icuSources/common/unicode/bytestriebuilder.h

   1 /*
   2 *******************************************************************************
   3 *   Copyright (C) 2010-2012, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 *******************************************************************************
   6 *   file name:  bytestriebuilder.h
   7 *   encoding:   US-ASCII
   8 *   tab size:   8 (not used)
   9 *   indentation:4
  10 *
  11 *   created on: 2010sep25
  12 *   created by: Markus W. Scherer
  13 */
  14
  15 #ifndef __BYTESTRIEBUILDER_H__
  16 #define __BYTESTRIEBUILDER_H__
  17
  18 #include "unicode/utypes.h"
  19 #include "unicode/bytestrie.h"
  20 #include "unicode/stringpiece.h"
  21 #include "unicode/stringtriebuilder.h"
  22
  23 U_NAMESPACE_BEGIN
  24
  25 class BytesTrieElement;
  26 class CharString;
  27
  28 /**
  29  * Builder class for BytesTrie.
  30  *
  31  * This class is not intended for public subclassing.
  32  * @stable ICU 4.8
  33  */
  34 class U_COMMON_API BytesTrieBuilder : public StringTrieBuilder {
  35 public:
  36     /**
  37      * Constructs an empty builder.
  38      * @param errorCode Standard ICU error code.
  39      * @stable ICU 4.8
  40      */
  41     BytesTrieBuilder(UErrorCode &errorCode);
  42
  43     /**
  44      * Destructor.
  45      * @stable ICU 4.8
  46      */
  47     virtual ~BytesTrieBuilder();
  48
  49     /**
  50      * Adds a (byte sequence, value) pair.
  51      * The byte sequence must be unique.
  52      * The bytes will be copied; the builder does not keep
  53      * a reference to the input StringPiece or its data().
  54      * @param s The input byte sequence.
  55      * @param value The value associated with this byte sequence.
  56      * @param errorCode Standard ICU error code. Its input value must
  57      *                  pass the U_SUCCESS() test, or else the function returns
  58      *                  immediately. Check for U_FAILURE() on output or use with
  59      *                  function chaining. (See User Guide for details.)
  60      * @return *this
  61      * @stable ICU 4.8
  62      */
  63     BytesTrieBuilder &add(const StringPiece &s, int32_t value, UErrorCode &errorCode);
  64
  65     /**
  66      * Builds a BytesTrie for the add()ed data.
  67      * Once built, no further data can be add()ed until clear() is called.
  68      *
  69      * This method passes ownership of the builder's internal result array to the new trie object.
  70      * Another call to any build() variant will re-serialize the trie.
  71      * After clear() has been called, a new array will be used as well.
  72      * @param buildOption Build option, see UStringTrieBuildOption.
  73      * @param errorCode Standard ICU error code. Its input value must
  74      *                  pass the U_SUCCESS() test, or else the function returns
  75      *                  immediately. Check for U_FAILURE() on output or use with
  76      *                  function chaining. (See User Guide for details.)
  77      * @return A new BytesTrie for the add()ed data.
  78      * @stable ICU 4.8
  79      */
  80     BytesTrie *build(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
  81
  82     /**
  83      * Builds a BytesTrie for the add()ed data and byte-serializes it.
  84      * Once built, no further data can be add()ed until clear() is called.
  85      *
  86      * Multiple calls to buildStringPiece() return StringPieces referring to the
  87      * builder's same byte array, without rebuilding.
  88      * If buildStringPiece() is called after build(), the trie will be
  89      * re-serialized into a new array.
  90      * If build() is called after buildStringPiece(), the trie object will become
  91      * the owner of the previously returned array.
  92      * After clear() has been called, a new array will be used as well.
  93      * @param buildOption Build option, see UStringTrieBuildOption.
  94      * @param errorCode Standard ICU error code. Its input value must
  95      *                  pass the U_SUCCESS() test, or else the function returns
  96      *                  immediately. Check for U_FAILURE() on output or use with
  97      *                  function chaining. (See User Guide for details.)
  98      * @return A StringPiece which refers to the byte-serialized BytesTrie for the add()ed data.
  99      * @stable ICU 4.8
 100      */
 101     StringPiece buildStringPiece(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
 102
 103     /**
 104      * Removes all (byte sequence, value) pairs.
 105      * New data can then be add()ed and a new trie can be built.
 106      * @return *this
 107      * @stable ICU 4.8
 108      */
 109     BytesTrieBuilder &clear();
 110
 111 private:
 112     BytesTrieBuilder(const BytesTrieBuilder &other);  // no copy constructor
 113     BytesTrieBuilder &operator=(const BytesTrieBuilder &other);  // no assignment operator
 114
 115     void buildBytes(UStringTrieBuildOption buildOption, UErrorCode &errorCode);
 116
 117     virtual int32_t getElementStringLength(int32_t i) const;
 118     virtual UChar getElementUnit(int32_t i, int32_t byteIndex) const;
 119     virtual int32_t getElementValue(int32_t i) const;
 120
 121     virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t byteIndex) const;
 122
 123     virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t byteIndex) const;
 124     virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t byteIndex, int32_t count) const;
 125     virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t byteIndex, UChar byte) const;
 126
 127     virtual UBool matchNodesCanHaveValues() const { return FALSE; }
 128
 129     virtual int32_t getMaxBranchLinearSubNodeLength() const { return BytesTrie::kMaxBranchLinearSubNodeLength; }
 130     virtual int32_t getMinLinearMatch() const { return BytesTrie::kMinLinearMatch; }
 131     virtual int32_t getMaxLinearMatchLength() const { return BytesTrie::kMaxLinearMatchLength; }
 132
 133 #ifndef U_HIDE_INTERNAL_API
 134     /**
 135      * @internal
 136      */
 137     class BTLinearMatchNode : public LinearMatchNode {
 138     public:
 139         BTLinearMatchNode(const char *units, int32_t len, Node *nextNode);
 140         virtual UBool operator==(const Node &other) const;
 141         virtual void write(StringTrieBuilder &builder);
 142     private:
 143         const char *s;
 144     };
 145 #endif  /* U_HIDE_INTERNAL_API */
 146
 147     virtual Node *createLinearMatchNode(int32_t i, int32_t byteIndex, int32_t length,
 148                                         Node *nextNode) const;
 149
 150     UBool ensureCapacity(int32_t length);
 151     virtual int32_t write(int32_t byte);
 152     int32_t write(const char *b, int32_t length);
 153     virtual int32_t writeElementUnits(int32_t i, int32_t byteIndex, int32_t length);
 154     virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal);
 155     virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node);
 156     virtual int32_t writeDeltaTo(int32_t jumpTarget);
 157
 158     CharString *strings;  // Pointer not object so we need not #include internal charstr.h.
 159     BytesTrieElement *elements;
 160     int32_t elementsCapacity;
 161     int32_t elementsLength;
 162
 163     // Byte serialization of the trie.
 164     // Grows from the back: bytesLength measures from the end of the buffer!
 165     char *bytes;
 166     int32_t bytesCapacity;
 167     int32_t bytesLength;
 168 };
 169
 170 U_NAMESPACE_END
 171
 172 #endif  // __BYTESTRIEBUILDER_H__