Attachment #288393 for bug #161119

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2016-09-09  Myles C. Maxfield  <mmaxfield@apple.com>

        [Cocoa] Improve performance of glyph advance metrics gathering
        https://bugs.webkit.org/show_bug.cgi?id=161119

        Reviewed by Simon Fraser.

        Most of the glyphs in a GlyphPage are never read from. Therefore, we can get a performance boost
        by not populating as many items in the GlyphPage. Because of the performance characteristics of
        CTFontGetGlyphsForCharacters(), a better size for a GlyphPage is 16 items. This, coupled with
        using CTFontGetUnsummedAdvancesForGlyphsAndStyle(), causes between a 0.01%-0.5% speedup on PLT.

        No new tests because there is no behavior change.

        * platform/graphics/Font.cpp:
        (WebCore::Font::initCharWidths):
        (WebCore::Font::platformGlyphInit):
        (WebCore::createAndFillGlyphPage):
        * platform/graphics/Font.h:
        (WebCore::Font::widthForGlyph):
        * platform/graphics/GlyphMetricsMap.h:
        * platform/graphics/GlyphPage.h:
        * platform/graphics/cocoa/FontCocoa.mm:
        * platform/spi/cocoa/CoreTextSPI.h:
        (WebCore::Font::platformWidthForGlyph):
        (WebCore::canUseFastGlyphAdvanceGetter): Deleted.

2016-09-09  Antti Koivisto  <antti@apple.com>

        v3: WebContent crash due to RELEASE_ASSERT in WebCore: WebCore::StyleResolver::styleForElement



// Estimates of avgCharWidth and maxCharWidth for platforms that don't support accessing these values from the font.
void Font::initCharWidths()
{
    auto* glyphPageZero = glyphPage(GlyphPage::pageNumberForCodePoint('0'));

    // Treat the width of a '0' as the avgCharWidth.
    if (m_avgCharWidth <= 0.f && glyphPageZero) {
        Glyph digitZeroGlyph = glyphPageZero->glyphDataForCharacter('0').glyph;
        Glyph digitZeroGlyph = glyphPageZero->glyphDataForCharacter(digitZeroChar).glyph;
        if (digitZeroGlyph)
            m_avgCharWidth = widthForGlyph(digitZeroGlyph);
    }

void Font::platformGlyphInit()
{
    auto* glyphPageZero = glyphPage(0);
    auto* glyphPageCharacterZero = glyphPage(GlyphPage::pageNumberForCodePoint('0'));
    auto* glyphPageSpace = glyphPage(GlyphPage::pageNumberForCodePoint(space));
        return;
    }

    // Ask for the glyph for 0 to avoid paging in ZERO WIDTH SPACE. Control characters, including 0,
    // are mapped to the ZERO WIDTH SPACE glyph.
    if (glyphPageZero)
        m_zeroWidthSpaceGlyph = glyphPageZero->glyphDataForCharacter(0).glyph;

    // Nasty hack to determine if we should round or ceil space widths.
    // If the font is monospace or fake monospace we ceil to ensure that 
    // every character and the space are the same width. Otherwise we round.
    if (glyphPageSpace)
        m_spaceGlyph = glyphPageSpace->glyphDataForCharacter(space).glyph;
    float width = widthForGlyph(m_spaceGlyph);
    m_spaceWidth = width;
    if (glyphPageCharacterZero)
        m_zeroGlyph = glyphPageCharacterZero->glyphDataForCharacter('0').glyph;
    m_fontMetrics.setZeroWidth(widthForGlyph(m_zeroGlyph));
    determinePitch();
    m_adjustedSpaceWidth = m_treatAsFixedPitch ? ceilf(width) : roundf(width);

    // FIXME: Times New Roman contains Arabic glyphs, but Core Text doesn't know how to shape them. See <rdar://problem/9823975>.
    // Once we have the fix for <rdar://problem/9823975> then remove this code together with Font::shouldNotBeUsedForArabic()
    // in <rdar://problem/12096835>.
    if (GlyphPage::pageNumberIsUsedForArabic(pageNumber) && font.shouldNotBeUsedForArabic())
        return nullptr;
#endif

    unsigned glyphPageSize = GlyphPage::sizeForPageNumber(pageNumber);

    unsigned start = GlyphPage::startingCodePointInPageNumber(pageNumber);
    unsigned end = start + glyphPageSize;
    Vector<UChar> buffer(glyphPageSize * 2 + 2);
    unsigned bufferLength;
    // Fill in a buffer with the entire "page" of characters that we want to look up glyphs for.
    if (U_IS_BMP(start)) {
        bufferLength = glyphPageSize;
        for (unsigned i = 0; i < bufferLength; i++)
            buffer[i] = start + i;

