Merge pull request #579 from magodo/magodo/store_get_reset_expiry

`memoryStore.Read()` returns honor `Record.Expiry`

data/store/memory/memory.go

@@ -32,10 +32,16 @@ func (m *memoryStore) Dump() ([]*store.Record, error) {
 		d := v.r.Expiry
 		t := time.Since(v.c)
 
+		if d > time.Duration(0) {
 			// expired
-		if d > time.Duration(0) && t > d {
+			if t > d {
 				continue
 			}
+			// update expiry
+			v.r.Expiry -= t
+			v.c = time.Now()
+		}
+
 		values = append(values, v.r)
 	}
 
@@ -56,9 +62,14 @@ func (m *memoryStore) Read(key string) (*store.Record, error) {
 	t := time.Since(v.c)
 
 	// expired
-	if d > time.Duration(0) && t > d {
+	if d > time.Duration(0) {
+		if t > d {
 			return nil, store.ErrNotFound
 		}
+		// update expiry
+		v.r.Expiry -= t
+		v.c = time.Now()
+	}
 
 	return v.r, nil
 }

data/store/memory/memory_test.go

@@ -0,0 +1,37 @@
+package memory
+
+import (
+	"testing"
+	"time"
+
+	"github.com/micro/go-micro/data/store"
+)
+
+func TestReadRecordExpire(t *testing.T) {
+	s := NewStore()
+
+	var (
+		key    = "foo"
+		expire = 100 * time.Millisecond
+	)
+	rec := &store.Record{
+		Key:    key,
+		Value:  nil,
+		Expiry: expire,
+	}
+	s.Write(rec)
+
+	rrec, err := s.Read(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rrec.Expiry >= expire {
+		t.Fatal("expiry of read record is not changed")
+	}
+
+	time.Sleep(expire)
+
+	if _, err := s.Read(key); err != store.ErrNotFound {
+		t.Fatal("expire elapsed, but key still accessable")
+	}
+}