Fix for Bug#102404 (32435618), CONTRIBUTION: ADD TRACK SESSION STATE

CHANGE.

Author: soklakov

CHANGES

@@ -3,6 +3,9 @@
 
 Version 8.0.26
 
+  - Fix for Bug#102404 (32435618), CONTRIBUTION: ADD TRACK SESSION STATE CHANGE.
+    Thanks to William Lee for his contribution.
+
   - Fix for Bug#95280 (29757140), DATABASEMETADATA.GETIMPORTEDKEYS RETURNS DOUBLE THE ROWS.
     Thanks to Miron Balcerzak for his contribution.
 

src/main/core-api/java/com/mysql/cj/MysqlConnection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2020, Oracle and/or its affiliates.
+ * Copyright (c) 2015, 2021, Oracle and/or its affiliates.
  *
  * This program is free software; you can redistribute it and/or modify it under
  * the terms of the GNU General Public License, version 2.0, as published by the
@@ -33,6 +33,7 @@
 
 import com.mysql.cj.conf.PropertySet;
 import com.mysql.cj.exceptions.ExceptionInterceptor;
+import com.mysql.cj.protocol.ServerSessionStateController;
 
 public interface MysqlConnection {
 
@@ -76,4 +77,6 @@ public interface MysqlConnection {
      *            exception caused the connection clean up
      */
     void cleanup(Throwable whyCleanedUp);
+
+    ServerSessionStateController getServerSessionStateController();
 }

src/main/core-api/java/com/mysql/cj/conf/PropertyDefinitions.java

@@ -265,6 +265,9 @@ public enum DatabaseTerm {
                 new StringPropertyDefinition(PropertyKey.sessionVariables, DEFAULT_VALUE_NULL_STRING, RUNTIME_MODIFIABLE,
                         Messages.getString("ConnectionProperties.sessionVariables"), "3.1.8", CATEGORY_SESSION, Integer.MAX_VALUE),
 
+                new BooleanPropertyDefinition(PropertyKey.trackSessionState, DEFAULT_VALUE_FALSE, RUNTIME_MODIFIABLE,
+                        Messages.getString("ConnectionProperties.trackSessionState"), "8.0.26", CATEGORY_SESSION, Integer.MIN_VALUE),
+
                 //
                 // CATEGORY_NETWORK
                 //

src/main/core-api/java/com/mysql/cj/conf/PropertyKey.java

@@ -206,6 +206,7 @@ public enum PropertyKey {
     serverConfigCacheFactory("serverConfigCacheFactory", true), //
     serverRSAPublicKeyFile("serverRSAPublicKeyFile", true), //
     sessionVariables("sessionVariables", true), //
+    trackSessionState("trackSessionState", true), //
     slowQueryThresholdMillis("slowQueryThresholdMillis", true), //
     slowQueryThresholdNanos("slowQueryThresholdNanos", true), //
     socketFactory("socketFactory", true), //

src/main/core-api/java/com/mysql/cj/protocol/ServerSession.java

@@ -33,6 +33,8 @@
 import java.util.TimeZone;
 
 import com.mysql.cj.ServerVersion;
+import com.mysql.cj.exceptions.CJOperationNotSupportedException;
+import com.mysql.cj.exceptions.ExceptionFactory;
 
 /**
  * Keeps the effective states of server/session variables,
@@ -248,4 +250,9 @@ public interface ServerSession {
      * @return The default JVM time zone
      */
     TimeZone getDefaultTimeZone();
+
+    default ServerSessionStateController getServerSessionStateController() {
+        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, "Not supported");
+    }
+
 }

