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/*
* Copyright 2015-present Open Networking Laboratory
*
* 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.net.intent.impl;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import org.onosproject.net.intent.Intent;
import org.onosproject.net.intent.IntentCompiler;
import org.onosproject.net.intent.IntentException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
// TODO: consider a better name
class CompilerRegistry {
private final ConcurrentMap<Class<? extends Intent>,
IntentCompiler<? extends Intent>> compilers = new ConcurrentHashMap<>();
/**
* 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, IntentCompiler<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>, IntentCompiler<? extends Intent>> getCompilers() {
return ImmutableMap.copyOf(compilers);
}
/**
* Compiles an intent recursively.
*
* @param intent intent
* @param previousInstallables previous intent installables
* @return result of compilation
*/
List<Intent> compile(Intent intent, List<Intent> previousInstallables) {
if (intent.isInstallable()) {
return ImmutableList.of(intent);
}
registerSubclassCompilerIfNeeded(intent);
// FIXME: get previous resources
List<Intent> installable = new ArrayList<>();
for (Intent compiled : getCompiler(intent).compile(intent, previousInstallables)) {
installable.addAll(compile(compiled, previousInstallables));
}
return installable;
}
/**
* 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> IntentCompiler<T> getCompiler(T intent) {
@SuppressWarnings("unchecked")
IntentCompiler<T> compiler = (IntentCompiler<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)) {
IntentCompiler<?> compiler = compilers.get(cls);
if (compiler != null) {
compilers.put(intent.getClass(), compiler);
return;
}
}
cls = cls.getSuperclass();
}
}
}
}