| /* |
| * 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.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.logging.log4j.ThreadContext.ContextStack; |
| import org.apache.logging.log4j.util.StringBuilderFormattable; |
| import org.apache.logging.log4j.util.StringBuilders; |
| import org.apache.logging.log4j.util.Strings; |
| |
| /** |
| * A copy-on-write thread-safe variant of {@code org.apache.logging.log4j.spi.ThreadContextStack} in which all mutative |
| * operations (add, pop, and so on) are implemented by making a fresh copy of the underlying list. |
| */ |
| public class DefaultThreadContextStack implements ThreadContextStack, StringBuilderFormattable { |
| |
| private static final long serialVersionUID = 5050501L; |
| |
| private static final ThreadLocal<MutableThreadContextStack> STACK = new ThreadLocal<>(); |
| |
| private final boolean useStack; |
| |
| public DefaultThreadContextStack(final boolean useStack) { |
| this.useStack = useStack; |
| } |
| |
| private MutableThreadContextStack getNonNullStackCopy() { |
| final MutableThreadContextStack values = STACK.get(); |
| return (MutableThreadContextStack) (values == null ? new MutableThreadContextStack() : values.copy()); |
| } |
| |
| @Override |
| public boolean add(final String s) { |
| if (!useStack) { |
| return false; |
| } |
| final MutableThreadContextStack copy = getNonNullStackCopy(); |
| copy.add(s); |
| copy.freeze(); |
| STACK.set(copy); |
| return true; |
| } |
| |
| @Override |
| public boolean addAll(final Collection<? extends String> strings) { |
| if (!useStack || strings.isEmpty()) { |
| return false; |
| } |
| final MutableThreadContextStack copy = getNonNullStackCopy(); |
| copy.addAll(strings); |
| copy.freeze(); |
| STACK.set(copy); |
| return true; |
| } |
| |
| @Override |
| public List<String> asList() { |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null) { |
| return Collections.emptyList(); |
| } |
| return values.asList(); |
| } |
| |
| @Override |
| public void clear() { |
| STACK.remove(); |
| } |
| |
| @Override |
| public boolean contains(final Object o) { |
| final MutableThreadContextStack values = STACK.get(); |
| return values != null && values.contains(o); |
| } |
| |
| @Override |
| public boolean containsAll(final Collection<?> objects) { |
| if (objects.isEmpty()) { // quick check before accessing the ThreadLocal |
| return true; // looks counter-intuitive, but see |
| // j.u.AbstractCollection |
| } |
| final MutableThreadContextStack values = STACK.get(); |
| return values != null && values.containsAll(objects); |
| } |
| |
| @Override |
| public ThreadContextStack copy() { |
| MutableThreadContextStack values = null; |
| if (!useStack || (values = STACK.get()) == null) { |
| return new MutableThreadContextStack(); |
| } |
| return values.copy(); |
| } |
| |
| @Override |
| public boolean equals(final Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj == null) { |
| return false; |
| } |
| if (obj instanceof DefaultThreadContextStack) { |
| final DefaultThreadContextStack other = (DefaultThreadContextStack) obj; |
| if (this.useStack != other.useStack) { |
| return false; |
| } |
| } |
| if (!(obj instanceof ThreadContextStack)) { |
| return false; |
| } |
| final ThreadContextStack other = (ThreadContextStack) obj; |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null) { |
| return false; |
| } |
| return values.equals(other); |
| } |
| |
| @Override |
| public int getDepth() { |
| final MutableThreadContextStack values = STACK.get(); |
| return values == null ? 0 : values.getDepth(); |
| } |
| |
| @Override |
| public int hashCode() { |
| final MutableThreadContextStack values = STACK.get(); |
| final int prime = 31; |
| int result = 1; |
| // Factor in the stack itself to compare vs. other implementors. |
| result = prime * result + ((values == null) ? 0 : values.hashCode()); |
| return result; |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| final MutableThreadContextStack values = STACK.get(); |
| return values == null || values.isEmpty(); |
