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1 | /* |
2 | ******************************************************************************* | |
3 | * Copyright (C) 2012-2014, International Business Machines | |
4 | * Corporation and others. All Rights Reserved. | |
5 | ******************************************************************************* | |
6 | * collationkeys.h | |
7 | * | |
8 | * created on: 2012sep02 | |
9 | * created by: Markus W. Scherer | |
10 | */ | |
11 | ||
12 | #ifndef __COLLATIONKEYS_H__ | |
13 | #define __COLLATIONKEYS_H__ | |
14 | ||
15 | #include "unicode/utypes.h" | |
16 | ||
17 | #if !UCONFIG_NO_COLLATION | |
18 | ||
19 | #include "unicode/bytestream.h" | |
20 | #include "unicode/ucol.h" | |
21 | #include "charstr.h" | |
22 | #include "collation.h" | |
23 | ||
24 | U_NAMESPACE_BEGIN | |
25 | ||
26 | class CollationIterator; | |
27 | struct CollationDataReader; | |
28 | struct CollationSettings; | |
29 | ||
30 | class SortKeyByteSink : public ByteSink { | |
31 | public: | |
32 | SortKeyByteSink(char *dest, int32_t destCapacity) | |
33 | : buffer_(dest), capacity_(destCapacity), | |
34 | appended_(0), ignore_(0) {} | |
35 | virtual ~SortKeyByteSink(); | |
36 | ||
37 | void IgnoreBytes(int32_t numIgnore) { ignore_ = numIgnore; } | |
38 | ||
39 | virtual void Append(const char *bytes, int32_t n); | |
40 | void Append(uint32_t b) { | |
41 | if (ignore_ > 0) { | |
42 | --ignore_; | |
43 | } else { | |
44 | if (appended_ < capacity_ || Resize(1, appended_)) { | |
45 | buffer_[appended_] = (char)b; | |
46 | } | |
47 | ++appended_; | |
48 | } | |
49 | } | |
50 | virtual char *GetAppendBuffer(int32_t min_capacity, | |
51 | int32_t desired_capacity_hint, | |
52 | char *scratch, int32_t scratch_capacity, | |
53 | int32_t *result_capacity); | |
54 | int32_t NumberOfBytesAppended() const { return appended_; } | |
55 | ||
56 | /** | |
57 | * @return how many bytes can be appended (including ignored ones) | |
58 | * without reallocation | |
59 | */ | |
60 | int32_t GetRemainingCapacity() const { | |
61 | // Either ignore_ or appended_ should be 0. | |
62 | return ignore_ + capacity_ - appended_; | |
63 | } | |
64 | ||
65 | UBool Overflowed() const { return appended_ > capacity_; } | |
66 | /** @return FALSE if memory allocation failed */ | |
67 | UBool IsOk() const { return buffer_ != NULL; } | |
68 | ||
69 | protected: | |
70 | virtual void AppendBeyondCapacity(const char *bytes, int32_t n, int32_t length) = 0; | |
71 | virtual UBool Resize(int32_t appendCapacity, int32_t length) = 0; | |
72 | ||
73 | void SetNotOk() { | |
74 | buffer_ = NULL; | |
75 | capacity_ = 0; | |
76 | } | |
77 | ||
78 | char *buffer_; | |
79 | int32_t capacity_; | |
80 | int32_t appended_; | |
81 | int32_t ignore_; | |
82 | ||
83 | private: | |
84 | SortKeyByteSink(const SortKeyByteSink &); // copy constructor not implemented | |
85 | SortKeyByteSink &operator=(const SortKeyByteSink &); // assignment operator not implemented | |
86 | }; | |
87 | ||
88 | class U_I18N_API CollationKeys /* not : public UObject because all methods are static */ { | |
89 | public: | |
90 | class LevelCallback : public UMemory { | |
91 | public: | |
92 | virtual ~LevelCallback(); | |
93 | /** | |
94 | * @param level The next level about to be written to the ByteSink. | |
95 | * @return TRUE if the level is to be written | |
96 | * (the base class implementation always returns TRUE) | |
97 | */ | |
98 | virtual UBool needToWrite(Collation::Level level); | |
99 | }; | |
100 | ||
101 | /** | |
102 | * Writes the sort key bytes for minLevel up to the iterator data's strength. | |
103 | * Optionally writes the case level. | |
104 | * Stops writing levels when callback.needToWrite(level) returns FALSE. | |
