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f3c0d7a5 A |
1 | // © 2016 and later: Unicode, Inc. and others. |
2 | // License & terms of use: http://www.unicode.org/copyright.html | |
57a6839d A |
3 | /* |
4 | ******************************************************************************* | |
5 | * Copyright (C) 2010-2014, International Business Machines | |
6 | * Corporation and others. All Rights Reserved. | |
7 | ******************************************************************************* | |
8 | * collation.cpp | |
9 | * | |
10 | * created on: 2010oct27 | |
11 | * created by: Markus W. Scherer | |
12 | */ | |
13 | ||
14 | #include "unicode/utypes.h" | |
15 | ||
16 | #if !UCONFIG_NO_COLLATION | |
17 | ||
18 | #include "collation.h" | |
19 | #include "uassert.h" | |
20 | ||
21 | U_NAMESPACE_BEGIN | |
22 | ||
23 | // Some compilers don't care if constants are defined in the .cpp file. | |
24 | // MS Visual C++ does not like it, but gcc requires it. clang does not care. | |
25 | #ifndef _MSC_VER | |
b331163b A |
26 | const uint8_t Collation::LEVEL_SEPARATOR_BYTE; |
27 | const uint8_t Collation::MERGE_SEPARATOR_BYTE; | |
57a6839d A |
28 | const uint32_t Collation::ONLY_TERTIARY_MASK; |
29 | const uint32_t Collation::CASE_AND_TERTIARY_MASK; | |
30 | #endif | |
31 | ||
32 | uint32_t | |
33 | Collation::incTwoBytePrimaryByOffset(uint32_t basePrimary, UBool isCompressible, int32_t offset) { | |
34 | // Extract the second byte, minus the minimum byte value, | |
35 | // plus the offset, modulo the number of usable byte values, plus the minimum. | |
36 | // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. | |
37 | uint32_t primary; | |
38 | if(isCompressible) { | |
39 | offset += ((int32_t)(basePrimary >> 16) & 0xff) - 4; | |
40 | primary = (uint32_t)((offset % 251) + 4) << 16; | |
41 | offset /= 251; | |
42 | } else { | |
43 | offset += ((int32_t)(basePrimary >> 16) & 0xff) - 2; | |
44 | primary = (uint32_t)((offset % 254) + 2) << 16; | |
45 | offset /= 254; | |
46 | } | |
47 | // First byte, assume no further overflow. | |
48 | return primary | ((basePrimary & 0xff000000) + (uint32_t)(offset << 24)); | |
49 | } | |
50 | ||
51 | uint32_t | |
52 | Collation::incThreeBytePrimaryByOffset(uint32_t basePrimary, UBool isCompressible, int32_t offset) { | |
53 | // Extract the third byte, minus the minimum byte value, | |
54 | // plus the offset, modulo the number of usable byte values, plus the minimum. | |
55 | offset += ((int32_t)(basePrimary >> 8) & 0xff) - 2; | |
56 | uint32_t primary = (uint32_t)((offset % 254) + 2) << 8; | |
57 | offset /= 254; | |
58 | // Same with the second byte, | |
59 | // but reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. | |
60 | if(isCompressible) { | |
61 | offset += ((int32_t)(basePrimary >> 16) & 0xff) - 4; | |
62 | primary |= (uint32_t)((offset % 251) + 4) << 16; | |
63 | offset /= 251; | |
64 | } else { | |
65 | offset += ((int32_t)(basePrimary >> 16) & 0xff) - 2; | |
66 | primary |= (uint32_t)((offset % 254) + 2) << 16; | |
67 | offset /= 254; | |
68 | } | |
69 | // First byte, assume no further overflow. | |
70 | return primary | ((basePrimary & 0xff000000) + (uint32_t)(offset << 24)); | |
71 | } | |
72 | ||
73 | uint32_t | |
