001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017 package org.apache.logging.log4j.spi; 018 019 import java.util.ArrayList; 020 import java.util.Collection; 021 import java.util.Iterator; 022 import java.util.List; 023 024 /** 025 * 026 */ 027 public class MutableThreadContextStack implements ThreadContextStack { 028 029 private static final long serialVersionUID = 50505011L; 030 031 /** 032 * The underlying list (never null). 033 */ 034 private final List<String> list; 035 036 public MutableThreadContextStack(List<String> list) { 037 this.list = new ArrayList<String>(list); 038 } 039 040 private MutableThreadContextStack(MutableThreadContextStack stack) { 041 this.list = new ArrayList<String>(stack.list); 042 } 043 044 public String pop() { 045 if (list.isEmpty()) { 046 return null; 047 } 048 final int last = list.size() - 1; 049 final String result = list.remove(last); 050 return result; 051 } 052 053 public String peek() { 054 if (list.isEmpty()) { 055 return null; 056 } 057 final int last = list.size() - 1; 058 return list.get(last); 059 } 060 061 public void push(final String message) { 062 list.add(message); 063 } 064 065 public int getDepth() { 066 return list.size(); 067 } 068 069 public List<String> asList() { 070 return list; 071 } 072 073 public void trim(final int depth) { 074 if (depth < 0) { 075 throw new IllegalArgumentException("Maximum stack depth cannot be negative"); 076 } 077 if (list == null) { 078 return; 079 } 080 final List<String> copy = new ArrayList<String>(list.size()); 081 int count = Math.min(depth, list.size()); 082 for(int i = 0; i < count; i++) { 083 copy.add(list.get(i)); 084 } 085 list.clear(); 086 list.addAll(copy); 087 } 088 089 public ThreadContextStack copy() { 090 return new MutableThreadContextStack(this); 091 } 092 093 public void clear() { 094 list.clear(); 095 } 096 097 public int size() { 098 return list.size(); 099 } 100 101 public boolean isEmpty() { 102 return list.isEmpty(); 103 } 104 105 public boolean contains(Object o) { 106 return list.contains(o); 107 } 108 109 public Iterator<String> iterator() { 110 return list.iterator(); 111 } 112 113 public Object[] toArray() { 114 return list.toArray(); 115 } 116 117 public <T> T[] toArray(T[] ts) { 118 return list.toArray(ts); 119 } 120 121 public boolean add(String s) { 122 return list.add(s); 123 } 124 125 public boolean remove(Object o) { 126 return list.remove(o); 127 } 128 129 public boolean containsAll(Collection<?> objects) { 130 return list.containsAll(objects); 131 } 132 133 public boolean addAll(Collection<? extends String> strings) { 134 return list.addAll(strings); 135 } 136 137 public boolean removeAll(Collection<?> objects) { 138 return list.removeAll(objects); 139 } 140 141 public boolean retainAll(Collection<?> objects) { 142 return list.retainAll(objects); 143 } 144 }