| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.logging.log4j.spi; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.logging.log4j.ThreadContext.ContextStack; |
| |
| /** |
| * |
| */ |
| public class MutableThreadContextStack implements ThreadContextStack { |
| |
| private static final long serialVersionUID = 50505011L; |
| |
| /** |
| * The underlying list (never null). |
| */ |
| private final List<String> list; |
| private boolean frozen; |
| |
| /** |
| * Constructs an empty MutableThreadContextStack. |
| */ |
| public MutableThreadContextStack() { |
| this(new ArrayList<String>()); |
| } |
| |
| public MutableThreadContextStack(final List<String> list) { |
| this.list = new ArrayList<>(list); |
| } |
| |
| private MutableThreadContextStack(final MutableThreadContextStack stack) { |
| this.list = new ArrayList<>(stack.list); |
| } |
| |
| private void checkInvariants() { |
| if (frozen) { |
| throw new UnsupportedOperationException("context stack has been frozen"); |
| } |
| } |
| |
| @Override |
| public String pop() { |
| checkInvariants(); |
| if (list.isEmpty()) { |
| return null; |
| } |
| final int last = list.size() - 1; |
| final String result = list.remove(last); |
| return result; |
| } |
| |
| @Override |
| public String peek() { |
| if (list.isEmpty()) { |
| return null; |
| } |
| final int last = list.size() - 1; |
| return list.get(last); |
| } |
| |
| @Override |
| public void push(final String message) { |
| checkInvariants(); |
| list.add(message); |
| } |
| |
| @Override |
| public int getDepth() { |
| return list.size(); |
| } |
| |
| @Override |
| public List<String> asList() { |
| return list; |
| } |
| |
| @Override |
| public void trim(final int depth) { |
| checkInvariants(); |
| if (depth < 0) { |
| throw new IllegalArgumentException("Maximum stack depth cannot be negative"); |
| } |
| if (list == null) { |
| return; |
| } |
| final List<String> copy = new ArrayList<>(list.size()); |
| final int count = Math.min(depth, list.size()); |
| for (int i = 0; i < count; i++) { |
| copy.add(list.get(i)); |
| } |
| list.clear(); |
| list.addAll(copy); |
| } |
| |
| @Override |
| public ThreadContextStack copy() { |
| return new MutableThreadContextStack(this); |
| } |
| |
| @Override |
| public void clear() { |
| checkInvariants(); |
| list.clear(); |
| } |
| |
| @Override |
| public int size() { |
| return list.size(); |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return list.isEmpty(); |
| } |
| |
| @Override |
| public boolean contains(final Object o) { |
| return list.contains(o); |
| } |
| |
| @Override |
| public Iterator<String> iterator() { |
| return list.iterator(); |
| } |
| |
| @Override |
| public Object[] toArray() { |
| return list.toArray(); |
| } |
| |
| @Override |
| public <T> T[] toArray(final T[] ts) { |
| return list.toArray(ts); |
| } |
| |
| @Override |
| public boolean add(final String s) { |
| checkInvariants(); |
| return list.add(s); |
| } |
| |
| @Override |
| public boolean remove(final Object o) { |
| checkInvariants(); |
| return list.remove(o); |
| } |
| |
| @Override |
| public boolean containsAll(final Collection<?> objects) { |
| return list.containsAll(objects); |
| } |
| |
| @Override |
| public boolean addAll(final Collection<? extends String> strings) { |
| checkInvariants(); |
| return list.addAll(strings); |
| } |
| |
| @Override |
| public boolean removeAll(final Collection<?> objects) { |
| checkInvariants(); |
| return list.removeAll(objects); |
| } |
| |
| @Override |
| public boolean retainAll(final Collection<?> objects) { |
| checkInvariants(); |
| return list.retainAll(objects); |
| } |
| |
| @Override |
| public String toString() { |
| return String.valueOf(list); |
| } |
| |
| @Override |
| public int hashCode() { |
| final int prime = 31; |
| int result = 1; |
| result = prime * result + ((this.list == null) ? 0 : this.list.hashCode()); |
| return result; |
| } |
| |
| @Override |
| public boolean equals(final Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj == null) { |
| return false; |
| } |
| if (!(obj instanceof ThreadContextStack)) { |
| return false; |
| } |
| final ThreadContextStack other = (ThreadContextStack) obj; |
| final List<String> otherAsList = other.asList(); |
| if (this.list == null) { |
| if (otherAsList != null) { |
| return false; |
| } |
| } else if (!this.list.equals(otherAsList)) { |
| return false; |
| } |
| return true; |
| } |
| |
| @Override |
| public ContextStack getImmutableStackOrNull() { |
| return copy(); |
| } |
| |
| /** |
| * "Freezes" this context stack so it becomes immutable: all mutator methods will throw an exception from now on. |
| */ |
| public void freeze() { |
| frozen = true; |
| } |
| |
| public boolean isFrozen() { |
| return frozen; |
| } |
| } |