diff options
Diffstat (limited to 'src/main/java/com/google/devtools/build/lib/collect/nestedset/OnlyOneTransitiveNestedSet.java')
-rw-r--r-- | src/main/java/com/google/devtools/build/lib/collect/nestedset/OnlyOneTransitiveNestedSet.java | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/collect/nestedset/OnlyOneTransitiveNestedSet.java b/src/main/java/com/google/devtools/build/lib/collect/nestedset/OnlyOneTransitiveNestedSet.java new file mode 100644 index 0000000000..a3e2d1d711 --- /dev/null +++ b/src/main/java/com/google/devtools/build/lib/collect/nestedset/OnlyOneTransitiveNestedSet.java @@ -0,0 +1,68 @@ +// Copyright 2014 Google Inc. 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.collect.nestedset; + +import java.util.Objects; + +import javax.annotation.Nullable; + +/** + * Memory-efficient implementation for the case where we only have one transitive NestedSet. + * + * <p>Note that we cannot simply delegate to the inner NestedSet because the order could be + * different and the top-level order is the correct one. + */ +abstract class OnlyOneTransitiveNestedSet<E> extends MemoizedUniquefierNestedSet<E> { + + private static final Object[] EMPTY = new Object[0]; + + private final NestedSet<E> transitive; + private Object memo; + + public OnlyOneTransitiveNestedSet(NestedSet<E> transitive) { + this.transitive = transitive; + } + + @Override + Object getMemo() { return memo; } + + @Override + void setMemo(Object memo) { this.memo = memo; } + + @Override + Object[] directMembers() { + return EMPTY; + } + + @Override + NestedSet[] transitiveSets() { + return new NestedSet[]{transitive}; + } + + @Override + public boolean shallowEquals(@Nullable NestedSet<? extends E> other) { + if (this == other) { + return true; + } + return other != null + && getOrder().equals(other.getOrder()) + && other instanceof OnlyOneTransitiveNestedSet + && transitive == ((OnlyOneTransitiveNestedSet) other).transitive; + } + + @Override + public int shallowHashCode() { + return Objects.hash(getOrder(), transitive); + } +} |