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