ZOOKEEPER-4492: Merge readOnly field into ConnectRequest and Response

According to [this comment in ZOOKEEPER-102](https://issues.apache.org/jira/browse/ZOOKEEPER-102?focusedCommentId=16977000&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16977000) I introduce a `Protocol` abstraction and going to moving all wire protocol concept into `cnxn` and this scope, so that client and server's business logics handle only deserialized/real record.

cc eolivelli maoling Randgalt

This supersedes #1832.

Author: tison <wander4096@gmail.com>

Reviewers: Enrico Olivelli <eolivelli@apache.org>, Mate Szalay-Beko <symat@apache.org>

Closes #1837 from tisonkun/protocol

7 files changed, 10 insertions, 33 deletions

diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/MockPacket.java b/zookeeper-server/src/test/java/org/apache/zookeeper/MockPacket.java
index 9d880fd39..e4e6548ea 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/MockPacket.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/MockPacket.java
@@ -35,16 +35,6 @@ public class MockPacket extends ClientCnxn.Packet {
         super(requestHeader, replyHeader, request, response, watchRegistration);
     }
 
-    public MockPacket(
-        RequestHeader requestHeader,
-        ReplyHeader replyHeader,
-        Record request,
-        Record response,
-        WatchRegistration watchRegistration,
-        boolean readOnly) {
-        super(requestHeader, replyHeader, request, response, watchRegistration, readOnly);
-    }
-
     public ByteBuffer createAndReturnBB() {
         createBB();
         return this.bb;
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerCreationTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerCreationTest.java
index 03f6113de..ac46b4e0f 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerCreationTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerCreationTest.java
@@ -48,7 +48,6 @@ public class ZooKeeperServerCreationTest {
         zks.setZKDatabase(new ZKDatabase(fileTxnSnapLog));
         zks.createSessionTracker();
 
-        ServerCnxnFactory cnxnFactory = ServerCnxnFactory.createFactory();
         ServerCnxn cnxn = new MockServerCnxn();
 
         ConnectRequest connReq = new ConnectRequest();
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerTest.java
index bd1412069..4d41dac1a 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/server/ZooKeeperServerTest.java
@@ -162,10 +162,9 @@ public class ZooKeeperServerTest extends ZKTestCase {
         output.put((byte) 1);
         output.flip();
 
-        ServerCnxn.CloseRequestException e = assertThrows(ServerCnxn.CloseRequestException.class, () -> {
-            final NIOServerCnxn nioServerCnxn = mock(NIOServerCnxn.class);
-            zooKeeperServer.processConnectRequest(nioServerCnxn, output);
-        });
+        ServerCnxn.CloseRequestException e = assertThrows(
+                ServerCnxn.CloseRequestException.class,
+                () -> zooKeeperServer.processConnectRequest(new MockServerCnxn(), output));
         assertEquals(e.getReason(), ServerCnxn.DisconnectReason.CLIENT_ZXID_AHEAD);
     }
 
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/ReadOnlyZooKeeperServerTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/ReadOnlyZooKeeperServerTest.java
index 165dbdca1..3ee6016f0 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/ReadOnlyZooKeeperServerTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/ReadOnlyZooKeeperServerTest.java
@@ -22,7 +22,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.mock;
 import java.nio.ByteBuffer;
-import org.apache.zookeeper.server.NIOServerCnxn;
+import org.apache.zookeeper.server.MockServerCnxn;
 import org.apache.zookeeper.server.ServerCnxn;
 import org.apache.zookeeper.server.ZKDatabase;
 import org.apache.zookeeper.server.ZooKeeperServer;
@@ -55,8 +55,7 @@ public class ReadOnlyZooKeeperServerTest {
         output.flip();
 
         ServerCnxn.CloseRequestException e = assertThrows(ServerCnxn.CloseRequestException.class, () -> {
-            final NIOServerCnxn nioServerCnxn = mock(NIOServerCnxn.class);
-            readOnlyZooKeeperServer.processConnectRequest(nioServerCnxn, output);
+            readOnlyZooKeeperServer.processConnectRequest(new MockServerCnxn(), output);
         });
         assertEquals(e.getReason(), ServerCnxn.DisconnectReason.NOT_READ_ONLY_CLIENT);
     }
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/WatchLeakTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/WatchLeakTest.java
index 70f1844ea..2fadcf36f 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/WatchLeakTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/server/quorum/WatchLeakTest.java
@@ -255,8 +255,8 @@ public class WatchLeakTest {
         Random r = new Random(SESSION_ID ^ superSecret);
         byte[] p = new byte[16];
         r.nextBytes(p);
-        ConnectRequest conReq = new ConnectRequest(0, 1L, 30000, SESSION_ID, p);
-        MockPacket packet = new MockPacket(null, null, conReq, null, null, false);
+        ConnectRequest conReq = new ConnectRequest(0, 1L, 30000, SESSION_ID, p, false);
+        MockPacket packet = new MockPacket(null, null, conReq, null, null);
         return packet.createAndReturnBB();
     }
 
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/test/MaxCnxnsTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/test/MaxCnxnsTest.java
index f7c7a9534..0034fd6d0 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/test/MaxCnxnsTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/test/MaxCnxnsTest.java
@@ -51,18 +51,16 @@ public class MaxCnxnsTest extends ClientBase {
         }
 
         public void run() {
-            SocketChannel sChannel = null;
-            try {
+            try (SocketChannel sChannel = SocketChannel.open()) {
                 /*
                  * For future unwary socket programmers: although connect 'blocks' it
                  * does not require an accept on the server side to return. Therefore
                  * you can not assume that all the sockets are connected at the end of
                  * this for loop.
                  */
-                sChannel = SocketChannel.open();
                 sChannel.connect(new InetSocketAddress(host, port));
                 // Construct a connection request
-                ConnectRequest conReq = new ConnectRequest(0, 0, 10000, 0, "password".getBytes());
+                ConnectRequest conReq = new ConnectRequest(0, 0, 10000, 0, "password".getBytes(), false);
                 ByteArrayOutputStream baos = new ByteArrayOutputStream();
                 BinaryOutputArchive boa = BinaryOutputArchive.getArchive(baos);
                 boa.writeInt(-1, "len");
@@ -95,14 +93,6 @@ public class MaxCnxnsTest extends ClientBase {
                 }
             } catch (IOException io) {
                 // "Connection reset by peer"
-            } finally {
-                if (sChannel != null) {
-                    try {
-                        sChannel.close();
-                    } catch (Exception e) {
-                        // Do nothing
-                    }
-                }
             }
         }
 
diff --git a/zookeeper-server/src/test/java/org/apache/zookeeper/test/SessionInvalidationTest.java b/zookeeper-server/src/test/java/org/apache/zookeeper/test/SessionInvalidationTest.java
index a9229d2b1..1e7870bd2 100644
--- a/zookeeper-server/src/test/java/org/apache/zookeeper/test/SessionInvalidationTest.java
+++ b/zookeeper-server/src/test/java/org/apache/zookeeper/test/SessionInvalidationTest.java
@@ -53,7 +53,7 @@ public class SessionInvalidationTest extends ClientBase {
 
             // open a connection
             boa.writeInt(44, "len");
-            ConnectRequest conReq = new ConnectRequest(0, 0, 30000, 0, new byte[16]);
+            ConnectRequest conReq = new ConnectRequest(0, 0, 30000, 0, new byte[16], false);
             conReq.serialize(boa, "connect");
 
             // close connection