Refactor for issues loadattributes of a repository (#971)

* refactor for issues loadattributes of a repository

* refactors

3 files changed, 343 insertions, 64 deletions

diff --git a/models/helper.go b/models/helper.go
new file mode 100644
index 0000000000..93acadc989
--- /dev/null
+++ b/models/helper.go
@@ -0,0 +1,21 @@
+// Copyright 2017 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
+
+func keysInt64(m map[int64]struct{}) []int64 {
+	var keys = make([]int64, 0, len(m))
+	for k, _ := range m {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+func valuesRepository(m map[int64]*Repository) []*Repository {
+	var values = make([]*Repository, 0, len(m))
+	for _, v := range m {
+		values = append(values, v)
+	}
+	return values
+}
diff --git a/models/issue.go b/models/issue.go
index b160004fd5..4677da401e 100644
--- a/models/issue.go
+++ b/models/issue.go
@@ -1128,11 +1128,8 @@ func Issues(opts *IssuesOptions) ([]*Issue, error) {
 		return nil, fmt.Errorf("Find: %v", err)
 	}
 
-	// FIXME: use IssueList to improve performance.
-	for i := range issues {
-		if err := issues[i].LoadAttributes(); err != nil {
-			return nil, fmt.Errorf("LoadAttributes [%d]: %v", issues[i].ID, err)
-		}
+	if err := IssueList(issues).LoadAttributes(); err != nil {
+		return nil, fmt.Errorf("LoadAttributes: %v", err)
 	}
 