        // Code points 0x0 - 0x20 and 0x7F - 0xA0 are control character and shouldn't render. Map them to ZERO WIDTH SPACE.
        auto overwriteCodePoints = [&](unsigned minimum, unsigned maximum, UChar newCodePoint) {
            unsigned begin = std::max(start, minimum);
            unsigned complete = std::min(end, maximum);
            for (unsigned i = begin; i < complete; ++i)
                buffer[i - start] = newCodePoint;
        };

        auto overwriteCodePoint = [&](UChar codePoint, UChar newCodePoint) {
            if (codePoint >= start && codePoint < end)
                buffer[codePoint - start] = newCodePoint;
        };

        overwriteCodePoints(0x0, 0x20, zeroWidthSpace);
        overwriteCodePoints(0x7F, 0xA0, zeroWidthSpace);
        overwriteCodePoint(softHyphen, zeroWidthSpace);
        overwriteCodePoint('\n', space);
        overwriteCodePoint('\t', space);
        overwriteCodePoint(noBreakSpace, space);
        overwriteCodePoint(leftToRightMark, zeroWidthSpace);
        overwriteCodePoint(rightToLeftMark, zeroWidthSpace);
        overwriteCodePoint(leftToRightEmbed, zeroWidthSpace);
        overwriteCodePoint(rightToLeftEmbed, zeroWidthSpace);
        overwriteCodePoint(leftToRightOverride, zeroWidthSpace);
        overwriteCodePoint(rightToLeftOverride, zeroWidthSpace);
        overwriteCodePoint(leftToRightIsolate, zeroWidthSpace);
        overwriteCodePoint(rightToLeftIsolate, zeroWidthSpace);
        overwriteCodePoint(zeroWidthNonJoiner, zeroWidthSpace);
        overwriteCodePoint(zeroWidthJoiner, zeroWidthSpace);
        overwriteCodePoint(popDirectionalFormatting, zeroWidthSpace);
        overwriteCodePoint(popDirectionalIsolate, zeroWidthSpace);
        overwriteCodePoint(firstStrongIsolate, zeroWidthSpace);
        overwriteCodePoint(objectReplacementCharacter, zeroWidthSpace);
        overwriteCodePoint(zeroWidthNoBreakSpace, zeroWidthSpace);
    } else {
        bufferLength = glyphPageSize * 2;
        for (unsigned i = 0; i < glyphPageSize; i++) {
            int c = i + start;
            buffer[i * 2] = U16_LEAD(c);
            buffer[i * 2 + 1] = U16_TRAIL(c);

    // for only 128 out of 256 characters.
    Ref<GlyphPage> glyphPage = GlyphPage::create(font);

    bool haveGlyphs = fillGlyphPage(glyphPage, buffer.data(), bufferLength, font);
    if (!haveGlyphs)
        return nullptr;



Glyph Font::glyphForCharacter(UChar32 character) const
{
    auto* page = glyphPage(GlyphPage::pageNumberForCodePoint(character));
    if (!page)
        return 0;
    return page->glyphForCharacter(character);


GlyphData Font::glyphDataForCharacter(UChar32 character) const
{
    auto* page = glyphPage(GlyphPage::pageNumberForCodePoint(character));
    if (!page)
        return GlyphData();
    return page->glyphDataForCharacter(character);



        return width;

#if ENABLE(OPENTYPE_VERTICAL)
    if (m_verticalData) {
#if USE(CG) || USE(CAIRO)
        width = m_verticalData->advanceHeight(this, glyph) + m_syntheticBoldOffset;
#else
        width = m_verticalData->advanceHeight(this, glyph);
#endif
    } else
#endif
        width = platformWidthForGlyph(glyph);





    GlyphData glyphDataForCharacter(UChar32 c) const
    {
        unsigned index = GlyphPage::indexForCodePoint(c);
        ASSERT_WITH_SECURITY_IMPLICATION(index < GlyphPage::size);
        return { m_glyphs[index], m_fonts[index] };
    }

    void setGlyphDataForCharacter(UChar32 c, GlyphData glyphData)
    {
        setGlyphDataForIndex(GlyphPage::indexForCodePoint(c), glyphData);
    }

private:

    if (variant != NormalVariant)
        return glyphDataForVariant(c, description, variant, 0);

    const unsigned pageNumber = GlyphPage::pageNumberForCodePoint(c);

    auto& cacheEntry = pageNumber ? m_cachedPages.add(pageNumber, GlyphPageCacheEntry()).iterator->value : m_cachedPageZero;


Lines 54-60 private: a/Source/WebCore/platform/graphics/GlyphMetricsMap.h_sec1
- a/Source/WebCore/platform/graphics/GlyphMetricsMap.h -1 / +1 lines
54	class GlyphMetricsPage {	54	class GlyphMetricsPage {
55	WTF_MAKE_FAST_ALLOCATED;	55	WTF_MAKE_FAST_ALLOCATED;
56	public:	56	public:
57	static const size_t size = 256; // Usually covers Latin-1 in a single page.	57	static const size_t size = 16;
58		58
59	GlyphMetricsPage() = default;	59	GlyphMetricsPage() = default;
60	explicit GlyphMetricsPage(const T& initialValue)	60	explicit GlyphMetricsPage(const T& initialValue)




// A GlyphPage contains a fixed-size set of GlyphData mappings for a contiguous
// range of characters in the Unicode code space. GlyphPages are indexed
// starting from 0 and incrementing for each "size" number of glyphs.
class GlyphPage : public RefCounted<GlyphPage> {
public:
    static Ref<GlyphPage> create(const Font& font)


    static unsigned count() { return s_count; }

    static const unsigned size = 16;

    static unsigned sizeForPageNumber(unsigned) { return 16; }
    static unsigned indexForCodePoint(UChar32 c) { return c % size; }
    static unsigned pageNumberForCodePoint(UChar32 c) { return c / size; }
    static UChar32 startingCodePointInPageNumber(unsigned pageNumber) { return pageNumber * size; }
    static bool pageNumberIsUsedForArabic(unsigned pageNumber) { return startingCodePointInPageNumber(pageNumber) >= 0x600 && startingCodePointInPageNumber(pageNumber) + sizeForPageNumber(pageNumber) < 0x700; }

