From be176f98addd5d5bb7bd3e259b9f5edc78d70a5e Mon Sep 17 00:00:00 2001
From: Jonathan Klabunde Tomer <125505367+jkt-signal@users.noreply.github.com>
Date: Tue, 2 May 2023 13:03:49 -0700
Subject: [PATCH] metric for take-prekey yielding an empty result

---
 .../java/org/whispersystems/textsecuregcm/storage/Keys.java    | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/service/src/main/java/org/whispersystems/textsecuregcm/storage/Keys.java b/service/src/main/java/org/whispersystems/textsecuregcm/storage/Keys.java
index 9f1a99276..b9a35a268 100644
--- a/service/src/main/java/org/whispersystems/textsecuregcm/storage/Keys.java
+++ b/service/src/main/java/org/whispersystems/textsecuregcm/storage/Keys.java
@@ -9,6 +9,7 @@ import com.google.common.annotations.VisibleForTesting;
 import io.micrometer.core.instrument.DistributionSummary;
 import io.micrometer.core.instrument.Metrics;
 import io.micrometer.core.instrument.Timer;
+import io.micrometer.core.instrument.Counter;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
@@ -46,6 +47,7 @@ public class Keys extends AbstractDynamoDbStore {
   private static final Timer DELETE_KEYS_FOR_ACCOUNT_TIMER = Metrics.timer(name(Keys.class, "deleteKeysForAccount"));
   private static final DistributionSummary CONTESTED_KEY_DISTRIBUTION = Metrics.summary(name(Keys.class, "contestedKeys"));
   private static final DistributionSummary KEY_COUNT_DISTRIBUTION = Metrics.summary(name(Keys.class, "keyCount"));
+  private static final Counter KEYS_EMPTY_TAKE_COUNTER = Metrics.counter(name(Keys.class, "takeKeyEmpty"));
 
   public Keys(final DynamoDbClient dynamoDB, final String tableName) {
     super(dynamoDB);
@@ -104,6 +106,7 @@ public class Keys extends AbstractDynamoDbStore {
           contestedKeys++;
         }
 
+        KEYS_EMPTY_TAKE_COUNTER.increment();
         return Optional.empty();
       } finally {
         CONTESTED_KEY_DISTRIBUTION.record(contestedKeys);