| // Copyright 2014 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.actions; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.base.Joiner; |
| import com.google.common.base.Objects; |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable; |
| import javax.annotation.Nonnull; |
| import net.starlark.java.eval.EvalException; |
| |
| /** |
| * A pair of a string to be substituted and a string to substitute it with. For simplicity, these |
| * are called key and value. All implementations must be immutable, and always return the identical |
| * key. The returned values must be the same, though they need not be the same object. |
| * |
| * <p>It should be assumed that the {@link #getKey} invocation is cheap, and that the {@link |
| * #getValue} invocation is expensive. |
| */ |
| @Immutable // if the keys and values in the passed in lists and maps are all immutable |
| public abstract class Substitution { |
| private Substitution() {} |
| |
| public abstract String getKey(); |
| |
| public abstract String getValue() throws EvalException; |
| |
| /* Not intended for use in production code */ |
| // TODO(hvd): migrate usages and delete |
| @VisibleForTesting |
| public final String getValueUnchecked() { |
| try { |
| return getValue(); |
| } catch (EvalException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| |
| private static final class StringSubstitution extends Substitution { |
| private final String key; |
| private final String value; |
| |
| StringSubstitution(String key, String value) { |
| this.key = key; |
| this.value = value; |
| } |
| |
| @Override |
| public String getKey() { |
| return key; |
| } |
| |
| @Override |
| public String getValue() { |
| return value; |
| } |
| } |
| |
| private static final class ListSubstitution extends Substitution { |
| private final String key; |
| private final ImmutableList<?> value; |
| |
| ListSubstitution(String key, ImmutableList<?> value) { |
| this.key = key; |
| this.value = value; |
| } |
| |
| @Override |
| public String getKey() { |
| return key; |
| } |
| |
| @Override |
| public String getValue() { |
| return Joiner.on(" ").join(value); |
| } |
| } |
| |
| /** Returns an immutable Substitution instance for the given key and value. */ |
| public static Substitution of(@Nonnull final String key, @Nonnull final String value) { |
| Preconditions.checkNotNull(key); |
| Preconditions.checkNotNull(value); |
| return new StringSubstitution(key, value); |
| } |
| |
| /** |
| * Returns an immutable Substitution instance for the key and list of values. The values will be |
| * joined by spaces before substitution. |
| */ |
| public static Substitution ofSpaceSeparatedList( |
| @Nonnull final String key, @Nonnull final ImmutableList<?> value) { |
| Preconditions.checkNotNull(key); |
| Preconditions.checkNotNull(value); |
| return new ListSubstitution(key, value); |
| } |
| |
| @Override |
| public boolean equals(Object object) { |
| if (this == object) { |
| return true; |
| } |
| if (object instanceof Substitution) { |
| Substitution substitution = (Substitution) object; |
| return substitution.getKey().equals(this.getKey()) |
| && substitution.getValueUnchecked().equals(this.getValueUnchecked()); |
| } |
| return false; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hashCode(getKey(), getValueUnchecked()); |
| } |
| |
| @Override |
| public String toString() { |
| return "Substitution(" + getKey() + " -> " + getValueUnchecked() + ")"; |
| } |
| |
| /** |
| * A substitution with a fixed key, and a computed value. The computed value must not change over |
| * the lifetime of an instance, though the {@link #getValue} method may return different String |
| * objects. |
| * |
| * <p>It should be assumed that the {@link #getKey} invocation is cheap, and that the {@link |
| * #getValue} invocation is expensive. |
| */ |
| public abstract static class ComputedSubstitution extends Substitution { |
| private final String key; |
| |
| public ComputedSubstitution(@Nonnull String key) { |
| Preconditions.checkNotNull(key); |
| this.key = key; |
| } |
| |
| @Override |
| public String getKey() { |
| return key; |
| } |
| } |
| } |