    GlyphData glyphDataForCharacter(UChar32 c) const
    {
        return glyphDataForIndex(indexForCodePoint(c));
    }

    Glyph glyphForCharacter(UChar32 c) const
    {
        return glyphForIndex(indexForCodePoint(c));
    }

    GlyphData glyphDataForIndex(unsigned index) const



    return boundingBox;
}

#if !((PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200) || (PLATFORM(IOS) && __IPHONE_OS_VERSION_MIN_REQUIRED >= 100000))
static inline Optional<CGSize> advanceForColorBitmapFont(const FontPlatformData& platformData, Glyph glyph)
{
    CTFontRef font = platformData.font();

    }
    return true;
}
#endif

float Font::platformWidthForGlyph(Glyph glyph) const
{
    CGSize advance = CGSizeZero;
    bool horizontal = platformData().orientation() == Horizontal;
    CGFontRenderingStyle style = kCGFontRenderingStyleAntialiasing | kCGFontRenderingStyleSubpixelPositioning | kCGFontRenderingStyleSubpixelQuantization | kCGFontAntialiasingStyleUnfiltered;

#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200) || (PLATFORM(IOS) && __IPHONE_OS_VERSION_MIN_REQUIRED >= 100000)
    if (platformData().size()) {
        CTFontOrientation orientation = horizontal || m_isBrokenIdeographFallback ? kCTFontOrientationHorizontal : kCTFontOrientationVertical;
        // FIXME: Remove this special-casing when <rdar://problem/28197291> is fixed.
        if (CTFontIsAppleColorEmoji(m_platformData.ctFont()))
            CTFontGetAdvancesForGlyphs(m_platformData.ctFont(), orientation, &glyph, &advance, 1);
        else
            CTFontGetUnsummedAdvancesForGlyphsAndStyle(m_platformData.ctFont(), orientation, style, &glyph, &advance, 1);
    }

#else

    bool populatedAdvance = false;
    if ((horizontal || m_isBrokenIdeographFallback) && canUseFastGlyphAdvanceGetter(this->platformData(), glyph, advance, populatedAdvance)) {
        float pointSize = platformData().size();
        CGAffineTransform m = CGAffineTransformMakeScale(pointSize, pointSize);
        CGFontRenderingStyle style = kCGFontRenderingStyleAntialiasing | kCGFontRenderingStyleSubpixelPositioning | kCGFontRenderingStyleSubpixelQuantization | kCGFontAntialiasingStyleUnfiltered;
        if (!CGFontGetGlyphAdvancesForStyle(platformData().cgFont(), &m, style, &glyph, 1, &advance)) {
            RetainPtr<CFStringRef> fullName = adoptCF(CGFontCopyFullName(platformData().cgFont()));
            LOG_ERROR("Unable to cache glyph widths for %@ %f", fullName.get(), pointSize);

        }
    } else if (!populatedAdvance && platformData().size())
        CTFontGetAdvancesForGlyphs(m_platformData.ctFont(), horizontal ? kCTFontOrientationHorizontal : kCTFontOrientationVertical, &glyph, &advance, 1);
#endif

    return advance.width + m_syntheticBoldOffset;
}

Lines 71-76 CTLineRef CTLineCreateWithUniCharProvider(CTUniCharProviderCallback provide, CTU a/Source/WebCore/platform/spi/cocoa/CoreTextSPI.h_sec1
- a/Source/WebCore/platform/spi/cocoa/CoreTextSPI.h +1 lines
71	void CTRunGetBaseAdvancesAndOrigins(CTRunRef, CFRange, CGSize baseAdvances[], CGPoint origins[]);	71	void CTRunGetBaseAdvancesAndOrigins(CTRunRef, CFRange, CGSize baseAdvances[], CGPoint origins[]);
72	CTTypesetterRef CTTypesetterCreateWithUniCharProviderAndOptions(CTUniCharProviderCallback provide, CTUniCharDisposeCallback dispose, void* refCon, CFDictionaryRef options);	72	CTTypesetterRef CTTypesetterCreateWithUniCharProviderAndOptions(CTUniCharProviderCallback provide, CTUniCharDisposeCallback dispose, void* refCon, CFDictionaryRef options);
73	bool CTFontGetVerticalGlyphsForCharacters(CTFontRef, const UniChar characters[], CGGlyph glyphs[], CFIndex count);	73	bool CTFontGetVerticalGlyphsForCharacters(CTFontRef, const UniChar characters[], CGGlyph glyphs[], CFIndex count);
		74	void CTFontGetUnsummedAdvancesForGlyphsAndStyle(CTFontRef, CTFontOrientation, CGFontRenderingStyle, const CGGlyph[], CGSize advances[], CFIndex count);
74		75
75	CTFontDescriptorRef CTFontDescriptorCreateForUIType(CTFontUIFontType, CGFloat size, CFStringRef language);	76	CTFontDescriptorRef CTFontDescriptorCreateForUIType(CTFontUIFontType, CGFloat size, CFStringRef language);
76	CTFontDescriptorRef CTFontDescriptorCreateWithTextStyle(CFStringRef style, CFStringRef size, CFStringRef language);	77	CTFontDescriptorRef CTFontDescriptorCreateWithTextStyle(CFStringRef style, CFStringRef size, CFStringRef language);

