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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 :
139 0 : virtual UBool matchNodesCanHaveValues() const { return FALSE; }
140 :
141 0 : virtual int32_t getMaxBranchLinearSubNodeLength() const { return BytesTrie::kMaxBranchLinearSubNodeLength; }
142 0 : virtual int32_t getMinLinearMatch() const { return BytesTrie::kMinLinearMatch; }
143 0 : virtual int32_t getMaxLinearMatchLength() const { return BytesTrie::kMaxLinearMatchLength; }
144 :
145 : /**
146 : * @internal
147 : */
148 0 : 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 : // don't use #ifndef U_HIDE_INTERNAL_API with private class members or virtual methods.
158 : virtual Node *createLinearMatchNode(int32_t i, int32_t byteIndex, int32_t length,
159 : Node *nextNode) const;
160 :
161 : UBool ensureCapacity(int32_t length);
162 : virtual int32_t write(int32_t byte);
163 : int32_t write(const char *b, int32_t length);
164 : virtual int32_t writeElementUnits(int32_t i, int32_t byteIndex, int32_t length);
165 : virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal);
166 : virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node);
167 : virtual int32_t writeDeltaTo(int32_t jumpTarget);
168 :
169 : CharString *strings; // Pointer not object so we need not #include internal charstr.h.
170 : BytesTrieElement *elements;
171 : int32_t elementsCapacity;
172 : int32_t elementsLength;
173 :
174 : // Byte serialization of the trie.
175 : // Grows from the back: bytesLength measures from the end of the buffer!
176 : char *bytes;
177 : int32_t bytesCapacity;
178 : int32_t bytesLength;
179 : };
180 :
181 : U_NAMESPACE_END
182 :
183 : #endif // __BYTESTRIEBUILDER_H__
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