1// Copyright (C) 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
27U_NAMESPACE_BEGIN
28
29class UCharsTrie;
30class BytesTrie;
31
32class U_COMMON_API DictionaryData : public UMemory {
33public:
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 */
69class U_COMMON_API DictionaryMatcher : public UMemory {
70public:
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
102class U_COMMON_API UCharsDictionaryMatcher : public DictionaryMatcher {
103public:
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;
112private:
113    const UChar *characters;
114    UDataMemory *file;
115};
116
117// Implementation of the DictionaryMatcher interface for a BytesTrie dictionary
118class U_COMMON_API BytesDictionaryMatcher : public DictionaryMatcher {
119public:
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;
130private:
131    UChar32 transform(UChar32 c) const;
132
133    const char *characters;
134    int32_t transformConstant;
135    UDataMemory *file;
136};
137
138U_NAMESPACE_END
139
140U_CAPI int32_t U_EXPORT2
141udict_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