/*
 * 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.pdfbox.io;

import java.io.IOException;

/**
 * An interface to allow PDF files to be stored completely in memory or
 * to use a scratch file on the disk.
 *
 * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
 * @version $Revision: 1.2 $
 */
public interface RandomAccess
{

    /**
     * Release resources that are being held.
     *
     * @throws IOException If there is an error closing this resource.
     */
    public void close() throws IOException;

    /**
     * Seek to a position in the data.
     *
     * @param position The position to seek to.
     * @throws IOException If there is an error while seeking.
     */
    public void seek(long position) throws IOException;

    /**
     * Read a single byte of data.
     *
     * @return The byte of data that is being read.
     *
     * @throws IOException If there is an error while reading the data.
     */
    public int read() throws IOException;

    /**
     * Read a buffer of data.
     *
     * @param b The buffer to write the data to.
     * @param offset Offset into the buffer to start writing.
     * @param length The amount of data to attempt to read.
     * @return The number of bytes that were actually read.
     * @throws IOException If there was an error while reading the data.
     */
    public int read(byte[] b, int offset, int length) throws IOException;

    /**
     * The total number of bytes that are available.
     *
     * @return The number of bytes available.
     *
     * @throws IOException If there is an IO error while determining the
     * length of the data stream.
     */
    public long length() throws IOException;

    /**
     * Write a byte to the stream.
     *
     * @param b The byte to write.
     * @throws IOException If there is an IO error while writing.
     */
    public void write(int b) throws IOException;

    /**
     * Write a buffer of data to the stream.
     *
     * @param b The buffer to get the data from.
     * @param offset An offset into the buffer to get the data from.
     * @param length The length of data to write.
     * @throws IOException If there is an error while writing the data.
     */
    public void write(byte[] b, int offset, int length) throws IOException;

}