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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html
      3 /*
      4 *******************************************************************************
      5 * Copyright (C) 2014, International Business Machines
      6 * Corporation and others.  All Rights Reserved.
      7 *******************************************************************************
      8 * dictionarydata.h
      9 *
     10 * created on: 2012may31
     11 * created by: Markus W. Scherer & Maxime Serrano
     12 */
     13 
     14 #ifndef __DICTIONARYDATA_H__
     15 #define __DICTIONARYDATA_H__
     16 
     17 #include "unicode/utypes.h"
     18 
     19 #if !UCONFIG_NO_BREAK_ITERATION
     20 
     21 #include "unicode/utext.h"
     22 #include "unicode/udata.h"
     23 #include "udataswp.h"
     24 #include "unicode/uobject.h"
     25 #include "unicode/ustringtrie.h"
     26 
     27 U_NAMESPACE_BEGIN
     28 
     29 class UCharsTrie;
     30 class BytesTrie;
     31 
     32 class U_COMMON_API DictionaryData : public UMemory {
     33 public:
     34     static const int32_t TRIE_TYPE_BYTES; // = 0;
     35     static const int32_t TRIE_TYPE_UCHARS; // = 1;
     36     static const int32_t TRIE_TYPE_MASK; // = 7;
     37     static const int32_t TRIE_HAS_VALUES; // = 8;
     38 
     39     static const int32_t TRANSFORM_NONE; // = 0;
     40     static const int32_t TRANSFORM_TYPE_OFFSET; // = 0x1000000;
     41     static const int32_t TRANSFORM_TYPE_MASK; // = 0x7f000000;
     42     static const int32_t TRANSFORM_OFFSET_MASK; // = 0x1fffff;
     43 
     44     enum {
     45         // Byte offsets from the start of the data, after the generic header.
     46         IX_STRING_TRIE_OFFSET,
     47         IX_RESERVED1_OFFSET,
     48         IX_RESERVED2_OFFSET,
     49         IX_TOTAL_SIZE,
     50 
     51         // Trie type: TRIE_HAS_VALUES | TRIE_TYPE_BYTES etc.
     52         IX_TRIE_TYPE,
     53         // Transform specification: TRANSFORM_TYPE_OFFSET | 0xe00 etc.
     54         IX_TRANSFORM,
     55 
     56         IX_RESERVED6,
     57         IX_RESERVED7,
     58         IX_COUNT
     59     };
     60 };
     61 
     62 /**
     63  * Wrapper class around generic dictionaries, implementing matches().
     64  * getType() should return a TRIE_TYPE_??? constant from DictionaryData.
     65  *
     66  * All implementations of this interface must be thread-safe if they are to be used inside of the
     67  * dictionary-based break iteration code.
     68  */
     69 class U_COMMON_API DictionaryMatcher : public UMemory {
     70 public:
     71     DictionaryMatcher() {};
     72     virtual ~DictionaryMatcher();
     73     // this should emulate CompactTrieDictionary::matches()
     74     /*  @param text      The text in which to look for matching words. Matching begins
     75      *                   at the current position of the UText.
     76      *  @param maxLength The max length of match to consider. Units are the native indexing
     77      *                   units of the UText.
     78      *  @param limit     Capacity of output arrays, which is also the maximum number of
     79      *                   matching words to be found.
     80      *  @param lengths   output array, filled with the lengths of the matches, in order,
     81      *                   from shortest to longest. Lengths are in native indexing units
     82      *                   of the UText. May be NULL.
     83      *  @param cpLengths output array, filled with the lengths of the matches, in order,
     84      *                   from shortest to longest. Lengths are the number of Unicode code points.
     85      *                   May be NULL.
     86      *  @param values    Output array, filled with the values associated with the words found.
     87      *                   May be NULL.
     88      *  @param prefix    Output parameter, the code point length of the prefix match, even if that
     89      *                   prefix didn't lead to a complete word. Will always be >= the cpLength
     90      *                   of the longest complete word matched. May be NULL.
     91      *  @return          Number of matching words found.
     92      */
     93     virtual int32_t matches(UText *text, int32_t maxLength, int32_t limit,
     94                             int32_t *lengths, int32_t *cpLengths, int32_t *values,
     95                             int32_t *prefix) const = 0;
     96 
     97     /** @return DictionaryData::TRIE_TYPE_XYZ */
     98     virtual int32_t getType() const = 0;
     99 };
    100 
    101 // Implementation of the DictionaryMatcher interface for a UCharsTrie dictionary
    102 class U_COMMON_API UCharsDictionaryMatcher : public DictionaryMatcher {
    103 public:
    104     // constructs a new UCharsDictionaryMatcher.
