1 package org.apache.maven.index.reader;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.io.Closeable;
23 import java.io.IOException;
24 import java.io.OutputStream;
25
26 /**
27 * Maven 2 Index writable {@link ResourceHandler}, is capable of saving resources too. Needed only if incremental index
28 * updates are wanted, to store the index state locally, and be able to calculate incremental diffs on next {@link
29 * IndexReader} invocation. Is used by single thread only.
30 *
31 * @see ResourceHandler
32 * @since 5.1.2
33 */
34 public interface WritableResourceHandler
35 extends ResourceHandler
36 {
37 /**
38 * Resource that is writable.
39 */
40 interface WritableResource
41 extends Resource, Closeable
42 {
43 /**
44 * Returns the {@link OutputStream} stream of the resource, if exists, it will replace the existing content, or
45 * if not exists, the resource will be created. The stream should be closed by caller, otherwise resource leaks
46 * might be introduced. How and when content is written is left to implementation, but it is guaranteed that
47 * this method is called only once, and will be followed by {@link #close()} on the resource itself.
48 * Implementation does not have to be "read consistent", in a way to worry what subsequent {@link #read()}
49 * method will return, as mixed calls will not happen on same instance of resource.
50 */
51 OutputStream write()
52 throws IOException;
53 }
54
55 /**
56 * Returns the {@link WritableResource} with {@code name}. Returned locator should be handled as
57 * resource, is {@link Closeable}.
58 *
59 * @param name Resource name, guaranteed to be non-{@code null} and is FS and URL safe string.
60 */
61 WritableResource locate( String name )
62 throws IOException;
63 }