Make timeline cache date calculation smarter

pkg/hubbub/search.go

@@ -105,6 +105,14 @@ func (h *Engine) SearchIssues(ctx context.Context, org string, project string, f
 	var filtered []*Conversation
 	klog.V(1).Infof("%s/%s aggregate issue count: %d, filtering for:\n%s", org, project, len(is), toYAML(fs))
 
+	// Avoids updating PR references on a quiet repository
+	mostRecentUpdate := time.Time{}
+	for _, i := range is {
+		if i.GetUpdatedAt().After(mostRecentUpdate) {
+			mostRecentUpdate = i.GetUpdatedAt()
+		}
+	}
+
 	for _, i := range is {
 		// Inconsistency warning: issues use a list of labels, prs a list of label pointers
 		labels := []*github.Label{}
@@ -157,7 +165,7 @@ func (h *Engine) SearchIssues(ctx context.Context, org string, project string, f
 
 		// Some labels are judged by linked PR state. Ensure that they are updated to the same timestamp.
 		if len(co.PullRequestRefs) > 0 {
-			co.PullRequestRefs = h.updateLinkedPRs(ctx, co, age)
+			co.PullRequestRefs = h.updateLinkedPRs(ctx, co, mostRecentUpdate)
 		}
 
 		if !postEventsMatch(co, fs) {

pkg/hubbub/timeline.go

@@ -33,12 +33,12 @@ func (h *Engine) cachedTimeline(ctx context.Context, org string, project string,
 		return x.Timeline, nil
 	}
 
-	klog.V(1).Infof("cache miss for %s newer than %s", key, newerThan)
+	klog.Infof("cache miss for %s newer than %s", key, newerThan)
 	return h.updateTimeline(ctx, org, project, num, key)
 }
 
 func (h *Engine) updateTimeline(ctx context.Context, org string, project string, num int, key string) ([]*github.Timeline, error) {
-	klog.Infof("Downloading event timeline for %s/%s #%d", org, project, num)
+	//	klog.Infof("Downloading event timeline for %s/%s #%d", org, project, num)
 
 	opt := &github.ListOptions{
 		PerPage: 100,
@@ -118,7 +118,7 @@ func (h *Engine) addEvents(ctx context.Context, co *Conversation, timeline []*gi
 					continue
 				}
 
-				ref := h.prRef(ctx, ri, co.Seen)
+				ref := h.prRef(ctx, ri, co.Updated)
 				co.PullRequestRefs = append(co.PullRequestRefs, ref)
 				refTag := reviewStateTag(ref.ReviewState)
 				refTag.ID = fmt.Sprintf("pr-%s", refTag.ID)
@@ -139,6 +139,10 @@ func (h *Engine) prRef(ctx context.Context, pr GitHubItem, age time.Time) *Relat
 		newerThan = h.mtime(pr)
 	}
 
+	if !pr.GetClosedAt().IsZero() {
+		newerThan = pr.GetClosedAt()
+	}
+
 	klog.V(1).Infof("Creating PR reference for #%d, updated at %s(state=%s)", pr.GetNumber(), pr.GetUpdatedAt(), pr.GetState())
 
 	co := h.conversation(pr, nil, age)
@@ -172,13 +176,19 @@ func (h *Engine) prRef(ctx context.Context, pr GitHubItem, age time.Time) *Relat
 func (h *Engine) updateLinkedPRs(ctx context.Context, parent *Conversation, newerThan time.Time) []*RelatedConversation {
 	newRefs := []*RelatedConversation{}
 
+	for _, ref := range parent.PullRequestRefs {
+		if h.mtimeRef(ref).After(newerThan) {
+			newerThan = h.mtimeRef(ref)
+		}
+	}
+
 	for _, ref := range parent.PullRequestRefs {
 		if newerThan.Before(ref.Seen) || newerThan == ref.Seen {
 			newRefs = append(newRefs, ref)
 			continue
 		}
 
-		klog.Infof("updating PR ref: %s/%s #%d from %s to %s", ref.Organization, ref.Project, ref.ID, ref.Seen, newerThan)
+		klog.V(1).Infof("updating PR ref: %s/%s #%d from %s to %s", ref.Organization, ref.Project, ref.ID, ref.Seen, newerThan)
 		pr, age, err := h.cachedPR(ctx, ref.Organization, ref.Project, ref.ID, newerThan)
 		if err != nil {
 			klog.Errorf("error updating cached PR: %v", err)

pkg/hubbub/update_tracker.go

@@ -42,6 +42,26 @@ func (h *Engine) mtime(i GitHubItem) time.Time {
 	return updatedAt
 }
 
+// mtimeRef is like mtime, but for related conversations
+func (h *Engine) mtimeRef(rc *RelatedConversation) time.Time {
+	updatedAt := rc.Updated
+	key := fmt.Sprintf("%s/%s#%d", rc.Organization, rc.Project, rc.ID)
+	updateSeen := h.updatedAt[key]
+
+	if updateSeen == updatedAt {
+		return updatedAt
+	}
+
+	if updateSeen.After(updatedAt) {
+		klog.V(1).Infof("%s has updates from %s, after last update %s", key, updateSeen, updatedAt)
+		return updateSeen
+	} else if !updatedAt.IsZero() {
+		klog.V(3).Infof("%s has updates from %s, before last update %s", key, updateSeen, updatedAt)
+	}
+
+	return updatedAt
+}
+
 func updateKey(i GitHubItem) string {
 	// https://github.com/kubernetes/minikube/pull/8431
 	parts := strings.Split(i.GetHTMLURL(), "/")