In Golang, the 'Add' function of the Memcached client is commonly used when you want to set a new key-value pair only if the key does not already exist in the cache. This can be useful when preventing overwrites of existing data or ensuring uniqueness.
Here's an example of how to use it:
package main import ( "fmt" "github.com/bradfitz/gomemcache/memcache" ) func main() { mc := memcache.New("127.0.0.1:11211") err := mc.Add(&memcache.Item{Key: "Hello", Value: []byte("World")}) if err != nil { fmt.Println(err) } else { it, _ := mc.Get("Hello") fmt.Println(string(it.Value)) } }
In this code, we first instantiate a Memcached client that connects to a local Memcached server. Then, we attempt to add a key-value pair ("Hello": "World") to the cache using the Add
function. If the key already exists, it will return an error. If the operation was successful, it retrieves the value associated with the key "Hello" and prints it out.
Add
function. It will return an error if the key already exists in the cache.Add
operation was successful. Always check the error returned by the Add
function.Q: What happens if I try to add a key-value pair that already exists in Memcached?
A: The Add
function will return an error if you try to add a key that already exists. You can use the Set
function if you want to overwrite the value of an existing key.
Q: Can I increase the maximum size of the keys and values in Memcached?
A: Yes, you can configure these limits when starting up your Memcached server, but it's generally recommended to stay within the defaults as increasing them may lead to inefficient usage of memory.
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.