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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 *
      6 *   Copyright (C) 2007, International Business Machines
      7 *   Corporation and others.  All Rights Reserved.
      8 *
      9 ******************************************************************************
     10 *   file name:  unisetspan.h
     11 *   encoding:   UTF-8
     12 *   tab size:   8 (not used)
     13 *   indentation:4
     14 *
     15 *   created on: 2007mar01
     16 *   created by: Markus W. Scherer
     17 */
     18 
     19 #ifndef __UNISETSPAN_H__
     20 #define __UNISETSPAN_H__
     21 
     22 #include "unicode/utypes.h"
     23 #include "unicode/uniset.h"
     24 
     25 U_NAMESPACE_BEGIN
     26 
     27 /*
     28  * Implement span() etc. for a set with strings.
     29  * Avoid recursion because of its exponential complexity.
     30  * Instead, try multiple paths at once and track them with an IndexList.
     31  */
     32 class UnicodeSetStringSpan : public UMemory {
     33 public:
     34     /*
     35      * Which span() variant will be used?
     36      * The object is either built for one variant and used once,
     37      * or built for all and may be used many times.
     38      */
     39     enum {
     40         FWD             = 0x20,
     41         BACK            = 0x10,
     42         UTF16           = 8,
     43         UTF8            = 4,
     44         CONTAINED       = 2,
     45         NOT_CONTAINED   = 1,
     46 
     47         ALL             = 0x3f,
     48 
     49         FWD_UTF16_CONTAINED     = FWD  | UTF16 |     CONTAINED,
     50         FWD_UTF16_NOT_CONTAINED = FWD  | UTF16 | NOT_CONTAINED,
     51         FWD_UTF8_CONTAINED      = FWD  | UTF8  |     CONTAINED,
     52         FWD_UTF8_NOT_CONTAINED  = FWD  | UTF8  | NOT_CONTAINED,
     53         BACK_UTF16_CONTAINED    = BACK | UTF16 |     CONTAINED,
     54         BACK_UTF16_NOT_CONTAINED= BACK | UTF16 | NOT_CONTAINED,
     55         BACK_UTF8_CONTAINED     = BACK | UTF8  |     CONTAINED,
     56         BACK_UTF8_NOT_CONTAINED = BACK | UTF8  | NOT_CONTAINED
     57     };
     58 
     59     UnicodeSetStringSpan(const UnicodeSet &set, const UVector &setStrings, uint32_t which);
     60 
     61     // Copy constructor. Assumes which==ALL for a frozen set.
     62     UnicodeSetStringSpan(const UnicodeSetStringSpan &otherStringSpan, const UVector &newParentSetStrings);
     63 
     64     ~UnicodeSetStringSpan();
     65 
     66     /*
     67      * Do the strings need to be checked in span() etc.?
     68      * @return TRUE if strings need to be checked (call span() here),
     69      *         FALSE if not (use a BMPSet for best performance).
     70      */
     71     inline UBool needsStringSpanUTF16();
     72     inline UBool needsStringSpanUTF8();
     73 
     74     // For fast UnicodeSet::contains(c).
     75     inline UBool contains(UChar32 c) const;
     76 
     77     int32_t span(const UChar *s, int32_t length, USetSpanCondition spanCondition) const;
     78 
     79     int32_t spanBack(const UChar *s, int32_t length, USetSpanCondition spanCondition) const;
     80 
     81     int32_t spanUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const;
     82 
     83     int32_t spanBackUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const;
     84 
     85 private:
     86     // Special spanLength byte values.
     87     enum {
     88         // The spanLength is >=0xfe.
     89         LONG_SPAN=0xfe,
     90         // All code points in the string are contained in the parent set.
     91         ALL_CP_CONTAINED=0xff
     92     };
     93 
     94     // Add a starting or ending string character to the spanNotSet
     95     // so that a character span ends before any string.
     96     void addToSpanNotSet(UChar32 c);
     97 
     98     int32_t spanNot(const UChar *s, int32_t length) const;
     99     int32_t spanNotBack(const UChar *s, int32_t length) const;
    100     int32_t spanNotUTF8(const uint8_t *s, int32_t length) const;
    101     int32_t spanNotBackUTF8(const uint8_t *s, int32_t length) const;
    102 
    103     // Set for span(). Same as parent but without strings.
    104     UnicodeSet spanSet;
    105 
    106     // Set for span(not contained).
    107     // Same as spanSet, plus characters that start or end strings.
    108     UnicodeSet *pSpanNotSet;
    109 
    110     // The strings of the parent set.
    111     const UVector &strings;
    112 
    113     // Pointer to the UTF-8 string lengths.
    114     // Also pointer to further allocated storage for meta data and
    115     // UTF-8 string contents as necessary.
    116     int32_t *utf8Lengths;
    117 
    118     // Pointer to the part of the (utf8Lengths) memory block that stores
    119     // the lengths of span(), spanBack() etc. for each string.
    120     uint8_t *spanLengths;
    121 
    122     // Pointer to the part of the (utf8Lengths) memory block that stores
    123     // the UTF-8 versions of the parent set's strings.
    124     uint8_t *utf8;
    125 
    126     // Number of bytes for all UTF-8 versions of strings together.
    127     int32_t utf8Length;
    128 
    129     // Maximum lengths of relevant strings.
    130     int32_t maxLength16;
    131     int32_t maxLength8;
    132 
    133     // Set up for all variants of span()?
    134     UBool all;
    135 
    136     // Memory for small numbers and lengths of strings.
    137     // For example, for 8 strings:
    138     // 8 UTF-8 lengths, 8*4 bytes span lengths, 8*2 3-byte UTF-8 characters
    139     // = 112 bytes = int32_t[28].
    140     int32_t staticLengths[32];
    141 };
    142 
    143 UBool UnicodeSetStringSpan::needsStringSpanUTF16() {
    144     return (UBool)(maxLength16!=0);
    145 }
    146 
    147 UBool UnicodeSetStringSpan::needsStringSpanUTF8() {
    148     return (UBool)(maxLength8!=0);
    149 }
    150 
    151 UBool UnicodeSetStringSpan::contains(UChar32 c) const {
    152     return spanSet.contains(c);
    153 }
    154 
    155 U_NAMESPACE_END
    156 
    157 #endif
    158