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/*
* Copyright (C) 2010 Apple 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:
* 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.
*/
#include "config.h"
#ifdef SKIP_STATIC_CONSTRUCTORS_ON_GCC
#define ATOMICSTRING_HIDE_GLOBALS 1
#endif
#include "AtomicString.h"
#include "MainThread.h"
#include "NeverDestroyed.h"
#include "StaticConstructors.h"
#include "StringImpl.h"
#if USE(WEB_THREAD)
#include <pthread.h>
#endif
namespace WTF {
StringImpl* StringImpl::empty()
{
static NeverDestroyed<StringImpl> emptyString(ConstructEmptyString);
return &emptyString.get();
}
// Set the hash early, so that all empty unique StringImpls have a hash,
// and don't use the normal hashing algorithm - the unique nature of these
// keys means that we don't need them to match any other string (in fact,
// that's exactly the oposite of what we want!), and the normal hash would
// lead to lots of conflicts.
unsigned StringImpl::hashAndFlagsForEmptyUnique()
{
static unsigned s_nextHashAndFlagsForEmptyUnique = BufferInternal | s_hashFlag8BitBuffer | s_hashFlagIsAtomic;
s_nextHashAndFlagsForEmptyUnique += 1 << s_flagCount;
s_nextHashAndFlagsForEmptyUnique |= 1 << 31;
return s_nextHashAndFlagsForEmptyUnique;
}
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, nullAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, emptyAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, textAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, commentAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, starAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, xmlAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, xmlnsAtom)
WTF_EXPORTDATA DEFINE_GLOBAL(AtomicString, xlinkAtom)
NEVER_INLINE unsigned StringImpl::hashSlowCase() const
{
if (is8Bit())
setHash(StringHasher::computeHashAndMaskTop8Bits(m_data8, m_length));
else
setHash(StringHasher::computeHashAndMaskTop8Bits(m_data16, m_length));
return existingHash();
}
void AtomicString::init()
{
static bool initialized;
if (!initialized) {
// Initialization is not thread safe, so this function must be called from the main thread first.
ASSERT(isUIThread());
// Use placement new to initialize the globals.
new (NotNull, (void*)&nullAtom) AtomicString;
new (NotNull, (void*)&emptyAtom) AtomicString("");
new (NotNull, (void*)&textAtom) AtomicString("#text", AtomicString::ConstructFromLiteral);
new (NotNull, (void*)&commentAtom) AtomicString("#comment", AtomicString::ConstructFromLiteral);
new (NotNull, (void*)&starAtom) AtomicString("*", AtomicString::ConstructFromLiteral);
new (NotNull, (void*)&xmlAtom) AtomicString("xml", AtomicString::ConstructFromLiteral);
new (NotNull, (void*)&xmlnsAtom) AtomicString("xmlns", AtomicString::ConstructFromLiteral);
new (NotNull, (void*)&xlinkAtom) AtomicString("xlink", AtomicString::ConstructFromLiteral);
initialized = true;
}
}
}
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