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/*
* Copyright (C) 2013 Google 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE COPYRIGHT
* OWNER 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.
*/
#include "third_party/blink/renderer/platform/fonts/font_data_cache.h"
#include "build/build_config.h"
#include "third_party/blink/renderer/platform/fonts/simple_font_data.h"
namespace blink {
#if !defined(OS_ANDROID)
const unsigned kCMaxInactiveFontData = 250;
const unsigned kCTargetInactiveFontData = 200;
#else
const unsigned kCMaxInactiveFontData = 225;
const unsigned kCTargetInactiveFontData = 200;
#endif
scoped_refptr<SimpleFontData> FontDataCache::Get(const FontPlatformData* platform_data,
ShouldRetain should_retain,
bool subpixel_ascent_descent) {
if (!platform_data)
return nullptr;
// TODO: crbug.com/446376 - This should not happen, but we currently
// do not have a reproduction for the crash that an empty typeface()
// causes downstream from here.
if (!platform_data->Typeface()) {
DLOG(ERROR)
<< "Empty typeface() in FontPlatformData when accessing FontDataCache.";
return nullptr;
}
Cache::iterator result = cache_.find(platform_data);
if (result == cache_.end()) {
std::pair<scoped_refptr<SimpleFontData>, unsigned> new_value(
SimpleFontData::Create(*platform_data, nullptr,
subpixel_ascent_descent),
should_retain == kRetain ? 1 : 0);
// The new SimpleFontData takes a copy of the incoming FontPlatformData
// object. The incoming key may be temporary. So, for cache storage, take
// the address of the newly created FontPlatformData that is copied an owned
// by SimpleFontData.
cache_.Set(&new_value.first->PlatformData(), new_value);
if (should_retain == kDoNotRetain)
inactive_font_data_.insert(new_value.first);
return std::move(new_value.first);
}
if (!result.Get()->value.second) {
DCHECK(inactive_font_data_.Contains(result.Get()->value.first));
inactive_font_data_.erase(result.Get()->value.first);
}
if (should_retain == kRetain) {
result.Get()->value.second++;
} else if (!result.Get()->value.second) {
// If shouldRetain is DoNotRetain and count is 0, we want to remove the
// fontData from m_inactiveFontData (above) and re-add here to update LRU
// position.
inactive_font_data_.insert(result.Get()->value.first);
}
return result.Get()->value.first;
}
bool FontDataCache::Contains(const FontPlatformData* font_platform_data) const {
return cache_.Contains(font_platform_data);
}
void FontDataCache::Release(const SimpleFontData* font_data) {
DCHECK(!font_data->IsCustomFont());
Cache::iterator it = cache_.find(&(font_data->PlatformData()));
DCHECK_NE(it, cache_.end());
if (it == cache_.end())
return;
DCHECK(it->value.second);
if (!--it->value.second)
inactive_font_data_.insert(it->value.first);
}
bool FontDataCache::Purge(PurgeSeverity purge_severity) {
if (purge_severity == kForcePurge)
return PurgeLeastRecentlyUsed(INT_MAX);
if (inactive_font_data_.size() > kCMaxInactiveFontData)
return PurgeLeastRecentlyUsed(inactive_font_data_.size() -
kCTargetInactiveFontData);
return false;
}
bool FontDataCache::PurgeLeastRecentlyUsed(int count) {
// Guard against reentry when e.g. a deleted FontData releases its small caps
// FontData.
static bool is_purging;
if (is_purging)
return false;
is_purging = true;
Vector<scoped_refptr<SimpleFontData>, 20> font_data_to_delete;
auto end = inactive_font_data_.end();
auto it = inactive_font_data_.begin();
for (int i = 0; i < count && it != end; ++it, ++i) {
scoped_refptr<SimpleFontData>& font_data = *it.Get();
cache_.erase(&(font_data->PlatformData()));
// We should not delete SimpleFontData here because deletion can modify
// m_inactiveFontData. See http://trac.webkit.org/changeset/44011
font_data_to_delete.push_back(font_data);
}
if (it == end) {
// Removed everything
inactive_font_data_.clear();
} else {
for (int i = 0; i < count; ++i)
inactive_font_data_.erase(inactive_font_data_.begin());
}
bool did_work = font_data_to_delete.size();
font_data_to_delete.clear();
is_purging = false;
return did_work;
}
} // namespace blink
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