code: func (f *LogFile) bytes() int {
  	var b int
  	b += 24 // mu RWMutex is 24 bytes
  	b += 16 // wg WaitGroup is 16 bytes
  	b += int(unsafe.Sizeof(f.id))
  	// Do not include f.data because it is mmap'd
  	// TODO(jacobmarble): Uncomment when we are using go >= 1.10.0
  	//b += int(unsafe.Sizeof(f.w)) + f.w.Size()
  	b += int(unsafe.Sizeof(f.buf)) + len(f.buf)
  	b += int(unsafe.Sizeof(f.keyBuf)) + len(f.keyBuf)
  	// Do not count SeriesFile because it belongs to the code that constructed this Index.
  	b += int(unsafe.Sizeof(f.size))
  	b += int(unsafe.Sizeof(f.modTime))
  	b += int(unsafe.Sizeof(f.seriesIDSet)) + f.seriesIDSet.Bytes()
  	b += int(unsafe.Sizeof(f.tombstoneSeriesIDSet)) + f.tombstoneSeriesIDSet.Bytes()
  	b += int(unsafe.Sizeof(f.mms)) + f.mms.bytes()
  	b += int(unsafe.Sizeof(f.path)) + len(f.path)
  	return b
  }
docs: // bytes estimates the memory footprint of this LogFile, in bytes.