| // 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.sandbox; |
| |
| import com.google.common.collect.ForwardingSortedMap; |
| import com.google.devtools.build.lib.vfs.Path; |
| |
| import java.util.Map; |
| import java.util.SortedMap; |
| import java.util.TreeMap; |
| |
| /** |
| * A map that throws an exception when trying to replace a key (i.e. once a key gets a value, |
| * any additional attempt of putting a value on the same key will throw an exception). |
| * |
| * <p>Returns entries sorted by path depth (shorter paths first) and in lexicographical order. |
| */ |
| final class MountMap extends ForwardingSortedMap<Path, Path> { |
| final TreeMap<Path, Path> delegate = new TreeMap<>(); |
| |
| @Override |
| protected SortedMap<Path, Path> delegate() { |
| return delegate; |
| } |
| |
| @Override |
| public Path put(Path key, Path value) { |
| Path previousValue = get(key); |
| if (previousValue == null) { |
| return super.put(key, value); |
| } else if (previousValue.equals(value)) { |
| return value; |
| } else { |
| throw new IllegalArgumentException( |
| String.format("Cannot mount both '%s' and '%s' onto '%s'", previousValue, value, key)); |
| } |
| } |
| |
| @Override |
| public void putAll(Map<? extends Path, ? extends Path> map) { |
| for (Entry<? extends Path, ? extends Path> entry : map.entrySet()) { |
| put(entry.getKey(), entry.getValue()); |
| } |
| } |
| } |