001 /*
002 * Copyright (c) Andrey Kuznetsov. All Rights Reserved.
003 *
004 * http://uio.imagero.com
005 *
006 * Redistribution and use in source and binary forms, with or without
007 * modification, are permitted provided that the following conditions are met:
008 *
009 * o Redistributions of source code must retain the above copyright notice,
010 * this list of conditions and the following disclaimer.
011 *
012 * o Redistributions in binary form must reproduce the above copyright notice,
013 * this list of conditions and the following disclaimer in the documentation
014 * and/or other materials provided with the distribution.
015 *
016 * o Neither the name of Andrey Kuznetsov nor the names of
017 * its contributors may be used to endorse or promote products derived
018 * from this software without specific prior written permission.
019 *
020 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
021 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
022 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
023 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
024 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
025 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
026 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
027 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
028 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
029 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
030 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
031 */
032 package com.imagero.uio.bio.content;
033
034 import java.io.IOException;
035
036 /**
037 *
038 * @author Andrey Kuznetsov
039 */
040 public abstract class Content {
041
042 /**
043 * Load stream content to specified buffer
044 * @param offset stream offset
045 * @param buffer byte array
046 * @return how much bytes were loaded
047 * @throws java.io.IOException
048 */
049 public final int load(long offset, byte[] buffer) throws IOException {
050 return load(offset, 0, buffer);
051 }
052
053 /**
054 * Load stream content to specified buffer
055 * @param offset stream offset
056 * @param bpos buffer position
057 * @param buffer byte array
058 * @return how much bytes were loaded
059 * @throws java.io.IOException
060 */
061 public abstract int load(long offset, int bpos, byte[] buffer) throws IOException;
062
063 /**
064 * Save buffer content to stream.
065 * Not always supported.
066 * @param offset stream offset
067 * @param bpos buffer position
068 * @param buffer byte array
069 * @param length how much bytes should be saved
070 * @throws java.io.IOException
071 */
072 public abstract void save(long offset, int bpos, byte[] buffer, int length) throws IOException;
073
074 /**
075 * Get stream length. Not always known.
076 * @return
077 * @throws java.io.IOException
078 */
079 public abstract long length() throws IOException;
080
081 /**
082 * close stream
083 */
084 public abstract void close();
085
086 /**
087 * Determine if data may be reloaded or not.
088 * For example: data from InputStream cannot be reloaded,
089 * however if content uses file or memory based cache then it is possible to reload data.
090 * @return true if data can be reloaded.
091 */
092 public abstract boolean canReload();
093
094 public abstract boolean writable();
095
096 protected void finalize() throws Throwable {
097 super.finalize();
098 close();
099 }
100
101
102 }