Performance optimization for pull request files loading comments attachments (#33585) (#33592)

Backport #33585 by @lunny

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/issues/comment_code.go

@@ -86,8 +86,10 @@ func findCodeComments(ctx context.Context, opts FindCommentsOptions, issue *Issu
 			ids = append(ids, comment.ReviewID)
 		}
 	}
-	if err := e.In("id", ids).Find(&reviews); err != nil {
+	if len(ids) > 0 {
-		return nil, err
+		if err := e.In("id", ids).Find(&reviews); err != nil {
+			return nil, err
+		}
 	}
 
 	n := 0

routers/web/repo/pull.go

@@ -785,18 +785,18 @@ func viewPullFiles(ctx *context.Context, specifiedStartCommit, specifiedEndCommi
 		return
 	}
 
+	allComments := issues_model.CommentList{}
 	for _, file := range diff.Files {
 		for _, section := range file.Sections {
 			for _, line := range section.Lines {
-				for _, comment := range line.Comments {
+				allComments = append(allComments, line.Comments...)
-					if err := comment.LoadAttachments(ctx); err != nil {
-						ctx.ServerError("LoadAttachments", err)
-						return
-					}
-				}
 			}
 		}
 	}
+	if err := allComments.LoadAttachments(ctx); err != nil {
+		ctx.ServerError("LoadAttachments", err)
+		return
+	}
 
 	pb, err := git_model.GetFirstMatchProtectedBranchRule(ctx, pull.BaseRepoID, pull.BaseBranch)
 	if err != nil {

services/gitdiff/gitdiff.go

@@ -80,7 +80,7 @@ type DiffLine struct {
 	Match       int
 	Type        DiffLineType
 	Content     string
-	Comments    []*issues_model.Comment
+	Comments    issues_model.CommentList
 	SectionInfo *DiffLineSectionInfo
 }