1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
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
26 const uint8_t Collation::LEVEL_SEPARATOR_BYTE;
27 const uint8_t Collation::MERGE_SEPARATOR_BYTE;
28 const uint32_t Collation::ONLY_TERTIARY_MASK;
29 const uint32_t Collation::CASE_AND_TERTIARY_MASK;
30 #endif
31
32 uint32_t
incTwoBytePrimaryByOffset(uint32_t basePrimary,UBool isCompressible,int32_t offset)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
incThreeBytePrimaryByOffset(uint32_t basePrimary,UBool isCompressible,int32_t offset)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
decTwoBytePrimaryByOneStep(uint32_t basePrimary,UBool isCompressible,int32_t step)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
decThreeBytePrimaryByOneStep(uint32_t basePrimary,UBool isCompressible,int32_t step)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
getThreeBytePrimaryForOffsetData(UChar32 c,int64_t dataCE)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
unassignedPrimaryFromCodePoint(UChar32 c)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
151