Source/JavaScriptCore/yarr/YarrUnicodeProperties.cpp

/*
 * Copyright (C) 2017 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#include "config.h"
#include "YarrUnicodeProperties.h"

#include "Yarr.h"
#include "YarrPattern.h"
#include <wtf/text/WTFString.h>

namespace JSC { namespace Yarr {

struct HashIndex {
    int16_t value;
    int16_t next;
};

struct HashValue {
    const char* key;
    int index;
};

struct HashTable {
    int numberOfValues;
    int indexMask;
    const HashValue* values;
    const HashIndex* index;

    ALWAYS_INLINE int entry(WTF::String& key) const
    {
        int indexEntry = key.impl()->hash() & indexMask;
        int valueIndex = index[indexEntry].value;

        if (valueIndex == -1)
            return -1;

        while (true) {
            if (WTF::equal(key, StringView::fromLatin1(values[valueIndex].key)))
                return values[valueIndex].index;

            indexEntry = index[indexEntry].next;
            if (indexEntry == -1)
                return -1;
            valueIndex = index[indexEntry].value;
            ASSERT(valueIndex != -1);
        };
    }
};

#include "UnicodePatternTables.h"

std::optional<BuiltInCharacterClassID> unicodeMatchPropertyValue(WTF::String unicodePropertyName, WTF::String unicodePropertyValue)
{
    int propertyIndex = -1;

    if (unicodePropertyName == "Script"_s || unicodePropertyName == "sc"_s)
        propertyIndex = scriptHashTable.entry(unicodePropertyValue);
    else if (unicodePropertyName == "Script_Extensions"_s || unicodePropertyName == "scx"_s)
        propertyIndex = scriptExtensionHashTable.entry(unicodePropertyValue);
    else if (unicodePropertyName == "General_Category"_s || unicodePropertyName == "gc"_s)
        propertyIndex = generalCategoryHashTable.entry(unicodePropertyValue);

    if (propertyIndex == -1)
        return std::nullopt;

    return std::optional<BuiltInCharacterClassID>(static_cast<BuiltInCharacterClassID>(static_cast<int>(BuiltInCharacterClassID::BaseUnicodePropertyID) + propertyIndex));
}

std::optional<BuiltInCharacterClassID> unicodeMatchProperty(WTF::String unicodePropertyValue)
{
    int propertyIndex = -1;

    propertyIndex = binaryPropertyHashTable.entry(unicodePropertyValue);
    if (propertyIndex == -1)
        propertyIndex = generalCategoryHashTable.entry(unicodePropertyValue);
    
    if (propertyIndex == -1)
        return std::nullopt;

    return std::optional<BuiltInCharacterClassID>(static_cast<BuiltInCharacterClassID>(static_cast<int>(BuiltInCharacterClassID::BaseUnicodePropertyID) + propertyIndex));
}

std::unique_ptr<CharacterClass> createUnicodeCharacterClassFor(BuiltInCharacterClassID unicodeClassID)
{
    unsigned unicodePropertyIndex = static_cast<unsigned>(unicodeClassID) - static_cast<unsigned>(BuiltInCharacterClassID::BaseUnicodePropertyID);

    return createFunctions[unicodePropertyIndex]();
}

} } // namespace JSC::Yarr