| } |
| |
| @Override |
| public Iterator<String> iterator() { |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null) { |
| final List<String> empty = Collections.emptyList(); |
| return empty.iterator(); |
| } |
| return values.iterator(); |
| } |
| |
| @Override |
| public String peek() { |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null || values.size() == 0) { |
| return Strings.EMPTY; |
| } |
| return values.peek(); |
| } |
| |
| @Override |
| public String pop() { |
| if (!useStack) { |
| return Strings.EMPTY; |
| } |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null || values.size() == 0) { |
| // Like version 1.2 |
| return Strings.EMPTY; |
| } |
| final MutableThreadContextStack copy = (MutableThreadContextStack) values.copy(); |
| final String result = copy.pop(); |
| copy.freeze(); |
| STACK.set(copy); |
| return result; |
| } |
| |
| @Override |
| public void push(final String message) { |
| if (!useStack) { |
| return; |
| } |
| add(message); |
| } |
| |
| @Override |
| public boolean remove(final Object o) { |
| if (!useStack) { |
| return false; |
| } |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null || values.size() == 0) { |
| return false; |
| } |
| final MutableThreadContextStack copy = (MutableThreadContextStack) values.copy(); |
| final boolean result = copy.remove(o); |
| copy.freeze(); |
| STACK.set(copy); |
| return result; |
| } |
| |
| @Override |
| public boolean removeAll(final Collection<?> objects) { |
| if (!useStack || objects.isEmpty()) { |
| return false; |
| } |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null || values.isEmpty()) { |
| return false; |
| } |
| final MutableThreadContextStack copy = (MutableThreadContextStack) values.copy(); |
| final boolean result = copy.removeAll(objects); |
| copy.freeze(); |
| STACK.set(copy); |
| return result; |
| } |
| |
| @Override |
| public boolean retainAll(final Collection<?> objects) { |
| if (!useStack || objects.isEmpty()) { |
| return false; |
| } |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null || values.isEmpty()) { |
| return false; |
| } |
| final MutableThreadContextStack copy = (MutableThreadContextStack) values.copy(); |
| final boolean result = copy.retainAll(objects); |
| copy.freeze(); |
| STACK.set(copy); |
| return result; |
| } |
| |
| @Override |
| public int size() { |
| final MutableThreadContextStack values = STACK.get(); |
| return values == null ? 0 : values.size(); |
| } |
| |
| @Override |
| public Object[] toArray() { |
| final MutableThreadContextStack result = STACK.get(); |
| if (result == null) { |
| return new String[0]; |
| } |
| return result.toArray(new Object[0]); |
| } |
| |
| @Override |
| public <T> T[] toArray(final T[] ts) { |
| final MutableThreadContextStack result = STACK.get(); |
| if (result == null) { |
| if (ts.length > 0) { // as per the contract of j.u.List#toArray(T[]) |
| ts[0] = null; |
| } |
| return ts; |
| } |
| return result.toArray(ts); |
| } |
| |
| @Override |
| public String toString() { |
| final MutableThreadContextStack values = STACK.get(); |
| return values == null ? "[]" : values.toString(); |
| } |
| |
| @Override |
| public void formatTo(final StringBuilder buffer) { |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null) { |
| buffer.append("[]"); |
| } else { |
| StringBuilders.appendValue(buffer, values); |
| } |
| } |
| |
| @Override |
| public void trim(final int depth) { |
| if (depth < 0) { |
| throw new IllegalArgumentException("Maximum stack depth cannot be negative"); |
| } |
| final MutableThreadContextStack values = STACK.get(); |
| if (values == null) { |
| return; |
| } |
| final MutableThreadContextStack copy = (MutableThreadContextStack) values.copy(); |
| copy.trim(depth); |
| copy.freeze(); |
| STACK.set(copy); |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.apache.logging.log4j.ThreadContext.ContextStack#getImmutableStackOrNull() |
| */ |
| @Override |
| public ContextStack getImmutableStackOrNull() { |
| return STACK.get(); |
| } |
| } |