count, lzma_vli index_list_size)
49 {
50 	// Index Indicator + Number of Records + List of Records + CRC32
51 	return 1 + lzma_vli_size(count) + index_list_size + 4;
52 }
53 
54 
55 /// Calculate the size of the Index field including Index Padding
56 static inline lzma_vli
57 index_size(lzma_vli count, lzma_vli index_list_size)
58 {
59 	return vli_ceil4(index_size_unpadded(count, index_list_size));
60 }
61 
62 
63 /// Calculate the total size of the Stream
64 static inline lzma_vli
65 index_stream_size(lzma_vli blocks_size,
66 		lzma_vli count, lzma_vli index_list_size)
67 {
68 	return LZMA_STREAM_HEADER_SIZE + blocks_size
69 			+ index_size(count, index_list_size)
70 			+ LZMA_STREAM_HEADER_SIZE;
71 }
72 
73 #endif
74