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TtlMap is golang package that implements atime-to-live map such that after a given amount of time, items in the map are deleted.

• The map key can be anycomparable data type, via Generics.
• Any data type can be used as a map value. Internally,interface{} is used for this.

Full example using many data types

Small example:

package mainimport ("fmt""time""github.com/jftuga/TtlMap")funcmain() {maxTTL:=time.Duration(time.Second*4)// a key's time to live in secondsstartSize:=3// initial number of items in mappruneInterval:=time.Duration(time.Second*1)// search for expired items every 'pruneInterval' secondsrefreshLastAccessOnGet:=true// update item's 'lastAccessTime' on a .Get()// any comparable data type such as int, uint64, pointers and struct types (if all field types are comparable)// can be used as the key type, not just stringt:=TtlMap.New[string](maxTTL,startSize,pruneInterval,refreshLastAccessOnGet)defert.Close()// populate the TtlMapt.Put("myString","a b c")t.Put("int_array", []int{1,2,3})fmt.Println("TtlMap length:",t.Len())// display all items in TtlMapall:=t.All()fork,v:=rangeall {fmt.Printf("[%9s] %v\n",k,v.Value)}fmt.Println()sleepTime:=maxTTL+pruneIntervalfmt.Printf("Sleeping %v seconds, items should be 'nil' after this time\n",sleepTime)time.Sleep(sleepTime)fmt.Printf("[%9s] %v\n","myString",t.Get("myString"))fmt.Printf("[%9s] %v\n","int_array",t.Get("int_array"))fmt.Println("TtlMap length:",t.Len())}

Output:

$ go run small.goTtlMap length: 2[ myString] a b c[int_array] [1 2 3]Sleeping 5 seconds, items should be 'nil' after this time[ myString] <nil>[int_array] <nil>TtlMap length: 0

• New: initialize aTtlMap
• Close: this stops the goroutine that checks for expired items; use withdefer
• Len: return the number of items in the map
• Put: add a key/value
• Get: get the current value of the given key; returnnil if the key is not found in the map
• GetNoUpdate: same asGet, but do not update thelastAccess expiration time
• • • This ignores therefreshLastAccessOnGet parameter
• All: returns acopy of all items in the map
• Delete: delete an item; returntrue if the item was deleted,false if the item was not found in the map
• Clear: remove all items from the map

• Searching for expired items runs in O(n) time, where n = number of items in theTtlMap.
• • This inefficiency can be somewhat mitigated by increasing the value of thepruneInterval time.
• In most cases you wantpruneInterval > maxTTL; otherwise expired items will stay in the map longer than expected.

• Adopted from:Map with TTL option in Go
• • Answer created by:OneOfOne
• /u/skeeto: suggestions for theNew function
• @zhayes on the Go Discord: helping me with Go Generics

This program was completely developed on my own personal time, for my own personal benefit, and on my personally owned equipment.