| package org.apache.lucene.store; |
| |
| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Apache" and "Apache Software Foundation" and |
| * "Apache Lucene" must not be used to endorse or promote products |
| * derived from this software without prior written permission. For |
| * written permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * "Apache Lucene", nor may "Apache" appear in their name, without |
| * prior written permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| import java.io.IOException; |
| |
| /* |
| Java's filesystem API is not used directly, but rather through these |
| classes. This permits: |
| . implementation of RAM-based indices, useful for summarization, etc.; |
| . implementation of an index as a single file. |
| |
| */ |
| |
| /** |
| A Directory is a flat list of files. Files may be written once, |
| when they are created. Once a file is created it may only be opened for |
| read, or deleted. Random access is permitted when reading and writing. |
| |
| @author Doug Cutting |
| */ |
| |
| abstract public class Directory { |
| /** Returns an array of strings, one for each file in the directory. */ |
| abstract public String[] list() |
| throws IOException, SecurityException; |
| |
| /** Returns true iff a file with the given name exists. */ |
| abstract public boolean fileExists(String name) |
| throws IOException, SecurityException; |
| |
| /** Returns the time the named file was last modified. */ |
| abstract public long fileModified(String name) |
| throws IOException, SecurityException; |
| |
| /** Removes an existing file in the directory. */ |
| abstract public void deleteFile(String name) |
| throws IOException, SecurityException; |
| |
| /** Renames an existing file in the directory. |
| If a file already exists with the new name, then it is replaced. |
| This replacement should be atomic. */ |
| abstract public void renameFile(String from, String to) |
| throws IOException, SecurityException; |
| |
| /** Returns the length of a file in the directory. */ |
| abstract public long fileLength(String name) |
| throws IOException, SecurityException; |
| |
| /** Creates a new, empty file in the directory with the given name. |
| Returns a stream writing this file. */ |
| abstract public OutputStream createFile(String name) |
| throws IOException, SecurityException; |
| |
| /** Returns a stream reading an existing file. */ |
| abstract public InputStream openFile(String name) |
| throws IOException, SecurityException; |
| |
| /** Construct a {@link Lock}. |
| * @param name the name of the lock file |
| */ |
| abstract public Lock makeLock(String name); |
| |
| /** Closes the store. */ |
| abstract public void close() |
| throws IOException, SecurityException; |
| } |