| // 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.util; |
| |
| import javax.annotation.Nullable; |
| |
| /** |
| * Provides bidirectional {@link String} ⇔ unique {@link Integer} mapping. |
| * |
| * <p>{@link Integer} is used in place of primitive {@code int} as it is assumed that indices will |
| * be stored in maps. Passing {@link Integer} across API boundaries makes it less likely to store |
| * duplicate instances and create garbage due to autoboxing. |
| */ |
| public interface StringIndexer { |
| |
| /** Removes all mappings. */ |
| void clear(); |
| |
| /** Returns the number of strings in the index. */ |
| int size(); |
| |
| /** Creates new mapping for the given string if necessary and returns string index. */ |
| Integer getOrCreateIndex(String s); |
| |
| /** |
| * Returns the unique index for the given string if one was created via {@link #getOrCreateIndex}, |
| * or else {@code null}. |
| */ |
| @Nullable |
| Integer getIndex(String s); |
| |
| /** |
| * Returns the string associated with the given index or {@code null} if it is not in the index. |
| */ |
| @Nullable |
| String getStringForIndex(Integer i); |
| } |