From b3130056f5a38d571225a279a732d4edb31c13c7 Mon Sep 17 00:00:00 2001
From: Steve Loughran <stevel@cloudera.com>
Date: Tue, 18 Jul 2023 14:23:19 +0100
Subject: [PATCH] HADOOP-18808. LogExactlyOnce to add a debug() method (#5850)

Contributed by Steve Loughran
---
 .../org/apache/hadoop/fs/store/LogExactlyOnce.java    | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/store/LogExactlyOnce.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/store/LogExactlyOnce.java
index 04cd5111e9..e32c0e424a 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/store/LogExactlyOnce.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/store/LogExactlyOnce.java
@@ -49,4 +49,15 @@ public void error(String format, Object...args) {
       log.error(format, args);
     }
   }
+
+  /**
+   * Log at DEBUG if nothing has been logged yet.
+   * @param format format string
+   * @param args arguments
+   */
+  public void debug(String format, Object...args) {
+    if (!logged.getAndSet(true)) {
+      log.debug(format, args);
+    }
+  }
 }