/*
* Copyright 2013 the original author or authors.
*
* 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.gradle.model.internal.core.rule.describe;
import com.google.common.base.Function;
import com.google.common.base.Joiner;
import com.google.common.base.Objects;
import com.google.common.collect.Iterables;
import net.jcip.annotations.ThreadSafe;
import org.gradle.api.UncheckedIOException;
import org.gradle.model.internal.method.WeaklyTypeReferencingMethod;
import org.gradle.model.internal.type.ModelType;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
// TODO some kind of context of why the method was attached (e.g. which plugin declared the rule)
// TODO some kind of instance state for the method (might be the same as context above)
@ThreadSafe
public class MethodModelRuleDescriptor extends AbstractModelRuleDescriptor {
private final static Cache DESCRIPTOR_CACHE = new Cache();
private final static Joiner PARAM_JOINER = Joiner.on(", ");
private static final Function<ModelType<?>, String> TYPE_DISPLAYNAME_FUNCTION = new Function<ModelType<?>, String>() {
@Override
public String apply(ModelType<?> input) {
return input.getDisplayName();
}
};
private final WeaklyTypeReferencingMethod<?, ?> method;
private String description;
private int hashCode;
public MethodModelRuleDescriptor(WeaklyTypeReferencingMethod<?, ?> method) {
this.method = method;
}
@Override
public void describeTo(Appendable appendable) {
try {
appendable.append(getDescription());
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
private String getDescription() {
if (description == null) {
description = createDescription();
}
return description;
}
private String createDescription() {
return getClassName() + "#" + method.getName() + "(" + toParameterList(method.getGenericParameterTypes()) + ")";
}
private static String toParameterList(List<ModelType<?>> genericParameterTypes) {
return PARAM_JOINER.join(Iterables.transform(genericParameterTypes, TYPE_DISPLAYNAME_FUNCTION));
}
private String getClassName() {
return method.getDeclaringType().getDisplayName();
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
MethodModelRuleDescriptor that = (MethodModelRuleDescriptor) o;
return Objects.equal(method, that.method);
}
@Override
public int hashCode() {
int result = hashCode;
if (result != 0) {
return result;
}
result = Objects.hashCode(method);
hashCode = result;
return result;
}
public static <T, R> ModelRuleDescriptor of(WeaklyTypeReferencingMethod<T, R> method) {
return DESCRIPTOR_CACHE.get(method);
}
private static class Cache {
private final WeakHashMap<Class<?>, CacheEntry> cached = new WeakHashMap<Class<?>, CacheEntry>();
public synchronized <T, R> ModelRuleDescriptor get(WeaklyTypeReferencingMethod<T, R> method) {
Class<?> clazz = method.getDeclaringType().getConcreteClass();
CacheEntry cacheEntry = cached.get(clazz);
if (cacheEntry == null) {
cacheEntry = new CacheEntry(clazz);
cached.put(clazz, cacheEntry);
}
MethodModelRuleDescriptor methodModelRuleDescriptor = cacheEntry.get(method);
if (methodModelRuleDescriptor == null) {
methodModelRuleDescriptor = new MethodModelRuleDescriptor(method);
}
return methodModelRuleDescriptor;
}
private static class CacheEntry {
private final Map<WeaklyTypeReferencingMethod<?, ?>, MethodModelRuleDescriptor> descriptors;
public CacheEntry(Class<?> clazz) {
this.descriptors = new HashMap<WeaklyTypeReferencingMethod<?, ?>, MethodModelRuleDescriptor>(clazz.getDeclaredMethods().length);
}
public <T, R> MethodModelRuleDescriptor get(WeaklyTypeReferencingMethod<T, R> weakMethod) {
MethodModelRuleDescriptor desc = descriptors.get(weakMethod);
if (desc != null) {
return desc;
}
desc = new MethodModelRuleDescriptor(weakMethod);
// Only cache non-overloaded methods by name
descriptors.put(weakMethod, desc);
return desc;
}
}
}
}