 	return issues, nil
@@ -1399,62 +1396,3 @@ func updateIssue(e Engine, issue *Issue) error {
 func UpdateIssue(issue *Issue) error {
 	return updateIssue(x, issue)
 }
-
-// IssueList defines a list of issues
-type IssueList []*Issue
-
-func (issues IssueList) getRepoIDs() []int64 {
-	repoIDs := make([]int64, 0, len(issues))
-	for _, issue := range issues {
-		var has bool
-		for _, repoID := range repoIDs {
-			if repoID == issue.RepoID {
-				has = true
-				break
-			}
-		}
-		if !has {
-			repoIDs = append(repoIDs, issue.RepoID)
-		}
-	}
-	return repoIDs
-}
-
-func (issues IssueList) loadRepositories(e Engine) ([]*Repository, error) {
-	if len(issues) == 0 {
-		return nil, nil
-	}
-
-	repoIDs := issues.getRepoIDs()
-	rows, err := e.
-		Where("id > 0").
-		In("id", repoIDs).
-		Rows(new(Repository))
-	if err != nil {
-		return nil, fmt.Errorf("find repository: %v", err)
-	}
-	defer rows.Close()
-
-	repositories := make([]*Repository, 0, len(repoIDs))
-	repoMaps := make(map[int64]*Repository, len(repoIDs))
-	for rows.Next() {
-		var repo Repository
-		err = rows.Scan(&repo)
-		if err != nil {
-			return nil, fmt.Errorf("find repository: %v", err)
-		}
-
-		repositories = append(repositories, &repo)
-		repoMaps[repo.ID] = &repo
-	}
-
-	for _, issue := range issues {
-		issue.Repo = repoMaps[issue.RepoID]
-	}
-	return repositories, nil
-}
-
-// LoadRepositories loads issues' all repositories
-func (issues IssueList) LoadRepositories() ([]*Repository, error) {
-	return issues.loadRepositories(x)
-}
diff --git a/models/issue_list.go b/models/issue_list.go
new file mode 100644
index 0000000000..692243eff7
--- /dev/null
+++ b/models/issue_list.go
@@ -0,0 +1,320 @@
+// Copyright 2017 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
+
+import "fmt"
+
+// IssueList defines a list of issues
+type IssueList []*Issue
+
+func (issues IssueList) getRepoIDs() []int64 {
+	repoIDs := make(map[int64]struct{}, len(issues))
+	for _, issue := range issues {
+		if _, ok := repoIDs[issue.RepoID]; !ok {
+			repoIDs[issue.RepoID] = struct{}{}
+		}
+	}
+	return keysInt64(repoIDs)
+}
+
+func (issues IssueList) loadRepositories(e Engine) ([]*Repository, error) {
+	if len(issues) == 0 {
+		return nil, nil
+	}
+
+	repoIDs := issues.getRepoIDs()
+	repoMaps := make(map[int64]*Repository, len(repoIDs))
+	err := e.
+		In("id", repoIDs).
+		Find(&repoMaps)
+	if err != nil {
+		return nil, fmt.Errorf("find repository: %v", err)
+	}
+
+	for _, issue := range issues {
+		issue.Repo = repoMaps[issue.RepoID]
+	}
+	return valuesRepository(repoMaps), nil
+}
+
+// LoadRepositories loads issues' all repositories
+func (issues IssueList) LoadRepositories() ([]*Repository, error) {
+	return issues.loadRepositories(x)
+}
+
+func (issues IssueList) getPosterIDs() []int64 {
+	posterIDs := make(map[int64]struct{}, len(issues))
+	for _, issue := range issues {
+		if _, ok := posterIDs[issue.PosterID]; !ok {
+			posterIDs[issue.PosterID] = struct{}{}
+		}
+	}
+	return keysInt64(posterIDs)
+}
+
+func (issues IssueList) loadPosters(e Engine) error {
+	if len(issues) == 0 {
+		return nil
+	}
+
+	postgerIDs := issues.getPosterIDs()
+	posterMaps := make(map[int64]*User, len(postgerIDs))
+	err := e.
+		In("id", postgerIDs).
+		Find(&posterMaps)
+	if err != nil {
+		return err
+	}
+
+	for _, issue := range issues {
+		issue.Poster = posterMaps[issue.PosterID]
+	}
+	return nil
+}
+
+func (issues IssueList) getIssueIDs() []int64 {
+	var ids = make([]int64, 0, len(issues))
+	for _, issue := range issues {
+		ids = append(ids, issue.ID)
+	}
+	return ids
+}
+
+func (issues IssueList) loadLabels(e Engine) error {
+	if len(issues) == 0 {
+		return nil
+	}
+
+	type LabelIssue struct {
+		Label      *Label      `xorm:"extends"`
+		IssueLabel *IssueLabel `xorm:"extends"`
+	}
+
+	var issueLabels = make(map[int64][]*Label, len(issues)*3)
+	rows, err := e.Table("label").
+		Join("LEFT", "issue_label", "issue_label.label_id = label.id").
+		In("issue_label.issue_id", issues.getIssueIDs()).
+		Asc("label.name").
+		Rows(new(LabelIssue))
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var labelIssue LabelIssue
+		err = rows.Scan(&labelIssue)
+		if err != nil {
+			return err
+		}
+		issueLabels[labelIssue.IssueLabel.IssueID] = append(issueLabels[labelIssue.IssueLabel.IssueID], labelIssue.Label)
+	}
