| /* |
| * 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.kotlin |
| |
| /** |
| * An interface-based "mixin" to easily add a log val to a class, named by the enclosing class. This allows |
| * code like this: |
| * |
| * ``` |
| * import org.apache.logging.log4j.kotlin.Logging |
| * |
| * class MyClass: Logging { |
| * // use `logger` as necessary |
| * } |
| * |
| * ``` |
| * |
| * Or declaring the interface on a companion object works just as well: |
| * |
| * ``` |
| * import org.apache.logging.log4j.kotlin.logger |
| * |
| * class MyClass { |
| * companion object: Logging |
| * |
| * // use `logger` as necessary |
| * } |
| * |
| * ``` |
| * |
| * Note that this is significantly slower than creating a logger explicitly, as it requires a lookup of the |
| * logger on each call via the property getter, since we cannot store any state in an interface. We attempt to |
| * minimize the overhead of this by caching the loggers, but according to microbenchmarks, it is still about |
| * 3.5 times slower than creating a logger once and using it (about 4.2 nanoseconds per call instead of 1.2 |
| * nanoseconds). |
| */ |
| interface Logging { |
| /** |
| * Provides a logger automatically named after the class that extends this mixin interface. |
| */ |
| val logger |
| get() = cachedLoggerOf(this.javaClass) |
| } |