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// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.vespa.model.utils.internal;
import com.google.common.reflect.TypeToken;
import com.yahoo.config.ChangesRequiringRestart;
import com.yahoo.config.ConfigInstance;
import com.yahoo.vespa.config.ConfigKey;
import com.yahoo.vespa.model.ConfigProducer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
/**
* Utility class containing static methods for retrieving information about the config producer tree.
*
* @author Ulf Lilleengen
* @author bjorncs
* @author gjoranv
*/
public final class ReflectionUtil {
private ReflectionUtil() {}
public static Set<ConfigKey<?>> getAllConfigsProduced(Class<? extends ConfigProducer> producerClass, String configId) {
// TypeToken is @Beta in guava, so consider implementing a simple recursive method instead.
TypeToken<? extends ConfigProducer>.TypeSet interfaces = TypeToken.of(producerClass).getTypes().interfaces();
return interfaces.rawTypes().stream()
.filter(ReflectionUtil::isConcreteProducer)
.map(i -> createConfigKeyFromInstance(i.getEnclosingClass(), configId))
.collect(Collectors.toCollection(() -> new LinkedHashSet<>()));
}
/**
* Determines if the config class contains the methods required for detecting config value changes
* between two config instances.
*/
public static boolean hasRestartMethods(Class<? extends ConfigInstance> configClass) {
try {
configClass.getDeclaredMethod("containsFieldsFlaggedWithRestart");
configClass.getDeclaredMethod("getChangesRequiringRestart", configClass);
return true;
} catch (NoSuchMethodException e) {
return false;
}
}
/**
* Determines if the config definition for the given config class contains key-values flagged with restart.
*/
public static boolean containsFieldsFlaggedWithRestart(Class<? extends ConfigInstance> configClass) {
try {
Method m = configClass.getDeclaredMethod("containsFieldsFlaggedWithRestart");
m.setAccessible(true);
return (boolean) m.invoke(null);
} catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
/**
* Compares the config instances and lists any differences that will require service restart.
*
* @param from The previous config.
* @param to The new config.
* @return An object describing the difference.
*/
public static ChangesRequiringRestart getChangesRequiringRestart(ConfigInstance from, ConfigInstance to) {
Class<?> clazz = from.getClass();
if (!clazz.equals(to.getClass())) {
throw new IllegalArgumentException(String.format("%s != %s", clazz, to.getClass()));
}
try {
Method m = clazz.getDeclaredMethod("getChangesRequiringRestart", clazz);
m.setAccessible(true);
return (ChangesRequiringRestart) m.invoke(from, to);
} catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
public static List<Class<?>> getAllSuperclasses(Class<?> cls) {
var result = new ArrayList<Class<?>>();
for(Class<?> superClass = cls.getSuperclass(); superClass != null; superClass = superClass.getSuperclass()) {
result.add(superClass);
}
return result;
}
private static ConfigKey<?> createConfigKeyFromInstance(Class<?> configInstClass, String configId) {
String defName = ConfigInstance.getDefName(configInstClass);
String defNamespace = ConfigInstance.getDefNamespace(configInstClass);
return new ConfigKey<>(defName, configId, defNamespace);
}
private static boolean isConcreteProducer(Class<?> producerInterface) {
if (isRootConfigProducerInterface(producerInterface)) return false;
boolean parentIsConfigInstance = false;
for (Class<?> ifaceParent : producerInterface.getInterfaces()) {
if (isConfigInstanceProducer(ifaceParent)) {
parentIsConfigInstance = true;
}
}
return (ConfigInstance.Producer.class.isAssignableFrom(producerInterface)
&& parentIsConfigInstance
&& !isConfigInstanceProducer(producerInterface));
}
private static boolean isConfigInstanceProducer(Class<?> clazz) {
return clazz.getName().equals(ConfigInstance.Producer.class.getName());
}
private static boolean isRootConfigProducerInterface(Class<?> clazz) {
return clazz.getCanonicalName().equals(ConfigProducer.class.getCanonicalName());
}
}
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