go-redis/cache library implements a cache using Redis as a key/value storage. It uses MessagePack to marshal values.
Optionally, you can use TinyLFU or any other cache algorithm as a local in-process cache.
If you are interested in monitoring cache hit rate, see the guide for Monitoring using OpenTelemetry Metrics.
go-redis/cache supports 2 last Go versions and requires a Go version with modules support. So make sure to initialize a Go module:
go mod init github.com/my/repo
And then install go-redis/cache/v8 (note v8 in the import; omitting it is a popular mistake):
go get github.com/go-redis/cache/v8
package cache_test
import (
"context"
"fmt"
"time"
"github.com/go-redis/redis/v8"
"github.com/go-redis/cache/v8"
)
type Object struct {
Str string
Num int
}
func Example_basicUsage() {
ring := redis.NewRing(&redis.RingOptions{
Addrs: map[string]string{
"server1": ":6379",
"server2": ":6380",
},
})
mycache := cache.New(&cache.Options{
Redis: ring,
LocalCache: cache.NewTinyLFU(1000, time.Minute),
})
ctx := context.TODO()
key := "mykey"
obj := &Object{
Str: "mystring",
Num: 42,
}
if err := mycache.Set(&cache.Item{
Ctx: ctx,
Key: key,
Value: obj,
TTL: time.Hour,
}); err != nil {
panic(err)
}
var wanted Object
if err := mycache.Get(ctx, key, &wanted); err == nil {
fmt.Println(wanted)
}
// Output: {mystring 42}
}
func Example_advancedUsage() {
ring := redis.NewRing(&redis.RingOptions{
Addrs: map[string]string{
"server1": ":6379",
"server2": ":6380",
},
})
mycache := cache.New(&cache.Options{
Redis: ring,
LocalCache: cache.NewTinyLFU(1000, time.Minute),
})
obj := new(Object)
err := mycache.Once(&cache.Item{
Key: "mykey",
Value: obj, // destination
Do: func(*cache.Item) (interface{}, error) {
return &Object{
Str: "mystring",
Num: 42,
}, nil
},
})
if err != nil {
panic(err)
}
fmt.Println(obj)
// Output: &{mystring 42}
}