Add conf option for disabling sync id checking (#14084)

Change-Id: If3fcc88e69d797b219f5af5906853a42d81f693c

6 files changed, 62 insertions, 5 deletions

diff --git a/server/src/com/vaadin/server/Constants.java b/server/src/com/vaadin/server/Constants.java
index 39329c32ce..34c9b5b767 100644
--- a/server/src/com/vaadin/server/Constants.java
+++ b/server/src/com/vaadin/server/Constants.java
@@ -126,6 +126,7 @@ public interface Constants {
     static final String SERVLET_PARAMETER_PUSH_MODE = "pushMode";
     static final String SERVLET_PARAMETER_UI_PROVIDER = "UIProvider";
     static final String SERVLET_PARAMETER_LEGACY_PROPERTY_TOSTRING = "legacyPropertyToString";
+    static final String SERVLET_PARAMETER_SYNC_ID_CHECK = "syncIdCheck";
 
     // Configurable parameter names
     static final String PARAMETER_VAADIN_RESOURCES = "Resources";
diff --git a/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java b/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java
index e72b411720..97790e7c0c 100644
--- a/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java
+++ b/server/src/com/vaadin/server/DefaultDeploymentConfiguration.java
@@ -51,6 +51,11 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
      */
     public static final LegacyProperyToStringMode DEFAULT_LEGACY_PROPERTY_TO_STRING = LegacyProperyToStringMode.WARNING;
 
+    /**
+     * Default value for {@link #isSyncIdCheckEnabled()} = {@value} .
+     */
+    public static final boolean DEFAULT_SYNC_ID_CHECK = true;
+
     private final Properties initParameters;
     private boolean productionMode;
     private boolean xsrfProtectionEnabled;
@@ -60,6 +65,7 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
     private PushMode pushMode;
     private final Class<?> systemPropertyBaseClass;
     private LegacyProperyToStringMode legacyPropertyToStringMode;
+    private boolean syncIdCheck;
 
     /**
      * Create a new deployment configuration instance.
@@ -83,6 +89,7 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
         checkCloseIdleSessions();
         checkPushMode();
         checkLegacyPropertyToString();
+        checkSyncIdCheck();
     }
 
     private void checkLegacyPropertyToString() {
@@ -238,6 +245,16 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
     /**
      * {@inheritDoc}
      * <p>
+     * The default value is <code>true</code>.
+     */
+    @Override
+    public boolean isSyncIdCheckEnabled() {
+        return syncIdCheck;
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p>
      * The default mode is {@link PushMode#DISABLED}.
      */
     @Override
@@ -321,6 +338,12 @@ public class DefaultDeploymentConfiguration implements DeploymentConfiguration {
         }
     }
 
+    private void checkSyncIdCheck() {
+        syncIdCheck = getApplicationOrSystemProperty(
+                Constants.SERVLET_PARAMETER_SYNC_ID_CHECK,
+                Boolean.toString(DEFAULT_SYNC_ID_CHECK)).equals("true");
+    }
+
     private Logger getLogger() {
         return Logger.getLogger(getClass().getName());
     }
diff --git a/server/src/com/vaadin/server/DeploymentConfiguration.java b/server/src/com/vaadin/server/DeploymentConfiguration.java
index b600d01cbd..50d84812ea 100644
--- a/server/src/com/vaadin/server/DeploymentConfiguration.java
+++ b/server/src/com/vaadin/server/DeploymentConfiguration.java
@@ -85,6 +85,17 @@ public interface DeploymentConfiguration extends Serializable {
     public boolean isXsrfProtectionEnabled();
 
     /**
+     * Returns whether sync id checking is enabled. The sync id is used to
+     * gracefully handle situations when the client sends a message to a
+     * connector that has recently been removed on the server.
+     * 
+     * @since
+     * @return <code>true</code> if sync id checking is enabled;
+     *         <code>false</code> otherwise
+     */
+    public boolean isSyncIdCheckEnabled();
+
+    /**
      * Returns the time resources can be cached in the browsers, in seconds.
      * 
      * @return The resource cache time.
diff --git a/server/src/com/vaadin/server/communication/ServerRpcHandler.java b/server/src/com/vaadin/server/communication/ServerRpcHandler.java
index 89d87567d7..36bfc8bcc6 100644
--- a/server/src/com/vaadin/server/communication/ServerRpcHandler.java
+++ b/server/src/com/vaadin/server/communication/ServerRpcHandler.java
@@ -75,10 +75,16 @@ public class ServerRpcHandler implements Serializable {
         private final int syncId;
         private final JSONObject json;
 
