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 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

  * vim: set ts=8 sts=4 et sw=4 tw=99:

  * This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef js_CharacterEncoding_h

 #define js_CharacterEncoding_h

 #include "mozilla/NullPtr.h"

 #include "mozilla/Range.h"

 #include "js/TypeDecls.h"

 #include "js/Utility.h"

 namespace js {

 struct ThreadSafeContext;

 }

 namespace JS {

 /*

  * By default, all C/C++ 1-byte-per-character strings passed into the JSAPI

  * are treated as ISO/IEC 8859-1, also known as Latin-1. That is, each

  * byte is treated as a 2-byte character, and there is no way to pass in a

  * string containing characters beyond U+00FF.

  */

 class Latin1Chars : public mozilla::Range<unsigned char>

 {

     typedef mozilla::Range<unsigned char> Base;

   public:

     Latin1Chars() : Base() {}

     Latin1Chars(char *aBytes, size_t aLength) : Base(reinterpret_cast<unsigned char *>(aBytes), aLength) {}

     Latin1Chars(const char *aBytes, size_t aLength)

       : Base(reinterpret_cast<unsigned char *>(const_cast<char *>(aBytes)), aLength)

     {}

 };

 /*

  * A Latin1Chars, but with \0 termination for C compatibility.

  */

 class Latin1CharsZ : public mozilla::RangedPtr<unsigned char>

 {

     typedef mozilla::RangedPtr<unsigned char> Base;

   public:

     Latin1CharsZ() : Base(nullptr, 0) {}

     Latin1CharsZ(char *aBytes, size_t aLength)

       : Base(reinterpret_cast<unsigned char *>(aBytes), aLength)

     {

         MOZ_ASSERT(aBytes[aLength] == '\0');

     }

     Latin1CharsZ(unsigned char *aBytes, size_t aLength)

       : Base(aBytes, aLength)

     {

         MOZ_ASSERT(aBytes[aLength] == '\0');

     }

     using Base::operator=;

     char *c_str() { return reinterpret_cast<char *>(get()); }

 };

 class UTF8Chars : public mozilla::Range<unsigned char>

 {

     typedef mozilla::Range<unsigned char> Base;

   public:

     UTF8Chars() : Base() {}

     UTF8Chars(char *aBytes, size_t aLength)

       : Base(reinterpret_cast<unsigned char *>(aBytes), aLength)

     {}

     UTF8Chars(const char *aBytes, size_t aLength)

       : Base(reinterpret_cast<unsigned char *>(const_cast<char *>(aBytes)), aLength)

     {}

 };

 /*

  * SpiderMonkey also deals directly with UTF-8 encoded text in some places.

  */

 class UTF8CharsZ : public mozilla::RangedPtr<unsigned char>

 {

     typedef mozilla::RangedPtr<unsigned char> Base;

   public:

     UTF8CharsZ() : Base(nullptr, 0) {}

     UTF8CharsZ(char *aBytes, size_t aLength)

       : Base(reinterpret_cast<unsigned char *>(aBytes), aLength)

     {

         MOZ_ASSERT(aBytes[aLength] == '\0');

     }

     UTF8CharsZ(unsigned char *aBytes, size_t aLength)

       : Base(aBytes, aLength)

     {

         MOZ_ASSERT(aBytes[aLength] == '\0');

     }

     using Base::operator=;

     char *c_str() { return reinterpret_cast<char *>(get()); }

 };

 /*

  * SpiderMonkey uses a 2-byte character representation: it is a

  * 2-byte-at-a-time view of a UTF-16 byte stream. This is similar to UCS-2,

  * but unlike UCS-2, we do not strip UTF-16 extension bytes. This allows a

  * sufficiently dedicated JavaScript program to be fully unicode-aware by

  * manually interpreting UTF-16 extension characters embedded in the JS

  * string.

  */

 class TwoByteChars : public mozilla::Range<jschar>

 {

     typedef mozilla::Range<jschar> Base;

   public:

     TwoByteChars() : Base() {}

     TwoByteChars(jschar *aChars, size_t aLength) : Base(aChars, aLength) {}

     TwoByteChars(const jschar *aChars, size_t aLength) : Base(const_cast<jschar *>(aChars), aLength) {}

 };

 /*

  * A TwoByteChars, but \0 terminated for compatibility with JSFlatString.

  */

 class TwoByteCharsZ : public mozilla::RangedPtr<jschar>

 {

     typedef mozilla::RangedPtr<jschar> Base;

   public:

     TwoByteCharsZ() : Base(nullptr, 0) {}

     TwoByteCharsZ(jschar *chars, size_t length)

       : Base(chars, length)

     {

         MOZ_ASSERT(chars[length] == '\0');

     }

     using Base::operator=;

 };

 typedef mozilla::RangedPtr<const jschar> ConstCharPtr;

 /*

  * Like TwoByteChars, but the chars are const.

  */

 class ConstTwoByteChars : public mozilla::RangedPtr<const jschar>

 {

   public:

     ConstTwoByteChars(const ConstTwoByteChars &s) : ConstCharPtr(s) {}

     ConstTwoByteChars(const mozilla::RangedPtr<const jschar> &s) : ConstCharPtr(s) {}

     ConstTwoByteChars(const jschar *s, size_t len) : ConstCharPtr(s, len) {}

     ConstTwoByteChars(const jschar *pos, const jschar *start, size_t len)

       : ConstCharPtr(pos, start, len)

     {}

     using ConstCharPtr::operator=;

 };

 /*

  * Convert a 2-byte character sequence to "ISO-Latin-1". This works by

  * truncating each 2-byte pair in the sequence to a 1-byte pair. If the source

  * contains any UTF-16 extension characters, then this may give invalid Latin1

  * output. The returned string is zero terminated. The returned string or the

  * returned string's |start()| must be freed with JS_free or js_free,

  * respectively. If allocation fails, an OOM error will be set and the method

  * will return a nullptr chars (which can be tested for with the ! operator).

  * This method cannot trigger GC.

  */

 extern Latin1CharsZ

 LossyTwoByteCharsToNewLatin1CharsZ(js::ThreadSafeContext *cx, TwoByteChars tbchars);

 extern UTF8CharsZ

 TwoByteCharsToNewUTF8CharsZ(js::ThreadSafeContext *cx, TwoByteChars tbchars);

 uint32_t

 Utf8ToOneUcs4Char(const uint8_t *utf8Buffer, int utf8Length);

 /*

  * Inflate bytes in UTF-8 encoding to jschars.

  * - On error, returns an empty TwoByteCharsZ.

  * - On success, returns a malloc'd TwoByteCharsZ, and updates |outlen| to hold

  *   its length;  the length value excludes the trailing null.

  */

 extern TwoByteCharsZ

 UTF8CharsToNewTwoByteCharsZ(JSContext *cx, const UTF8Chars utf8, size_t *outlen);

 /*

  * The same as UTF8CharsToNewTwoByteCharsZ(), except that any malformed UTF-8 characters

  * will be replaced by \uFFFD. No exception will be thrown for malformed UTF-8

  * input.

  */

 extern TwoByteCharsZ

 LossyUTF8CharsToNewTwoByteCharsZ(JSContext *cx, const UTF8Chars utf8, size_t *outlen);

 } // namespace JS

 inline void JS_free(JS::Latin1CharsZ &ptr) { js_free((void*)ptr.get()); }

 inline void JS_free(JS::UTF8CharsZ &ptr) { js_free((void*)ptr.get()); }

 #endif /* js_CharacterEncoding_h */