From 950fb7da618fb178c70c3fbd0a8021ee07048d80 Mon Sep 17 00:00:00 2001
From: Terry Wilson <tmwilson@google.com>
Date: Mon, 10 Oct 2022 13:38:03 -0700
Subject: [PATCH] rls: Migrate RLS LB to acceptResolvedAddresses() (#9612)

Second attempt at this, now with the understanding that RLS actually can
accept empty address lists.

This seems contrary to the behavior this LB advertizes with the canHandleEmptyAddressListFromNameResolution() method. This method is not overridden, so the default response of false is preserved. Empty address lists are supported though, and the parent LB never called the canHandleEmptyAddressListFromNameResolution() method.
---
 rls/src/main/java/io/grpc/rls/RlsLoadBalancer.java     | 3 ++-
 rls/src/test/java/io/grpc/rls/RlsLoadBalancerTest.java | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/rls/src/main/java/io/grpc/rls/RlsLoadBalancer.java b/rls/src/main/java/io/grpc/rls/RlsLoadBalancer.java
index 2aac96cadc..5d4e749087 100644
--- a/rls/src/main/java/io/grpc/rls/RlsLoadBalancer.java
+++ b/rls/src/main/java/io/grpc/rls/RlsLoadBalancer.java
@@ -49,7 +49,7 @@ final class RlsLoadBalancer extends LoadBalancer {
   }
 
   @Override
-  public void handleResolvedAddresses(ResolvedAddresses resolvedAddresses) {
+  public boolean acceptResolvedAddresses(ResolvedAddresses resolvedAddresses) {
     logger.log(ChannelLogLevel.DEBUG, "Received resolution result: {0}", resolvedAddresses);
     LbPolicyConfiguration lbPolicyConfiguration =
         (LbPolicyConfiguration) resolvedAddresses.getLoadBalancingPolicyConfig();
@@ -78,6 +78,7 @@ final class RlsLoadBalancer extends LoadBalancer {
       //  not required.
       this.lbPolicyConfiguration = lbPolicyConfiguration;
     }
+    return true;
   }
 
   @Override
diff --git a/rls/src/test/java/io/grpc/rls/RlsLoadBalancerTest.java b/rls/src/test/java/io/grpc/rls/RlsLoadBalancerTest.java
index b469ee6fe3..9f95200d50 100644
--- a/rls/src/test/java/io/grpc/rls/RlsLoadBalancerTest.java
+++ b/rls/src/test/java/io/grpc/rls/RlsLoadBalancerTest.java
@@ -445,7 +445,7 @@ public class RlsLoadBalancerTest {
     ConfigOrError parsedConfigOrError =
         provider.parseLoadBalancingPolicyConfig(getServiceConfig());
     assertThat(parsedConfigOrError.getConfig()).isNotNull();
-    rlsLb.handleResolvedAddresses(ResolvedAddresses.newBuilder()
+    rlsLb.acceptResolvedAddresses(ResolvedAddresses.newBuilder()
         .setAddresses(ImmutableList.of(new EquivalentAddressGroup(mock(SocketAddress.class))))
         .setLoadBalancingPolicyConfig(parsedConfigOrError.getConfig())
         .build());