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/*
* Copyright (C) 2012 Apple Inc. All rights reserved.
* Copyright (C) 2015 Google Inc. All rights reserved.
* Copyright (C) 2023 Igalia S.L. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* 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
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_NG_SHAPE_CACHE_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_NG_SHAPE_CACHE_H_
#include "base/hash/hash.h"
#include "base/memory/weak_ptr.h"
#include "third_party/blink/renderer/platform/fonts/shaping/shape_result.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_map.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/text/text_direction.h"
#include "third_party/blink/renderer/platform/wtf/forward.h"
#include "third_party/blink/renderer/platform/wtf/hash_functions.h"
#include "third_party/blink/renderer/platform/wtf/hash_table_deleted_value_type.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
class NGShapeCache : public GarbageCollected<NGShapeCache> {
public:
static constexpr unsigned kMaxTextLengthOfEntries = 30;
static constexpr unsigned kMaxSize = 2048;
explicit NGShapeCache(const SimpleFontData* primary_font)
: primary_font_(primary_font) {
DCHECK(RuntimeEnabledFeatures::LayoutNGShapeCacheEnabled());
}
NGShapeCache(const NGShapeCache&) = delete;
NGShapeCache& operator=(const NGShapeCache&) = delete;
void Trace(Visitor* visitor) const {
visitor->Trace(ltr_string_map_);
visitor->Trace(rtl_string_map_);
visitor->Trace(primary_font_);
}
template <typename ShapeResultFunc>
const ShapeResult* GetOrCreate(const String& text,
TextDirection direction,
const ShapeResultFunc& shape_result_func) {
if (text.length() > kMaxTextLengthOfEntries) {
return shape_result_func();
}
auto& map = IsLtr(direction) ? ltr_string_map_ : rtl_string_map_;
if (map.size() >= kMaxSize) [[unlikely]] {
const auto it = map.find(text);
return (it != map.end() && it->value) ? it->value.Get()
: shape_result_func();
}
const auto add_result = map.insert(text, nullptr);
if (add_result.stored_value->value) {
return add_result.stored_value->value;
}
const ShapeResult* result = shape_result_func();
// Only shape-results without font-fallback are valid, because the cache is
// in the `primary_font_`.
if (!result->HasFallbackFonts(primary_font_)) {
add_result.stored_value->value = result;
}
return result;
}
private:
typedef HeapHashMap<String, WeakMember<const ShapeResult>> SmallStringMap;
SmallStringMap ltr_string_map_;
SmallStringMap rtl_string_map_;
Member<const SimpleFontData> primary_font_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_NG_SHAPE_CACHE_H_
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