go-cache is an in-memory key:value store/cache similar to memcached that is suitable for applications running on a single machine. Its major advantage is that, being essentially a thread-safe map[string]interface{} with expiration times, it doesn't need to serialize or transmit its contents over the network.
Any object can be stored, for a given duration or forever, and the cache can be safely used by multiple goroutines.
Although go-cache isn't meant to be used as a persistent datastore, the entire cache can be saved to and loaded from a file (using c.Items() to retrieve the items map to serialize, and NewFrom() to create a cache from a deserialized one) to recover from downtime quickly. (See the docs for NewFrom() for caveats.)
go get github.com/patrickmn/go-cache
import ( "fmt" "github.com/patrickmn/go-cache" "time" ) func main() { // Create a cache with a default expiration time of 5 minutes, and which // purges expired items every 10 minutes c := cache.New(5*time.Minute, 10*time.Minute) // Set the value of the key "foo" to "bar", with the default expiration time c.Set("foo", "bar", cache.DefaultExpiration) // Set the value of the key "baz" to 42, with no expiration time // (the item won't be removed until it is re-set, or removed using // c.Delete("baz") c.Set("baz", 42, cache.NoExpiration) // Get the string associated with the key "foo" from the cache foo, found := c.Get("foo") if found { fmt.Println(foo) } // Since Go is statically typed, and cache values can be anything, type // assertion is needed when values are being passed to functions that don't // take arbitrary types, (i.e. interface{}). The simplest way to do this for // values which will only be used once--e.g. for passing to another // function--is: foo, found := c.Get("foo") if found { MyFunction(foo.(string)) } // This gets tedious if the value is used several times in the same function. // You might do either of the following instead: if x, found := c.Get("foo"); found { foo := x.(string) // ... } // or var foo string if x, found := c.Get("foo"); found { foo = x.(string) } // ... // foo can then be passed around freely as a string // Want performance? Store pointers! c.Set("foo", &MyStruct, cache.DefaultExpiration) if x, found := c.Get("foo"); found { foo := x.(*MyStruct) // ... } }