Return to Bug 161119

Lines 81-92 Font::Font(const FontPlatformData& platformData, bool isCustomFont, bool isLoadi a/Source/WebCore/platform/graphics/Font.cpp_sec1
- a/Source/WebCore/platform/graphics/Font.cpp -54 / +57 lines
81	// Estimates of avgCharWidth and maxCharWidth for platforms that don't support accessing these values from the font.	81	// Estimates of avgCharWidth and maxCharWidth for platforms that don't support accessing these values from the font.
82	void Font::initCharWidths()	82	void Font::initCharWidths()
83	{	83	{
84	auto* glyphPageZero = glyphPage(0);	84	auto* glyphPageZero = glyphPage(GlyphPage::pageNumberForCodePoint('0'));
85		85
86	// Treat the width of a '0' as the avgCharWidth.	86	// Treat the width of a '0' as the avgCharWidth.
87	if (m_avgCharWidth <= 0.f && glyphPageZero) {	87	if (m_avgCharWidth <= 0.f && glyphPageZero) {
88	static const UChar32 digitZeroChar = '0';	88	Glyph digitZeroGlyph = glyphPageZero->glyphDataForCharacter('0').glyph;
89	Glyph digitZeroGlyph = glyphPageZero->glyphDataForCharacter(digitZeroChar).glyph;
90	if (digitZeroGlyph)	89	if (digitZeroGlyph)
91	m_avgCharWidth = widthForGlyph(digitZeroGlyph);	90	m_avgCharWidth = widthForGlyph(digitZeroGlyph);
92	}	91	}
Lines 102-123 void Font::initCharWidths() a/Source/WebCore/platform/graphics/Font.cpp_sec2
102	void Font::platformGlyphInit()	101	void Font::platformGlyphInit()
103	{	102	{
104	auto* glyphPageZero = glyphPage(0);	103	auto* glyphPageZero = glyphPage(0);
105	if (!glyphPageZero) {	104	auto* glyphPageCharacterZero = glyphPage(GlyphPage::pageNumberForCodePoint('0'));
106	determinePitch();	105	auto* glyphPageSpace = glyphPage(GlyphPage::pageNumberForCodePoint(space));
107	return;
108	}
109		106
110	// Ask for the glyph for 0 to avoid paging in ZERO WIDTH SPACE. Control characters, including 0,	107	// Ask for the glyph for 0 to avoid paging in ZERO WIDTH SPACE. Control characters, including 0,
111	// are mapped to the ZERO WIDTH SPACE glyph.	108	// are mapped to the ZERO WIDTH SPACE glyph.
112	m_zeroWidthSpaceGlyph = glyphPageZero->glyphDataForCharacter(0).glyph;	109	if (glyphPageZero)
		110	m_zeroWidthSpaceGlyph = glyphPageZero->glyphDataForCharacter(0).glyph;
113		111
114	// Nasty hack to determine if we should round or ceil space widths.	112	// Nasty hack to determine if we should round or ceil space widths.
115	// If the font is monospace or fake monospace we ceil to ensure that	113	// If the font is monospace or fake monospace we ceil to ensure that
116	// every character and the space are the same width. Otherwise we round.	114	// every character and the space are the same width. Otherwise we round.
117	m_spaceGlyph = glyphPageZero->glyphDataForCharacter(' ').glyph;	115	if (glyphPageSpace)
		116	m_spaceGlyph = glyphPageSpace->glyphDataForCharacter(space).glyph;
118	float width = widthForGlyph(m_spaceGlyph);	117	float width = widthForGlyph(m_spaceGlyph);
119	m_spaceWidth = width;	118	m_spaceWidth = width;
120	m_zeroGlyph = glyphPageZero->glyphDataForCharacter('0').glyph;	119	if (glyphPageCharacterZero)
		120	m_zeroGlyph = glyphPageCharacterZero->glyphDataForCharacter('0').glyph;
121	m_fontMetrics.setZeroWidth(widthForGlyph(m_zeroGlyph));	121	m_fontMetrics.setZeroWidth(widthForGlyph(m_zeroGlyph));
122	determinePitch();	122	determinePitch();
123	m_adjustedSpaceWidth = m_treatAsFixedPitch ? ceilf(width) : roundf(width);	123	m_adjustedSpaceWidth = m_treatAsFixedPitch ? ceilf(width) : roundf(width);
Lines 152-207 static RefPtr<GlyphPage> createAndFillGlyphPage(unsigned pageNumber, const Font& a/Source/WebCore/platform/graphics/Font.cpp_sec3
152	// FIXME: Times New Roman contains Arabic glyphs, but Core Text doesn't know how to shape them. See <rdar://problem/9823975>.	152	// FIXME: Times New Roman contains Arabic glyphs, but Core Text doesn't know how to shape them. See <rdar://problem/9823975>.
153	// Once we have the fix for <rdar://problem/9823975> then remove this code together with Font::shouldNotBeUsedForArabic()	153	// Once we have the fix for <rdar://problem/9823975> then remove this code together with Font::shouldNotBeUsedForArabic()
154	// in <rdar://problem/12096835>.	154	// in <rdar://problem/12096835>.
155	if (pageNumber == 6 && font.shouldNotBeUsedForArabic())	155	if (GlyphPage::pageNumberIsUsedForArabic(pageNumber) && font.shouldNotBeUsedForArabic())
156	return nullptr;	156	return nullptr;
157	#endif	157	#endif
158		158
159	unsigned start = pageNumber * GlyphPage::size;	159	unsigned glyphPageSize = GlyphPage::sizeForPageNumber(pageNumber);
160	UChar buffer[GlyphPage::size * 2 + 2];	160
		161	unsigned start = GlyphPage::startingCodePointInPageNumber(pageNumber);
		162	unsigned end = start + glyphPageSize;
		163	Vector<UChar> buffer(glyphPageSize * 2 + 2);
161	unsigned bufferLength;	164	unsigned bufferLength;
162	// Fill in a buffer with the entire "page" of characters that we want to look up glyphs for.	165	// Fill in a buffer with the entire "page" of characters that we want to look up glyphs for.
163	if (U_IS_BMP(start)) {	166	if (U_IS_BMP(start)) {
164	bufferLength = GlyphPage::size;	167	bufferLength = glyphPageSize;
165	for (unsigned i = 0; i < GlyphPage::size; i++)	168	for (unsigned i = 0; i < bufferLength; i++)
166	buffer[i] = start + i;	169	buffer[i] = start + i;
167		170
168	if (!start) {	171	// Code points 0x0 - 0x20 and 0x7F - 0xA0 are control character and shouldn't render. Map them to ZERO WIDTH SPACE.
