nsUnicodeProperties.cpp

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=4 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsUnicodeProperties.h"
#include "nsUnicodePropertyData.cpp"

#include "mozilla/ArrayUtils.h"
#include "mozilla/HashTable.h"
#include "nsCharTraits.h"

#include "unicode/uchar.h"
#include "unicode/unorm2.h"

#define UNICODE_BMP_LIMIT 0x10000
#define UNICODE_LIMIT 0x110000

const nsCharProps2& GetCharProps2(uint32_t aCh) {
  if (aCh < UNICODE_BMP_LIMIT) {
    return sCharProp2Values[sCharProp2Pages[0][aCh >> kCharProp2CharBits]]
                           [aCh & ((1 << kCharProp2CharBits) - 1)];
  }
  if (aCh < (kCharProp2MaxPlane + 1) * 0x10000) {
    return sCharProp2Values[sCharProp2Pages[sCharProp2Planes[(aCh >> 16) - 1]]
                                           [(aCh & 0xffff) >>
                                            kCharProp2CharBits]]
                           [aCh & ((1 << kCharProp2CharBits) - 1)];
  }

  MOZ_ASSERT_UNREACHABLE(
      "Getting CharProps for codepoint outside Unicode "
      "range");

  // Default values for unassigned
  using namespace mozilla::unicode;
  static const nsCharProps2 undefined = {
      VERTICAL_ORIENTATION_R,
      0  // IdentifierType
  };
  return undefined;
}

namespace mozilla {

namespace unicode {

/*
To store properties for a million Unicode codepoints compactly, we use
a three-level array structure, with the Unicode values considered as
three elements: Plane, Page, and Char.

Space optimization happens because multiple Planes can refer to the same
Page array, and multiple Pages can refer to the same Char array holding
the actual values. In practice, most of the higher planes are empty and
thus share the same data; and within the BMP, there are also many pages
that repeat the same data for any given property.

Plane is usually zero, so we skip a lookup in this case, and require
that the Plane 0 pages are always the first set of entries in the Page
array.

The division of the remaining 16 bits into Page and Char fields is
adjusted for each property (by experiment using the generation tool)
to provide the most compact storage, depending on the distribution
of values.
*/

const nsUGenCategory sDetailedToGeneralCategory[] = {
    // clang-format off
  /*
   * The order here corresponds to the HB_UNICODE_GENERAL_CATEGORY_* constants
   * of the hb_unicode_general_category_t enum in gfx/harfbuzz/src/hb-unicode.h.
   */
  /* CONTROL */             nsUGenCategory::kOther,
  /* FORMAT */              nsUGenCategory::kOther,
  /* UNASSIGNED */          nsUGenCategory::kOther,
  /* PRIVATE_USE */         nsUGenCategory::kOther,
  /* SURROGATE */           nsUGenCategory::kOther,
  /* LOWERCASE_LETTER */    nsUGenCategory::kLetter,
  /* MODIFIER_LETTER */     nsUGenCategory::kLetter,
  /* OTHER_LETTER */        nsUGenCategory::kLetter,
  /* TITLECASE_LETTER */    nsUGenCategory::kLetter,
  /* UPPERCASE_LETTER */    nsUGenCategory::kLetter,
  /* COMBINING_MARK */      nsUGenCategory::kMark,
  /* ENCLOSING_MARK */      nsUGenCategory::kMark,
  /* NON_SPACING_MARK */    nsUGenCategory::kMark,
  /* DECIMAL_NUMBER */      nsUGenCategory::kNumber,
  /* LETTER_NUMBER */       nsUGenCategory::kNumber,
  /* OTHER_NUMBER */        nsUGenCategory::kNumber,
  /* CONNECT_PUNCTUATION */ nsUGenCategory::kPunctuation,
  /* DASH_PUNCTUATION */    nsUGenCategory::kPunctuation,
  /* CLOSE_PUNCTUATION */   nsUGenCategory::kPunctuation,
  /* FINAL_PUNCTUATION */   nsUGenCategory::kPunctuation,
  /* INITIAL_PUNCTUATION */ nsUGenCategory::kPunctuation,
  /* OTHER_PUNCTUATION */   nsUGenCategory::kPunctuation,
  /* OPEN_PUNCTUATION */    nsUGenCategory::kPunctuation,
  /* CURRENCY_SYMBOL */     nsUGenCategory::kSymbol,
  /* MODIFIER_SYMBOL */     nsUGenCategory::kSymbol,
  /* MATH_SYMBOL */         nsUGenCategory::kSymbol,
  /* OTHER_SYMBOL */        nsUGenCategory::kSymbol,
  /* LINE_SEPARATOR */      nsUGenCategory::kSeparator,
  /* PARAGRAPH_SEPARATOR */ nsUGenCategory::kSeparator,
  /* SPACE_SEPARATOR */     nsUGenCategory::kSeparator
    // clang-format on
};