105 | * Separates levels with the LEVEL_SEPARATOR_BYTE | |
106 | * but does not write a TERMINATOR_BYTE. | |
107 | */ | |
108 | static void writeSortKeyUpToQuaternary(CollationIterator &iter, | |
109 | const UBool *compressibleBytes, | |
110 | const CollationSettings &settings, | |
111 | SortKeyByteSink &sink, | |
112 | Collation::Level minLevel, LevelCallback &callback, | |
113 | UBool preflight, UErrorCode &errorCode); | |
114 | private: | |
115 | friend struct CollationDataReader; | |
116 | ||
117 | CollationKeys(); // no instantiation | |
118 | ||
119 | // Secondary level: Compress up to 33 common weights as 05..25 or 25..45. | |
120 | static const uint32_t SEC_COMMON_LOW = Collation::COMMON_BYTE; | |
121 | static const uint32_t SEC_COMMON_MIDDLE = SEC_COMMON_LOW + 0x20; | |
122 | static const uint32_t SEC_COMMON_HIGH = SEC_COMMON_LOW + 0x40; | |
123 | static const int32_t SEC_COMMON_MAX_COUNT = 0x21; | |
124 | ||
125 | // Case level, lowerFirst: Compress up to 7 common weights as 1..7 or 7..13. | |
126 | static const uint32_t CASE_LOWER_FIRST_COMMON_LOW = 1; | |
127 | static const uint32_t CASE_LOWER_FIRST_COMMON_MIDDLE = 7; | |
128 | static const uint32_t CASE_LOWER_FIRST_COMMON_HIGH = 13; | |
129 | static const int32_t CASE_LOWER_FIRST_COMMON_MAX_COUNT = 7; | |
130 | ||
131 | // Case level, upperFirst: Compress up to 13 common weights as 3..15. | |
132 | static const uint32_t CASE_UPPER_FIRST_COMMON_LOW = 3; | |
133 | static const uint32_t CASE_UPPER_FIRST_COMMON_HIGH = 15; | |
134 | static const int32_t CASE_UPPER_FIRST_COMMON_MAX_COUNT = 13; | |
135 | ||
136 | // Tertiary level only (no case): Compress up to 97 common weights as 05..65 or 65..C5. | |
137 | static const uint32_t TER_ONLY_COMMON_LOW = Collation::COMMON_BYTE; | |
138 | static const uint32_t TER_ONLY_COMMON_MIDDLE = TER_ONLY_COMMON_LOW + 0x60; | |
139 | static const uint32_t TER_ONLY_COMMON_HIGH = TER_ONLY_COMMON_LOW + 0xc0; | |
140 | static const int32_t TER_ONLY_COMMON_MAX_COUNT = 0x61; | |
141 | ||
142 | // Tertiary with case, lowerFirst: Compress up to 33 common weights as 05..25 or 25..45. | |
143 | static const uint32_t TER_LOWER_FIRST_COMMON_LOW = Collation::COMMON_BYTE; | |
144 | static const uint32_t TER_LOWER_FIRST_COMMON_MIDDLE = TER_LOWER_FIRST_COMMON_LOW + 0x20; | |
145 | static const uint32_t TER_LOWER_FIRST_COMMON_HIGH = TER_LOWER_FIRST_COMMON_LOW + 0x40; | |
146 | static const int32_t TER_LOWER_FIRST_COMMON_MAX_COUNT = 0x21; | |
147 | ||
148 | // Tertiary with case, upperFirst: Compress up to 33 common weights as 85..A5 or A5..C5. | |
149 | static const uint32_t TER_UPPER_FIRST_COMMON_LOW = Collation::COMMON_BYTE + 0x80; | |
150 | static const uint32_t TER_UPPER_FIRST_COMMON_MIDDLE = TER_UPPER_FIRST_COMMON_LOW + 0x20; | |
151 | static const uint32_t TER_UPPER_FIRST_COMMON_HIGH = TER_UPPER_FIRST_COMMON_LOW + 0x40; | |
152 | static const int32_t TER_UPPER_FIRST_COMMON_MAX_COUNT = 0x21; | |
153 | ||
154 | // Quaternary level: Compress up to 113 common weights as 1C..8C or 8C..FC. | |
155 | static const uint32_t QUAT_COMMON_LOW = 0x1c; | |
156 | static const uint32_t QUAT_COMMON_MIDDLE = QUAT_COMMON_LOW + 0x70; | |
157 | static const uint32_t QUAT_COMMON_HIGH = QUAT_COMMON_LOW + 0xE0; | |
158 | static const int32_t QUAT_COMMON_MAX_COUNT = 0x71; | |
159 | // Primary weights shifted to quaternary level must be encoded with | |
160 | // a lead byte below the common-weight compression range. | |
161 | static const uint32_t QUAT_SHIFTED_LIMIT_BYTE = QUAT_COMMON_LOW - 1; // 0x1b | |
162 | }; | |
163 | ||
164 | U_NAMESPACE_END | |
165 | ||
166 | #endif // !UCONFIG_NO_COLLATION | |
167 | #endif // __COLLATIONKEYS_H__ |