1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache license, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the license for the specific language governing permissions and 15 * limitations under the license. 16 */ 17 package org.apache.logging.log4j.core.layout; 18 19 import java.nio.ByteBuffer; 20 21 import org.apache.logging.log4j.core.appender.OutputStreamManager; 22 23 /** 24 * ByteBufferDestination is the destination that {@link Encoder}s write binary data to. It encapsulates a 25 * {@code ByteBuffer} and a {@code drain()} method the producer can call when the {@code ByteBuffer} is full. 26 * <p> 27 * This interface allows a producer to write arbitrary amounts of data to a destination. 28 * </p> 29 * @since 2.6 30 */ 31 public interface ByteBufferDestination { 32 /** 33 * Returns the buffer to write to. 34 * 35 * @return the buffer to write to 36 */ 37 ByteBuffer getByteBuffer(); 38 39 /** 40 * Consumes the buffer content and returns a buffer with more {@linkplain ByteBuffer#remaining() available} space 41 * (which may or may not be the same instance). 42 * <p> 43 * Called by the producer when buffer becomes too full to write to. 44 * 45 * @param buf the buffer to drain 46 * @return a buffer with more available space (which may or may not be the same instance) 47 */ 48 ByteBuffer drain(ByteBuffer buf); 49 50 /** 51 * Writes the given data to this ByteBufferDestination entirely. Call of this method should *not* be protected 52 * with synchronized on this ByteBufferDestination instance. ByteBufferDestination implementations should 53 * synchronize themselves inside this method, if needed. 54 * 55 * @since 2.9 (see LOG4J2-1874) 56 */ 57 void writeBytes(ByteBuffer data); 58 59 /** 60 * Writes the given data to this ByteBufferDestination. Call of this method should *not* be protected with 61 * synchronized on this ByteBufferDestination instance. ByteBufferDestination implementations should 62 * synchronize themselves inside this method, if needed. 63 * <p> 64 * This method should behave identically to {@code writeBytes(ByteBuffer.wrap(data, offset, length)}. 65 * It is provided to allow callers not to generate extra garbage. 66 * <p> 67 * This method is called writeBytes() to avoid clashing with {@link OutputStreamManager#write(byte[], int, int)}, 68 * which might be overridden in user-defined subclasses as protected, hence adding it to interface and requiring 69 * the method to be public breaks source compatibility. 70 * 71 * @since 2.9 (see LOG4J2-1874) 72 */ 73 void writeBytes(byte[] data, int offset, int length); 74 }