icuSources/common/unisetspan.h

   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