if len(buf) >= w.size {
		from := len(buf) - w.size
		w.data = append(w.data[:0], buf[from:]...)
		w.off = 0
		return
	}

	// Update off to point to the oldest remaining byte.
	free := w.size - len(w.data)
	if free == 0 {
		n := copy(w.data[w.off:], buf)
		if n == len(buf) {
			w.off += n
		} else {
			w.off = copy(w.data, buf[n:])
		}
	} else {
		if free >= len(buf) {
			w.data = append(w.data, buf...)

				b.uint32()
			}
		}

		u.off = b.off
		u.data = b.bytes(int(n - (b.off - dataOff)))
	}
	if b.err != nil {
		return nil, b.err
	}
	return units, nil
}

// offsetToUnit returns the index of the unit containing offset off.
// It returns -1 if no unit contains this offset.
func (d *Data) offsetToUnit(off Offset) int {
	// Find the unit after off
	next := sort.Search(len(d.unit), func(i int) bool {

		off := header.SetUint(ctxt.Arch, 8, uint64(state.nfunc))
		off = header.SetUint(ctxt.Arch, off, uint64(state.nfiles))
		if off != textStartOff {
			panic(fmt.Sprintf("pcHeader textStartOff: %d != %d", off, textStartOff))
		}
		off += int64(ctxt.Arch.PtrSize) // skip runtimeText relocation
		off = writeSymOffset(off, state.funcnametab)
		off = writeSymOffset(off, state.cutab)

                if ((off + stub_frag_len) > stub.length) {
                    // shouldn't happen if alloc_hint is correct or greater
                    byte[] tmp = new byte[off + stub_frag_len];
                    System.arraycopy(stub, 0, tmp, 0, off);
                    stub = tmp;
                }

                System.arraycopy(frag, 24, stub, off, stub_frag_len);
                off += stub_frag_len;

		is64, _ := b.format.dwarf64()
		if is64 {
			off *= 8
		} else {
			off *= 4
		}
		off += rnglistsBase
		if uint64(int(off)) != off {
			b.error("DW_FORM_rnglistx offset out of range")
		}

		b1 := makeBuf(b.dwarf, b.format, "rnglists", 0, b.dwarf.rngLists)
		b1.skip(int(off))
		if is64 {
			off = b1.uint64()
		} else {
			off = uint64(b1.uint32())
		}
		if b1.err != nil {
			b.err = b1.err

	)
}

func unpackUint32(msg []byte, off int) (uint32, int, error) {
	if off+uint32Len > len(msg) {
		return 0, off, errBaseLen
	}
	v := uint32(msg[off])<<24 | uint32(msg[off+1])<<16 | uint32(msg[off+2])<<8 | uint32(msg[off+3])
	return v, off + uint32Len, nil
}

func skipUint32(msg []byte, off int) (int, error) {
	if off+uint32Len > len(msg) {
		return off, errBaseLen
	}
	return off + uint32Len, nil

	if off < 0 || off > 4096-clearLoopCutoff || cnt > clearLoopCutoff {
		p = pp.Append(p, s390x.AADD, obj.TYPE_CONST, 0, off, obj.TYPE_REG, s390x.REGRT1, 0)
		p.Reg = int16(s390x.REGSP)
		reg = s390x.REGRT1
		off = 0
	}

	// Generate a loop of large clears.
	if cnt > clearLoopCutoff {
		ireg := int16(s390x.REGRT2) // register holds number of remaining loop iterations

				return fmt.Errorf("Seek(-1, 1) from EOF = %d, %v, want %d, nil", -off, err, len(content)-1)
			}
			if off, err := r.Seek(int64(-len(content)/3), 1); off != int64(middle-1) || err != nil {
				return fmt.Errorf("Seek(%d, 1) from %d = %d, %v, want %d, nil", -len(content)/3, len(content)-1, off, err, middle-1)
			}
			if off, err := r.Seek(+1, 1); off != int64(middle) || err != nil {

		r.off++
		return rv, nil
	}
	return r.rdr.ReadByte()
}

func (r *MReader) Seek(offset int64, whence int) (int64, error) {
	if r.fileView == nil {
		return r.rdr.MustSeek(offset, whence), nil
	}
	switch whence {
	case io.SeekStart:
		r.off = offset
		return offset, nil
	case io.SeekCurrent:
		return r.off, nil
	case io.SeekEnd:
		r.off = int64(len(r.fileView)) + offset
		return r.off, nil
	}

        this.b = b;
        this.off = off;
        dataLength = len;
        command = SMB_COM_WRITE_ANDX;
    }

    void setParam( int fid, long offset, int remaining,
                    byte[] b, int off, int len ) {
        this.fid = fid;
        this.offset = offset;
        this.remaining = remaining;
        this.b = b;
        this.off = off;
        dataLength = len;