Make releases faster than before and resolved #490 (#588)

* make releases faster than before and resolved #490

* fix comment

models/release.go

@@ -22,12 +22,12 @@ import (
 
 // Release represents a release of repository.
 type Release struct {
-	ID               int64 `xorm:"pk autoincr"`
-	RepoID           int64
+	ID               int64       `xorm:"pk autoincr"`
+	RepoID           int64       `xorm:"index unique(n)"`
 	Repo             *Repository `xorm:"-"`
 	PublisherID      int64
-	Publisher        *User `xorm:"-"`
-	TagName          string
+	Publisher        *User  `xorm:"-"`
+	TagName          string `xorm:"index unique(n)"`
 	LowerTagName     string
 	Target           string
 	Title            string
@@ -213,6 +213,15 @@ func GetReleasesByRepoID(repoID int64, page, pageSize int) (rels []*Release, err
 	return rels, err
 }
 
+// GetReleasesByRepoIDAndNames returns a list of releases of repository accroding repoID and tagNames.
+func GetReleasesByRepoIDAndNames(repoID int64, tagNames []string) (rels []*Release, err error) {
+	err = x.
+		Desc("created_unix").
+		In("tag_name", tagNames).
+		Find(&rels, Release{RepoID: repoID})
+	return rels, err
+}
+
 type releaseSorter struct {
 	rels []*Release
 }