From 486244ab58cd2fdd5658d9deab2ed2eee66ea269 Mon Sep 17 00:00:00 2001
From: Samir Patel <48686912+54mir@users.noreply.github.com>
Date: Thu, 10 Jun 2021 10:48:44 -0500
Subject: [PATCH] reset cache if outdated on call

---
 api.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/api.go b/api.go
index 7bc31142e..59cde8d1f 100644
--- a/api.go
+++ b/api.go
@@ -957,7 +957,17 @@ func (api *API) Usage(ctx context.Context, remote bool) (map[string]NodeUsage, e
 
 	api.usageCache.muAssign.Lock()
 	lastUpdated := api.usageCache.lastUpdated
+	cacheN := len(api.usageCache.data[api.server.nodeID].Disk.IndexUsage)
 	api.usageCache.muAssign.Unlock()
+	holderN := len(api.holder.Indexes())
+
+	// reset cache if server was started with no data, and data has subsequently been added
+	if cacheN == 0 && holderN > 0 {
+		err := api.ResetUsageCache()
+		if err != nil {
+			api.server.logger.Infof("data detected but could not recalculate cache: %s", err)
+		}
+	}
 
 	var t time.Time
 	if lastUpdated == t {
@@ -968,6 +978,15 @@ func (api *API) Usage(ctx context.Context, remote bool) (map[string]NodeUsage, e
 		api.requestUsageOfNodes()
 	}
 
+	// triggers recalculation of cache in background, ahead of schedule, if number of indexes in
+	// cache differs from number of indexes in holder
+	if cacheN > 0 && cacheN != holderN {
+		err := api.ResetUsageCache()
+		if err != nil {
+			api.server.logger.Infof("resetting cache in background: %s", err)
+		}
+	}
+
 	return api.usageCache.data, nil
 }