feat(cache): add cache options with customizable expiry settings

pkg/cache/cacheopt.go

@@ -0,0 +1,49 @@
+package cache
+
+import "time"
+
+const (
+	defaultExpiry         = time.Hour * 24 * 7
+	defaultNotFoundExpiry = time.Minute
+)
+
+type (
+	// Options is used to store the cache options.
+	Options struct {
+		Expiry         time.Duration
+		NotFoundExpiry time.Duration
+	}
+
+	// Option defines the method to customize an Options.
+	Option func(o *Options)
+)
+
+func newOptions(opts ...Option) Options {
+	var o Options
+	for _, opt := range opts {
+		opt(&o)
+	}
+
+	if o.Expiry <= 0 {
+		o.Expiry = defaultExpiry
+	}
+	if o.NotFoundExpiry <= 0 {
+		o.NotFoundExpiry = defaultNotFoundExpiry
+	}
+
+	return o
+}
+
+// WithExpiry returns a func to customize an Options with given expiry.
+func WithExpiry(expiry time.Duration) Option {
+	return func(o *Options) {
+		o.Expiry = expiry
+	}
+}
+
+// WithNotFoundExpiry returns a func to customize an Options with given not found expiry.
+func WithNotFoundExpiry(expiry time.Duration) Option {
+	return func(o *Options) {
+		o.NotFoundExpiry = expiry
+	}
+}