func()

in v1storage/persistence.go [1525:1585]

• 57 lines of code
• 15 McCabe index (conditional complexity)

func (p *persistence) checkpointFPMappings(fpm fpMappings) (err error) {
	log.Info("Checkpointing fingerprint mappings...")
	begin := time.Now()
	f, err := os.OpenFile(p.mappingsTempFileName(), os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0640)
	if err != nil {
		return
	}

	defer func() {
		syncErr := f.Sync()
		closeErr := f.Close()
		if err != nil {
			return
		}
		err = syncErr
		if err != nil {
			return
		}
		err = closeErr
		if err != nil {
			return
		}
		err = os.Rename(p.mappingsTempFileName(), p.mappingsFileName())
		duration := time.Since(begin)
		log.Infof("Done checkpointing fingerprint mappings in %v.", duration)
	}()

	w := bufio.NewWriterSize(f, fileBufSize)

	if _, err = w.WriteString(mappingsMagicString); err != nil {
		return
	}
	if _, err = codable.EncodeUvarint(w, mappingsFormatVersion); err != nil {
		return
	}
	if _, err = codable.EncodeUvarint(w, uint64(len(fpm))); err != nil {
		return
	}

	for fp, mappings := range fpm {
		if err = codable.EncodeUint64(w, uint64(fp)); err != nil {
			return
		}
		if _, err = codable.EncodeUvarint(w, uint64(len(mappings))); err != nil {
			return
		}
		for ms, mappedFP := range mappings {
			if _, err = codable.EncodeUvarint(w, uint64(len(ms))); err != nil {
				return
			}
			if _, err = w.WriteString(ms); err != nil {
				return
			}
			if err = codable.EncodeUint64(w, uint64(mappedFP)); err != nil {
				return
			}
		}
	}
	err = w.Flush()
	return
}