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Diffstat (limited to 'intl/icu/source/common/dictionarydata.h')
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1 files changed, 191 insertions, 0 deletions
diff --git a/intl/icu/source/common/dictionarydata.h b/intl/icu/source/common/dictionarydata.h new file mode 100644 index 0000000000..8751e502d5 --- /dev/null +++ b/intl/icu/source/common/dictionarydata.h @@ -0,0 +1,191 @@ +// © 2016 and later: Unicode, Inc. and others. +// License & terms of use: http://www.unicode.org/copyright.html +/* +******************************************************************************* +* Copyright (C) 2014, International Business Machines +* Corporation and others. All Rights Reserved. +******************************************************************************* +* dictionarydata.h +* +* created on: 2012may31 +* created by: Markus W. Scherer & Maxime Serrano +*/ + +#ifndef __DICTIONARYDATA_H__ +#define __DICTIONARYDATA_H__ + +#include "unicode/utypes.h" + +#if !UCONFIG_NO_BREAK_ITERATION + +#include "unicode/utext.h" +#include "unicode/udata.h" +#include "udataswp.h" +#include "unicode/uobject.h" +#include "unicode/ustringtrie.h" + +U_NAMESPACE_BEGIN + +class UCharsTrie; +class BytesTrie; + +class U_COMMON_API DictionaryData : public UMemory { +public: + static const int32_t TRIE_TYPE_BYTES; // = 0; + static const int32_t TRIE_TYPE_UCHARS; // = 1; + static const int32_t TRIE_TYPE_MASK; // = 7; + static const int32_t TRIE_HAS_VALUES; // = 8; + + static const int32_t TRANSFORM_NONE; // = 0; + static const int32_t TRANSFORM_TYPE_OFFSET; // = 0x1000000; + static const int32_t TRANSFORM_TYPE_MASK; // = 0x7f000000; + static const int32_t TRANSFORM_OFFSET_MASK; // = 0x1fffff; + + enum { + // Byte offsets from the start of the data, after the generic header. + IX_STRING_TRIE_OFFSET, + IX_RESERVED1_OFFSET, + IX_RESERVED2_OFFSET, + IX_TOTAL_SIZE, + + // Trie type: TRIE_HAS_VALUES | TRIE_TYPE_BYTES etc. + IX_TRIE_TYPE, + // Transform specification: TRANSFORM_TYPE_OFFSET | 0xe00 etc. + IX_TRANSFORM, + + IX_RESERVED6, + IX_RESERVED7, + IX_COUNT + }; +}; + +/** + * Wrapper class around generic dictionaries, implementing matches(). + * getType() should return a TRIE_TYPE_??? constant from DictionaryData. + * + * All implementations of this interface must be thread-safe if they are to be used inside of the + * dictionary-based break iteration code. + */ +class U_COMMON_API DictionaryMatcher : public UMemory { +public: + DictionaryMatcher() {} + virtual ~DictionaryMatcher(); + // this should emulate CompactTrieDictionary::matches() + /* @param text The text in which to look for matching words. Matching begins + * at the current position of the UText. + * @param maxLength The max length of match to consider. Units are the native indexing + * units of the UText. + * @param limit Capacity of output arrays, which is also the maximum number of + * matching words to be found. + * @param lengths output array, filled with the lengths of the matches, in order, + * from shortest to longest. Lengths are in native indexing units + * of the UText. May be nullptr. + * @param cpLengths output array, filled with the lengths of the matches, in order, + * from shortest to longest. Lengths are the number of Unicode code points. + * May be nullptr. + * @param values Output array, filled with the values associated with the words found. + * May be nullptr. + * @param prefix Output parameter, the code point length of the prefix match, even if that + * prefix didn't lead to a complete word. Will always be >= the cpLength + * of the longest complete word matched. May be nullptr. + * @return Number of matching words found. + */ + virtual int32_t matches(UText *text, int32_t maxLength, int32_t limit, + int32_t *lengths, int32_t *cpLengths, int32_t *values, + int32_t *prefix) const = 0; + + /** @return DictionaryData::TRIE_TYPE_XYZ */ + virtual int32_t