74 | Collation::decTwoBytePrimaryByOneStep(uint32_t basePrimary, UBool isCompressible, int32_t step) { | |
75 | // Extract the second byte, minus the minimum byte value, | |
76 | // minus the step, modulo the number of usable byte values, plus the minimum. | |
77 | // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. | |
78 | // Assume no further underflow for the first byte. | |
79 | U_ASSERT(0 < step && step <= 0x7f); | |
80 | int32_t byte2 = ((int32_t)(basePrimary >> 16) & 0xff) - step; | |
81 | if(isCompressible) { | |
82 | if(byte2 < 4) { | |
83 | byte2 += 251; | |
84 | basePrimary -= 0x1000000; | |
85 | } | |
86 | } else { | |
87 | if(byte2 < 2) { | |
88 | byte2 += 254; | |
89 | basePrimary -= 0x1000000; | |
90 | } | |
91 | } | |
92 | return (basePrimary & 0xff000000) | ((uint32_t)byte2 << 16); | |
93 | } | |
94 | ||
95 | uint32_t | |
96 | Collation::decThreeBytePrimaryByOneStep(uint32_t basePrimary, UBool isCompressible, int32_t step) { | |
97 | // Extract the third byte, minus the minimum byte value, | |
98 | // minus the step, modulo the number of usable byte values, plus the minimum. | |
99 | U_ASSERT(0 < step && step <= 0x7f); | |
100 | int32_t byte3 = ((int32_t)(basePrimary >> 8) & 0xff) - step; | |
101 | if(byte3 >= 2) { | |
102 | return (basePrimary & 0xffff0000) | ((uint32_t)byte3 << 8); | |
103 | } | |
104 | byte3 += 254; | |
105 | // Same with the second byte, | |
106 | // but reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary. | |
107 | int32_t byte2 = ((int32_t)(basePrimary >> 16) & 0xff) - 1; | |
108 | if(isCompressible) { | |
109 | if(byte2 < 4) { | |
110 | byte2 = 0xfe; | |
111 | basePrimary -= 0x1000000; | |
112 | } | |
113 | } else { | |
114 | if(byte2 < 2) { | |
115 | byte2 = 0xff; | |
116 | basePrimary -= 0x1000000; | |
117 | } | |
118 | } | |
119 | // First byte, assume no further underflow. | |
120 | return (basePrimary & 0xff000000) | ((uint32_t)byte2 << 16) | ((uint32_t)byte3 << 8); | |
121 | } | |
122 | ||
123 | uint32_t | |
124 | Collation::getThreeBytePrimaryForOffsetData(UChar32 c, int64_t dataCE) { | |
125 | uint32_t p = (uint32_t)(dataCE >> 32); // three-byte primary pppppp00 | |
126 | int32_t lower32 = (int32_t)dataCE; // base code point b & step s: bbbbbbss (bit 7: isCompressible) | |
127 | int32_t offset = (c - (lower32 >> 8)) * (lower32 & 0x7f); // delta * increment | |
128 | UBool isCompressible = (lower32 & 0x80) != 0; | |
129 | return Collation::incThreeBytePrimaryByOffset(p, isCompressible, offset); | |
130 | } | |
131 | ||
132 | uint32_t | |
133 | Collation::unassignedPrimaryFromCodePoint(UChar32 c) { | |
134 | // Create a gap before U+0000. Use c=-1 for [first unassigned]. | |
135 | ++c; | |
136 | // Fourth byte: 18 values, every 14th byte value (gap of 13). | |
137 | uint32_t primary = 2 + (c % 18) * 14; | |
138 | c /= 18; | |
139 | // Third byte: 254 values. | |
140 | primary |= (2 + (c % 254)) << 8; | |
141 | c /= 254; | |
142 | // Second byte: 251 values 04..FE excluding the primary compression bytes. | |
143 | primary |= (4 + (c % 251)) << 16; | |
144 | // One lead byte covers all code points (c < 0x1182B4 = 1*251*254*18). | |
145 | return primary | (UNASSIGNED_IMPLICIT_BYTE << 24); | |
146 | } | |
147 | ||
148 | U_NAMESPACE_END | |
149 | ||
150 | #endif // !UCONFIG_NO_COLLATION |