Source/platform/fonts/shaping/ShapeCache.h - Issue 1192223002: Optimize Complex Text Shaping and Caching

Unified Diff: Source/platform/fonts/shaping/ShapeCache.h

Issue 1192223002: Optimize Complex Text Shaping and Caching (Closed) Base URL: svn://svn.chromium.org/blink/trunk

Patch Set: Created 5 years, 6 months ago

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Index: Source/platform/fonts/shaping/ShapeCache.h

diff --git a/Source/platform/fonts/WidthCache.h b/Source/platform/fonts/shaping/ShapeCache.h

similarity index 76%

rename from Source/platform/fonts/WidthCache.h

rename to Source/platform/fonts/shaping/ShapeCache.h

index 49b6e481e3bf8842dc67f5caf828223953a140e8..b8fd4105b6d39b4b6b39dd94c264edf0fd161f0b 100644

--- a/Source/platform/fonts/WidthCache.h

+++ b/Source/platform/fonts/shaping/ShapeCache.h

@@ -1,5 +1,6 @@

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

@@ -10,7 +11,7 @@

* 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

+ * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY

leviw_travelin_and_unemployed 2015/06/22 18:52:08 Are we supposed to make this change?

eae 2015/06/22 19:19:53 Oops, good catch. Only for _new_ files. Thanks!

* 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

@@ -23,10 +24,10 @@

* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

-#ifndef WidthCache_h

-#define WidthCache_h

+#ifndef ShapeCache_h

+#define ShapeCache_h

-#include "platform/geometry/FloatRectOutsets.h"

+#include "platform/fonts/shaping/HarfBuzzShaper.h"

#include "platform/text/TextRun.h"

#include "wtf/Forward.h"

#include "wtf/HashFunctions.h"

@@ -36,17 +37,20 @@

namespace blink {

-struct WidthCacheEntry {

- WidthCacheEntry()

+class Font;

+class GlyphBuffer;

+class SimpleFontData;

+class HarfBuzzShaper;

+struct ShapeCacheEntry {

+ ShapeCacheEntry()

{

- width = std::numeric_limits<float>::quiet_NaN();

+ m_shapeResult = nullptr;

}

- bool isValid() const { return !std::isnan(width); }

- float width;

- FloatRect glyphBounds;

+ RefPtr<ShapeResult> m_shapeResult;

};

-class WidthCache {

+class ShapeCache {

private:

// Used to optimize small strings as hash table keys. Avoids malloc'ing an out-of-line StringImpl.

class SmallStringKey {

@@ -54,17 +58,17 @@ private:

static unsigned capacity() { return s_capacity; }

SmallStringKey()

- : m_length(s_emptyValueLength)

+ : m_length(s_emptyValueLength), m_direction(LTR)

{

}

SmallStringKey(WTF::HashTableDeletedValueType)

- : m_length(s_deletedValueLength)

+ : m_length(s_deletedValueLength), m_direction(LTR)

{

}

- template<typename CharacterType> SmallStringKey(CharacterType* characters, unsigned short length)

- : m_length(length)

+ template<typename CharacterType> SmallStringKey(CharacterType* characters, unsigned short length, TextDirection direction)

+ : m_length(length), m_direction(direction)

{

ASSERT(length <= s_capacity);

@@ -91,6 +95,7 @@ private:

const UChar* characters() const { return m_characters; }

unsigned short length() const { return m_length; }

+ TextDirection direction() const { return static_cast<TextDirection>(m_direction); }

unsigned hash() const { return m_hash; }

bool isHashTableDeletedValue() const { return m_length == s_deletedValueLength; }

@@ -102,7 +107,8 @@ private:

static const unsigned s_deletedValueLength = s_capacity + 2;

unsigned m_hash;

- unsigned short m_length;

+ unsigned m_length : 15;

+ unsigned m_direction : 1;

UChar m_characters[s_capacity];

};

@@ -121,22 +127,13 @@ private:

friend bool operator==(const SmallStringKey&, const SmallStringKey&);

public:

- WidthCache()

- : m_interval(s_maxInterval)

- , m_countdown(m_interval)

- {

- }

+ ShapeCache() { }

- WidthCacheEntry* add(const TextRun& run, WidthCacheEntry entry)

