geocache is an in-memory cache that is suitable for geolocation based applications. It uses geolocation as a key for storing items. You can specify range on initialization and thats it! You can store any object, it uses interface.

go get github.com/melihmucuk/geocache

import (
	"fmt"
	"time"

	"github.com/melihmucuk/geocache"
)

func main() {
	c, err := geocache.NewCache(5*time.Minute, 30*time.Second, geocache.WithIn1KM)
	geoPoint := geocache.GeoPoint{Latitude: 40.9887, Longitude: 28.7817}
	if err != nil {
		fmt.Println("Error: ", err.Error())
	} else {
		c.Set(geoPoint, "helloooo", 2*time.Minute)
		v1, ok1 := c.Get(geocache.GeoPoint{Latitude: 41.2, Longitude: 29.3})
		v2, ok2 := c.Get(geocache.GeoPoint{Latitude: 41.2142, Longitude: 29.4234})
		v3, ok3 := c.Get(geocache.GeoPoint{Latitude: 40.9858, Longitude: 28.7852})
		v4, ok4 := c.Get(geocache.GeoPoint{Latitude: 40.9827, Longitude: 28.7883})
		fmt.Println(v1, ok1)
		fmt.Println(v2, ok2)
		fmt.Println(v3, ok3)
		fmt.Println(v4, ok4)
	}
}

outputs:

<nil>, false
<nil>, false
helloooo, true
helloooo, true

You can specify 8 different range. More info can be found here.

• WithIn11KM

The first decimal place is worth up to 11.1 km eg: 41.3, 29.6

• WithIn1KM

The second decimal place is worth up to 1.1 km eg: 41.36, 29.63

• WithIn110M

The third decimal place is worth up to 110 m eg: 41.367, 29.631

• WithIn11M

The fourth decimal place is worth up to 11 m eg: 41.3674, 29.6316

• WithIn1M

The fifth decimal place is worth up to 1.1 m eg: 41.36742, 29.63168

• WithIn11CM

The sixth decimal place is worth up to 0.11 m eg: 41.367421, 29.631689

• WithIn11MM

The seventh decimal place is worth up to 11 mm eg: 41.3674211, 29.6316893

• WithIn1MM

The eighth decimal place is worth up to 1.1 mm eg: 41.36742115, 29.63168932