src/main/core-api/java/com/mysql/cj/protocol/ServerSessionStateController.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, version 2.0, as published by the
+ * Free Software Foundation.
+ *
+ * This program is also distributed with certain software (including but not
+ * limited to OpenSSL) that is licensed under separate terms, as designated in a
+ * particular file or component or in included license documentation. The
+ * authors of MySQL hereby grant you an additional permission to link the
+ * program and your derivative works with the separately licensed software that
+ * they have included with MySQL.
+ *
+ * Without limiting anything contained in the foregoing, this file, which is
+ * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
+ * version 1.0, a copy of which can be found at
+ * http://oss.oracle.com/licenses/universal-foss-exception.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+ */
+
+package com.mysql.cj.protocol;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.mysql.cj.exceptions.CJOperationNotSupportedException;
+import com.mysql.cj.exceptions.ExceptionFactory;
+
+public interface ServerSessionStateController {
+
+    public static int SESSION_TRACK_SYSTEM_VARIABLES = 0x00;
+    public static int SESSION_TRACK_SCHEMA = 0x01;
+    public static int SESSION_TRACK_STATE_CHANGE = 0x02;
+    public static int SESSION_TRACK_GTIDS = 0x03;
+    public static int SESSION_TRACK_TRANSACTION_CHARACTERISTICS = 0x04;
+    public static int SESSION_TRACK_TRANSACTION_STATE = 0x05;
+
+    /**
+     * Set the object containing server session changes collected from the latest query execution. Used internally.
+     * 
+     * @param changes
+     *            {@link ServerSessionStateChanges} object.
+     * 
+     */
+    default void setSessionStateChanges(ServerSessionStateChanges changes) {
+        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, "Not supported");
+    }
+
+    /**
+     * Get the object containing server session changes collected from the latest query execution.
+     * <p>
+     * Please note that the driver could issue some queries internally. With that there is no guarantee that all session changes are reflected in the
+     * {@link ServerSessionStateChanges} object after the recent user's query. If this is an issue, a {@link SessionStateChangesListener} can be added via
+     * {@link #addSessionStateChangesListener(SessionStateChangesListener)} to catch all session changes.
+     * </p>
+     * 
+     * @return {@link ServerSessionStateChanges} object.
+     */
+    default ServerSessionStateChanges getSessionStateChanges() {
+        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, "Not supported");
+    }
+
+    @FunctionalInterface
+    public static interface SessionStateChangesListener {
+        void handleSessionStateChanges(ServerSessionStateChanges changes);
+    }
+
+    /**
+     * Add the {@link SessionStateChangesListener} that will process {@link ServerSessionStateChanges} on it's arrival.
+     * 
+     * @param l
+     *            {@link SessionStateChangesListener} object.
+     */
+    default void addSessionStateChangesListener(SessionStateChangesListener l) {
+        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, "Not supported");
+    }
+
+    /**
+     * Remove {@link SessionStateChangesListener}.
+     * 
+     * @param l
+     *            {@link SessionStateChangesListener} object.
+     */
+    default void removeSessionStateChangesListener(SessionStateChangesListener l) {
+        throw ExceptionFactory.createException(CJOperationNotSupportedException.class, "Not supported");
+    }
+
+    /**
+     * The object containing server session changes collected from the latest query execution.
+     * <p>
+     * Driver is getting these changes when connection property trackSessionState=true and server supports session tracking.
+     * </p>
+     * 
+     */
+    public static interface ServerSessionStateChanges {
+        List<SessionStateChange> getSessionStateChangesList();
+    }
+
+    /**
+     * A single server session change record.
+     * <p>
+     * The server messages about session changes are parsed according to their known types:
+     * <ul>
+     * <li>{@link #SESSION_TRACK_SYSTEM_VARIABLES} - two values, the system variable name and it's new value;</li>
+     * <li>{@link #SESSION_TRACK_SCHEMA} - single value, the new schema name;</li>
+     * <li>{@link #SESSION_TRACK_STATE_CHANGE} - single value, "1" or "0";</li>
+     * <li>{@link #SESSION_TRACK_GTIDS} - single value, list of GTIDs as reported by server;</li>
+     * <li>{@link #SESSION_TRACK_TRANSACTION_CHARACTERISTICS} - single value, transaction characteristics statement;</li>
+     * <li>{@link #SESSION_TRACK_TRANSACTION_STATE} - single value, transaction state record.</li>
+     * </ul>
+     * For the unknown change type the raw payload is written into the single value.
+     * </p>
+     * <p>
+     * See more details in the <a href="https://dev.mysql.com/doc/refman/8.0/en/session-state-tracking.html">server documentation</a>.
+     * </p>
+     */
+    public static class SessionStateChange {
+        private int type;
+        private List<String> values = new ArrayList<>();
+
+        public SessionStateChange(int type) {
+            this.type = type;
+        }
+
+        public int getType() {
+            return this.type;
+        }
+
+        public List<String> getValues() {
+            return this.values;
+        }
+
+        public SessionStateChange addValue(String value) {
+            this.values.add(value);
+            return this;
+        }
+    }
+}

src/main/protocol-impl/java/com/mysql/cj/protocol/a/NativeAuthenticationProvider.java

