From 4bf54bc2985154718c44c29728d0a061fb6e1591 Mon Sep 17 00:00:00 2001
From: David Mollitor <dam6923@gmail.com>
Date: Mon, 3 Nov 2025 10:49:39 -0500
Subject: [PATCH] Remove redundant sorted check before Arrays.sort()

Arrays.sort() uses TimSort which is already optimized for sorted arrays
with O(n) best-case complexity. The pre-sort check adds unnecessary
overhead for unsorted data (common case) without significant benefit.

Simplified toKeyValues() and toTags() by removing isSortedSet() method
and relying on TimSort's adaptive sorting behavior.

Signed-off-by: David Mollitor <dam6923@gmail.com>
---
 .../java/io/micrometer/common/KeyValues.java  | 28 ++-----------------
 .../io/micrometer/core/instrument/Tags.java   | 28 ++-----------------
 2 files changed, 4 insertions(+), 52 deletions(-)

diff --git a/micrometer-commons/src/main/java/io/micrometer/common/KeyValues.java b/micrometer-commons/src/main/java/io/micrometer/common/KeyValues.java
index 2d0eda45c9..fe9154af53 100644
--- a/micrometer-commons/src/main/java/io/micrometer/common/KeyValues.java
+++ b/micrometer-commons/src/main/java/io/micrometer/common/KeyValues.java
@@ -63,27 +63,6 @@ private KeyValues(KeyValue[] sortedSet, int length) {
         this.length = length;
     }
 
-    /**
-     * Checks if the first {@code length} elements of the {@code keyValues} array form an
-     * ordered set of key-values.
-     * @param keyValues an array of key-values.
-     * @param length the number of elements to check.
-     * @return {@code true} if the first {@code length} elements of {@code keyValues} form
-     * an ordered set; otherwise {@code false}.
-     */
-    private static boolean isSortedSet(KeyValue[] keyValues, int length) {
-        if (length > keyValues.length) {
-            return false;
-        }
-        for (int i = 0; i < length - 1; i++) {
-            int cmp = keyValues[i].compareTo(keyValues[i + 1]);
-            if (cmp >= 0) {
-                return false;
-            }
-        }
-        return true;
-    }
-
     /**
      * Constructs a {@code KeyValues} collection from the provided array of key-values.
      * @param keyValues an array of {@code KeyValue} objects, possibly unordered and/or
@@ -92,11 +71,8 @@ private static boolean isSortedSet(KeyValue[] keyValues, int length) {
      * key-values.
      */
     private static KeyValues toKeyValues(KeyValue[] keyValues) {
-        int len = keyValues.length;
-        if (!isSortedSet(keyValues, len)) {
-            Arrays.sort(keyValues);
-            len = dedup(keyValues);
-        }
+        Arrays.sort(keyValues);
+        int len = dedup(keyValues);
         return new KeyValues(keyValues, len);
     }
 
diff --git a/micrometer-core/src/main/java/io/micrometer/core/instrument/Tags.java b/micrometer-core/src/main/java/io/micrometer/core/instrument/Tags.java
index d84971e0de..84d6d30b14 100644
--- a/micrometer-core/src/main/java/io/micrometer/core/instrument/Tags.java
+++ b/micrometer-core/src/main/java/io/micrometer/core/instrument/Tags.java
@@ -60,27 +60,6 @@ private Tags(Tag[] sortedSet, int length) {
         this.length = length;
     }
 
-    /**
-     * Checks if the first {@code length} elements of the {@code tags} array form an
-     * ordered set of tags.
-     * @param tags an array of tags.
-     * @param length the number of elements to check.
-     * @return {@code true} if the first {@code length} elements of {@code tags} form an
-     * ordered set; otherwise {@code false}.
-     */
-    private static boolean isSortedSet(Tag[] tags, int length) {
-        if (length > tags.length) {
-            return false;
-        }
-        for (int i = 0; i < length - 1; i++) {
-            int cmp = tags[i].compareTo(tags[i + 1]);
-            if (cmp >= 0) {
-                return false;
-            }
-        }
-        return true;
-    }
-
     /**
      * Constructs a {@code Tags} collection from the provided array of tags.
      * @param tags an array of {@code Tag} objects, possibly unordered and/or containing
@@ -88,11 +67,8 @@ private static boolean isSortedSet(Tag[] tags, int length) {
      * @return a {@code Tags} instance with a deduplicated and ordered set of tags.
      */
     private static Tags toTags(Tag[] tags) {
-        int len = tags.length;
-        if (!isSortedSet(tags, len)) {
-            Arrays.sort(tags);
-            len = dedup(tags);
-        }
+        Arrays.sort(tags);
+        int len = dedup(tags);
         return new Tags(tags, len);
     }