pi-calendar/pkg/storage/storage.go

package storage

import (
	"encoding/json"
	"errors"
	"io/ioutil"
	"sync"

	"git.trj.tw/golang/utils"
)

// Storage -
type Storage struct {
	m        map[string]interface{}
	filePath string
	sync.Mutex
}

var s *Storage

// New storage
func New() *Storage {
	if s == nil {
		s = &Storage{
			m: make(map[string]interface{}),
		}
	}
	return s
}

// Get storage
func Get() *Storage { return s }

// Load storage data from file
func (p *Storage) Load(filePath string, ignoreNotExist bool) (err error) {
	filePath = utils.ParsePath(filePath)
	exist := utils.CheckExists(filePath, false)
	if !exist && !ignoreNotExist {
		return errors.New("storage file not found")
	}
	p.filePath = filePath

	if exist {
		b, err := ioutil.ReadFile(filePath)
		if err != nil {
			return err
		}

		if err := json.Unmarshal(b, &p.m); err != nil {
			return err
		}
	}

	return
}

func (p *Storage) Write() (err error) {
	p.Lock()
	defer p.Unlock()
	b, err := json.Marshal(p.m)
	if err != nil {
		return
	}
	err = ioutil.WriteFile(p.filePath, b, 0664)

	return
}

// Get data by key
func (p *Storage) Get(key string) (data interface{}, ok bool) {
	data, ok = p.m[key]
	return
}

// Set data by key
func (p *Storage) Set(key string, value interface{}) {
	p.m[key] = value
	_ = p.Write()
}

// Delete data by key
func (p *Storage) Delete(key string) {
	delete(p.m, key)
	_ = p.Write()
}