@@ -193,11 +193,10 @@ public void connect(ServerSession sessState, String user, String pass, String db
                         : (capabilityFlags & NativeServerSession.CLIENT_CONNECT_ATTRS))
                 | (this.propertySet.<SslMode>getEnumProperty(PropertyKey.sslMode).getValue() != SslMode.DISABLED
                         ? (capabilityFlags & NativeServerSession.CLIENT_SSL)
+                        : 0)
+                | (this.propertySet.getBooleanProperty(PropertyKey.trackSessionState).getValue() ? (capabilityFlags & NativeServerSession.CLIENT_SESSION_TRACK)
                         : 0);
 
-        // TODO MYSQLCONNJ-437
-        // clientParam |= (capabilityFlags & NativeServerSession.CLIENT_SESSION_TRACK);
-
         sessState.setClientParam(clientParam);
 
         /* First, negotiate SSL connection */
@@ -467,6 +466,7 @@ private void proceedHandshakeWithPluggableAuthentication(ServerSession serverSes
                 // read OK packet
                 OkPacket ok = OkPacket.parse(last_received, null);
                 serverSession.setStatusFlags(ok.getStatusFlags(), true);
+                serverSession.getServerSessionStateController().setSessionStateChanges(ok.getSessionStateChanges());
 
                 // if OK packet then finish handshake
                 plugin.destroy();

src/main/protocol-impl/java/com/mysql/cj/protocol/a/NativeProtocol.java

@@ -1747,6 +1747,7 @@ public final <T> T readServerStatusForResultSets(NativePacketPayload rowPacket,
             result = (T) ok;
 
             this.serverSession.setStatusFlags(ok.getStatusFlags(), saveOldStatus);
+            this.serverSession.getServerSessionStateController().setSessionStateChanges(ok.getSessionStateChanges());
             checkTransactionState();
 
             this.warningCount = ok.getWarningCount();

src/main/protocol-impl/java/com/mysql/cj/protocol/a/NativeServerSession.java

@@ -43,6 +43,7 @@
 import com.mysql.cj.exceptions.WrongArgumentException;
 import com.mysql.cj.protocol.ServerCapabilities;
 import com.mysql.cj.protocol.ServerSession;
+import com.mysql.cj.protocol.ServerSessionStateController;
 import com.mysql.cj.util.StringUtils;
 import com.mysql.cj.util.TimeUtil;
 
@@ -86,6 +87,7 @@ public class NativeServerSession implements ServerSession {
     private int statusFlags = 0;
     private int serverDefaultCollationIndex;
     private long clientParam = 0;
+    private NativeServerSessionStateController serverSessionStateController;
 
     /** The map of server variables that we retrieve at connection init. */
     private Map<String, String> serverVariables = new HashMap<>();
@@ -125,6 +127,7 @@ public class NativeServerSession implements ServerSession {
     public NativeServerSession(PropertySet propertySet) {
         this.propertySet = propertySet;
         this.cacheDefaultTimeZone = this.propertySet.getBooleanProperty(PropertyKey.cacheDefaultTimeZone);
+        this.serverSessionStateController = new NativeServerSessionStateController();
 
         // preconfigure some server variables which are consulted before their initialization from server
         this.serverVariables.put("character_set_server", "utf8");
@@ -570,4 +573,10 @@ public TimeZone getDefaultTimeZone() {
         }
         return TimeZone.getDefault();
     }
+
+    @Override
+    public ServerSessionStateController getServerSessionStateController() {
+        return this.serverSessionStateController;
+    }
+
 }