Github user jbertram commented on a diff in the pull request:
https://github.com/apache/activemq-artemis/pull/2228#discussion_r208790685
--- Diff:
artemis-selector/src/main/java/org/apache/activemq/artemis/selector/impl/SelectorParser.java
---
@@ -80,11 +78,15 @@ public static BooleanExpression parse(String sql)
throws FilterException {
StrictParser parser = new StrictParser(new
StringReader(actual));
e = parser.JmsSelector();
}
- cache.put(sql, e);
+ synchronized (cache) {
--- End diff --
My guess is that the LRUCache is there mainly because it was used in Apollo
and basically the whole selector implementation from Apollo was ported over to
the Artemis code-base during the Apache donation process. It is a simple
mitigation against excessive parsing, but perhaps it is premature optimization
as well. I don't see a big problem with pulling it out. It would simplify the
code-base a bit and eliminate the threading problem as well. I certainly don't
see any reason to invest resources into a more
robust/elegant/higher-performance cache implementation.
---