third_party/WebKit/Source/platform/wtf/text/StringStatics.cpp

/*
 * 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
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#include "platform/wtf/text/StringStatics.h"

#include "platform/wtf/DynamicAnnotations.h"
#include "platform/wtf/StaticConstructors.h"
#include "platform/wtf/text/AtomicString.h"
#include "platform/wtf/text/StringImpl.h"

namespace WTF {

WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_null_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_empty_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_star_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_xml_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_xmlns_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_xlink_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_http_atom);
WTF_EXPORT DEFINE_GLOBAL(AtomicString, g_https_atom);

// This is not an AtomicString because it is unlikely to be used as an
// event/element/attribute name, so it shouldn't pollute the AtomicString hash
// table.
WTF_EXPORT DEFINE_GLOBAL(String, g_xmlns_with_colon);

WTF_EXPORT DEFINE_GLOBAL(String, g_empty_string);
WTF_EXPORT DEFINE_GLOBAL(String, g_empty_string16_bit);

NEVER_INLINE unsigned StringImpl::HashSlowCase() const {
  if (Is8Bit())
    SetHash(StringHasher::ComputeHashAndMaskTop8Bits(Characters8(), length_));
  else
    SetHash(StringHasher::ComputeHashAndMaskTop8Bits(Characters16(), length_));
  return ExistingHash();
}

void AtomicString::Init() {
  DCHECK(IsMainThread());

  new (NotNull, (void*)&g_null_atom) AtomicString;
  new (NotNull, (void*)&g_empty_atom) AtomicString("");
}

template <unsigned charactersCount>
scoped_refptr<StringImpl> AddStaticASCIILiteral(
    const char (&characters)[charactersCount]) {
  unsigned length = charactersCount - 1;
  unsigned hash = StringHasher::ComputeHashAndMaskTop8Bits(
      reinterpret_cast<const LChar*>(characters), length);
  return base::AdoptRef(StringImpl::CreateStatic(characters, length, hash));
}

void StringStatics::Init() {
  DCHECK(IsMainThread());

  StringImpl::InitStatics();
  new (NotNull, (void*)&g_empty_string) String(StringImpl::empty_);
  new (NotNull, (void*)&g_empty_string16_bit) String(StringImpl::empty16_bit_);

  // FIXME: These should be allocated at compile time.
  new (NotNull, (void*)&g_star_atom) AtomicString("*");
  new (NotNull, (void*)&g_xml_atom) AtomicString(AddStaticASCIILiteral("xml"));
  new (NotNull, (void*)&g_xmlns_atom)
      AtomicString(AddStaticASCIILiteral("xmlns"));
  new (NotNull, (void*)&g_xlink_atom)
      AtomicString(AddStaticASCIILiteral("xlink"));
  new (NotNull, (void*)&g_xmlns_with_colon) String("xmlns:");
  new (NotNull, (void*)&g_http_atom)
      AtomicString(AddStaticASCIILiteral("http"));
  new (NotNull, (void*)&g_https_atom)
      AtomicString(AddStaticASCIILiteral("https"));
}

}  // namespace WTF