KAFKA-19140 ConnectAssignor#performAssignment parameter can be replace to ConnectProtocolCompatibility (#19476)

The protocol type; for Connect assignors this is "eager", "compatible",
or "sessioned"

Since `ConnectAssignor` is an interface and the protocol parameter is
restricted to "eager", "compatible", or "sessioned", it aligns with the
existing ConnectProtocolCompatibility enum. Therefore, we can update the
code to use `ConnectProtocolCompatibility` directly.

Reviewers: Chia-Ping Tsai <chia7712@gmail.com>

connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/ConnectAssignor.java

@@ -32,12 +32,12 @@ public interface ConnectAssignor {
      * method computes an assignment of connectors and tasks among the members of the worker group.
      *
      * @param leaderId the leader of the group
-     * @param protocol the protocol type; for Connect assignors this is "eager", "compatible", or "sessioned"
+     * @param protocol the protocol type
      * @param allMemberMetadata the metadata of all the active workers of the group
      * @param coordinator the worker coordinator that runs this assignor
      * @return the assignment of connectors and tasks to workers
      */
-    Map<String, ByteBuffer> performAssignment(String leaderId, String protocol,
+    Map<String, ByteBuffer> performAssignment(String leaderId, ConnectProtocolCompatibility protocol,
                                               List<JoinGroupResponseData.JoinGroupResponseMember> allMemberMetadata,
                                               WorkerCoordinator coordinator);
 }

connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/EagerAssignor.java

@@ -52,7 +52,7 @@ public class EagerAssignor implements ConnectAssignor {
     }
 
     @Override
-    public Map<String, ByteBuffer> performAssignment(String leaderId, String protocol,
+    public Map<String, ByteBuffer> performAssignment(String leaderId, ConnectProtocolCompatibility protocol,
                                                      List<JoinGroupResponseMember> allMemberMetadata,
                                                      WorkerCoordinator coordinator) {
         log.debug("Performing task assignment");

connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/IncrementalCooperativeAssignor.java

@@ -97,7 +97,7 @@ public class IncrementalCooperativeAssignor implements ConnectAssignor {
     }
 
     @Override
-    public Map<String, ByteBuffer> performAssignment(String leaderId, String protocol,
+    public Map<String, ByteBuffer> performAssignment(String leaderId, ConnectProtocolCompatibility protocol,
                                                      List<JoinGroupResponseMember> allMemberMetadata,
                                                      WorkerCoordinator coordinator) {
         log.debug("Performing task assignment");
@@ -117,7 +117,7 @@ public class IncrementalCooperativeAssignor implements ConnectAssignor {
         log.debug("Max config offset root: {}, local snapshot config offsets root: {}",
                   maxOffset, coordinator.configSnapshot().offset());
 
-        short protocolVersion = ConnectProtocolCompatibility.fromProtocol(protocol).protocolVersion();
+        short protocolVersion = protocol.protocolVersion();
 
         Long leaderOffset = ensureLeaderConfig(maxOffset, coordinator);
         if (leaderOffset == null) {

connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/WorkerCoordinator.java

@@ -229,9 +229,10 @@ public class WorkerCoordinator extends AbstractCoordinator implements Closeable
         if (skipAssignment)
             throw new IllegalStateException("Can't skip assignment because Connect does not support static membership.");
 
-        return ConnectProtocolCompatibility.fromProtocol(protocol) == EAGER
+        ConnectProtocolCompatibility protocolCompatibility = ConnectProtocolCompatibility.fromProtocol(protocol);
-               ? eagerAssignor.performAssignment(leaderId, protocol, allMemberMetadata, this)
+        return protocolCompatibility == EAGER
-               : incrementalAssignor.performAssignment(leaderId, protocol, allMemberMetadata, this);
+               ? eagerAssignor.performAssignment(leaderId, protocolCompatibility, allMemberMetadata, this)
+               : incrementalAssignor.performAssignment(leaderId, protocolCompatibility, allMemberMetadata, this);
     }
 
     @Override

connect/runtime/src/test/java/org/apache/kafka/connect/runtime/distributed/IncrementalCooperativeAssignorTest.java

@@ -1236,7 +1236,7 @@ public class IncrementalCooperativeAssignorTest {
         when(coordinator.configSnapshot()).thenReturn(configState());
         Map<String, ByteBuffer> serializedAssignments = assignor.performAssignment(
                 leader,
-                ConnectProtocolCompatibility.COMPATIBLE.protocol(),
+                ConnectProtocolCompatibility.COMPATIBLE,
                 memberMetadata,
                 coordinator
         );
@@ -1277,7 +1277,7 @@ public class IncrementalCooperativeAssignorTest {
         when(coordinator.configSnapshot()).thenReturn(configState());
         Map<String, ByteBuffer> serializedAssignments = assignor.performAssignment(
                 leader,
-                ConnectProtocolCompatibility.SESSIONED.protocol(),
+                ConnectProtocolCompatibility.SESSIONED,
                 memberMetadata,
                 coordinator
         );