Add skip and limit to git.GetTags (#16897)

* Make GetTags() api similar to GetBranches()
* Use it for Tag/Release page

modules/context/repo.go

 		return
 	}
 
-	tags, err := ctx.Repo.GitRepo.GetTags()
+	tags, err := ctx.Repo.GitRepo.GetTags(0, 0)
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return

modules/git/repo_tag_gogit.go

 }
 
 // GetTags returns all tags of the repository.
-func (repo *Repository) GetTags() ([]string, error) {
+// returning at most limit tags, or all if limit is 0.
+func (repo *Repository) GetTags(skip, limit int) ([]string, error) {
 	var tagNames []string
 
 	tags, err := repo.gogitRepo.Tags()
 		tagNames[i], tagNames[j] = tagNames[j], tagNames[i]
 	}
 
+	// since we have to reverse order we can paginate only afterwards
+	if len(tagNames) < skip {
+		tagNames = []string{}
+	} else {
+		tagNames = tagNames[skip:]
+	}
+	if limit != 0 && len(tagNames) > limit {
+		tagNames = tagNames[:limit]
+	}
+
 	return tagNames, nil
 }

modules/git/repo_tag_nogogit.go

 }
 
 // GetTags returns all tags of the repository.
-func (repo *Repository) GetTags() (tags []string, err error) {
-	tags, _, err = callShowRef(repo.Path, TagPrefix, "--tags", 0, 0)
+// returning at most limit tags, or all if limit is 0.
+func (repo *Repository) GetTags(skip, limit int) (tags []string, err error) {
+	tags, _, err = callShowRef(repo.Path, TagPrefix, "--tags", skip, limit)
 	return
 }

modules/repository/repo.go

 			}
 		}
 	}
-	tags, err := gitRepo.GetTags()
+	tags, err := gitRepo.GetTags(0, 0)
 	if err != nil {
 		return fmt.Errorf("GetTags: %v", err)
 	}

routers/web/repo/compare.go

 	if err != nil {
 		return false, nil, nil, err
 	}
-	tags, err := gitRepo.GetTags()
+	tags, err := gitRepo.GetTags(0, 0)
 	if err != nil {
 		return false, nil, nil, err
 	}
 	}
 
 	baseGitRepo := ctx.Repo.GitRepo
-	baseTags, err := baseGitRepo.GetTags()
+	baseTags, err := baseGitRepo.GetTags(0, 0)
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return
 	}
 	ctx.Data["HeadBranches"] = headBranches
 
-	headTags, err := headGitRepo.GetTags()
+	headTags, err := headGitRepo.GetTags(0, 0)
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return

routers/web/repo/release.go

 		ctx.Data["PageIsTagList"] = false
 	}
 
-	tags, err := ctx.Repo.GitRepo.GetTags()
+	listOptions := models.ListOptions{
+		Page:     ctx.FormInt("page"),
+		PageSize: ctx.FormInt("limit"),
+	}
+	if listOptions.PageSize == 0 {
+		listOptions.PageSize = setting.Repository.Release.DefaultPagingNum
+	}
+	if listOptions.PageSize > setting.API.MaxResponseItems {
+		listOptions.PageSize = setting.API.MaxResponseItems
+	}
+
+	tags, err := ctx.Repo.GitRepo.GetTags(listOptions.GetStartEnd())
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return
 
 	writeAccess := ctx.Repo.CanWrite(models.UnitTypeReleases)
 	ctx.Data["CanCreateRelease"] = writeAccess && !ctx.Repo.Repository.IsArchived
-	limit := ctx.FormInt("limit")
-	if limit == 0 {
-		limit = setting.Repository.Release.DefaultPagingNum
-	}
-	if limit > setting.API.MaxResponseItems {
-		limit = setting.API.MaxResponseItems
-	}
 
 	opts := models.FindReleasesOptions{
-		ListOptions: models.ListOptions{
-			Page:     ctx.FormInt("page"),
-			PageSize: limit,
-		},
+		ListOptions:   listOptions,
 		IncludeDrafts: writeAccess && !isTagList,
 		IncludeTags:   isTagList,
 	}