+
+	for _, issue := range issues {
+		issue.Labels = issueLabels[issue.ID]
+	}
+	return nil
+}
+
+func (issues IssueList) getMilestoneIDs() []int64 {
+	var ids = make(map[int64]struct{}, len(issues))
+	for _, issue := range issues {
+		if _, ok := ids[issue.MilestoneID]; !ok {
+			ids[issue.MilestoneID] = struct{}{}
+		}
+	}
+	return keysInt64(ids)
+}
+
+func (issues IssueList) loadMilestones(e Engine) error {
+	milestoneIDs := issues.getMilestoneIDs()
+	if len(milestoneIDs) == 0 {
+		return nil
+	}
+
+	milestoneMaps := make(map[int64]*Milestone, len(milestoneIDs))
+	err := e.
+		In("id", milestoneIDs).
+		Find(&milestoneMaps)
+	if err != nil {
+		return err
+	}
+
+	for _, issue := range issues {
+		issue.Milestone = milestoneMaps[issue.MilestoneID]
+	}
+	return nil
+}
+
+func (issues IssueList) getAssigneeIDs() []int64 {
+	var ids = make(map[int64]struct{}, len(issues))
+	for _, issue := range issues {
+		if _, ok := ids[issue.AssigneeID]; !ok {
+			ids[issue.AssigneeID] = struct{}{}
+		}
+	}
+	return keysInt64(ids)
+}
+
+func (issues IssueList) loadAssignees(e Engine) error {
+	assigneeIDs := issues.getAssigneeIDs()
+	if len(assigneeIDs) == 0 {
+		return nil
+	}
+
+	assigneeMaps := make(map[int64]*User, len(assigneeIDs))
+	err := e.
+		In("id", assigneeIDs).
+		Find(&assigneeMaps)
+	if err != nil {
+		return err
+	}
+
+	for _, issue := range issues {
+		issue.Assignee = assigneeMaps[issue.AssigneeID]
+	}
+	return nil
+}
+
+func (issues IssueList) getPullIssueIDs() []int64 {
+	var ids = make([]int64, 0, len(issues))
+	for _, issue := range issues {
+		if issue.IsPull && issue.PullRequest == nil {
+			ids = append(ids, issue.ID)
+		}
+	}
+	return ids
+}
+
+func (issues IssueList) loadPullRequests(e Engine) error {
+	issuesIDs := issues.getPullIssueIDs()
+	if len(issuesIDs) == 0 {
+		return nil
+	}
+
+	pullRequestMaps := make(map[int64]*PullRequest, len(issuesIDs))
+	rows, err := e.
+		In("issue_id", issuesIDs).
+		Rows(new(PullRequest))
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var pr PullRequest
+		err = rows.Scan(&pr)
+		if err != nil {
+			return err
+		}
+		pullRequestMaps[pr.IssueID] = &pr
+	}
+
+	for _, issue := range issues {
+		issue.PullRequest = pullRequestMaps[issue.ID]
+	}
+	return nil
+}
+
+func (issues IssueList) loadAttachments(e Engine) (err error) {
+	if len(issues) == 0 {
+		return nil
+	}
+
+	var attachments = make(map[int64][]*Attachment, len(issues))
+	rows, err := e.Table("attachment").
+		Join("INNER", "issue", "issue.id = attachment.issue_id").
+		In("issue.id", issues.getIssueIDs()).
+		Rows(new(Attachment))
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var attachment Attachment
+		err = rows.Scan(&attachment)
+		if err != nil {
+			return err
+		}
+		attachments[attachment.IssueID] = append(attachments[attachment.IssueID], &attachment)
+	}
+
+	for _, issue := range issues {
+		issue.Attachments = attachments[issue.ID]
+	}
+	return nil
+}
+
+func (issues IssueList) loadComments(e Engine) (err error) {
+	if len(issues) == 0 {
+		return nil
+	}
+
+	var comments = make(map[int64][]*Comment, len(issues))
+	rows, err := e.Table("comment").
+		Join("INNER", "issue", "issue.id = comment.issue_id").
+		In("issue.id", issues.getIssueIDs()).
+		Rows(new(Comment))
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var comment Comment
+		err = rows.Scan(&comment)
+		if err != nil {
+			return err
+		}
+		comments[comment.IssueID] = append(comments[comment.IssueID], &comment)
+	}
+
+	for _, issue := range issues {
+		issue.Comments = comments[issue.ID]
+	}
+	return nil
+}
+
+func (issues IssueList) loadAttributes(e Engine) (err error) {
+	if _, err = issues.loadRepositories(e); err != nil {
+		return
+	}
+
+	if err = issues.loadPosters(e); err != nil {
+		return
+	}
+
+	if err = issues.loadLabels(e); err != nil {
+		return
+	}
+
+	if err = issues.loadMilestones(e); err != nil {
+		return
+	}
+
+	if err = issues.loadAssignees(e); err != nil {
+		return
+	}
+
+	if err = issues.loadPullRequests(e); err != nil {
+		return
+	}
+
+	if err = issues.loadAttachments(e); err != nil {
+		return
+	}
+
+	if err = issues.loadComments(e); err != nil {
+		return
+	}
+
+	return nil
+}
+
+// LoadAttributes loads atrributes of the issues
+func (issues IssueList) LoadAttributes() error {
+	return issues.loadAttributes(x)
+}