• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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