Go expire map

Disclaimer!!

This package is considered deprecated as there are more API rich and faster solutions like ccache or ttlcache. Also, library uses UnixNano instead of time.Time, which makes it to fail during system time (wall clock) adjustments.

Quick start

package main
import (
    "fmt"
    "github.com/nursik/go-expire-map"
    "time"
)
func main() {
    expireMap := expiremap.New()
    // You must call Close(), when you do not need the map anymore
    defer expireMap.Close()
    // GMT Wednesday, 1 January 2025, 0:00:00
    far := time.Unix(1735689600, 0)
    ttl := far.Sub(time.Now())
    // Insert
    expireMap.Set(1, 1, ttl)
    // Get value
    v, ok := expireMap.Get(1)
    fmt.Println(v, ok)
    // Output 1 true
    // Get TTL
    v = expireMap.GetTTL(1)
    // The output is equal to ~ ttl
    fmt.Println(v)
    // Update TTL
    v, ok = expireMap.SetTTL(1, time.Second)
    fmt.Println(v, ok)
    // Output 1 true
    time.Sleep(time.Second + time.Millisecond)
    // Because key is already expired, it returns nil, false
    v, ok = expireMap.SetTTL(1, ttl)
    fmt.Println(v, ok)
    // Output nil false
    // Because key is already expired, it returns nil, false
    v, ok = expireMap.Get(1)
    fmt.Println(v, ok)
    // Output nil false
}

Why/when

• You need thread safe map with comparable keys and interface values
• You have a lot of inserts with the same TTL. If they all expire at the same time you don’t want your app freeze
• You need both active and passive expiration
• You need notifications about inserts, update, deletes and expirations