Ensure source filtering automatons are only compiled once (#20857)

This change adds a overloaded `XContentMapValues#filter` method that returns
a function enclosing the compiled automatons that can be reused across filter
calls. This for instance prevents compiling automatons over and over again when
hits are filtered or in the SourceFieldMapper for each document.

Closes #20839

1 files changed, 21 insertions, 20 deletions

diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/metrics/TopHitsTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/metrics/TopHitsTests.java
index 3f2b4c4462..98e2833903 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/metrics/TopHitsTests.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/metrics/TopHitsTests.java
@@ -107,26 +107,27 @@ public class TopHitsTests extends BaseAggregationTestCase<TopHitsAggregationBuil
                 excludes[i] = randomAsciiOfLengthBetween(5, 20);
             }
             switch (branch) {
-            case 0:
-                fetchSourceContext = new FetchSourceContext(randomBoolean());
-                break;
-            case 1:
-                fetchSourceContext = new FetchSourceContext(includes, excludes);
-                break;
-            case 2:
-                fetchSourceContext = new FetchSourceContext(randomAsciiOfLengthBetween(5, 20), randomAsciiOfLengthBetween(5, 20));
-                break;
-            case 3:
-                fetchSourceContext = new FetchSourceContext(true, includes, excludes);
-                break;
-            case 4:
-                fetchSourceContext = new FetchSourceContext(includes);
-                break;
-            case 5:
-                fetchSourceContext = new FetchSourceContext(randomAsciiOfLengthBetween(5, 20));
-                break;
-            default:
-                throw new IllegalStateException();
+                case 0:
+                    fetchSourceContext = new FetchSourceContext(randomBoolean());
+                    break;
+                case 1:
+                    fetchSourceContext = new FetchSourceContext(true, includes, excludes);
+                    break;
+                case 2:
+                    fetchSourceContext = new FetchSourceContext(true, new String[]{randomAsciiOfLengthBetween(5, 20)},
+                        new String[]{randomAsciiOfLengthBetween(5, 20)});
+                    break;
+                case 3:
+                    fetchSourceContext = new FetchSourceContext(true, includes, excludes);
+                    break;
+                case 4:
+                    fetchSourceContext = new FetchSourceContext(true, includes, null);
+                    break;
+                case 5:
+                    fetchSourceContext = new FetchSourceContext(true, new String[] {randomAsciiOfLengthBetween(5, 20)}, null);
+                    break;
+                default:
+                    throw new IllegalStateException();
             }
             factory.fetchSource(fetchSourceContext);
         }