| /* |
| * 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.message; |
| |
| import org.apache.logging.log4j.util.PerformanceSensitive; |
| import org.apache.logging.log4j.util.StringBuilderFormattable; |
| import org.osgi.annotation.versioning.ProviderType; |
| |
| /** |
| * Messages implementing this interface are reused between logging calls. |
| * <p> |
| * If a Message is reusable, downstream components should not hand over this instance to another thread, but extract its |
| * content (via the {@link StringBuilderFormattable#formatTo(StringBuilder)} method) instead. |
| * </p> |
| * @see ReusableMessageFactory |
| * @since 2.6 |
| */ |
| @PerformanceSensitive("allocation") |
| @ProviderType |
| public interface ReusableMessage extends Message, StringBuilderFormattable { |
| |
| /** |
| * Returns the parameter array that was used to initialize this reusable message and replaces it with the specified |
| * array. The returned parameter array will no longer be modified by this reusable message. The specified array is |
| * now "owned" by this reusable message and can be modified if necessary for the next log event. |
| * </p><p> |
| * ReusableMessages that have no parameters return the specified array. |
| * </p><p> |
| * This method is used by asynchronous loggers to pass the parameter array to a background thread without |
| * allocating new objects. |
| * The actual number of parameters in the returned array can be determined with {@link #getParameterCount()}. |
| * </p> |
| * |
| * @param emptyReplacement the parameter array that can be used for subsequent uses of this reusable message. |
| * This replacement array must have at least 10 elements (the number of varargs supported by the Logger |
| * API). |
| * @return the parameter array for the current message content. This may be a vararg array of any length, or it may |
| * be a reusable array of 10 elements used to hold the unrolled vararg parameters. |
| * @see #getParameterCount() |
| */ |
| Object[] swapParameters(Object[] emptyReplacement); |
| |
| /** |
| * Returns the number of parameters that was used to initialize this reusable message for the current content. |
| * <p> |
| * The parameter array returned by {@link #swapParameters(Object[])} may be larger than the actual number of |
| * parameters. Callers should use this method to determine how many elements the array contains. |
| * </p> |
| * @return the current number of parameters |
| */ |
| short getParameterCount(); |
| |
| /** |
| * Returns an immutable snapshot of the current internal state of this reusable message. The returned snapshot |
| * will not be affected by subsequent modifications of this reusable message. |
| * |
| * @return an immutable snapshot of this message |
| */ |
| Message memento(); |
| |
| /** |
| * Resets the object to a clean state. |
| * @since 2.24.0 |
| */ |
| void clear(); |
| } |