diff --git a/models/release.go b/models/release.go
index a60376d978..c047b2f557 100644
--- a/models/release.go
+++ b/models/release.go
@@ -38,12 +38,14 @@ type Release struct {
 	CreatedUnix int64
 }
 
+// BeforeInsert is invoked from XORM before inserting an object of this type.
 func (r *Release) BeforeInsert() {
 	if r.CreatedUnix == 0 {
 		r.CreatedUnix = time.Now().Unix()
 	}
 }
 
+// AfterSet is invoked from XORM after setting the value of a field of this object.
 func (r *Release) AfterSet(colName string, _ xorm.Cell) {
 	switch colName {
 	case "created_unix":
@@ -151,15 +153,15 @@ func GetReleasesByRepoID(repoID int64, page, pageSize int) (rels []*Release, err
 	return rels, err
 }
 
-type ReleaseSorter struct {
+type releaseSorter struct {
 	rels []*Release
 }
 
-func (rs *ReleaseSorter) Len() int {
+func (rs *releaseSorter) Len() int {
 	return len(rs.rels)
 }
 
-func (rs *ReleaseSorter) Less(i, j int) bool {
+func (rs *releaseSorter) Less(i, j int) bool {
 	diffNum := rs.rels[i].NumCommits - rs.rels[j].NumCommits
 	if diffNum != 0 {
 		return diffNum > 0
@@ -167,13 +169,13 @@ func (rs *ReleaseSorter) Less(i, j int) bool {
 	return rs.rels[i].Created.After(rs.rels[j].Created)
 }
 
-func (rs *ReleaseSorter) Swap(i, j int) {
+func (rs *releaseSorter) Swap(i, j int) {
 	rs.rels[i], rs.rels[j] = rs.rels[j], rs.rels[i]
 }
 
 // SortReleases sorts releases by number of commits and created time.
 func SortReleases(rels []*Release) {
-	sorter := &ReleaseSorter{rels: rels}
+	sorter := &releaseSorter{rels: rels}
 	sort.Sort(sorter)
 }