From c4b8ccfda19c10d92270af337ffa4dc1e5413a3b Mon Sep 17 00:00:00 2001
From: Aleksandr Nogikh <nogikh@google.com>
Date: Mon, 19 Sep 2022 13:26:03 +0000
Subject: dashboard: solve the N+1 query problem

Do not query crashes from inside needReport, because it's not really
needed there and because we query it for each opened bug on the main
page.
---
 dashboard/app/main.go      |  2 +-
 dashboard/app/reporting.go | 16 ++++++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/dashboard/app/main.go b/dashboard/app/main.go
index 5074f118b..f8e2715eb 100644
--- a/dashboard/app/main.go
+++ b/dashboard/app/main.go
@@ -888,7 +888,7 @@ func createUIBug(c context.Context, bug *Bug, state *ReportingState, managers []
 	var reported time.Time
 	var err error
 	if bug.Status == BugStatusOpen {
-		_, _, _, _, reportingIdx, status, link, err = needReport(c, "", state, bug)
+		_, _, reportingIdx, status, link, err = needReport(c, "", state, bug)
 		reported = bug.Reporting[reportingIdx].Reported
 		if err != nil {
 			status = err.Error()
diff --git a/dashboard/app/reporting.go b/dashboard/app/reporting.go
index 641af4e51..1231078c8 100644
--- a/dashboard/app/reporting.go
+++ b/dashboard/app/reporting.go
@@ -75,10 +75,16 @@ func reportingPollBugs(c context.Context, typ string) []*dashapi.BugReport {
 
 func handleReportBug(c context.Context, typ string, state *ReportingState, bug *Bug) (
 	*dashapi.BugReport, error) {
-	reporting, bugReporting, crash, crashKey, _, _, _, err := needReport(c, typ, state, bug)
+	reporting, bugReporting, _, _, _, err := needReport(c, typ, state, bug)
 	if err != nil || reporting == nil {
 		return nil, err
 	}
+	crash, crashKey, err := findCrashForBug(c, bug)
+	if err != nil {
+		return nil, err
+	} else if crash == nil {
+		return nil, fmt.Errorf("no crashes")
+	}
 	rep, err := createBugReport(c, bug, crash, crashKey, bugReporting, reporting)
 	if err != nil {
 		return nil, err
@@ -88,8 +94,8 @@ func handleReportBug(c context.Context, typ string, state *ReportingState, bug *
 }
 
 func needReport(c context.Context, typ string, state *ReportingState, bug *Bug) (
-	reporting *Reporting, bugReporting *BugReporting, crash *Crash,
-	crashKey *db.Key, reportingIdx int, status, link string, err error) {
+	reporting *Reporting, bugReporting *BugReporting, reportingIdx int,
+	status, link string, err error) {
 	reporting, bugReporting, reportingIdx, status, err = currentReporting(c, bug)
 	if err != nil || reporting == nil {
 		return
@@ -124,9 +130,7 @@ func needReport(c context.Context, typ string, state *ReportingState, bug *Bug)
 		reporting, bugReporting = nil, nil
 		return
 	}
-
-	crash, crashKey, err = findCrashForBug(c, bug)
-	if err != nil {
+	if bug.NumCrashes == 0 {
 		status = fmt.Sprintf("%v: no crashes!", reporting.DisplayTitle)
 		reporting, bugReporting = nil, nil
 		return
-- 
cgit mrf-deployment