169	// Control characters must not render at all.	172	auto overwriteCodePoints = [&](unsigned minimum, unsigned maximum, UChar newCodePoint) {
170	for (unsigned i = 0; i < 0x20; ++i)	173	unsigned begin = std::max(start, minimum);
171	buffer[i] = zeroWidthSpace;	174	unsigned complete = std::min(end, maximum);
172	for (unsigned i = 0x7F; i < 0xA0; i++)	175	for (unsigned i = begin; i < complete; ++i)
173	buffer[i] = zeroWidthSpace;	176	buffer[i - start] = newCodePoint;
174	buffer[softHyphen] = zeroWidthSpace;	177	};
175		178
176	// \n, \t, and nonbreaking space must render as a space.	179	auto overwriteCodePoint = [&](UChar codePoint, UChar newCodePoint) {
177	buffer[(int)'\n'] = ' ';	180	if (codePoint >= start && codePoint < end)
178	buffer[(int)'\t'] = ' ';	181	buffer[codePoint - start] = newCodePoint;
179	buffer[noBreakSpace] = ' ';	182	};
180	} else if (start == (leftToRightMark & ~(GlyphPage::size - 1))) {	183
181	// LRM, RLM, LRE, RLE, ZWNJ, ZWJ, and PDF must not render at all.	184	overwriteCodePoints(0x0, 0x20, zeroWidthSpace);
182	buffer[leftToRightMark - start] = zeroWidthSpace;	185	overwriteCodePoints(0x7F, 0xA0, zeroWidthSpace);
183	buffer[rightToLeftMark - start] = zeroWidthSpace;	186	overwriteCodePoint(softHyphen, zeroWidthSpace);
184	buffer[leftToRightEmbed - start] = zeroWidthSpace;	187	overwriteCodePoint('\n', space);
185	buffer[rightToLeftEmbed - start] = zeroWidthSpace;	188	overwriteCodePoint('\t', space);
186	buffer[leftToRightOverride - start] = zeroWidthSpace;	189	overwriteCodePoint(noBreakSpace, space);
187	buffer[rightToLeftOverride - start] = zeroWidthSpace;	190	overwriteCodePoint(leftToRightMark, zeroWidthSpace);
188	buffer[leftToRightIsolate - start] = zeroWidthSpace;	191	overwriteCodePoint(rightToLeftMark, zeroWidthSpace);
189	buffer[rightToLeftIsolate - start] = zeroWidthSpace;	192	overwriteCodePoint(leftToRightEmbed, zeroWidthSpace);
190	buffer[zeroWidthNonJoiner - start] = zeroWidthSpace;	193	overwriteCodePoint(rightToLeftEmbed, zeroWidthSpace);
191	buffer[zeroWidthJoiner - start] = zeroWidthSpace;	194	overwriteCodePoint(leftToRightOverride, zeroWidthSpace);
192	buffer[popDirectionalFormatting - start] = zeroWidthSpace;	195	overwriteCodePoint(rightToLeftOverride, zeroWidthSpace);
193	buffer[popDirectionalIsolate - start] = zeroWidthSpace;	196	overwriteCodePoint(leftToRightIsolate, zeroWidthSpace);
194	buffer[firstStrongIsolate - start] = zeroWidthSpace;	197	overwriteCodePoint(rightToLeftIsolate, zeroWidthSpace);
195	} else if (start == (objectReplacementCharacter & ~(GlyphPage::size - 1))) {	198	overwriteCodePoint(zeroWidthNonJoiner, zeroWidthSpace);
196	// Object replacement character must not render at all.	199	overwriteCodePoint(zeroWidthJoiner, zeroWidthSpace);
197	buffer[objectReplacementCharacter - start] = zeroWidthSpace;	200	overwriteCodePoint(popDirectionalFormatting, zeroWidthSpace);
198	} else if (start == (zeroWidthNoBreakSpace & ~(GlyphPage::size - 1))) {	201	overwriteCodePoint(popDirectionalIsolate, zeroWidthSpace);
199	// ZWNBS/BOM must not render at all.	202	overwriteCodePoint(firstStrongIsolate, zeroWidthSpace);
200	buffer[zeroWidthNoBreakSpace - start] = zeroWidthSpace;	203	overwriteCodePoint(objectReplacementCharacter, zeroWidthSpace);
201	}	204	overwriteCodePoint(zeroWidthNoBreakSpace, zeroWidthSpace);
202	} else {	205	} else {
203	bufferLength = GlyphPage::size * 2;	206	bufferLength = glyphPageSize * 2;
204	for (unsigned i = 0; i < GlyphPage::size; i++) {	207	for (unsigned i = 0; i < glyphPageSize; i++) {
205	int c = i + start;	208	int c = i + start;
206	buffer[i * 2] = U16_LEAD(c);	209	buffer[i * 2] = U16_LEAD(c);
207	buffer[i * 2 + 1] = U16_TRAIL(c);	210	buffer[i * 2 + 1] = U16_TRAIL(c);
Lines 215-221 static RefPtr<GlyphPage> createAndFillGlyphPage(unsigned pageNumber, const Font& a/Source/WebCore/platform/graphics/Font.cpp_sec4
215	// for only 128 out of 256 characters.	218	// for only 128 out of 256 characters.
216	Ref<GlyphPage> glyphPage = GlyphPage::create(font);	219	Ref<GlyphPage> glyphPage = GlyphPage::create(font);
217		220
218	bool haveGlyphs = fillGlyphPage(glyphPage, buffer, bufferLength, font);	221	bool haveGlyphs = fillGlyphPage(glyphPage, buffer.data(), bufferLength, font);
219	if (!haveGlyphs)	222	if (!haveGlyphs)
220	return nullptr;	223	return nullptr;
221		224
Lines 238-244 const GlyphPage* Font::glyphPage(unsigned pageNumber) const a/Source/WebCore/platform/graphics/Font.cpp_sec5
238		241
239	Glyph Font::glyphForCharacter(UChar32 character) const	242	Glyph Font::glyphForCharacter(UChar32 character) const
240	{	243	{
241	auto* page = glyphPage(character / GlyphPage::size);	244	auto* page = glyphPage(GlyphPage::pageNumberForCodePoint(character));
242	if (!page)	245	if (!page)
243	return 0;	246	return 0;
244	return page->glyphForCharacter(character);	247	return page->glyphForCharacter(character);
Lines 246-252 Glyph Font::glyphForCharacter(UChar32 character) const a/Source/WebCore/platform/graphics/Font.cpp_sec6
246		249
247	GlyphData Font::glyphDataForCharacter(UChar32 character) const	250	GlyphData Font::glyphDataForCharacter(UChar32 character) const
248	{	251	{
249	auto* page = glyphPage(character / GlyphPage::size);	252	auto* page = glyphPage(GlyphPage::pageNumberForCodePoint(character));
250	if (!page)	253	if (!page)
251	return GlyphData();	254	return GlyphData();
252	return page->glyphDataForCharacter(character);	255	return page->glyphDataForCharacter(character);

