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" ) funcmain(){// Create a cache with a default expiration time of 5 minutes, and which// purges expired items every 10 minutesc:=cache.New(5*time.Minute, 10*time.Minute) // Set the value of the key "foo" to "bar", with the default expiration timec.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 cachefoo, found:=c.Get("foo") iffound{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") iffound{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:ifx, found:=c.Get("foo"); found{foo:=x.(string) // ... } // orvarfoostringifx, 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) ifx, found:=c.Get("foo"); found{foo:=x.(*MyStruct) // ... } }