blob: 18e385e2a299d0dc39a3040d190b7ca30b08ee31 [file] [log] [blame]
/*
* Copyright (C) 2007 David Smith (catfish.man@gmail.com)
* Copyright (C) 2007, 2008, 2011-2014 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "SpaceSplitString.h"
#include "HTMLParserIdioms.h"
#include <wtf/HashMap.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/text/AtomStringHash.h>
namespace WebCore {
COMPILE_ASSERT(!(sizeof(SpaceSplitStringData) % sizeof(uintptr_t)), SpaceSplitStringDataTailIsAlignedToWordSize);
template <typename CharacterType, typename TokenProcessor>
static inline void tokenizeSpaceSplitString(TokenProcessor& tokenProcessor, const CharacterType* characters, unsigned length)
{
for (unsigned start = 0; ; ) {
while (start < length && isHTMLSpace(characters[start]))
++start;
if (start >= length)
break;
unsigned end = start + 1;
while (end < length && isNotHTMLSpace(characters[end]))
++end;
if (!tokenProcessor.processToken(characters + start, end - start))
return;
start = end + 1;
}
}
template<typename TokenProcessor>
static inline void tokenizeSpaceSplitString(TokenProcessor& tokenProcessor, const String& string)
{
ASSERT(!string.isNull());
const StringImpl& stringImpl = *string.impl();
if (stringImpl.is8Bit())
tokenizeSpaceSplitString(tokenProcessor, stringImpl.characters8(), stringImpl.length());
else
tokenizeSpaceSplitString(tokenProcessor, stringImpl.characters16(), stringImpl.length());
}
bool SpaceSplitStringData::containsAll(SpaceSplitStringData& other)
{
if (this == &other)
return true;
unsigned otherSize = other.m_size;
unsigned i = 0;
do {
if (!contains(other[i]))
return false;
++i;
} while (i < otherSize);
return true;
}
struct SpaceSplitStringTableKeyTraits : public HashTraits<AtomString>
{
// The number 200 for typicalNumberOfSpaceSplitString was based on the typical number of unique class names
// on typical websites on August 2013.
static const unsigned typicalNumberOfSpaceSplitString = 200;
static const int minimumTableSize = WTF::HashTableCapacityForSize<typicalNumberOfSpaceSplitString>::value;
};
typedef HashMap<AtomString, SpaceSplitStringData*, AtomStringHash, SpaceSplitStringTableKeyTraits> SpaceSplitStringTable;
static SpaceSplitStringTable& spaceSplitStringTable()
{
static NeverDestroyed<SpaceSplitStringTable> table;
return table;
}
void SpaceSplitString::set(const AtomString& inputString, bool shouldFoldCase)
{
if (inputString.isNull()) {
clear();
return;
}
m_data = SpaceSplitStringData::create(shouldFoldCase ? inputString.convertToASCIILowercase() : inputString);
}
class TokenIsEqualToCStringTokenProcessor {
public:
TokenIsEqualToCStringTokenProcessor(const char* referenceString, unsigned referenceStringLength)
: m_referenceString(referenceString)
, m_referenceStringLength(referenceStringLength)
, m_referenceStringWasFound(false)
{
}
template <typename CharacterType>
bool processToken(const CharacterType* characters, unsigned length)
{
if (length == m_referenceStringLength && equal(characters, reinterpret_cast<const LChar*>(m_referenceString), length)) {
m_referenceStringWasFound = true;
return false;
}
return true;
}
bool referenceStringWasFound() const { return m_referenceStringWasFound; }
private:
const char* m_referenceString;
unsigned m_referenceStringLength;
bool m_referenceStringWasFound;
};
bool SpaceSplitString::spaceSplitStringContainsValue(const String& inputString, const char* value, unsigned valueLength, bool shouldFoldCase)
{
if (inputString.isNull())
return false;
TokenIsEqualToCStringTokenProcessor tokenProcessor(value, valueLength);
tokenizeSpaceSplitString(tokenProcessor, shouldFoldCase ? inputString.impl()->convertToASCIILowercase() : inputString);
return tokenProcessor.referenceStringWasFound();
}
class TokenCounter {
WTF_MAKE_NONCOPYABLE(TokenCounter);
public:
TokenCounter() : m_tokenCount(0) { }
template<typename CharacterType> bool processToken(const CharacterType*, unsigned)
{
++m_tokenCount;
return true;
}
unsigned tokenCount() const { return m_tokenCount; }
private:
unsigned m_tokenCount;
};
class TokenAtomStringInitializer {
WTF_MAKE_NONCOPYABLE(TokenAtomStringInitializer);
public:
TokenAtomStringInitializer(AtomString* memory) : m_memoryBucket(memory) { }
template<typename CharacterType> bool processToken(const CharacterType* characters, unsigned length)
{
new (NotNull, m_memoryBucket) AtomString(characters, length);
++m_memoryBucket;
return true;
}
const AtomString* nextMemoryBucket() const { return m_memoryBucket; }
private:
AtomString* m_memoryBucket;
};
inline Ref<SpaceSplitStringData> SpaceSplitStringData::create(const AtomString& keyString, unsigned tokenCount)
{
ASSERT(tokenCount);
RELEASE_ASSERT(tokenCount < (std::numeric_limits<unsigned>::max() - sizeof(SpaceSplitStringData)) / sizeof(AtomString));
unsigned sizeToAllocate = sizeof(SpaceSplitStringData) + tokenCount * sizeof(AtomString);
SpaceSplitStringData* spaceSplitStringData = static_cast<SpaceSplitStringData*>(fastMalloc(sizeToAllocate));
new (NotNull, spaceSplitStringData) SpaceSplitStringData(keyString, tokenCount);
AtomString* tokenArrayStart = spaceSplitStringData->tokenArrayStart();
TokenAtomStringInitializer tokenInitializer(tokenArrayStart);
tokenizeSpaceSplitString(tokenInitializer, keyString);
ASSERT(static_cast<unsigned>(tokenInitializer.nextMemoryBucket() - tokenArrayStart) == tokenCount);
ASSERT(reinterpret_cast<const char*>(tokenInitializer.nextMemoryBucket()) == reinterpret_cast<const char*>(spaceSplitStringData) + sizeToAllocate);
return adoptRef(*spaceSplitStringData);
}
RefPtr<SpaceSplitStringData> SpaceSplitStringData::create(const AtomString& keyString)
{
ASSERT(isMainThread());
ASSERT(!keyString.isNull());
auto addResult = spaceSplitStringTable().add(keyString, nullptr);
if (!addResult.isNewEntry)
return addResult.iterator->value;
// Nothing in the cache? Let's create a new SpaceSplitStringData if the input has something useful.
// 1) We find the number of strings in the input to know how much size we need to allocate.
TokenCounter tokenCounter;
tokenizeSpaceSplitString(tokenCounter, keyString);
unsigned tokenCount = tokenCounter.tokenCount();
if (!tokenCount)
return nullptr;
RefPtr<SpaceSplitStringData> spaceSplitStringData = create(keyString, tokenCount);
addResult.iterator->value = spaceSplitStringData.get();
return spaceSplitStringData;
}
void SpaceSplitStringData::destroy(SpaceSplitStringData* spaceSplitString)
{
ASSERT(isMainThread());
spaceSplitStringTable().remove(spaceSplitString->m_keyString);
unsigned i = 0;
unsigned size = spaceSplitString->size();
const AtomString* data = spaceSplitString->tokenArrayStart();
do {
data[i].~AtomString();
++i;
} while (i < size);
spaceSplitString->~SpaceSplitStringData();
fastFree(spaceSplitString);
}
} // namespace WebCore