const hb_unicode_general_category_t sICUtoHBcategory[U_CHAR_CATEGORY_COUNT] = {
    // clang-format off
  HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED, // U_GENERAL_OTHER_TYPES = 0,
  HB_UNICODE_GENERAL_CATEGORY_UPPERCASE_LETTER, // U_UPPERCASE_LETTER = 1,
  HB_UNICODE_GENERAL_CATEGORY_LOWERCASE_LETTER, // U_LOWERCASE_LETTER = 2,
  HB_UNICODE_GENERAL_CATEGORY_TITLECASE_LETTER, // U_TITLECASE_LETTER = 3,
  HB_UNICODE_GENERAL_CATEGORY_MODIFIER_LETTER, // U_MODIFIER_LETTER = 4,
  HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER, // U_OTHER_LETTER = 5,
  HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK, // U_NON_SPACING_MARK = 6,
  HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK, // U_ENCLOSING_MARK = 7,
  HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK, // U_COMBINING_SPACING_MARK = 8,
  HB_UNICODE_GENERAL_CATEGORY_DECIMAL_NUMBER, // U_DECIMAL_DIGIT_NUMBER = 9,
  HB_UNICODE_GENERAL_CATEGORY_LETTER_NUMBER, // U_LETTER_NUMBER = 10,
  HB_UNICODE_GENERAL_CATEGORY_OTHER_NUMBER, // U_OTHER_NUMBER = 11,
  HB_UNICODE_GENERAL_CATEGORY_SPACE_SEPARATOR, // U_SPACE_SEPARATOR = 12,
  HB_UNICODE_GENERAL_CATEGORY_LINE_SEPARATOR, // U_LINE_SEPARATOR = 13,
  HB_UNICODE_GENERAL_CATEGORY_PARAGRAPH_SEPARATOR, // U_PARAGRAPH_SEPARATOR = 14,
  HB_UNICODE_GENERAL_CATEGORY_CONTROL, // U_CONTROL_CHAR = 15,
  HB_UNICODE_GENERAL_CATEGORY_FORMAT, // U_FORMAT_CHAR = 16,
  HB_UNICODE_GENERAL_CATEGORY_PRIVATE_USE, // U_PRIVATE_USE_CHAR = 17,
  HB_UNICODE_GENERAL_CATEGORY_SURROGATE, // U_SURROGATE = 18,
  HB_UNICODE_GENERAL_CATEGORY_DASH_PUNCTUATION, // U_DASH_PUNCTUATION = 19,
  HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION, // U_START_PUNCTUATION = 20,
  HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION, // U_END_PUNCTUATION = 21,
  HB_UNICODE_GENERAL_CATEGORY_CONNECT_PUNCTUATION, // U_CONNECTOR_PUNCTUATION = 22,
  HB_UNICODE_GENERAL_CATEGORY_OTHER_PUNCTUATION, // U_OTHER_PUNCTUATION = 23,
  HB_UNICODE_GENERAL_CATEGORY_MATH_SYMBOL, // U_MATH_SYMBOL = 24,
  HB_UNICODE_GENERAL_CATEGORY_CURRENCY_SYMBOL, // U_CURRENCY_SYMBOL = 25,
  HB_UNICODE_GENERAL_CATEGORY_MODIFIER_SYMBOL, // U_MODIFIER_SYMBOL = 26,
  HB_UNICODE_GENERAL_CATEGORY_OTHER_SYMBOL, // U_OTHER_SYMBOL = 27,
  HB_UNICODE_GENERAL_CATEGORY_INITIAL_PUNCTUATION, // U_INITIAL_PUNCTUATION = 28,
  HB_UNICODE_GENERAL_CATEGORY_FINAL_PUNCTUATION, // U_FINAL_PUNCTUATION = 29,
    // clang-format on
};

