001/*
002 * ====================================================================
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *   http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing,
014 * software distributed under the License is distributed on an
015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
016 * KIND, either express or implied.  See the License for the
017 * specific language governing permissions and limitations
018 * under the License.
019 * ====================================================================
020 *
021 * This software consists of voluntary contributions made by many
022 * individuals on behalf of the Apache Software Foundation.  For more
023 * information on the Apache Software Foundation, please see
024 * <http://www.apache.org/>.
025 *
026 */
027
028package org.apache.http.nio;
029
030import java.io.IOException;
031import java.nio.ByteBuffer;
032
033/**
034 * Abstract HTTP content encoder. HTTP content encoders can be used
035 * to apply the required coding transformation and write entity
036 * content to the underlying channel in small chunks.
037 *
038 * @since 4.0
039 */
040public interface ContentEncoder {
041
042    /**
043     * Writes a portion of entity content to the underlying channel.
044     *
045     * @param src The buffer from which content is to be retrieved
046     * @return The number of bytes read, possibly zero
047     * @throws IOException if I/O error occurs while writing content
048     */
049    int write(ByteBuffer src) throws IOException;
050
051    /**
052     * Terminates the content stream.
053     *
054     * @throws IOException if I/O error occurs while writing content
055     */
056    void complete() throws IOException;
057
058    /**
059     * Returns {@code true} if the entity has been transferred in its
060     * entirety.
061     *
062     * @return {@code true} if all the content has been produced,
063     * {@code false} otherwise.
064     */
065    boolean isCompleted();
066
067}