VPP-119: JVpp notifications

- add notification DTOs to JVpp
- add notification callbacks
- add notification registry
- provide/implement notification registry from future and callback facades

Change-Id: I1060ef2ec8ba1eb2e8cff279c93b73aa7c9f9aee
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>

1 files changed, 164 insertions, 0 deletions

diff --git a/vpp-api/java/jvpp/gen/notification_gen.py b/vpp-api/java/jvpp/gen/notification_gen.py
new file mode 100644
index 00000000000..4ca3c070431
--- /dev/null
+++ b/vpp-api/java/jvpp/gen/notification_gen.py
@@ -0,0 +1,164 @@
+#!/usr/bin/env python
+#
+# Copyright (c) 2016 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+import callback_gen
+import util
+from string import Template
+
+from util import remove_suffix
+
+notification_registry_template = Template("""
+package $base_package.$notification_package;
+
+/**
+ * <p>Registry for notification callbacks.
+ * <br>It was generated by notification_gen.py based on $inputfile
+ * <br>(python representation of vpe.api generated by vppapigen).
+ */
+public interface NotificationRegistry extends java.lang.AutoCloseable {
+
+    $register_callback_methods
+
+    @Override
+    void close();
+}
+""")
+
+global_notification_callback_template = Template("""
+package $base_package.$notification_package;
+
+/**
+ * <p>Aggregated callback interface for notifications only.
+ * <br>It was generated by notification_gen.py based on $inputfile
+ * <br>(python representation of vpe.api generated by vppapigen).
+ */
+public interface GlobalNotificationCallback extends $callbacks {
+
+}
+""")
+
+notification_registry_impl_template = Template("""
+package $base_package.$notification_package;
+
+/**
+ * <p>Notification registry delegating notification processing to registered callbacks.
+ * <br>It was generated by notification_gen.py based on $inputfile
+ * <br>(python representation of vpe.api generated by vppapigen).
+ */
+public final class NotificationRegistryImpl implements NotificationRegistry, GlobalNotificationCallback {
+
+    // TODO add a special NotificationCallback interface and only allow those to be registered
+    private final java.util.concurrent.ConcurrentMap<Class<? extends $base_package.$dto_package.JVppNotification>, $base_package.$callback_package.JVppNotificationCallback> registeredCallbacks =
+        new java.util.concurrent.ConcurrentHashMap<>();
+
+    $register_callback_methods
+    $handler_methods
+
+    @Override
+    public void close() {
+        registeredCallbacks.clear();
+    }
+}
+""")
+
+register_callback_impl_template = Template("""
+    public java.lang.AutoCloseable register$callback(final $base_package.$callback_package.$callback callback){
+        if(null != registeredCallbacks.putIfAbsent($base_package.$dto_package.$notification.class, callback)){
+            throw new IllegalArgumentException("Callback for " + $base_package.$dto_package.$notification.class +
+                "notification already registered");
+        }
+        return () -> registeredCallbacks.remove($base_package.$dto_package.$notification.class);
+    }
+""")
+
+handler_impl_template = Template("""
+    @Override
+    public void on$notification(
+        final $base_package.$dto_package.$notification notification) {
+        final $base_package.$callback_package.JVppNotificationCallback JVppNotificationCallback = registeredCallbacks.get($base_package.$dto_package.$notification.class);
+        if (null != JVppNotificationCallback) {
+            (($base_package.$callback_package.$callback) registeredCallbacks
+                .get($base_package.$dto_package.$notification.class))
+                .on$notification(notification);
+        }
+    }
+""")
+
+
+def generate_notification_registry(func_list, base_package, notification_package, callback_package, dto_package, inputfile):
+    """ Generates notification registry interface and implementation """
+    print "Generating Notification interfaces and implementation"
+
+    if not os.path.exists(notification_package):
+        raise Exception("%s folder is missing" % notification_package)
+
+    callbacks = []
+    register_callback_methods = []
+    register_callback_methods_impl = []
+    handler_methods = []
+    for func in func_list:
+
+        if not util.is_notification(func['name']):
+            continue
+
+        camel_case_name_with_suffix = util.underscore_to_camelcase_upper(func['name'])
+        notification_dto = util.add_notification_suffix(camel_case_name_with_suffix)
+        callback_ifc = notification_dto + callback_gen.callback_suffix
+        fully_qualified_callback_ifc = "{0}.{1}.{2}".format(base_package, callback_package, callback_ifc)
+        callbacks.append(fully_qualified_callback_ifc)
+
+        # TODO create NotificationListenerRegistration and return that instead of AutoCloseable to better indicate
+        # that the registration should be closed
+        register_callback_methods.append("java.lang.AutoCloseable register{0}({1} callback);"
+                                         .format(callback_ifc, fully_qualified_callback_ifc))
+        register_callback_methods_impl.append(register_callback_impl_template.substitute(base_package=base_package,
+                                                                                         callback_package=callback_package,
+                                                                                         dto_package=dto_package,
+                                                                                         notification=notification_dto,
+                                                                                         callback=callback_ifc))
+        handler_methods.append(handler_impl_template.substitute(base_package=base_package,
+                                                                callback_package=callback_package,
+                                                                dto_package=dto_package,
+                                                                notification=notification_dto,
+                                                                callback=callback_ifc))
+
+    callback_file = open(os.path.join(notification_package, "NotificationRegistry.java"), 'w')
+    callback_file.write(notification_registry_template.substitute(inputfile=inputfile,
+                                                                  register_callback_methods="\n    ".join(register_callback_methods),
+                                                                  base_package=base_package,
+                                                                  notification_package=notification_package))
+    callback_file.flush()
+    callback_file.close()
+
+    callback_file = open(os.path.join(notification_package, "GlobalNotificationCallback.java"), 'w')
+    callback_file.write(global_notification_callback_template.substitute(inputfile=inputfile,
+                                                                         callbacks=", ".join(callbacks),
+                                                                         base_package=base_package,
+                                                                         notification_package=notification_package))
+    callback_file.flush()
+    callback_file.close()
+
+    callback_file = open(os.path.join(notification_package, "NotificationRegistryImpl.java"), 'w')
+    callback_file.write(notification_registry_impl_template.substitute(inputfile=inputfile,
+                                                                       callback_package=callback_package,
+                                                                       dto_package=dto_package,
+                                                                       register_callback_methods="".join(register_callback_methods_impl),
+                                                                       handler_methods="".join(handler_methods),
+                                                                       base_package=base_package,
+                                                                       notification_package=notification_package))
+    callback_file.flush()
+    callback_file.close()