#define DEFINE_BMP_1PLANE_MAPPING_GET_FUNC(prefix_)             \
  uint32_t Get##prefix_(uint32_t aCh) {                         \
    if (aCh >= UNICODE_BMP_LIMIT) {                             \
      return aCh;                                               \
    }                                                           \
    auto page = s##prefix_##Pages[aCh >> k##prefix_##CharBits]; \
    auto index = aCh & ((1 << k##prefix_##CharBits) - 1);       \
    uint32_t v = s##prefix_##Values[page][index];               \
    return v ? v : aCh;                                         \
  }

// full-width mappings only exist for BMP characters; all others are
// returned unchanged
DEFINE_BMP_1PLANE_MAPPING_GET_FUNC(FullWidth)
DEFINE_BMP_1PLANE_MAPPING_GET_FUNC(FullWidthInverse)

bool IsClusterExtender(uint32_t aCh, uint8_t aCategory) {
  return (
      (aCategory >= HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK &&
       aCategory <= HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) ||
      (aCh >= 0x200c && aCh <= 0x200d) ||    // ZWJ, ZWNJ
      (aCh >= 0xff9e && aCh <= 0xff9f) ||    // katakana sound marks
      (aCh >= 0x1F3FB && aCh <= 0x1F3FF) ||  // fitzpatrick skin tone modifiers
      (aCh >= 0xe0020 && aCh <= 0xe007f));   // emoji (flag) tag characters
}

enum HSType {
  HST_NONE = U_HST_NOT_APPLICABLE,
  HST_L = U_HST_LEADING_JAMO,
  HST_V = U_HST_VOWEL_JAMO,
  HST_T = U_HST_TRAILING_JAMO,
  HST_LV = U_HST_LV_SYLLABLE,
  HST_LVT = U_HST_LVT_SYLLABLE
};

static HSType GetHangulSyllableType(uint32_t aCh) {
  return HSType(u_getIntPropertyValue(aCh, UCHAR_HANGUL_SYLLABLE_TYPE));
}

void ClusterIterator::Next() {
  if (AtEnd()) {
    NS_WARNING("ClusterIterator has already reached the end");
    return;
  }

  uint32_t ch = *mPos++;

  if (mPos < mLimit && NS_IS_SURROGATE_PAIR(ch, *mPos)) {
    ch = SURROGATE_TO_UCS4(ch, *mPos++);
  } else if ((ch & ~0xff) == 0x1100 || (ch >= 0xa960 && ch <= 0xa97f) ||
             (ch >= 0xac00 && ch <= 0xd7ff)) {
    // Handle conjoining Jamo that make Hangul syllables
    HSType hangulState = GetHangulSyllableType(ch);
    while (mPos < mLimit) {
      ch = *mPos;
      HSType hangulType = GetHangulSyllableType(ch);
      switch (hangulType) {
        case HST_L:
        case HST_LV:
        case HST_LVT:
          if (hangulState == HST_L) {
            hangulState = hangulType;
            mPos++;
            continue;
          }
          break;
        case HST_V:
          if ((hangulState != HST_NONE) && (hangulState != HST_T) &&
              (hangulState != HST_LVT)) {
            hangulState = hangulType;
            mPos++;
            continue;
          }
          break;
        case HST_T:
          if (hangulState != HST_NONE && hangulState != HST_L) {
            hangulState = hangulType;
            mPos++;
            continue;
          }
          break;
        default:
          break;
      }
      break;
    }
  }

  const uint32_t kVS16 = 0xfe0f;
  const uint32_t kZWJ = 0x200d;
  // UTF-16 surrogate values for Fitzpatrick type modifiers
  const uint32_t kFitzpatrickHigh = 0xD83C;
  const uint32_t kFitzpatrickLowFirst = 0xDFFB;
  const uint32_t kFitzpatrickLowLast = 0xDFFF;

  bool baseIsEmoji = (GetEmojiPresentation(ch) == EmojiDefault) ||
                     (GetEmojiPresentation(ch) == TextDefault &&
                      ((mPos < mLimit && *mPos == kVS16) ||
                       (mPos + 1 < mLimit && *mPos == kFitzpatrickHigh &&
                        *(mPos + 1) >= kFitzpatrickLowFirst &&
                        *(mPos + 1) <= kFitzpatrickLowLast)));
  bool prevWasZwj = false;

  while (mPos < mLimit) {
    ch = *mPos;
    size_t chLen = 1;

