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:  ucharstriebuilder.h
9*   encoding:   UTF-8
10*   tab size:   8 (not used)
11*   indentation:4
12*
13*   created on: 2010nov14
14*   created by: Markus W. Scherer
15*/
16
17#ifndef __UCHARSTRIEBUILDER_H__
18#define __UCHARSTRIEBUILDER_H__
19
20#include "unicode/utypes.h"
21#include "unicode/stringtriebuilder.h"
22#include "unicode/ucharstrie.h"
23#include "unicode/unistr.h"
24
25/**
26 * \file
27 * \brief C++ API: Builder for icu::UCharsTrie
28 */
29
30U_NAMESPACE_BEGIN
31
32class UCharsTrieElement;
33
34/**
35 * Builder class for UCharsTrie.
36 *
37 * This class is not intended for public subclassing.
38 * @stable ICU 4.8
39 */
40class U_COMMON_API UCharsTrieBuilder : public StringTrieBuilder {
41public:
42    /**
43     * Constructs an empty builder.
44     * @param errorCode Standard ICU error code.
45     * @stable ICU 4.8
46     */
47    UCharsTrieBuilder(UErrorCode &errorCode);
48
49    /**
50     * Destructor.
51     * @stable ICU 4.8
52     */
53    virtual ~UCharsTrieBuilder();
54
55    /**
56     * Adds a (string, value) pair.
57     * The string must be unique.
58     * The string contents will be copied; the builder does not keep
59     * a reference to the input UnicodeString or its buffer.
60     * @param s The input string.
61     * @param value The value associated with this string.
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    UCharsTrieBuilder &add(const UnicodeString &s, int32_t value, UErrorCode &errorCode);
70
71    /**
72     * Builds a UCharsTrie for the add()ed data.
73     * Once built, no further data can be add()ed until clear() is called.
74     *
75     * A UCharsTrie cannot be empty. At least one (string, 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 UCharsTrie for the add()ed data.
87     * @stable ICU 4.8
88     */
89    UCharsTrie *build(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
90
91    /**
92     * Builds a UCharsTrie for the add()ed data and char16_t-serializes it.
93     * Once built, no further data can be add()ed until clear() is called.
94     *
95     * A UCharsTrie cannot be empty. At least one (string, value) pair
96     * must have been add()ed.
97     *
98     * Multiple calls to buildUnicodeString() set the UnicodeStrings to the
99     * builder's same char16_t array, without rebuilding.
100     * If buildUnicodeString() is called after build(), the trie will be
101     * re-serialized into a new array.
102     * If build() is called after buildUnicodeString(), 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 result A UnicodeString which will be set to the char16_t-serialized
107     *               UCharsTrie for the add()ed data.
108     * @param errorCode Standard ICU error code. Its input value must
109     *                  pass the U_SUCCESS() test, or else the function returns
110     *                  immediately. Check for U_FAILURE() on output or use with
111     *                  function chaining. (See User Guide for details.)
112     * @return result
113     * @stable ICU 4.8
114     */
115    UnicodeString &buildUnicodeString(UStringTrieBuildOption buildOption, UnicodeString &result,
116                                      UErrorCode &errorCode);
117
118    /**
119     * Removes all (string, 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    UCharsTrieBuilder &clear() {
125        strings.remove();
126        elementsLength=0;
127        ucharsLength=0;
128        return *this;
129    }
130
131private:
132    UCharsTrieBuilder(const UCharsTrieBuilder &other);  // no copy constructor
133    UCharsTrieBuilder &operator=(const UCharsTrieBuilder &other);  // no assignment operator
134
135    void buildUChars(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
136
137    virtual int32_t getElementStringLength(int32_t i) const;
138    virtual char16_t getElementUnit(int32_t i, int32_t unitIndex) const;
139    virtual int32_t getElementValue(int32_t i) const;
140
141    virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t unitIndex) const;
142
143    virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t unitIndex) const;
144    virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t unitIndex, int32_t count) const;
145    virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t unitIndex, char16_t unit) const;
146
147    virtual UBool matchNodesCanHaveValues() const { return TRUE; }
148
149    virtual int32_t getMaxBranchLinearSubNodeLength() const { return UCharsTrie::kMaxBranchLinearSubNodeLength; }
150    virtual int32_t getMinLinearMatch() const { return UCharsTrie::kMinLinearMatch; }
151    virtual int32_t getMaxLinearMatchLength() const { return UCharsTrie::kMaxLinearMatchLength; }
152
153    class UCTLinearMatchNode : public LinearMatchNode {
154    public:
155        UCTLinearMatchNode(const char16_t *units, int32_t len, Node *nextNode);
156        virtual UBool operator==(const Node &other) const;
157        virtual void write(StringTrieBuilder &builder);
158    private:
159        const char16_t *s;
160    };
161
162    virtual Node *createLinearMatchNode(int32_t i, int32_t unitIndex, int32_t length,
163                                        Node *nextNode) const;
164
165    UBool ensureCapacity(int32_t length);
166    virtual int32_t write(int32_t unit);
167    int32_t write(const char16_t *s, int32_t length);
168    virtual int32_t writeElementUnits(int32_t i, int32_t unitIndex, int32_t length);
169    virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal);
170    virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node);
171    virtual int32_t writeDeltaTo(int32_t jumpTarget);
172
173    UnicodeString strings;
174    UCharsTrieElement *elements;
175    int32_t elementsCapacity;
176    int32_t elementsLength;
177
178    // char16_t serialization of the trie.
179    // Grows from the back: ucharsLength measures from the end of the buffer!
180    char16_t *uchars;
181    int32_t ucharsCapacity;
182    int32_t ucharsLength;
183};
184
185U_NAMESPACE_END
186
187#endif  // __UCHARSTRIEBUILDER_H__
188