+ ShapeCacheEntry* add(const TextRun& run, ShapeCacheEntry entry)

{

if (static_cast<unsigned>(run.length()) > SmallStringKey::capacity())

return 0;

- if (m_countdown > 0) {

- --m_countdown;

- return 0;

- }

return addSlowCase(run, entry);

}

@@ -147,11 +144,11 @@ public:

}

private:

- WidthCacheEntry* addSlowCase(const TextRun& run, WidthCacheEntry entry)

+ ShapeCacheEntry* addSlowCase(const TextRun& run, ShapeCacheEntry entry)

{

int length = run.length();

bool isNewEntry;

- WidthCacheEntry *value;

+ ShapeCacheEntry *value;

if (length == 1) {

SingleCharMap::AddResult addResult = m_singleCharMap.add(run[0], entry);

isNewEntry = addResult.isNewEntry;

@@ -159,9 +156,9 @@ private:

} else {

SmallStringKey smallStringKey;

if (run.is8Bit())

- smallStringKey = SmallStringKey(run.characters8(), length);

+ smallStringKey = SmallStringKey(run.characters8(), length, run.direction());

else

- smallStringKey = SmallStringKey(run.characters16(), length);

+ smallStringKey = SmallStringKey(run.characters16(), length, run.direction());

Map::AddResult addResult = m_map.add(smallStringKey, entry);

isNewEntry = addResult.isNewEntry;

@@ -170,43 +167,35 @@ private:

// Cache hit: ramp up by sampling the next few words.

if (!isNewEntry) {

- m_interval = s_minInterval;

return value;

}

- // Cache miss: ramp down by increasing our sampling interval.

- if (m_interval < s_maxInterval)

- ++m_interval;

- m_countdown = m_interval;

- if ((m_singleCharMap.size() + m_map.size()) < s_maxSize)

+ if ((m_singleCharMap.size() + m_map.size()) < s_maxSize) {

leviw_travelin_and_unemployed 2015/06/22 18:52:08 Nit: unnecessary braces.

eae 2015/06/22 19:19:53 Done.

return value;

+ }

// No need to be fancy: we're just trying to avoid pathological growth.

m_singleCharMap.clear();

m_map.clear();

return 0;

}

- typedef HashMap<SmallStringKey, WidthCacheEntry, SmallStringKeyHash, SmallStringKeyHashTraits> Map;

- typedef HashMap<uint32_t, WidthCacheEntry, DefaultHash<uint32_t>::Hash, WTF::UnsignedWithZeroKeyHashTraits<uint32_t>> SingleCharMap;

- static const int s_minInterval = -3; // A cache hit pays for about 3 cache misses.

- static const int s_maxInterval = 20; // Sampling at this interval has almost no overhead.

- static const unsigned s_maxSize = 500000; // Just enough to guard against pathological growth.

+ typedef HashMap<SmallStringKey, ShapeCacheEntry, SmallStringKeyHash, SmallStringKeyHashTraits> Map;

leviw_travelin_and_unemployed 2015/06/22 18:52:08 Nit: Maybe a slightly more descriptive name?

eae 2015/06/22 19:19:53 Done.

+ typedef HashMap<uint32_t, ShapeCacheEntry, DefaultHash<uint32_t>::Hash, WTF::UnsignedWithZeroKeyHashTraits<uint32_t>> SingleCharMap;

+ static const unsigned s_maxSize = 10000;

leviw_travelin_and_unemployed 2015/06/22 18:52:08 Magic #1 replaced by magic #2 :p It'd be nice if

eae 2015/06/22 19:19:53 Done.

- int m_interval;

- int m_countdown;

SingleCharMap m_singleCharMap;

Map m_map;

};

-inline bool operator==(const WidthCache::SmallStringKey& a, const WidthCache::SmallStringKey& b)

+inline bool operator==(const ShapeCache::SmallStringKey& a, const ShapeCache::SmallStringKey& b)

{

- if (a.length() != b.length())

+ if (a.length() != b.length() || a.direction() != b.direction())

return false;

return WTF::equal(a.characters(), b.characters(), a.length());

}

} // namespace blink

-#endif // WidthCache_h

+#endif // ShapeCache_h

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