Improve performance of dashboard (#4977)

models/issue_comment_list.go

@@ -0,0 +1,58 @@
+// Copyright 2018 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 models
+
+// CommentList defines a list of comments
+type CommentList []*Comment
+
+func (comments CommentList) getPosterIDs() []int64 {
+	commentIDs := make(map[int64]struct{}, len(comments))
+	for _, comment := range comments {
+		if _, ok := commentIDs[comment.PosterID]; !ok {
+			commentIDs[comment.PosterID] = struct{}{}
+		}
+	}
+	return keysInt64(commentIDs)
+}
+
+// LoadPosters loads posters from database
+func (comments CommentList) LoadPosters() error {
+	return comments.loadPosters(x)
+}
+
+func (comments CommentList) loadPosters(e Engine) error {
+	if len(comments) == 0 {
+		return nil
+	}
+
+	posterIDs := comments.getPosterIDs()
+	posterMaps := make(map[int64]*User, len(posterIDs))
+	var left = len(posterIDs)
+	for left > 0 {
+		var limit = defaultMaxInSize
+		if left < limit {
+			limit = left
+		}
+		err := e.
+			In("id", posterIDs[:limit]).
+			Find(&posterMaps)
+		if err != nil {
+			return err
+		}
+		left = left - limit
+		posterIDs = posterIDs[limit:]
+	}
+
+	for _, comment := range comments {
+		if comment.PosterID <= 0 {
+			continue
+		}
+		var ok bool
+		if comment.Poster, ok = posterMaps[comment.PosterID]; !ok {
+			comment.Poster = NewGhostUser()
+		}
+	}
+	return nil
+}