OpaqueJSString.h 3.7 KB

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  1. /*
  2. * Copyright (C) 2008 Apple Inc. All rights reserved.
  3. *
  4. * Redistribution and use in source and binary forms, with or without
  5. * modification, are permitted provided that the following conditions
  6. * are met:
  7. * 1. Redistributions of source code must retain the above copyright
  8. * notice, this list of conditions and the following disclaimer.
  9. * 2. Redistributions in binary form must reproduce the above copyright
  10. * notice, this list of conditions and the following disclaimer in the
  11. * documentation and/or other materials provided with the distribution.
  12. *
  13. * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14. * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16. * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
  17. * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18. * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19. * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20. * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21. * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22. * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23. * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24. */
  25. #ifndef OpaqueJSString_h
  26. #define OpaqueJSString_h
  27. #include <atomic>
  28. #include <wtf/ThreadSafeRefCounted.h>
  29. #include <wtf/text/WTFString.h>
  30. namespace JSC {
  31. class Identifier;
  32. class VM;
  33. }
  34. struct OpaqueJSString : public ThreadSafeRefCounted<OpaqueJSString> {
  35. static Ref<OpaqueJSString> create()
  36. {
  37. return adoptRef(*new OpaqueJSString);
  38. }
  39. static Ref<OpaqueJSString> create(const LChar* characters, unsigned length)
  40. {
  41. return adoptRef(*new OpaqueJSString(characters, length));
  42. }
  43. static Ref<OpaqueJSString> create(const UChar* characters, unsigned length)
  44. {
  45. return adoptRef(*new OpaqueJSString(characters, length));
  46. }
  47. JS_EXPORT_PRIVATE static RefPtr<OpaqueJSString> tryCreate(const String&);
  48. JS_EXPORT_PRIVATE static RefPtr<OpaqueJSString> tryCreate(String&&);
  49. JS_EXPORT_PRIVATE ~OpaqueJSString();
  50. bool is8Bit() { return m_string.is8Bit(); }
  51. const LChar* characters8() { return m_string.characters8(); }
  52. const UChar* characters16() { return m_string.characters16(); }
  53. unsigned length() { return m_string.length(); }
  54. const UChar* characters();
  55. JS_EXPORT_PRIVATE String string() const;
  56. JSC::Identifier identifier(JSC::VM*) const;
  57. static bool equal(const OpaqueJSString*, const OpaqueJSString*);
  58. private:
  59. friend class WTF::ThreadSafeRefCounted<OpaqueJSString>;
  60. OpaqueJSString()
  61. : m_characters(nullptr)
  62. {
  63. }
  64. OpaqueJSString(const String& string)
  65. : m_string(string.isolatedCopy())
  66. , m_characters(m_string.impl() && m_string.is8Bit() ? nullptr : const_cast<UChar*>(m_string.characters16()))
  67. {
  68. }
  69. explicit OpaqueJSString(String&& string)
  70. : m_string(WTFMove(string))
  71. , m_characters(m_string.impl() && m_string.is8Bit() ? nullptr : const_cast<UChar*>(m_string.characters16()))
  72. {
  73. }
  74. OpaqueJSString(const LChar* characters, unsigned length)
  75. : m_string(characters, length)
  76. , m_characters(nullptr)
  77. {
  78. }
  79. OpaqueJSString(const UChar* characters, unsigned length)
  80. : m_string(characters, length)
  81. , m_characters(m_string.impl() && m_string.is8Bit() ? nullptr : const_cast<UChar*>(m_string.characters16()))
  82. {
  83. }
  84. String m_string;
  85. // This will be initialized on demand when characters() is called if the string needs up-conversion.
  86. std::atomic<UChar*> m_characters;
  87. };
  88. #endif