From 77f604a9284887758e604e92d2c9b40697db0a23 Mon Sep 17 00:00:00 2001
From: 6543 <6543@obermui.de>
Date: Fri, 10 Sep 2021 19:30:37 +0200
Subject: [PATCH] Add skip and limit to git.GetTags (#16897)

* Make GetTags() api similar to GetBranches()
* Use it for Tag/Release page
---
 modules/context/repo.go         |  2 +-
 modules/git/repo_tag_gogit.go   | 13 ++++++++++++-
 modules/git/repo_tag_nogogit.go |  5 +++--
 modules/repository/repo.go      |  2 +-
 routers/web/repo/compare.go     |  6 +++---
 routers/web/repo/release.go     | 25 +++++++++++++------------
 6 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/modules/context/repo.go b/modules/context/repo.go
index df71638350..89ff890cc3 100644
--- a/modules/context/repo.go
+++ b/modules/context/repo.go
@@ -547,7 +547,7 @@ func RepoAssignment(ctx *Context) (cancel context.CancelFunc) {
 		return
 	}
 
-	tags, err := ctx.Repo.GitRepo.GetTags()
+	tags, err := ctx.Repo.GitRepo.GetTags(0, 0)
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return
diff --git a/modules/git/repo_tag_gogit.go b/modules/git/repo_tag_gogit.go
index 3022fe96f7..ff8a6d53ee 100644
--- a/modules/git/repo_tag_gogit.go
+++ b/modules/git/repo_tag_gogit.go
@@ -21,7 +21,8 @@ func (repo *Repository) IsTagExist(name string) bool {
 }
 
 // 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()
@@ -40,5 +41,15 @@ func (repo *Repository) GetTags() ([]string, error) {
 		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
 }
diff --git a/modules/git/repo_tag_nogogit.go b/modules/git/repo_tag_nogogit.go
index 0170f0cc76..172b6fd66c 100644
--- a/modules/git/repo_tag_nogogit.go
+++ b/modules/git/repo_tag_nogogit.go
@@ -18,7 +18,8 @@ func (repo *Repository) IsTagExist(name string) bool {
 }
 
 // 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
 }
diff --git a/modules/repository/repo.go b/modules/repository/repo.go
index 6b87039775..00413549ee 100644
--- a/modules/repository/repo.go
+++ b/modules/repository/repo.go
@@ -250,7 +250,7 @@ func SyncReleasesWithTags(repo *models.Repository, gitRepo *git.Repository) erro
 			}
 		}
 	}
-	tags, err := gitRepo.GetTags()
+	tags, err := gitRepo.GetTags(0, 0)
 	if err != nil {
 		return fmt.Errorf("GetTags: %v", err)
 	}
diff --git a/routers/web/repo/compare.go b/routers/web/repo/compare.go
index eb6c37a1a6..0a0b38f078 100644
--- a/routers/web/repo/compare.go
+++ b/routers/web/repo/compare.go
@@ -606,7 +606,7 @@ func getBranchesAndTagsForRepo(user *models.User, repo *models.Repository) (bool
 	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
 	}
@@ -632,7 +632,7 @@ func CompareDiff(ctx *context.Context) {
 	}
 
 	baseGitRepo := ctx.Repo.GitRepo
-	baseTags, err := baseGitRepo.GetTags()
+	baseTags, err := baseGitRepo.GetTags(0, 0)
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return
@@ -646,7 +646,7 @@ func CompareDiff(ctx *context.Context) {
 	}
 	ctx.Data["HeadBranches"] = headBranches
 
-	headTags, err := headGitRepo.GetTags()
+	headTags, err := headGitRepo.GetTags(0, 0)
 	if err != nil {
 		ctx.ServerError("GetTags", err)
 		return
diff --git a/routers/web/repo/release.go b/routers/web/repo/release.go
index ef98790f52..0603f0ee97 100644
--- a/routers/web/repo/release.go
+++ b/routers/web/repo/release.go
@@ -83,7 +83,18 @@ func releasesOrTags(ctx *context.Context, isTagList bool) {
 		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
@@ -92,19 +103,9 @@ func releasesOrTags(ctx *context.Context, isTagList bool) {
 
 	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,
 	}