    105     // The UDataMemory * will be closed on this object's destruction.
    106     UCharsDictionaryMatcher(const UChar *c, UDataMemory *f) : characters(c), file(f) { }
    107     virtual ~UCharsDictionaryMatcher();
    108     virtual int32_t matches(UText *text, int32_t maxLength, int32_t limit,
    109                             int32_t *lengths, int32_t *cpLengths, int32_t *values,
    110                             int32_t *prefix) const;
    111     virtual int32_t getType() const;
    112 private:
    113     const UChar *characters;
    114     UDataMemory *file;
    115 };
    116 
    117 // Implementation of the DictionaryMatcher interface for a BytesTrie dictionary
    118 class U_COMMON_API BytesDictionaryMatcher : public DictionaryMatcher {
    119 public:
    120     // constructs a new BytesTrieDictionaryMatcher
    121     // the transform constant should be the constant read from the file, not a masked version!
    122     // the UDataMemory * fed in here will be closed on this object's destruction
    123     BytesDictionaryMatcher(const char *c, int32_t t, UDataMemory *f)
    124             : characters(c), transformConstant(t), file(f) { }
    125     virtual ~BytesDictionaryMatcher();
    126     virtual int32_t matches(UText *text, int32_t maxLength, int32_t limit,
    127                             int32_t *lengths, int32_t *cpLengths, int32_t *values,
    128                             int32_t *prefix) const;
    129     virtual int32_t getType() const;
    130 private:
    131     UChar32 transform(UChar32 c) const;
    132 
    133     const char *characters;
    134     int32_t transformConstant;
    135     UDataMemory *file;
    136 };
    137 
    138 U_NAMESPACE_END
    139 
    140 U_CAPI int32_t U_EXPORT2
    141 udict_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData, UErrorCode *pErrorCode);
    142 
    143 /**
    144  * Format of dictionary .dict data files.
    145  * Format version 1.0.
    146  *
    147  * A dictionary .dict data file contains a byte-serialized BytesTrie or
    148  * a UChars-serialized UCharsTrie.
    149  * Such files are used in dictionary-based break iteration (DBBI).
    150  *
    151  * For a BytesTrie, a transformation type is specified for
    152  * transforming Unicode strings into byte sequences.
    153  *
    154  * A .dict file begins with a standard ICU data file header
    155  * (DataHeader, see ucmndata.h and unicode/udata.h).
    156  * The UDataInfo.dataVersion field is currently unused (set to 0.0.0.0).
    157  *
    158  * After the header, the file contains the following parts.
    159  * Constants are defined in the DictionaryData class.
    160  *
    161  * For the data structure of BytesTrie & UCharsTrie see
    162  * http://site.icu-project.org/design/struct/tries
    163  * and the bytestrie.h and ucharstrie.h header files.
    164  *
    165  * int32_t indexes[indexesLength]; -- indexesLength=indexes[IX_STRING_TRIE_OFFSET]/4;
    166  *
    167  *      The first four indexes are byte offsets in ascending order.
    168  *      Each byte offset marks the start of the next part in the data file,
    169  *      and the end of the previous one.
    170  *      When two consecutive byte offsets are the same, then the corresponding part is empty.
    171  *      Byte offsets are offsets from after the header,
    172  *      that is, from the beginning of the indexes[].
    173  *      Each part starts at an offset with proper alignment for its data.
    174  *      If necessary, the previous part may include padding bytes to achieve this alignment.
    175  *
    176  *      trieType=indexes[IX_TRIE_TYPE] defines the trie type.
    177  *      transform=indexes[IX_TRANSFORM] defines the Unicode-to-bytes transformation.
    178  *          If the transformation type is TRANSFORM_TYPE_OFFSET,
    179  *          then the lower 21 bits contain the offset code point.
    180  *          Each code point c is mapped to byte b = (c - offset).
    181  *          Code points outside the range offset..(offset+0xff) cannot be mapped
    182  *          and do not occur in the dictionary.
    183  *
    184  * stringTrie; -- a serialized BytesTrie or UCharsTrie
    185  *
    186  *      The dictionary maps strings to specific values (TRIE_HAS_VALUES bit set in trieType),
    187  *      or it maps all strings to 0 (TRIE_HAS_VALUES bit not set).
    188  */
    189 
    190 #endif  /* !UCONFIG_NO_BREAK_ITERATION */
    191 #endif  /* __DICTIONARYDATA_H__ */
    192