    // Check for surrogate pairs; note that isolated surrogates will just
    // be treated as generic (non-cluster-extending) characters here,
    // which is fine for cluster-iterating purposes
    if (mPos < mLimit - 1 && NS_IS_SURROGATE_PAIR(ch, *(mPos + 1))) {
      ch = SURROGATE_TO_UCS4(ch, *(mPos + 1));
      chLen = 2;
    }

    bool extendCluster =
        IsClusterExtender(ch) ||
        (baseIsEmoji && prevWasZwj &&
         ((GetEmojiPresentation(ch) == EmojiDefault) ||
          (GetEmojiPresentation(ch) == TextDefault && mPos + chLen < mLimit &&
           *(mPos + chLen) == kVS16)));
    if (!extendCluster) {
      break;
    }

    prevWasZwj = (ch == kZWJ);
    mPos += chLen;
  }

  NS_ASSERTION(mText < mPos && mPos <= mLimit,
               "ClusterIterator::Next has overshot the string!");
}

void ClusterReverseIterator::Next() {
  if (AtEnd()) {
    NS_WARNING("ClusterReverseIterator has already reached the end");
    return;
  }

  uint32_t ch;
  do {
    ch = *--mPos;

    if (mPos > mLimit && NS_IS_SURROGATE_PAIR(*(mPos - 1), ch)) {
      ch = SURROGATE_TO_UCS4(*--mPos, ch);
    }

    if (!IsClusterExtender(ch)) {
      break;
    }
  } while (mPos > mLimit);

  // XXX May need to handle conjoining Jamo

  NS_ASSERTION(mPos >= mLimit,
               "ClusterReverseIterator::Next has overshot the string!");
}

uint32_t CountGraphemeClusters(const char16_t* aText, uint32_t aLength) {
  ClusterIterator iter(aText, aLength);
  uint32_t result = 0;
  while (!iter.AtEnd()) {
    ++result;
    iter.Next();
  }
  return result;
}

uint32_t GetNaked(uint32_t aCh) {
  using namespace mozilla;

  static const UNormalizer2* normalizer;
  static HashMap<uint32_t, uint32_t> nakedCharCache;

  NS_ASSERTION(!IsCombiningDiacritic(aCh),
               "This character needs to be skipped");

  HashMap<uint32_t, uint32_t>::Ptr entry = nakedCharCache.lookup(aCh);
  if (entry.found()) {
    return entry->value();
  }

  UErrorCode error = U_ZERO_ERROR;
  if (!normalizer) {
    normalizer = unorm2_getNFDInstance(&error);
    if (U_FAILURE(error)) {
      return aCh;
    }
  }

  static const size_t MAX_DECOMPOSITION_SIZE = 16;
  UChar decomposition[MAX_DECOMPOSITION_SIZE];
  UChar* combiners;
  int32_t decompositionLen;
  uint32_t baseChar, nextChar;
  decompositionLen = unorm2_getDecomposition(normalizer, aCh, decomposition,
                                             MAX_DECOMPOSITION_SIZE, &error);
  if (decompositionLen < 1) {
    // The character does not decompose.
    return aCh;
  }

  if (NS_IS_HIGH_SURROGATE(decomposition[0])) {
    baseChar = SURROGATE_TO_UCS4(decomposition[0], decomposition[1]);
    combiners = decomposition + 2;
  } else {
    baseChar = decomposition[0];
    combiners = decomposition + 1;
  }

  if (IS_IN_BMP(baseChar) != IS_IN_BMP(aCh)) {
    // Mappings that would change the length of a UTF-16 string are not
    // currently supported.
    baseChar = aCh;
    goto cache;
  }

  if (decompositionLen > 1) {
    if (NS_IS_HIGH_SURROGATE(combiners[0])) {
      nextChar = SURROGATE_TO_UCS4(combiners[0], combiners[1]);
    } else {
      nextChar = combiners[0];
    }
    if (!IsCombiningDiacritic(nextChar)) {
      // Hangul syllables decompose but do not actually have diacritics.
      // This also excludes decompositions with the Japanese marks U+3099 and
      // U+309A (COMBINING KATAKANA-HIRAGANA [SEMI-]VOICED SOUND MARK), which
      // we should not ignore for searching (bug 1624244).
      baseChar = aCh;
    }
  }

cache:
  if (!nakedCharCache.putNew(aCh, baseChar)) {
    // We're out of memory, so delete the cache to free some up.
    nakedCharCache.clearAndCompact();
  }

  return baseChar;
}

}  // end namespace unicode

}  // end namespace mozilla