Lines 337-349 ALWAYS_INLINE float Font::widthForGlyph(Glyph glyph) const a/Source/WebCore/platform/graphics/Font.h_sec1
- a/Source/WebCore/platform/graphics/Font.h -2 / +2 lines
337	return width;	337	return width;
338		338
339	#if ENABLE(OPENTYPE_VERTICAL)	339	#if ENABLE(OPENTYPE_VERTICAL)
340	if (m_verticalData)	340	if (m_verticalData) {
341	#if USE(CG) \|\| USE(CAIRO)	341	#if USE(CG) \|\| USE(CAIRO)
342	width = m_verticalData->advanceHeight(this, glyph) + m_syntheticBoldOffset;	342	width = m_verticalData->advanceHeight(this, glyph) + m_syntheticBoldOffset;
343	#else	343	#else
344	width = m_verticalData->advanceHeight(this, glyph);	344	width = m_verticalData->advanceHeight(this, glyph);
345	#endif	345	#endif
346	else	346	} else
347	#endif	347	#endif
348	width = platformWidthForGlyph(glyph);	348	width = platformWidthForGlyph(glyph);
349		349

Lines 596-601 FloatRect Font::platformBoundsForGlyph(Glyph glyph) const a/Source/WebCore/platform/graphics/cocoa/FontCocoa.mm_sec1
- a/Source/WebCore/platform/graphics/cocoa/FontCocoa.mm -1 / +17 lines
596	return boundingBox;	596	return boundingBox;
597	}	597	}
598		598
		599	#if !((PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200) \|\| (PLATFORM(IOS) && __IPHONE_OS_VERSION_MIN_REQUIRED >= 100000))
599	static inline Optional<CGSize> advanceForColorBitmapFont(const FontPlatformData& platformData, Glyph glyph)	600	static inline Optional<CGSize> advanceForColorBitmapFont(const FontPlatformData& platformData, Glyph glyph)
600	{	601	{
601	CTFontRef font = platformData.font();	602	CTFontRef font = platformData.font();
Lines 617-632 static inline bool canUseFastGlyphAdvanceGetter(const FontPlatformData& platform a/Source/WebCore/platform/graphics/cocoa/FontCocoa.mm_sec2
617	}	618	}
618	return true;	619	return true;
619	}	620	}
		621	#endif
620		622
621	float Font::platformWidthForGlyph(Glyph glyph) const	623	float Font::platformWidthForGlyph(Glyph glyph) const
622	{	624	{
623	CGSize advance = CGSizeZero;	625	CGSize advance = CGSizeZero;
624	bool horizontal = platformData().orientation() == Horizontal;	626	bool horizontal = platformData().orientation() == Horizontal;
		627	CGFontRenderingStyle style = kCGFontRenderingStyleAntialiasing \| kCGFontRenderingStyleSubpixelPositioning \| kCGFontRenderingStyleSubpixelQuantization \| kCGFontAntialiasingStyleUnfiltered;
		628
		629	#if (PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200) \|\| (PLATFORM(IOS) && __IPHONE_OS_VERSION_MIN_REQUIRED >= 100000)
		630	if (platformData().size()) {
		631	CTFontOrientation orientation = horizontal \|\| m_isBrokenIdeographFallback ? kCTFontOrientationHorizontal : kCTFontOrientationVertical;
		632	// FIXME: Remove this special-casing when <rdar://problem/28197291> is fixed.
		633	if (CTFontIsAppleColorEmoji(m_platformData.ctFont()))
		634	CTFontGetAdvancesForGlyphs(m_platformData.ctFont(), orientation, &glyph, &advance, 1);
		635	else
		636	CTFontGetUnsummedAdvancesForGlyphsAndStyle(m_platformData.ctFont(), orientation, style, &glyph, &advance, 1);
		637	}
		638
		639	#else
		640
625	bool populatedAdvance = false;	641	bool populatedAdvance = false;
626	if ((horizontal \|\| m_isBrokenIdeographFallback) && canUseFastGlyphAdvanceGetter(this->platformData(), glyph, advance, populatedAdvance)) {	642	if ((horizontal \|\| m_isBrokenIdeographFallback) && canUseFastGlyphAdvanceGetter(this->platformData(), glyph, advance, populatedAdvance)) {
