From f0ff385c7cf2208de7070f4c58398d0f7858d165 Mon Sep 17 00:00:00 2001
From: Justin Bertram <jbertram@apache.org>
Date: Mon, 29 Aug 2022 14:28:06 -0500
Subject: [PATCH] ARTEMIS-3962 porting changes from AMQ-9052

Optimisations to improve the efficiency of the selectors.
---
 .../selector/filter/ComparisonExpression.java | 25 +++++++++++++++++++
 .../selector/filter/UnaryExpression.java      | 10 ++++++++
 2 files changed, 35 insertions(+)

diff --git a/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/ComparisonExpression.java b/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/ComparisonExpression.java
index 0cfd122b33..13f2f5b336 100755
--- a/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/ComparisonExpression.java
+++ b/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/ComparisonExpression.java
@@ -232,6 +232,31 @@ public abstract class ComparisonExpression extends BinaryExpression implements B
             return Boolean.FALSE;
          }
 
+         @Override
+         public boolean matches(Filterable message) throws FilterException {
+            Object lv = left.evaluate(message);
+            Object rv = right.evaluate(message);
+
+            // If one of the values is null
+            if (lv == null ^ rv == null) {
+               return false;
+            }
+            if (lv == rv || lv.equals(rv)) {
+               return true;
+            }
+            if (lv.getClass() == rv.getClass()) {
+               // same class, but 'equals' return false, and they are not the same object
+               // there is no point in doing 'compare'
+               // this case happens often while comparing non equals Strings
+               return false;
+            }
+            if (lv instanceof Comparable && rv instanceof Comparable) {
+               Boolean compareResult = compare((Comparable) lv, (Comparable) rv);
+               return compareResult != null && compareResult;
+            }
+            return false;
+         }
+
          @Override
          protected boolean asBoolean(int answer) {
             return answer == 0;
diff --git a/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/UnaryExpression.java b/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/UnaryExpression.java
index e70de83861..265d089b6c 100755
--- a/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/UnaryExpression.java
+++ b/artemis-selector/src/main/java/org/apache/activemq/artemis/selector/filter/UnaryExpression.java
@@ -139,6 +139,16 @@ public abstract class UnaryExpression implements Expression {
             return !lvalue.booleanValue();
          }
 
+         @Override
+         public boolean matches(Filterable message) throws FilterException {
+            Boolean lvalue = (Boolean) right.evaluate(message);
+            if (lvalue == null) {
+               // NOT NULL returns NULL that eventually fails the selector
+               return false;
+            }
+            return !lvalue;
+         }
+
          @Override
          public String getExpressionSymbol() {
             return "NOT";