From 65e585e12213d81d4509bbdb91b36bb5f3a6c5b3 Mon Sep 17 00:00:00 2001
From: Jon Chambers <jon@signal.org>
Date: Sat, 3 Oct 2020 10:42:41 -0400
Subject: [PATCH] Pause only if we're running low on queues to persist.

---
 .../textsecuregcm/storage/MessagePersister.java      | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagePersister.java b/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagePersister.java
index 0ff36ea2b..c186ad3f9 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagePersister.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/storage/MessagePersister.java
@@ -58,8 +58,12 @@ public class MessagePersister implements Managed {
         this.workerThread = new Thread(() -> {
             while (running) {
                 try {
-                    persistNextQueues(Instant.now());
-                    Util.sleep(100);
+                    final int queuesPersisted = persistNextQueues(Instant.now());
+                    queueCountHistogram.update(queuesPersisted);
+
+                    if (queuesPersisted == 0) {
+                        Util.sleep(100);
+                    }
                 } catch (final Throwable t) {
                     logger.warn("Failed to persist queues", t);
                 }
@@ -92,7 +96,7 @@ public class MessagePersister implements Managed {
     }
 
     @VisibleForTesting
-    void persistNextQueues(final Instant currentTime) {
+    int persistNextQueues(final Instant currentTime) {
         final int slot = messagesCache.getNextSlotToPersist();
 
         List<String> queuesToPersist;
@@ -118,7 +122,7 @@ public class MessagePersister implements Managed {
             queuesPersisted += queuesToPersist.size();
         } while (queuesToPersist.size() >= QUEUE_BATCH_LIMIT);
 
-        queueCountHistogram.update(queuesPersisted);
+        return queuesPersisted;
     }
 
     @VisibleForTesting