getType() const = 0; +}; + +// Implementation of the DictionaryMatcher interface for a UCharsTrie dictionary +class U_COMMON_API UCharsDictionaryMatcher : public DictionaryMatcher { +public: + // constructs a new UCharsDictionaryMatcher. + // The UDataMemory * will be closed on this object's destruction. + UCharsDictionaryMatcher(const char16_t *c, UDataMemory *f) : characters(c), file(f) { } + virtual ~UCharsDictionaryMatcher(); + virtual int32_t matches(UText *text, int32_t maxLength, int32_t limit, + int32_t *lengths, int32_t *cpLengths, int32_t *values, + int32_t *prefix) const override; + virtual int32_t getType() const override; +private: + const char16_t *characters; + UDataMemory *file; +}; + +// Implementation of the DictionaryMatcher interface for a BytesTrie dictionary +class U_COMMON_API BytesDictionaryMatcher : public DictionaryMatcher { +public: + // constructs a new BytesTrieDictionaryMatcher + // the transform constant should be the constant read from the file, not a masked version! + // the UDataMemory * fed in here will be closed on this object's destruction + BytesDictionaryMatcher(const char *c, int32_t t, UDataMemory *f) + : characters(c), transformConstant(t), file(f) { } + virtual ~BytesDictionaryMatcher(); + virtual int32_t matches(UText *text, int32_t maxLength, int32_t limit, + int32_t *lengths, int32_t *cpLengths, int32_t *values, + int32_t *prefix) const override; + virtual int32_t getType() const override; +private: + UChar32 transform(UChar32 c) const; + + const char *characters; + int32_t transformConstant; + UDataMemory *file; +}; + +U_NAMESPACE_END + +U_CAPI int32_t U_EXPORT2 +udict_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData, UErrorCode *pErrorCode); + +/** + * Format of dictionary .dict data files. + * Format version 1.0. + * + * A dictionary .dict data file contains a byte-serialized BytesTrie or + * a UChars-serialized UCharsTrie. + * Such files are used in dictionary-based break iteration (DBBI). + * + * For a BytesTrie, a transformation type is specified for + * transforming Unicode strings into byte sequences. + * + * A .dict file begins with a standard ICU data file header + * (DataHeader, see ucmndata.h and unicode/udata.h). + * The UDataInfo.dataVersion field is currently unused (set to 0.0.0.0). + * + * After the header, the file contains the following parts. + * Constants are defined in the DictionaryData class. + * + * For the data structure of BytesTrie & UCharsTrie see + * https://icu.unicode.org/design/struct/tries + * and the bytestrie.h and ucharstrie.h header files. + * + * int32_t indexes[indexesLength]; -- indexesLength=indexes[IX_STRING_TRIE_OFFSET]/4; + * + * The first four indexes are byte offsets in ascending order. + * Each byte offset marks the start of the next part in the data file, + * and the end of the previous one. + * When two consecutive byte offsets are the same, then the corresponding part is empty. + * Byte offsets are offsets from after the header, + * that is, from the beginning of the indexes[]. + * Each part starts at an offset with proper alignment for its data. + * If necessary, the previous part may include padding bytes to achieve this alignment. + * + * trieType=indexes[IX_TRIE_TYPE] defines the trie type. + * transform=indexes[IX_TRANSFORM] defines the Unicode-to-bytes transformation. + * If the transformation type is TRANSFORM_TYPE_OFFSET, + * then the lower 21 bits contain the offset code point. + * Each code point c is mapped to byte b = (c - offset). + * Code points outside the range offset..(offset+0xff) cannot be mapped + * and do not occur in the dictionary. + * + * stringTrie; -- a serialized BytesTrie or UCharsTrie + * + * The dictionary maps strings to specific values (TRIE_HAS_VALUES bit set in trieType), + * or it maps all strings to 0 (TRIE_HAS_VALUES bit not set). + */ + +#endif /* !UCONFIG_NO_BREAK_ITERATION */ +#endif /* __DICTIONARYDATA_H__ */ |