[ONOS-6163] (vnet) revise intent service for vnets
Revise intent service for virtual networks.
Change-Id: I4955cde2296e58d8f0e356d19483e84f51193318
diff --git a/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/intent/VirtualIntentCompilerRegistry.java b/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/intent/VirtualIntentCompilerRegistry.java
new file mode 100644
index 0000000..f922c22
--- /dev/null
+++ b/incubator/net/src/main/java/org/onosproject/incubator/net/virtual/impl/intent/VirtualIntentCompilerRegistry.java
@@ -0,0 +1,170 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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.
+ */
+
+package org.onosproject.incubator.net.virtual.impl.intent;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import org.onosproject.incubator.net.virtual.NetworkId;
+import org.onosproject.incubator.net.virtual.intent.VirtualIntentCompiler;
+import org.onosproject.net.intent.Intent;
+import org.onosproject.net.intent.IntentException;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+public final class VirtualIntentCompilerRegistry {
+ private final ConcurrentMap<Class<? extends Intent>,
+ VirtualIntentCompiler<? extends Intent>> compilers = new ConcurrentHashMap<>();
+
+ // non-instantiable (except for our Singleton)
+ private VirtualIntentCompilerRegistry() {
+
+ }
+
+ public static VirtualIntentCompilerRegistry getInstance() {
+ return SingletonHelper.INSTANCE;
+ }
+
+ /**
+ * Registers the specified compiler for the given intent class.
+ *
+ * @param cls intent class
+ * @param compiler intent compiler
+ * @param <T> the type of intent
+ */
+ public <T extends Intent> void registerCompiler(Class<T> cls,
+ VirtualIntentCompiler<T> compiler) {
+ compilers.put(cls, compiler);
+ }
+
+ /**
+ * Unregisters the compiler for the specified intent class.
+ *
+ * @param cls intent class
+ * @param <T> the type of intent
+ */
+ public <T extends Intent> void unregisterCompiler(Class<T> cls) {
+ compilers.remove(cls);
+ }
+
+ /**
+ * Returns immutable set of bindings of currently registered intent compilers.
+ *
+ * @return the set of compiler bindings
+ */
+ public Map<Class<? extends Intent>, VirtualIntentCompiler<? extends Intent>> getCompilers() {
+ return ImmutableMap.copyOf(compilers);
+ }
+
+ /**
+ * Compiles an intent recursively.
+ *
+ * @param networkId network identifier
+ * @param intent intent
+ * @param previousInstallables previous intent installables
+ * @return result of compilation
+ */
+ public List<Intent> compile(NetworkId networkId,
+ Intent intent, List<Intent> previousInstallables) {
+ if (intent.isInstallable()) {
+ return ImmutableList.of(intent);
+ }
+
+ // FIXME: get previous resources
+ List<Intent> installables = new ArrayList<>();
+ Queue<Intent> compileQueue = new LinkedList<>();
+ compileQueue.add(intent);
+
+ Intent compiling;
+ while ((compiling = compileQueue.poll()) != null) {
+ registerSubclassCompilerIfNeeded(compiling);
+
+ List<Intent> compiled = getCompiler(compiling)
+ .compile(networkId, compiling, previousInstallables);
+
+ compiled.forEach(i -> {
+ if (i.isInstallable()) {
+ installables.add(i);
+ } else {
+ compileQueue.add(i);
+ }
+ });
+ }
+ return installables;
+ }
+
+ /**
+ * Returns the corresponding intent compiler to the specified intent.
+ *
+ * @param intent intent
+ * @param <T> the type of intent
+ * @return intent compiler corresponding to the specified intent
+ */
+ private <T extends Intent> VirtualIntentCompiler<T> getCompiler(T intent) {
+ @SuppressWarnings("unchecked")
+ VirtualIntentCompiler<T> compiler =
+ (VirtualIntentCompiler<T>) compilers.get(intent.getClass());
+ if (compiler == null) {
+ throw new IntentException("no compiler for class " + intent.getClass());
+ }
+ return compiler;
+ }
+
+ /**
+ * Registers an intent compiler of the specified intent if an intent compiler
+ * for the intent is not registered. This method traverses the class hierarchy of
+ * the intent. Once an intent compiler for a parent type is found, this method
+ * registers the found intent compiler.
+ *
+ * @param intent intent
+ */
+ private void registerSubclassCompilerIfNeeded(Intent intent) {
+ if (!compilers.containsKey(intent.getClass())) {
+ Class<?> cls = intent.getClass();
+ while (cls != Object.class) {
+ // As long as we're within the Intent class descendants
+ if (Intent.class.isAssignableFrom(cls)) {
+ VirtualIntentCompiler<?> compiler = compilers.get(cls);
+ if (compiler != null) {
+ compilers.put(intent.getClass(), compiler);
+ return;
+ }
+ }
+ cls = cls.getSuperclass();
+ }
+ }
+ }
+
+ /**
+ * Prevents object instantiation from external.
+ */
+ private static final class SingletonHelper {
+ private static final String ILLEGAL_ACCESS_MSG =
+ "Should not instantiate this class.";
+ private static final VirtualIntentCompilerRegistry INSTANCE =
+ new VirtualIntentCompilerRegistry();
+
+ private SingletonHelper() {
+ throw new IllegalAccessError(ILLEGAL_ACCESS_MSG);
+ }
+ }
+}