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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache license, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License. You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the license for the specific language governing permissions and
15   * limitations under the license.
16   */
17  package org.apache.logging.log4j.util;
18  
19  /**
20   * Exposes methods to add and remove key-value pairs to and from {@code ReadOnlyStringMap}.
21   *
22   * @see ReadOnlyStringMap
23   * @since 2.7
24   */
25  public interface StringMap extends ReadOnlyStringMap {
26  
27      /**
28       * Removes all key-value pairs from this collection.
29       * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
30       *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
31       *          {@link #forEach(TriConsumer, Object)}.
32       * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
33       */
34      void clear();
35  
36      /**
37       * Indicates whether some other object is "equal to" this one.
38       *
39       * @param obj
40       *            the reference object with which to compare.
41       * @return {@code true} if this object is the same as the obj argument; {@code false} otherwise.
42       * @see #hashCode()
43       */
44      @Override
45      boolean equals(final Object obj);
46  
47      /**
48       * Makes this collection immutable. Attempts to modify the collection after the {@code freeze()} method was called
49       * will result in an {@code UnsupportedOperationException} being thrown.
50       */
51      void freeze();
52  
53      /**
54       * Returns a hash code value for the object.
55       * @return a hash code value for this object.
56       */
57      @Override
58      int hashCode();
59  
60      /**
61       * Returns {@code true} if this object has been {@linkplain #freeze() frozen}, {@code false} otherwise.
62       * @return  {@code true} if this object has been {@linkplain #freeze() frozen}, {@code false} otherwise
63       */
64      boolean isFrozen();
65  
66      /**
67       * Copy all key-value pairs from the specified {@code ReadOnlyStringMap} into this {@code StringMap}.
68       * @param source the {@code ReadOnlyStringMap} to copy key-value pairs from
69       * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
70       *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
71       *          {@link #forEach(TriConsumer, Object)}.
72       * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
73       */
74      void putAll(final ReadOnlyStringMap source);
75  
76      /**
77       * Puts the specified key-value pair into the collection.
78       *
79       * @param key the key to add or remove. Keys may be {@code null}.
80       * @param value the value to add. Values may be {@code null}.
81       * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
82       *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
83       *          {@link #forEach(TriConsumer, Object)}.
84       * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
85       */
86      void putValue(final String key, final Object value);
87  
88      /**
89       * Removes the key-value pair for the specified key from this data structure.
90       *
91       * @param key the key to remove. May be {@code null}.
92       * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
93       *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
94       *          {@link #forEach(TriConsumer, Object)}.
95       * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
96       */
97      void remove(final String key);
98  }