627	float pointSize = platformData().size();	643	float pointSize = platformData().size();
628	CGAffineTransform m = CGAffineTransformMakeScale(pointSize, pointSize);	644	CGAffineTransform m = CGAffineTransformMakeScale(pointSize, pointSize);
629	CGFontRenderingStyle style = kCGFontRenderingStyleAntialiasing \| kCGFontRenderingStyleSubpixelPositioning \| kCGFontRenderingStyleSubpixelQuantization \| kCGFontAntialiasingStyleUnfiltered;
630	if (!CGFontGetGlyphAdvancesForStyle(platformData().cgFont(), &m, style, &glyph, 1, &advance)) {	645	if (!CGFontGetGlyphAdvancesForStyle(platformData().cgFont(), &m, style, &glyph, 1, &advance)) {
631	RetainPtr<CFStringRef> fullName = adoptCF(CGFontCopyFullName(platformData().cgFont()));	646	RetainPtr<CFStringRef> fullName = adoptCF(CGFontCopyFullName(platformData().cgFont()));
632	LOG_ERROR("Unable to cache glyph widths for %@ %f", fullName.get(), pointSize);	647	LOG_ERROR("Unable to cache glyph widths for %@ %f", fullName.get(), pointSize);
Lines 634-639 float Font::platformWidthForGlyph(Glyph glyph) const a/Source/WebCore/platform/graphics/cocoa/FontCocoa.mm_sec3
634	}	649	}
635	} else if (!populatedAdvance && platformData().size())	650	} else if (!populatedAdvance && platformData().size())
636	CTFontGetAdvancesForGlyphs(m_platformData.ctFont(), horizontal ? kCTFontOrientationHorizontal : kCTFontOrientationVertical, &glyph, &advance, 1);	651	CTFontGetAdvancesForGlyphs(m_platformData.ctFont(), horizontal ? kCTFontOrientationHorizontal : kCTFontOrientationVertical, &glyph, &advance, 1);
		652	#endif
637		653
638	return advance.width + m_syntheticBoldOffset;	654	return advance.width + m_syntheticBoldOffset;
639	}	655	}

Lines 1-3 a/Source/WebCore/ChangeLog_sec1
- a/Source/WebCore/ChangeLog +27 lines
		1	2016-09-09 Myles C. Maxfield <mmaxfield@apple.com>
		2
		3	[Cocoa] Improve performance of glyph advance metrics gathering
		4	https://bugs.webkit.org/show_bug.cgi?id=161119
		5
		6	Reviewed by Simon Fraser.
		7
		8	Most of the glyphs in a GlyphPage are never read from. Therefore, we can get a performance boost
		9	by not populating as many items in the GlyphPage. Because of the performance characteristics of
		10	CTFontGetGlyphsForCharacters(), a better size for a GlyphPage is 16 items. This, coupled with
		11	using CTFontGetUnsummedAdvancesForGlyphsAndStyle(), causes between a 0.01%-0.5% speedup on PLT.
		12
		13	No new tests because there is no behavior change.
		14
		15	* platform/graphics/Font.cpp:
		16	(WebCore::Font::initCharWidths):
		17	(WebCore::Font::platformGlyphInit):
		18	(WebCore::createAndFillGlyphPage):
		19	* platform/graphics/Font.h:
		20	(WebCore::Font::widthForGlyph):
		21	* platform/graphics/GlyphMetricsMap.h:
		22	* platform/graphics/GlyphPage.h:
		23	* platform/graphics/cocoa/FontCocoa.mm:
		24	* platform/spi/cocoa/CoreTextSPI.h:
		25	(WebCore::Font::platformWidthForGlyph):
		26	(WebCore::canUseFastGlyphAdvanceGetter): Deleted.
		27
1	2016-09-09 Antti Koivisto <antti@apple.com>	28	2016-09-09 Antti Koivisto <antti@apple.com>
2		29
3	v3: WebContent crash due to RELEASE_ASSERT in WebCore: WebCore::StyleResolver::styleForElement	30	v3: WebContent crash due to RELEASE_ASSERT in WebCore: WebCore::StyleResolver::styleForElement

