question: private final String _decodeShortUnicodeName ( int len ) throws IOException , JsonParseException { int outPtr = 0 ; char [ ] outBuf = _textBuffer . emptyAndGetCurrentSegment ( ) ; int inPtr = _inputPtr ; _inputPtr += len ; final int [ ] codes = SmileConstants . sUtf8UnitLengths ; final byte [ ] inBuf = _inputBuffer ; for ( int end = inPtr + len ; inPtr < end ; ) { int i = inBuf [ inPtr ++ ] & 0xFF ; int code = codes [ i ] ; if ( code != 0 ) { switch ( code ) { case 1 : i = ( ( i & 0x1F ) << 6 ) | ( inBuf [ inPtr ++ ] & 0x3F ) ; break ; case 2 : i = ( ( i & 0x0F ) << 12 ) | ( ( inBuf [ inPtr ++ ] & 0x3F ) << 6 ) | ( inBuf [ inPtr ++ ] & 0x3F ) ; break ; case 3 : i = ( ( i & 0x07 ) << 18 ) | ( ( inBuf [ inPtr ++ ] & 0x3F ) << 12 ) | ( ( inBuf [ inPtr ++ ] & 0x3F ) << 6 ) | ( inBuf [ inPtr ++ ] & 0x3F ) ; i -= 0x10000 ; outBuf [ outPtr ++ ] = ( char ) ( 0xD800 | ( i > > 10 ) ) ; i = 0xDC00 | ( i & 0x3FF ) ; break ; default : _reportError ( "Invalid byte " + Integer . toHexString ( i ) + " in short Unicode text block" ) ; } } outBuf [ outPtr ++ ] = ( char ) i ; } _textBuffer . setCurrentLength ( outPtr ) ; return _textBuffer . contentsAsString ( ) ; }
target:  Helper method used to decode short Unicode string, length for which actual length (in bytes) is known