Merge pull request #9 from wI2L/cache-length

cache: add Len() method to Cache type.

cache.go

@@ -212,3 +212,11 @@ func (c *Cache) Set(key string, i interface{}) {
 	c.cache[key] = &CachedElement{Value: i, Timestamp: time.Now()}
 	c.cacheMutex.Unlock()
 }
+
+// Len returns the length of the cache.
+func (c *Cache) Len() int {
+	c.cacheMutex.RLock()
+	defer c.cacheMutex.RUnlock()
+
+	return len(c.cache)
+}

cache_test.go

@@ -39,6 +39,10 @@ func Test(t *testing.T) {
 	if nbHit != 2 { // foo1, bar1
 		t.Errorf("Should have 2 hits on cache getter func after foo1/bar1, got %d", nbHit)
 	}
+	cacheLen := cache.Len()
+	if cacheLen != 2 {
+		t.Errorf("expected cache length to be 2, got %d", cacheLen)
+	}
 
 	time.Sleep(1 * time.Second) // Sleep to force expiration
 	// Concurrent get (cache queue)
@@ -71,7 +75,12 @@ func Test(t *testing.T) {
 	if nbHit != 4 { // foo1, bar1, foo3, foo5
 		t.Errorf("Should have 4 hits on cache getter func after foo5, got %d", nbHit)
 	}
+	time.Sleep(1 * time.Second)
 
+	cacheLen = cache.Len()
+	if cacheLen != 0 {
+		t.Errorf("expected cache length to be 0, got %d", cacheLen)
+	}
 }
 
 func TestError(t *testing.T) {
@@ -151,4 +160,9 @@ func TestSet(t *testing.T) {
 	if c2 != forceSet {
 		t.Errorf("Expected '%s', got '%s'", forceSet, c2)
 	}
+
+	cacheLen := cache.Len()
+	if cacheLen != 1 {
+		t.Errorf("expected cache length to be 1, got %d", cacheLen)
+	}
 }