Working with Go


Storing Objects in Memcache

How to store objects in memcache using bradfitz/gomemcache package. Memcache stores data as []byte, so you need to first encode the object prior to storing.

I typically encode using JSON, often the data is already or will soon be in JSON format, plus human readable helps debugging. If space and performance is a concern, see encoding/gob for another format.

package main

import (


// define Dog object type
type Dog struct {
    Name  string
    Color string

func main() {

    // connect to memcache server
    mc := memcache.New("")

    // try to pull from memcache
    fetchItem, err := mc.Get("dog")

    // check for cache hit
    if err != memcache.ErrCacheMiss {
        if err != nil {
            fmt.Println("Error fetching from memcache", err)
        } else {
            fmt.Println("Cache hit!")

            dog, err := DecodeData(fetchItem.Value)
            if err != nil {
                fmt.Println("Error decoding data from memcache", err)
            } else {
                fmt.Println("Dog name is: ", dog.Name)

    // create instance of object and set properties
    spot := Dog{Name: "Spot", Color: "brown"}

    // create memcache item to store
    setItem := memcache.Item{
        Key: "dog",
        Value: EncodeData(spot),
        Expiration: 300

    err = mc.Set(&setItem)
    if err != nil {
        fmt.Println("Error setting memcache item", err)

    // run twice

func DecodeData(raw []byte) (dog Dog, err error) {
    err = json.Unmarshal(raw, &dog)
    return dog, err

func EncodeData(dog Dog) []byte {
    enc, err := json.Marshal(dog)
    if err != nil {
        fmt.Println("Error encoding Action to JSON", err)
    return enc