Add commit count caching (#2774)

* Add commit count caching

* Small refactoring

* Add different key prefix for refs and commits

* Add configuratuion option to allow to change caching time or disable it

2 files changed, 21 insertions, 3 deletions

diff --git a/models/repo.go b/models/repo.go
index 1b1be62f87..eca71568ee 100644
--- a/models/repo.go
+++ b/models/repo.go
@@ -258,6 +258,17 @@ func (repo *Repository) APIFormat(mode AccessMode) *api.Repository {
 	return repo.innerAPIFormat(mode, false)
 }
 
+// GetCommitsCountCacheKey returns cache key used for commits count caching.
+func (repo *Repository) GetCommitsCountCacheKey(contextName string, isRef bool) string {
+	var prefix string
+	if isRef {
+		prefix = "ref"
+	} else {
+		prefix = "commit"
+	}
+	return fmt.Sprintf("commits-count-%d-%s-%s", repo.ID, prefix, contextName)
+}
+
 func (repo *Repository) innerAPIFormat(mode AccessMode, isParent bool) *api.Repository {
 	var parent *api.Repository
 
diff --git a/models/update.go b/models/update.go
index 62d13ce209..82369bf636 100644
--- a/models/update.go
+++ b/models/update.go
@@ -11,7 +11,7 @@ import (
 	"strings"
 
 	"code.gitea.io/git"
-
+	"code.gitea.io/gitea/modules/cache"
 	"code.gitea.io/gitea/modules/log"
 )
 
@@ -205,19 +205,26 @@ func pushUpdate(opts PushUpdateOptions) (repo *Repository, err error) {
 	var commits = &PushCommits{}
 	if strings.HasPrefix(opts.RefFullName, git.TagPrefix) {
 		// If is tag reference
+		tagName := opts.RefFullName[len(git.TagPrefix):]
 		if isDelRef {
-			err = pushUpdateDeleteTag(repo, gitRepo, opts.RefFullName[len(git.TagPrefix):])
+			err = pushUpdateDeleteTag(repo, gitRepo, tagName)
 			if err != nil {
 				return nil, fmt.Errorf("pushUpdateDeleteTag: %v", err)
 			}
 		} else {
-			err = pushUpdateAddTag(repo, gitRepo, opts.RefFullName[len(git.TagPrefix):])
+			// Clear cache for tag commit count
+			cache.Remove(repo.GetCommitsCountCacheKey(tagName, true))
+			err = pushUpdateAddTag(repo, gitRepo, tagName)
 			if err != nil {
 				return nil, fmt.Errorf("pushUpdateAddTag: %v", err)
 			}
 		}
 	} else if !isDelRef {
 		// If is branch reference
+
+		// Clear cache for branch commit count
+		cache.Remove(repo.GetCommitsCountCacheKey(opts.RefFullName[len(git.BranchPrefix):], true))
+
 		newCommit, err := gitRepo.GetCommit(opts.NewCommitID)
 		if err != nil {
 			return nil, fmt.Errorf("gitRepo.GetCommit: %v", err)