codekingpro/portable-devtools

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
33U_NAMESPACE_BEGIN
34
35class BytesTrieElement;
36class CharString;
37/**
38 * Builder class for BytesTrie.
39 *
40 * This class is not intended for public subclassing.
41 * @stable ICU 4.8
42 */
43class U_COMMON_API BytesTrieBuilder : public StringTrieBuilder {
44public:
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
126private:
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
142    virtual UBool matchNodesCanHaveValues() const { return FALSE; }
143
144    virtual int32_t getMaxBranchLinearSubNodeLength() const { return BytesTrie::kMaxBranchLinearSubNodeLength; }
145    virtual int32_t getMinLinearMatch() const { return BytesTrie::kMinLinearMatch; }
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
183U_NAMESPACE_END
184
185#endif /* U_SHOW_CPLUSPLUS_API */
186
187#endif  // __BYTESTRIEBUILDER_H__
188