KQL plugin - Code cleanup (#116180)

x-pack/plugin/kql/build.gradle

@@ -17,7 +17,7 @@ base {
 
 dependencies {
   compileOnly project(path: xpackModule('core'))
-  compileOnly "org.antlr:antlr4-runtime:${versions.antlr4}"
+  api "org.antlr:antlr4-runtime:${versions.antlr4}"
 
   testImplementation "org.antlr:antlr4-runtime:${versions.antlr4}"
   testImplementation project(':test:framework')

x-pack/plugin/kql/licenses/antlr4-runtime-LICENSE.txt

@@ -0,0 +1,26 @@
+[The "BSD license"]
+Copyright (c) 2015 Terence Parr, Sam Harwell
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+ 1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+ 3. The name of the author may not be used to endorse or promote products
+    derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

x-pack/plugin/kql/src/main/java/module-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+module org.elasticsearch.kql {
+    requires org.elasticsearch.server;
+    requires org.elasticsearch.xcontent;
+    requires org.antlr.antlr4.runtime;
+    requires org.elasticsearch.base;
+    requires org.apache.lucene.queryparser;
+    requires org.elasticsearch.logging;
+    requires org.apache.lucene.core;
+
+    exports org.elasticsearch.xpack.kql;
+    exports org.elasticsearch.xpack.kql.parser;
+}

x-pack/plugin/kql/src/main/java/org/elasticsearch/xpack/kql/parser/ParserUtils.java

@@ -12,11 +12,11 @@
 import org.antlr.v4.runtime.tree.ParseTree;
 import org.antlr.v4.runtime.tree.ParseTreeVisitor;
 import org.antlr.v4.runtime.tree.TerminalNode;
-import org.apache.logging.log4j.util.Strings;
 import org.apache.lucene.queryparser.classic.QueryParser;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 
 /**
  * Utility class for parsing and processing KQL expressions.
@@ -211,15 +211,15 @@ private static boolean isEscapedKeywordSequence(String input, int startIndex) {
         if (startIndex + 1 >= input.length()) {
             return false;
         }
-        String remaining = Strings.toRootLowerCase(input.substring(startIndex));
+        String remaining = input.substring(startIndex).toLowerCase(Locale.ROOT);
         return remaining.startsWith("and") || remaining.startsWith("or") || remaining.startsWith("not");
     }
 
     private static String handleKeywordSequence(String input, int startIndex) {
         String remaining = input.substring(startIndex);
-        if (Strings.toRootLowerCase(remaining).startsWith("and")) return remaining.substring(0, 3);
-        if (Strings.toRootLowerCase(remaining).startsWith("or")) return remaining.substring(0, 2);
-        if (Strings.toRootLowerCase(remaining).startsWith("not")) return remaining.substring(0, 3);
+        if (remaining.toLowerCase(Locale.ROOT).startsWith("and")) return remaining.substring(0, 3);
+        if (remaining.toLowerCase(Locale.ROOT).startsWith("or")) return remaining.substring(0, 2);
+        if (remaining.toLowerCase(Locale.ROOT).startsWith("not")) return remaining.substring(0, 3);
         return "";
     }