arazmj / gerdu

package weakcache

import (

	"github.com/arazmj/gerdu/metrics"

	"github.com/ivanrad/go-weakref/weakref"

	"sync"

)

// WeakCache data structure

type WeakCache struct {

	sync.Map

}

// NewWeakCache constructor

func NewWeakCache() *WeakCache {

	return &WeakCache{}

}

// Put a new key value pair

func (c *WeakCache) Put(key string, value string) (created bool) {

	metrics.Adds.Inc()

	ref := weakref.NewWeakRef(value)

	c.Store(key, ref)

	return true

}

// Get value by key

func (c *WeakCache) Get(key string) (value string, ok bool) {

	v, ok := c.Load(key)

	if ok {

		ref := v.(*weakref.WeakRef)

		if ref.IsAlive() {

			metrics.Hits.Inc()

			return ref.GetTarget().(string), true

		}

		metrics.Deletes.Inc()

		c.Delete(key)

	}

	metrics.Miss.Inc()

	return "", false

}

//Delete deletes the key