return ((0xFL << 4) | (codePoint >>> 18))
        | ((0x80L | (0x3F & (codePoint >>> 12))) << 8)
        | ((0x80L | (0x3F & (codePoint >>> 6))) << 16)
        | ((0x80L | (0x3F & codePoint)) << 24);
  }

  private static long charToThreeUtf8Bytes(char c) {
    return ((0x7L << 5) | (c >>> 12))
        | ((0x80 | (0x3F & (c >>> 6))) << 8)
        | ((0x80 | (0x3F & c)) << 16);
  }

                ch = src[si++] & 0xFF;
                if ((ch & 0xC0) != 0x80 ) {
                    throw new IOException( "Invalid UTF-8 sequence" );
                } else {
                    uni[ui] |= (ch & 0x3F) << 6;
                    ch = src[si++] & 0xFF;
                    uni[ui] |=  ch & 0x3F;
                    if ((ch & 0xC0) != 0x80 || uni[ui] < 0x800) {
                        throw new IOException( "Invalid UTF-8 sequence" );

     * 
     */
    public static final int FILE_COMPLETE_IF_OPLOCKED = 0x100;
    /**
     * 
     */
    public static final int FILE_NO_EA_KNOWLEDGE = 0x200;
    /**
     * 
     */
    public static final int FILE_OPEN_REMOTE_INSTANCE = 0x400;
    /**
     * 
     */
    public static final int FILE_RANDOM_ACCESS = 0x800;
    /**
     * 
     */

 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class CharStreams {

  // 2K chars (4K bytes)
  private static final int DEFAULT_BUF_SIZE = 0x800;

  /** Creates a new {@code CharBuffer} for buffering reads or writes. */
  static CharBuffer createBuffer() {
    return CharBuffer.allocate(DEFAULT_BUF_SIZE);
  }

  private CharStreams() {}

  /**

                ch = src[ si++ ] & 0xFF;
                if ( ( ch & 0xC0 ) != 0x80 ) {
                    throw new IOException("Invalid UTF-8 sequence");
                }
                uni[ ui ] |= ( ch & 0x3F ) << 6;
                ch = src[ si++ ] & 0xFF;
                uni[ ui ] |= ch & 0x3F;
                if ( ( ch & 0xC0 ) != 0x80 || uni[ ui ] < 0x800 ) {
                    throw new IOException("Invalid UTF-8 sequence");

	// but these seem to be the values agreed on by tools.
	s_IFMT   = 0xf000
	s_IFSOCK = 0xc000
	s_IFLNK  = 0xa000
	s_IFREG  = 0x8000
	s_IFBLK  = 0x6000
	s_IFDIR  = 0x4000
	s_IFCHR  = 0x2000
	s_IFIFO  = 0x1000
	s_ISUID  = 0x800
	s_ISGID  = 0x400
	s_ISVTX  = 0x200

	msdosDir      = 0x10
	msdosReadOnly = 0x01
)

// Mode returns the permission and mode bits for the [FileHeader].

	utf8Valid1, utf8Require1 := detectUTF8(fh.Name)
	utf8Valid2, utf8Require2 := detectUTF8(fh.Comment)
	switch {
	case fh.NonUTF8:
		fh.Flags &^= 0x800
	case (utf8Require1 || utf8Require2) && (utf8Valid1 && utf8Valid2):
		fh.Flags |= 0x800
	}

	fh.CreatorVersion = fh.CreatorVersion&0xff00 | zipVersion20 // preserve compatibility byte
	fh.ReaderVersion = zipVersion20

		// Some ZIP writers use UTF-8 encoding without setting the UTF-8 flag.
		// Since it is impossible to always distinguish valid UTF-8 from some
		// other encoding (e.g., GBK or Shift-JIS), we trust the flag.
		f.NonUTF8 = f.Flags&0x800 == 0
	}

	needUSize := f.UncompressedSize == ^uint32(0)
	needCSize := f.CompressedSize == ^uint32(0)
	needHeaderOffset := f.headerOffset == int64(^uint32(0))

	// Best effort to find what we need.

        dst[ dstIndex + OPCODE_OFFSET ] = (byte) ( ( this.isResponse ? 0x80 : 0x00 ) + ( ( this.opCode << 3 ) & 0x78 )
                + ( this.isAuthAnswer ? 0x04 : 0x00 ) + ( this.isTruncated ? 0x02 : 0x00 ) + ( this.isRecurDesired ? 0x01 : 0x00 ) );
        dst[ dstIndex + OPCODE_OFFSET
                + 1 ] = (byte) ( ( this.isRecurAvailable ? 0x80 : 0x00 ) + ( this.isBroadcast ? 0x10 : 0x00 ) + ( this.resultCode & 0x0F ) );

        dst[dstIndex + OPCODE_OFFSET] = (byte)(( isResponse ? 0x80 : 0x00 ) +
                        (( opCode << 3 ) & 0x78 ) +
                        ( isAuthAnswer ? 0x04 : 0x00 ) +
                        ( isTruncated ? 0x02 : 0x00 ) +
                        ( isRecurDesired ? 0x01 : 0x00 ));
        dst[dstIndex + OPCODE_OFFSET + 1] = (byte)(( isRecurAvailable ? 0x80 : 0x00 ) +
                        ( isBroadcast ? 0x10 : 0x00 ) +