-        public RpcRequest(String jsonString) throws JSONException {
+        public RpcRequest(String jsonString, VaadinRequest request)
+                throws JSONException {
             json = new JSONObject(jsonString);
             csrfToken = json.getString(ApplicationConstants.CSRF_TOKEN);
-            syncId = json.getInt(ApplicationConstants.SERVER_SYNC_ID);
+            if (request.getService().getDeploymentConfiguration()
+                    .isSyncIdCheckEnabled()) {
+                syncId = json.getInt(ApplicationConstants.SERVER_SYNC_ID);
+            } else {
+                syncId = -1;
+            }
             invocations = new JSONArray(
                     json.getString(ApplicationConstants.RPC_INVOCATIONS));
         }
@@ -157,7 +163,7 @@ public class ServerRpcHandler implements Serializable {
             return;
         }
 
-        RpcRequest rpcRequest = new RpcRequest(changeMessage);
+        RpcRequest rpcRequest = new RpcRequest(changeMessage, request);
 
         // Security: double cookie submission pattern unless disabled by
         // property
diff --git a/server/src/com/vaadin/server/communication/UidlWriter.java b/server/src/com/vaadin/server/communication/UidlWriter.java
index 00522e2aa5..9d55f7e197 100644
--- a/server/src/com/vaadin/server/communication/UidlWriter.java
+++ b/server/src/com/vaadin/server/communication/UidlWriter.java
@@ -37,6 +37,7 @@ import com.vaadin.server.JsonPaintTarget;
 import com.vaadin.server.LegacyCommunicationManager;
 import com.vaadin.server.LegacyCommunicationManager.ClientCache;
 import com.vaadin.server.SystemMessages;
+import com.vaadin.server.VaadinService;
 import com.vaadin.server.VaadinSession;
 import com.vaadin.shared.ApplicationConstants;
 import com.vaadin.ui.ConnectorTracker;
@@ -75,10 +76,11 @@ public class UidlWriter implements Serializable {
     public void write(UI ui, Writer writer, boolean repaintAll, boolean async)
             throws IOException, JSONException {
         VaadinSession session = ui.getSession();
+        VaadinService service = session.getService();
 
         // Purge pending access calls as they might produce additional changes
         // to write out
-        session.getService().runPendingAccessTasks(session);
+        service.runPendingAccessTasks(session);
 
         ArrayList<ClientConnector> dirtyVisibleConnectors = ui
                 .getConnectorTracker().getDirtyVisibleConnectors();
@@ -99,8 +101,12 @@ public class UidlWriter implements Serializable {
 
         uiConnectorTracker.setWritingResponse(true);
         try {
+
+            int syncId = service.getDeploymentConfiguration()
+                    .isSyncIdCheckEnabled() ? uiConnectorTracker
+                    .getCurrentSyncId() : -1;
             writer.write("\"" + ApplicationConstants.SERVER_SYNC_ID + "\": "
-                    + uiConnectorTracker.getCurrentSyncId() + ", ");
+                    + syncId + ", ");
 
             writer.write("\"changes\" : ");
 
diff --git a/server/tests/src/com/vaadin/tests/util/MockDeploymentConfiguration.java b/server/tests/src/com/vaadin/tests/util/MockDeploymentConfiguration.java
index d113efdfaf..fe7f9ba03e 100644
--- a/server/tests/src/com/vaadin/tests/util/MockDeploymentConfiguration.java
+++ b/server/tests/src/com/vaadin/tests/util/MockDeploymentConfiguration.java
@@ -19,6 +19,7 @@ public class MockDeploymentConfiguration implements DeploymentConfiguration {
     private Properties initParameters = new Properties();
     private Map<String, String> applicationOrSystemProperty = new HashMap<String, String>();
     private LegacyProperyToStringMode legacyPropertyToStringMode = LegacyProperyToStringMode.DISABLED;
+    private boolean syncIdCheckEnabled = true;
 
     @Override
     public boolean isProductionMode() {
@@ -34,6 +35,15 @@ public class MockDeploymentConfiguration implements DeploymentConfiguration {
         return xsrfProtectionEnabled;
     }
 
+    @Override
+    public boolean isSyncIdCheckEnabled() {
+        return syncIdCheckEnabled;
+    }
+
+    public void setSyncIdCheckEnabled(boolean syncIdCheckEnabled) {
+        this.syncIdCheckEnabled = syncIdCheckEnabled;
+    }
+
     public void setXsrfProtectionEnabled(boolean xsrfProtectionEnabled) {
         this.xsrfProtectionEnabled = xsrfProtectionEnabled;
     }