Write warn log if Filter is empty; Add comments (opensearch-project#1…

…2067) Signed-off-by: Robin Friedmann <[email protected]>
robinf95 · Feb 5, 2024 · c154bd7 · c154bd7
1 parent d0bb649
commit c154bd7
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/libs/core/src/main/java/org/opensearch/core/xcontent/filtering/FilterPath.java b/libs/core/src/main/java/org/opensearch/core/xcontent/filtering/FilterPath.java
@@ -32,6 +32,8 @@
 
 package org.opensearch.core.xcontent.filtering;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.opensearch.common.Glob;
 
 import java.util.ArrayList;
@@ -46,7 +48,7 @@
 public class FilterPath {
 
     static final FilterPath EMPTY = new FilterPath();
-
+    private static final Logger logger = LogManager.getLogger(FilterPath.class);
     private final String filter;
     private final String segment;
     private final FilterPath next;
@@ -103,17 +105,22 @@ public static FilterPath[] compile(Set<String> filters) {
                 filter = filter.trim();
                 if (filter.length() > 0) {
                     paths.add(parse(filter));
+                } else {
+                    logger.warn("Filter is empty!");
                 }
             }
         }
         return paths.toArray(new FilterPath[0]);
     }
 
     private static FilterPath parse(final String filter) {
+        // Split the filter into segments using a regex
+        // that avoids splitting escaped dots.
         String[] segments = filter.split("(?<!\\\\)\\.");
         FilterPath next = EMPTY;
 
         for (int i = segments.length - 1; i >= 0; i--) {
+            // Replace escaped dots with actual dots in the current segment.
             String segment = segments[i].replaceAll("\\\\.", ".");
             next = new FilterPath(filter, segment, next);
         }

diff --git a/libs/core/src/test/java/org/opensearch/core/xcontent/filtering/FilterPathTests.java b/libs/core/src/test/java/org/opensearch/core/xcontent/filtering/FilterPathTests.java
@@ -32,10 +32,10 @@
 
 package org.opensearch.core.xcontent.filtering;
 
-import java.util.HashSet;
 import org.opensearch.common.util.set.Sets;
 import org.opensearch.test.OpenSearchTestCase;
 
+import java.util.HashSet;
 import java.util.Set;
 
 import static java.util.Collections.singleton;