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// Copyright 2015 The Bazel Authors. All rights reserved.
//
// 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 com.google.devtools.build.lib.packages;
import static com.google.common.collect.Iterables.getOnlyElement;
import com.google.common.collect.ImmutableCollection;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.Multimap;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Objects;
/**
* Objects of this class contain values of some attributes of rules. Used for passing this
* information to the aspects.
*/
public final class AspectParameters {
private final ImmutableMultimap<String, String> attributes;
private AspectParameters(Multimap<String, String> attributes) {
this.attributes = ImmutableMultimap.copyOf(attributes);
}
public static final AspectParameters EMPTY = new AspectParameters(ImmutableMultimap.of());
private static AspectParameters create(ImmutableMultimap<String, String> attributes) {
if (attributes.isEmpty()) {
return EMPTY;
}
return new AspectParameters(attributes);
}
/**
* A builder for @{link {@link AspectParameters} class.
*/
public static class Builder {
private final ImmutableMultimap.Builder<String, String> attributes =
ImmutableMultimap.builder();
/** Adds a new pair of attribute-value. */
@CanIgnoreReturnValue
public Builder addAttribute(String name, String value) {
attributes.put(name, value);
return this;
}
/**
* Creates a new instance of {@link AspectParameters} class.
*/
public AspectParameters build() {
return create(attributes.build());
}
}
/**
* Returns collection of values for specified key, or an empty collection if key is missing.
*/
public ImmutableCollection<String> getAttribute(String key) {
return attributes.get(key);
}
public ImmutableMultimap<String, String> getAttributes() {
return attributes;
}
/**
* Similar to {@link #getAttribute}}, but asserts that there's only one value for the provided
* key.
* Uses Guava's {@link Iterables#getOnlyElement}, which may throw exceptions if there isn't
* exactly one element.
*/
public String getOnlyValueOfAttribute(String key) {
return getOnlyElement(getAttribute(key));
}
public boolean isEmpty() {
return this.equals(AspectParameters.EMPTY);
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (!(other instanceof AspectParameters)) {
return false;
}
AspectParameters that = (AspectParameters) other;
return Objects.equals(this.attributes, that.attributes);
}
@Override
public int hashCode() {
return Objects.hashCode(attributes);
}
@Override
public String toString() {
return attributes.toString();
}
}