From d76f34ef519f773ab66f2ba9f91c65a3aaf6537e Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Sat, 11 Feb 2017 20:01:33 +0800
Subject: [PATCH] small optimization for get issue labels

---
 models/issue_label.go | 21 ++++-----------------
 models/models.go      |  1 +
 2 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/models/issue_label.go b/models/issue_label.go
index 015e7f128..67e0ac77b 100644
--- a/models/issue_label.go
+++ b/models/issue_label.go
@@ -190,23 +190,10 @@ func GetLabelsByRepoID(repoID int64, sortType string) ([]*Label, error) {
 }
 
 func getLabelsByIssueID(e Engine, issueID int64) ([]*Label, error) {
-	issueLabels, err := getIssueLabels(e, issueID)
-	if err != nil {
-		return nil, fmt.Errorf("getIssueLabels: %v", err)
-	} else if len(issueLabels) == 0 {
-		return []*Label{}, nil
-	}
-
-	labelIDs := make([]int64, len(issueLabels))
-	for i := range issueLabels {
-		labelIDs[i] = issueLabels[i].LabelID
-	}
-
-	labels := make([]*Label, 0, len(labelIDs))
-	return labels, e.
-		Where("id > 0").
-		In("id", labelIDs).
-		Asc("name").
+	var labels []*Label
+	return labels, e.Where("issue_label.issue_id = ?", issueID).
+		Join("LEFT", "issue_label", "issue_label.label_id = label.id").
+		Asc("label.name").
 		Find(&labels)
 }
 
diff --git a/models/models.go b/models/models.go
index 659083403..7f0ef5954 100644
--- a/models/models.go
+++ b/models/models.go
@@ -42,6 +42,7 @@ type Engine interface {
 	Insert(...interface{}) (int64, error)
 	InsertOne(interface{}) (int64, error)
 	Iterate(interface{}, xorm.IterFunc) error
+	Join(joinOperator string, tablename interface{}, condition string, args ...interface{}) *xorm.Session
 	SQL(interface{}, ...interface{}) *xorm.Session
 	Where(interface{}, ...interface{}) *xorm.Session
 }