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      1 /*
      2 *******************************************************************************
      3 *   Copyright (C) 2010-2013, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 *******************************************************************************
      6 *   file name:  ucharstriebuilder.h
      7 *   encoding:   US-ASCII
      8 *   tab size:   8 (not used)
      9 *   indentation:4
     10 *
     11 *   created on: 2010nov14
     12 *   created by: Markus W. Scherer
     13 */
     14 
     15 #ifndef __UCHARSTRIEBUILDER_H__
     16 #define __UCHARSTRIEBUILDER_H__
     17 
     18 #include "unicode/utypes.h"
     19 #include "unicode/stringtriebuilder.h"
     20 #include "unicode/ucharstrie.h"
     21 #include "unicode/unistr.h"
     22 
     23 /**
     24  * \file
     25  * \brief C++ API: Builder for icu::UCharsTrie
     26  */
     27 
     28 U_NAMESPACE_BEGIN
     29 
     30 class UCharsTrieElement;
     31 
     32 /**
     33  * Builder class for UCharsTrie.
     34  *
     35  * This class is not intended for public subclassing.
     36  * @stable ICU 4.8
     37  */
     38 class U_COMMON_API UCharsTrieBuilder : public StringTrieBuilder {
     39 public:
     40     /**
     41      * Constructs an empty builder.
     42      * @param errorCode Standard ICU error code.
     43      * @stable ICU 4.8
     44      */
     45     UCharsTrieBuilder(UErrorCode &errorCode);
     46 
     47     /**
     48      * Destructor.
     49      * @stable ICU 4.8
     50      */
     51     virtual ~UCharsTrieBuilder();
     52 
     53     /**
     54      * Adds a (string, value) pair.
     55      * The string must be unique.
     56      * The string contents will be copied; the builder does not keep
     57      * a reference to the input UnicodeString or its buffer.
     58      * @param s The input string.
     59      * @param value The value associated with this string.
     60      * @param errorCode Standard ICU error code. Its input value must
     61      *                  pass the U_SUCCESS() test, or else the function returns
     62      *                  immediately. Check for U_FAILURE() on output or use with
     63      *                  function chaining. (See User Guide for details.)
     64      * @return *this
     65      * @stable ICU 4.8
     66      */
     67     UCharsTrieBuilder &add(const UnicodeString &s, int32_t value, UErrorCode &errorCode);
     68 
     69     /**
     70      * Builds a UCharsTrie for the add()ed data.
     71      * Once built, no further data can be add()ed until clear() is called.
     72      *
     73      * A UCharsTrie cannot be empty. At least one (string, value) pair
     74      * must have been add()ed.
     75      *
     76      * This method passes ownership of the builder's internal result array to the new trie object.
     77      * Another call to any build() variant will re-serialize the trie.
     78      * After clear() has been called, a new array will be used as well.
     79      * @param buildOption Build option, see UStringTrieBuildOption.
     80      * @param errorCode Standard ICU error code. Its input value must
     81      *                  pass the U_SUCCESS() test, or else the function returns
     82      *                  immediately. Check for U_FAILURE() on output or use with
     83      *                  function chaining. (See User Guide for details.)
     84      * @return A new UCharsTrie for the add()ed data.
     85      * @stable ICU 4.8
     86      */
     87     UCharsTrie *build(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
     88 
     89     /**
     90      * Builds a UCharsTrie for the add()ed data and UChar-serializes it.
     91      * Once built, no further data can be add()ed until clear() is called.
     92      *
     93      * A UCharsTrie cannot be empty. At least one (string, value) pair
     94      * must have been add()ed.
     95      *
     96      * Multiple calls to buildUnicodeString() set the UnicodeStrings to the
     97      * builder's same UChar array, without rebuilding.
     98      * If buildUnicodeString() is called after build(), the trie will be
     99      * re-serialized into a new array.
    100      * If build() is called after buildUnicodeString(), the trie object will become
    101      * the owner of the previously returned array.
    102      * After clear() has been called, a new array will be used as well.
    103      * @param buildOption Build option, see UStringTrieBuildOption.
    104      * @param result A UnicodeString which will be set to the UChar-serialized
    105      *               UCharsTrie for the add()ed data.
    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 result
    111      * @stable ICU 4.8
    112      */
    113     UnicodeString &buildUnicodeString(UStringTrieBuildOption buildOption, UnicodeString &result,
    114                                       UErrorCode &errorCode);
    115 
    116     /**
    117      * Removes all (string, value) pairs.
    118      * New data can then be add()ed and a new trie can be built.
    119      * @return *this
    120      * @stable ICU 4.8
    121      */
    122     UCharsTrieBuilder &clear() {
    123         strings.remove();
    124         elementsLength=0;
    125         ucharsLength=0;
    126         return *this;
    127     }
    128 
    129 private:
    130     UCharsTrieBuilder(const UCharsTrieBuilder &other);  // no copy constructor
    131     UCharsTrieBuilder &operator=(const UCharsTrieBuilder &other);  // no assignment operator
    132 
    133     void buildUChars(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
    134 
    135     virtual int32_t getElementStringLength(int32_t i) const;
    136     virtual UChar getElementUnit(int32_t i, int32_t unitIndex) const;
    137     virtual int32_t getElementValue(int32_t i) const;
    138 
    139     virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t unitIndex) const;
    140 
    141     virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t unitIndex) const;
    142     virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t unitIndex, int32_t count) const;
    143     virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t unitIndex, UChar unit) const;
    144 
    145     virtual UBool matchNodesCanHaveValues() const { return TRUE; }
    146 
    147     virtual int32_t getMaxBranchLinearSubNodeLength() const { return UCharsTrie::kMaxBranchLinearSubNodeLength; }
    148     virtual int32_t getMinLinearMatch() const { return UCharsTrie::kMinLinearMatch; }
    149     virtual int32_t getMaxLinearMatchLength() const { return UCharsTrie::kMaxLinearMatchLength; }
    150 
    151 #ifndef U_HIDE_INTERNAL_API
    152     class UCTLinearMatchNode : public LinearMatchNode {
    153     public:
    154         UCTLinearMatchNode(const UChar *units, int32_t len, Node *nextNode);
    155         virtual UBool operator==(const Node &other) const;
    156         virtual void write(StringTrieBuilder &builder);
    157     private:
    158         const UChar *s;
    159     };
    160 #endif
    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 UChar *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     // UChar serialization of the trie.
    179     // Grows from the back: ucharsLength measures from the end of the buffer!
    180     UChar *uchars;
    181     int32_t ucharsCapacity;
    182     int32_t ucharsLength;
    183 };
    184 
    185 U_NAMESPACE_END
    186 
    187 #endif  // __UCHARSTRIEBUILDER_H__
    188