From b8a11d6d5b1d9f8cc9c7624d4c1d0873b953c139 Mon Sep 17 00:00:00 2001
From: Patrick Strawderman <pstrawderman@netflix.com>
Date: Sun, 11 Sep 2022 14:13:02 -0700
Subject: [PATCH] Override ArrayTagSet::spliterator to return Spliterator with
 exact size

Override ArrayTagSet::spliterator to return a Spliterator which reports an exact size
as well as other important characteristics such as IMMUTABLE and SORTED.
---
 .../java/com/netflix/spectator/api/ArrayTagSet.java |  9 +++++++++
 .../com/netflix/spectator/api/ArrayTagSetTest.java  | 13 +++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/spectator-api/src/main/java/com/netflix/spectator/api/ArrayTagSet.java b/spectator-api/src/main/java/com/netflix/spectator/api/ArrayTagSet.java
index 1d263fbe6..788629148 100644
--- a/spectator-api/src/main/java/com/netflix/spectator/api/ArrayTagSet.java
+++ b/spectator-api/src/main/java/com/netflix/spectator/api/ArrayTagSet.java
@@ -23,6 +23,8 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Spliterator;
+import java.util.Spliterators;
 import java.util.concurrent.ConcurrentMap;
 import java.util.function.BiPredicate;
 import java.util.function.Predicate;
@@ -482,4 +484,11 @@ private static int dedupInPlace(String[] data, int len) {
     }
     return builder.toString();
   }
+
+  @Override
+  public Spliterator<Tag> spliterator() {
+    return Spliterators.spliterator(iterator(), size(),
+            (Spliterator.ORDERED | Spliterator.SORTED | Spliterator.NONNULL
+                    | Spliterator.DISTINCT | Spliterator.IMMUTABLE));
+  }
 }
diff --git a/spectator-api/src/test/java/com/netflix/spectator/api/ArrayTagSetTest.java b/spectator-api/src/test/java/com/netflix/spectator/api/ArrayTagSetTest.java
index 36c2c8169..3ccc05fb1 100644
--- a/spectator-api/src/test/java/com/netflix/spectator/api/ArrayTagSetTest.java
+++ b/spectator-api/src/test/java/com/netflix/spectator/api/ArrayTagSetTest.java
@@ -26,6 +26,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
+import java.util.Spliterator;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -573,4 +574,16 @@ public int size() {
 
     Assertions.assertSame(tags, updated);
   }
+
+  @Test
+  public void spliteratorSizeAndCharacteristics() {
+    ArrayTagSet tags = ArrayTagSet.create("k1", "v1", "k2", "v2", "k3", "v3");
+    Spliterator<Tag> spliterator = tags.spliterator();
+    Assertions.assertTrue(spliterator.hasCharacteristics(Spliterator.IMMUTABLE));
+    Assertions.assertTrue(spliterator.hasCharacteristics(Spliterator.ORDERED));
+    Assertions.assertTrue(spliterator.hasCharacteristics(Spliterator.SORTED));
+    Assertions.assertTrue(spliterator.hasCharacteristics(Spliterator.NONNULL));
+    Assertions.assertTrue(spliterator.hasCharacteristics(Spliterator.SIZED));
+    Assertions.assertEquals(3L, spliterator.getExactSizeIfKnown());
+  }
 }