Fetch does not return stale items

This commit is contained in:
David Palm 2016-02-03 16:07:59 +01:00
parent 74754c77cc
commit d5307b40af
2 changed files with 22 additions and 5 deletions

View file

@ -81,12 +81,12 @@ func (c *Cache) Replace(key string, value interface{}) bool {
return true
}
// Attempts to get the value from the cache and calles fetch on a miss.
// If fetch returns an error, no value is cached and the error is returned back
// to the caller.
// Attempts to get the value from the cache and calles fetch on a miss (missing
// or stale item). If fetch returns an error, no value is cached and the error
// is returned back to the caller.
func (c *Cache) Fetch(key string, duration time.Duration, fetch func() (interface{}, error)) (*Item, error) {
item := c.Get(key)
if item != nil {
if item != nil && !item.Expired() {
return item, nil
}
value, err := fetch()

View file

@ -1,10 +1,11 @@
package ccache
import (
. "github.com/karlseguin/expect"
"strconv"
"testing"
"time"
. "github.com/karlseguin/expect"
)
type CacheTests struct{}
@ -22,6 +23,22 @@ func (_ CacheTests) DeletesAValue() {
Expect(cache.Get("worm").Value()).To.Equal("sand")
}
func (_ CacheTests) FetchesExpiredItems() {
cache := New(Configure())
fn := func() (interface{}, error) { return "moo-moo", nil }
cache.Set("beef", "moo", time.Second)
Expect(cache.Get("beef").Value()).To.Equal("moo")
out, _ := cache.Fetch("beef", time.Second, fn)
Expect(out.Value()).To.Equal("moo")
time.Sleep(2 * time.Second)
out2, _ := cache.Fetch("beef", time.Second, fn)
Expect(out2.Value()).To.Equal("moo-moo")
}
func (_ CacheTests) GCsTheOldestItems() {
cache := New(Configure().ItemsToPrune(10))
for i := 0; i < 500; i++ {