1 // © 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /* 4 ******************************************************************************* 5 * Copyright (C) 2010-2016, International Business Machines 6 * Corporation and others. All Rights Reserved. 7 ******************************************************************************* 8 * file name: bytestriebuilder.h 9 * encoding: UTF-8 10 * tab size: 8 (not used) 11 * indentation:4 12 * 13 * created on: 2010sep25 14 * created by: Markus W. Scherer 15 */ 16 17 /** 18 * \file 19 * \brief C++ API: Builder for icu::BytesTrie 20 */ 21 22 #ifndef __BYTESTRIEBUILDER_H__ 23 #define __BYTESTRIEBUILDER_H__ 24 25 #include "unicode/utypes.h" 26 27 #if U_SHOW_CPLUSPLUS_API 28 29 #include "unicode/bytestrie.h" 30 #include "unicode/stringpiece.h" 31 #include "unicode/stringtriebuilder.h" 32 33 U_NAMESPACE_BEGIN 34 35 class BytesTrieElement; 36 class CharString; 37 /** 38 * Builder class for BytesTrie. 39 * 40 * This class is not intended for public subclassing. 41 * @stable ICU 4.8 42 */ 43 class U_COMMON_API BytesTrieBuilder : public StringTrieBuilder { 44 public: 45 /** 46 * Constructs an empty builder. 47 * @param errorCode Standard ICU error code. 48 * @stable ICU 4.8 49 */ 50 BytesTrieBuilder(UErrorCode &errorCode); 51 52 /** 53 * Destructor. 54 * @stable ICU 4.8 55 */ 56 virtual ~BytesTrieBuilder(); 57 58 /** 59 * Adds a (byte sequence, value) pair. 60 * The byte sequence must be unique. 61 * The bytes will be copied; the builder does not keep 62 * a reference to the input StringPiece or its data(). 63 * @param s The input byte sequence. 64 * @param value The value associated with this byte sequence. 65 * @param errorCode Standard ICU error code. Its input value must 66 * pass the U_SUCCESS() test, or else the function returns 67 * immediately. Check for U_FAILURE() on output or use with 68 * function chaining. (See User Guide for details.) 69 * @return *this 70 * @stable ICU 4.8 71 */ 72 BytesTrieBuilder &add(StringPiece s, int32_t value, UErrorCode &errorCode); 73 74 /** 75 * Builds a BytesTrie for the add()ed data. 76 * Once built, no further data can be add()ed until clear() is called. 77 * 78 * A BytesTrie cannot be empty. At least one (byte sequence, value) pair 79 * must have been add()ed. 80 * 81 * This method passes ownership of the builder's internal result array to the new trie object. 82 * Another call to any build() variant will re-serialize the trie. 83 * After clear() has been called, a new array will be used as well. 84 * @param buildOption Build option, see UStringTrieBuildOption. 85 * @param errorCode Standard ICU error code. Its input value must 86 * pass the U_SUCCESS() test, or else the function returns 87 * immediately. Check for U_FAILURE() on output or use with 88 * function chaining. (See User Guide for details.) 89 * @return A new BytesTrie for the add()ed data. 90 * @stable ICU 4.8 91 */ 92 BytesTrie *build(UStringTrieBuildOption buildOption, UErrorCode &errorCode); 93 94 /** 95 * Builds a BytesTrie for the add()ed data and byte-serializes it. 96 * Once built, no further data can be add()ed until clear() is called. 97 * 98 * A BytesTrie cannot be empty. At least one (byte sequence, value) pair 99 * must have been add()ed. 100 * 101 * Multiple calls to buildStringPiece() return StringPieces referring to the 102 * builder's same byte array, without rebuilding. 103 * If buildStringPiece() is called after build(), the trie will be 104 * re-serialized into a new array. 105 * If build() is called after buildStringPiece(), the trie object will become 106 * the owner of the previously returned array. 107 * After clear() has been called, a new array will be used as well. 108 * @param buildOption Build option, see UStringTrieBuildOption. 109 * @param errorCode Standard ICU error code. Its input value must 110 * pass the U_SUCCESS() test, or else the function returns 111 * immediately. Check for U_FAILURE() on output or use with 112 * function chaining. (See User Guide for details.) 113 * @return A StringPiece which refers to the byte-serialized BytesTrie for the add()ed data. 114 * @stable ICU 4.8 115 */ 116 StringPiece buildStringPiece(UStringTrieBuildOption buildOption, UErrorCode &errorCode); 117 118 /** 119 * Removes all (byte sequence, value) pairs. 120 * New data can then be add()ed and a new trie can be built. 121 * @return *this 122 * @stable ICU 4.8 123 */ 124 BytesTrieBuilder &clear(); 125 126 private: 127 BytesTrieBuilder(const BytesTrieBuilder &other); // no copy constructor 128 BytesTrieBuilder &operator=(const BytesTrieBuilder &other); // no assignment operator 129 130 void buildBytes(UStringTrieBuildOption buildOption, UErrorCode &errorCode); 131 132 virtual int32_t getElementStringLength(int32_t i) const; 133 virtual char16_t getElementUnit(int32_t i, int32_t byteIndex) const; 134 virtual int32_t getElementValue(int32_t i) const; 135 136 virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t byteIndex) const; 137 138 virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t byteIndex) const; 139 virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t byteIndex, int32_t count) const; 140 virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t byteIndex, char16_t byte) const; 141 matchNodesCanHaveValues()142 virtual UBool matchNodesCanHaveValues() const { return FALSE; } 143 getMaxBranchLinearSubNodeLength()144 virtual int32_t getMaxBranchLinearSubNodeLength() const { return BytesTrie::kMaxBranchLinearSubNodeLength; } getMinLinearMatch()145 virtual int32_t getMinLinearMatch() const { return BytesTrie::kMinLinearMatch; } getMaxLinearMatchLength()146 virtual int32_t getMaxLinearMatchLength() const { return BytesTrie::kMaxLinearMatchLength; } 147 148 /** 149 * @internal (private) 150 */ 151 class BTLinearMatchNode : public LinearMatchNode { 152 public: 153 BTLinearMatchNode(const char *units, int32_t len, Node *nextNode); 154 virtual UBool operator==(const Node &other) const; 155 virtual void write(StringTrieBuilder &builder); 156 private: 157 const char *s; 158 }; 159 160 virtual Node *createLinearMatchNode(int32_t i, int32_t byteIndex, int32_t length, 161 Node *nextNode) const; 162 163 UBool ensureCapacity(int32_t length); 164 virtual int32_t write(int32_t byte); 165 int32_t write(const char *b, int32_t length); 166 virtual int32_t writeElementUnits(int32_t i, int32_t byteIndex, int32_t length); 167 virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal); 168 virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node); 169 virtual int32_t writeDeltaTo(int32_t jumpTarget); 170 171 CharString *strings; // Pointer not object so we need not #include internal charstr.h. 172 BytesTrieElement *elements; 173 int32_t elementsCapacity; 174 int32_t elementsLength; 175 176 // Byte serialization of the trie. 177 // Grows from the back: bytesLength measures from the end of the buffer! 178 char *bytes; 179 int32_t bytesCapacity; 180 int32_t bytesLength; 181 }; 182 183 U_NAMESPACE_END 184 185 #endif /* U_SHOW_CPLUSPLUS_API */ 186 187 #endif // __BYTESTRIEBUILDER_H__ 188