com.google.devtools.build.lib.analysis.config.transitions.ComposingPatchTransition.java Source code

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Here is the source code for com.google.devtools.build.lib.analysis.config.transitions.ComposingPatchTransition.java

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// Copyright 2017 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.analysis.config.transitions;

import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.analysis.config.BuildOptions;
import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;

/**
 * A {@link ComposingSplitTransition} that only supports {@link PatchTransition}s
 *
 * <p>Calling code that doesn't want to have to handle splits should prefer this version.
 */
@AutoCodec
public class ComposingPatchTransition implements PatchTransition {
    private final ComposingSplitTransition delegate;

    /**
     * Creates a {@link ComposingPatchTransition} that applies the sequence: {@code fromOptions ->
     * transition1 -> transition2 -> toOptions }.
     *
     * <p>Note that it's possible to create silly transitions with this constructor (e.g., if one or
     * both of the transitions is NoTransition). Use composePatchTransitions instead, which checks for
     * these states and avoids instantiation appropriately.
     *
     * @see TransitionResolver#composePatchTransitions
     */
    public ComposingPatchTransition(PatchTransition transition1, PatchTransition transition2) {
        this(new ComposingSplitTransition(transition1, transition2));
    }

    @AutoCodec.Instantiator
    ComposingPatchTransition(ComposingSplitTransition delegate) {
        Preconditions.checkArgument(delegate.isPatchOnly());
        this.delegate = delegate;
    }

    @Override
    public BuildOptions patch(BuildOptions options) {
        return Iterables.getOnlyElement(delegate.split(options));
    }

    @Override
    public String getName() {
        return delegate.getName();
    }

    @Override
    public int hashCode() {
        return delegate.hashCode();
    }

    @Override
    public boolean equals(Object other) {
        return other instanceof ComposingPatchTransition
                && ((ComposingPatchTransition) other).delegate.equals(this.delegate);
    }
}