Function ReadFile

msgp/file.go:22–38

ReadFile reads a file into 'dst' using a read-only memory mapping. Consequently, the file must be mmap-able, and the Unmarshaler should never write to the source memory. (Methods generated by the msgp tool obey that constraint, but user-defined implementations may not.) Reading and writing through

(dst Unmarshaler, file *os.File)

// files are best read and written using
// the ordinary streaming interfaces.
func ReadFile(dst Unmarshaler, file *os.File) error {
	stat, err := file.Stat()
	if err != nil {
		return err
	}
	data, err := syscall.Mmap(int(file.Fd()), 0, int(stat.Size()), syscall.PROT_READ, syscall.MAP_SHARED)
	if err != nil {
		return err
	}
	adviseRead(data)
	_, err = dst.UnmarshalMsg(data)
	uerr := syscall.Munmap(data)
	if err == nil {
		err = uerr
	}
	return err
}

// MarshalSizer is the combination
// of the Marshaler and Sizer