/*
* Copyright 2014 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;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import net.jcip.annotations.ThreadSafe;
import org.gradle.api.Nullable;
import org.gradle.internal.Cast;
import org.gradle.model.internal.type.ModelType;
/**
* A model reference is a speculative reference to a potential model element.
* <p>
* Rule subjects/inputs are defined in terms of references, as opposed to concrete identity.
* The reference may be by type only, or by path only.
* <p>
* A reference doesn't include the notion of readonly vs. writable as the context of the reference implies this.
* Having this be part of the reference would open opportunities for mismatch of that flag in the context.
*
* @param <T> the type of the reference.
*/
@ThreadSafe
public class ModelReference<T> {
public static final ModelReference<Object> ANY = of(ModelType.untyped());
@Nullable
private final ModelPath path;
private final ModelType<T> type;
@Nullable
private final ModelPath scope;
private final ModelNode.State state;
@Nullable
private final String description;
private int hashCode;
private ModelReference(@Nullable ModelPath path, ModelType<T> type, @Nullable ModelPath scope, @Nullable ModelNode.State state, @Nullable String description) {
this.path = path;
this.type = Preconditions.checkNotNull(type, "type");
this.scope = scope;
this.description = description;
this.state = state != null ? state : ModelNode.State.GraphClosed;
}
public static ModelReference<Object> any() {
return ANY;
}
public static <T> ModelReference<T> of(ModelPath path, ModelType<T> type, String description) {
return Cast.uncheckedCast(new ModelReference<T>(path, type, null, null, description));
}
public static <T> ModelReference<T> of(String path, ModelType<T> type, String description) {
return of(ModelPath.path(path), type, description);
}
public static <T> ModelReference<T> of(ModelPath path, ModelType<T> type) {
return Cast.uncheckedCast(new ModelReference<T>(path, type, null, null, null));
}
public static <T> ModelReference<T> of(ModelPath path, ModelType<T> type, ModelNode.State state) {
return Cast.uncheckedCast(new ModelReference<T>(path, type, null, state, null));
}
public static <T> ModelReference<T> of(ModelPath path, Class<T> type) {
return of(path, ModelType.of(type));
}
public static <T> ModelReference<T> of(String path, Class<T> type) {
return of(ModelPath.path(path), ModelType.of(type));
}
public static <T> ModelReference<T> of(String path, ModelType<T> type) {
return of(path == null ? null : ModelPath.path(path), type);
}
public static <T> ModelReference<T> of(Class<T> type) {
return of((ModelPath) null, ModelType.of(type));
}
public static <T> ModelReference<T> of(ModelType<T> type) {
return of((ModelPath) null, type);
}
public static ModelReference<Object> of(String path) {
return of(ModelPath.path(path), ModelType.UNTYPED);
}
public static ModelReference<Object> of(ModelPath path) {
return of(path, ModelType.UNTYPED);
}
public static ModelReference<Object> untyped(ModelPath path) {
return untyped(path, null);
}
public static ModelReference<Object> untyped(ModelPath path, String description) {
return of(path, ModelType.UNTYPED, description);
}
@Nullable
public ModelPath getPath() {
return path;
}
/**
* Return the path of the scope of the node to select, or null if scope is not relevant.
*
* <p>A node will be selected if its path or its parent's path equals the specified path.</p>
*/
@Nullable
public ModelPath getScope() {
return scope;
}
@Nullable
public String getDescription() {
return description;
}
public ModelType<T> getType() {
return type;
}
public ModelNode.State getState() {
return state;
}
public boolean isUntyped() {
return type.equals(ModelType.UNTYPED);
}
public ModelReference<T> inScope(ModelPath scope) {
if (scope.equals(this.scope)) {
return this;
}
return Cast.uncheckedCast(new ModelReference<T>(path, type, scope, state, description));
}
public ModelReference<T> withPath(ModelPath path) {
return Cast.uncheckedCast(new ModelReference<T>(path, type, scope, state, description));
}
public ModelReference<T> atState(ModelNode.State state) {
if (state.equals(this.state)) {
return this;
}
return Cast.uncheckedCast(new ModelReference<T>(path, type, scope, state, description));
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
ModelReference<?> that = (ModelReference<?>) o;
return Objects.equal(path, that.path) && Objects.equal(scope, that.scope) && type.equals(that.type) && state.equals(that.state) && Objects.equal(description, that.description);
}
@Override
public int hashCode() {
int result = hashCode;
if (result != 0) {
return result;
}
result = path == null ? 0 : path.hashCode();
result = 31 * result + (scope == null ? 0 : scope.hashCode());
result = 31 * result + type.hashCode();
result = 31 * result + state.hashCode();
result = 31 * result + (description == null ? 0 : description.hashCode());
hashCode = result;
return result;
}
@Override
public String toString() {
return "ModelReference{path=" + path + ", scope=" + scope + ", type=" + type + ", state=" + state + '}';
}
}