From e07499a771afbc335e1f7f08a82f8197e5826939 Mon Sep 17 00:00:00 2001
From: Robson Araujo <robson.araujo@glean.com>
Date: Tue, 5 Nov 2024 11:08:13 -0800
Subject: [PATCH] Improve performance for resolving derived fields (#16564)

Doing the type check before the string comparison makes it much faster to resolve derived fields.

Signed-off-by: Robson Araujo <robson.araujo@glean.com>
---
 .../opensearch/index/mapper/DefaultDerivedFieldResolver.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/src/main/java/org/opensearch/index/mapper/DefaultDerivedFieldResolver.java b/server/src/main/java/org/opensearch/index/mapper/DefaultDerivedFieldResolver.java
index 4dd17703b6f55..1e8ef4134a8e7 100644
--- a/server/src/main/java/org/opensearch/index/mapper/DefaultDerivedFieldResolver.java
+++ b/server/src/main/java/org/opensearch/index/mapper/DefaultDerivedFieldResolver.java
@@ -72,7 +72,7 @@ public Set<String> resolvePattern(String pattern) {
         Set<String> derivedFields = new HashSet<>();
         if (queryShardContext != null && queryShardContext.getMapperService() != null) {
             for (MappedFieldType fieldType : queryShardContext.getMapperService().fieldTypes()) {
-                if (Regex.simpleMatch(pattern, fieldType.name()) && fieldType instanceof DerivedFieldType) {
+                if (fieldType instanceof DerivedFieldType && Regex.simpleMatch(pattern, fieldType.name())) {
                     derivedFields.add(fieldType.name());
                 }
             }