Lines 48-61 public: a/Source/WebCore/platform/graphics/FontCascadeFonts.cpp_sec1
- a/Source/WebCore/platform/graphics/FontCascadeFonts.cpp -3 / +3 lines
48		48
49	GlyphData glyphDataForCharacter(UChar32 c) const	49	GlyphData glyphDataForCharacter(UChar32 c) const
50	{	50	{
51	unsigned index = GlyphPage::indexForCharacter(c);	51	unsigned index = GlyphPage::indexForCodePoint(c);
52	ASSERT_WITH_SECURITY_IMPLICATION(index < GlyphPage::size);	52	ASSERT_WITH_SECURITY_IMPLICATION(index < GlyphPage::size);
53	return { m_glyphs[index], m_fonts[index] };	53	return { m_glyphs[index], m_fonts[index] };
54	}	54	}
55		55
56	void setGlyphDataForCharacter(UChar32 c, GlyphData glyphData)	56	void setGlyphDataForCharacter(UChar32 c, GlyphData glyphData)
57	{	57	{
58	setGlyphDataForIndex(GlyphPage::indexForCharacter(c), glyphData);	58	setGlyphDataForIndex(GlyphPage::indexForCodePoint(c), glyphData);
59	}	59	}
60		60
61	private:	61	private:
Lines 428-434 GlyphData FontCascadeFonts::glyphDataForCharacter(UChar32 c, const FontCascadeDe a/Source/WebCore/platform/graphics/FontCascadeFonts.cpp_sec2
428	if (variant != NormalVariant)	428	if (variant != NormalVariant)
429	return glyphDataForVariant(c, description, variant, 0);	429	return glyphDataForVariant(c, description, variant, 0);
430		430
431	const unsigned pageNumber = c / GlyphPage::size;	431	const unsigned pageNumber = GlyphPage::pageNumberForCodePoint(c);
432		432
433	auto& cacheEntry = pageNumber ? m_cachedPages.add(pageNumber, GlyphPageCacheEntry()).iterator->value : m_cachedPageZero;	433	auto& cacheEntry = pageNumber ? m_cachedPages.add(pageNumber, GlyphPageCacheEntry()).iterator->value : m_cachedPageZero;
434		434

Lines 57-63 struct GlyphData { a/Source/WebCore/platform/graphics/GlyphPage.h_sec1
- a/Source/WebCore/platform/graphics/GlyphPage.h -5 / +10 lines
57		57
58	// A GlyphPage contains a fixed-size set of GlyphData mappings for a contiguous	58	// A GlyphPage contains a fixed-size set of GlyphData mappings for a contiguous
59	// range of characters in the Unicode code space. GlyphPages are indexed	59	// range of characters in the Unicode code space. GlyphPages are indexed
60	// starting from 0 and incrementing for each 256 glyphs.	60	// starting from 0 and incrementing for each "size" number of glyphs.
61	class GlyphPage : public RefCounted<GlyphPage> {	61	class GlyphPage : public RefCounted<GlyphPage> {
62	public:	62	public:
63	static Ref<GlyphPage> create(const Font& font)	63	static Ref<GlyphPage> create(const Font& font)
Lines 72-88 public: a/Source/WebCore/platform/graphics/GlyphPage.h_sec2
72		72
73	static unsigned count() { return s_count; }	73	static unsigned count() { return s_count; }
74		74
75	static const size_t size = 256; // Covers Latin-1 in a single page.	75	static const unsigned size = 16;
76	static unsigned indexForCharacter(UChar32 c) { return c % GlyphPage::size; }	76
		77	static unsigned sizeForPageNumber(unsigned) { return 16; }
		78	static unsigned indexForCodePoint(UChar32 c) { return c % size; }
		79	static unsigned pageNumberForCodePoint(UChar32 c) { return c / size; }
		80	static UChar32 startingCodePointInPageNumber(unsigned pageNumber) { return pageNumber * size; }
		81	static bool pageNumberIsUsedForArabic(unsigned pageNumber) { return startingCodePointInPageNumber(pageNumber) >= 0x600 && startingCodePointInPageNumber(pageNumber) + sizeForPageNumber(pageNumber) < 0x700; }
77		82
78	GlyphData glyphDataForCharacter(UChar32 c) const	83	GlyphData glyphDataForCharacter(UChar32 c) const
79	{	84	{
80	return glyphDataForIndex(indexForCharacter(c));	85	return glyphDataForIndex(indexForCodePoint(c));
81	}	86	}
82		87
83	Glyph glyphForCharacter(UChar32 c) const	88	Glyph glyphForCharacter(UChar32 c) const
84	{	89	{
85	return glyphForIndex(indexForCharacter(c));	90	return glyphForIndex(indexForCodePoint(c));
86	}	91	}
87		92
88	GlyphData glyphDataForIndex(unsigned index) const	93	GlyphData glyphDataForIndex(unsigned index) const