/*
 * EmptyConsumer.java February 2007
 *
 * Copyright (C) 2001, Niall Gallagher <niallg@users.sf.net>
 *
 * Licensed 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.simpleframework.http.message;

import org.simpleframework.transport.Cursor;

/**
 * The <code>EmptyConsumer</code> object is used to represent a body of zero
 * length. This is the most common body consumer created as it represents the
 * body for GET messages that have nothing within the body part.
 * 
 * @author Niall Gallagher
 */
public class EmptyConsumer implements BodyConsumer {

    /**
     * This is used to acquire the body that has been consumed. This will return
     * a body which can be used to read the content of the message, also if the
     * request is multipart upload then all of the parts are provided as
     * <code>Attachment</code> objects. Each part can then be read as an
     * individual message.
     * 
     * @return the body that has been consumed by this instance
     */
    @Override
    public Body getBody() {
        return new BufferBody();
    }

    /**
     * This method will not consume any bytes from the cursor. This ensures that
     * the next byte read from the stream is the first character of the next
     * HTTP message within the pipeline.
     * 
     * @param cursor
     *            this is the cursor which will not be read from
     */
    @Override
    public void consume(Cursor cursor) {
        return;
    }

    /**
     * This will return true immediately. Because the empty consumer represents
     * a zero length body and no bytes are read from the cursor, this should not
     * be processed and return finished.
     * 
     * @return this will always return true for the zero length body
     */
    @Override
    public boolean isFinished() {
        return true;
    }
}