Some repository refactors (#17950)

* some repository refactors

* remove unnecessary code

* Fix test

* Remove unnecessary banner

models/repo/star.go

@@ -0,0 +1,90 @@
+// Copyright 2016 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package repo
+
+import (
+	"code.gitea.io/gitea/models/db"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/timeutil"
+)
+
+// Star represents a starred repo by an user.
+type Star struct {
+	ID          int64              `xorm:"pk autoincr"`
+	UID         int64              `xorm:"UNIQUE(s)"`
+	RepoID      int64              `xorm:"UNIQUE(s)"`
+	CreatedUnix timeutil.TimeStamp `xorm:"INDEX created"`
+}
+
+func init() {
+	db.RegisterModel(new(Star))
+}
+
+// StarRepo or unstar repository.
+func StarRepo(userID, repoID int64, star bool) error {
+	ctx, committer, err := db.TxContext()
+	if err != nil {
+		return err
+	}
+	defer committer.Close()
+	staring := isStaring(db.GetEngine(ctx), userID, repoID)
+
+	if star {
+		if staring {
+			return nil
+		}
+
+		if err := db.Insert(ctx, &Star{UID: userID, RepoID: repoID}); err != nil {
+			return err
+		}
+		if _, err := db.Exec(ctx, "UPDATE `repository` SET num_stars = num_stars + 1 WHERE id = ?", repoID); err != nil {
+			return err
+		}
+		if _, err := db.Exec(ctx, "UPDATE `user` SET num_stars = num_stars + 1 WHERE id = ?", userID); err != nil {
+			return err
+		}
+	} else {
+		if !staring {
+			return nil
+		}
+
+		if _, err := db.DeleteByBean(ctx, &Star{UID: userID, RepoID: repoID}); err != nil {
+			return err
+		}
+		if _, err := db.Exec(ctx, "UPDATE `repository` SET num_stars = num_stars - 1 WHERE id = ?", repoID); err != nil {
+			return err
+		}
+		if _, err := db.Exec(ctx, "UPDATE `user` SET num_stars = num_stars - 1 WHERE id = ?", userID); err != nil {
+			return err
+		}
+	}
+
+	return committer.Commit()
+}
+
+// IsStaring checks if user has starred given repository.
+func IsStaring(userID, repoID int64) bool {
+	return isStaring(db.GetEngine(db.DefaultContext), userID, repoID)
+}
+
+func isStaring(e db.Engine, userID, repoID int64) bool {
+	has, _ := e.Get(&Star{UID: userID, RepoID: repoID})
+	return has
+}
+
+// GetStargazers returns the users that starred the repo.
+func GetStargazers(repo *Repository, opts db.ListOptions) ([]*user_model.User, error) {
+	sess := db.GetEngine(db.DefaultContext).Where("star.repo_id = ?", repo.ID).
+		Join("LEFT", "star", "`user`.id = star.uid")
+	if opts.Page > 0 {
+		sess = db.SetSessionPagination(sess, &opts)
+
+		users := make([]*user_model.User, 0, opts.PageSize)
+		return users, sess.Find(&users)
+	}
+
+	users := make([]*user_model.User, 0, 8)
+	return users, sess.Find(&users)
+}