1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.eclipse.aether.spi.connector.checksum;
20
21 import java.nio.ByteBuffer;
22
23 /**
24 * Implementation performing checksum calculation for specific algorithm. Instances of this interface are stateful,
25 * non-thread safe, and should not be reused.
26 *
27 * @since 1.8.0
28 */
29 public interface ChecksumAlgorithm {
30 /**
31 * Updates the checksum algorithm inner state with input.
32 */
33 void update(ByteBuffer input);
34
35 /**
36 * Returns the algorithm end result as string, never {@code null}. After invoking this method, this instance should
37 * be discarded and not reused. For new checksum calculation you have to get new instance.
38 *
39 * Values returned by this method are handled as "opaque strings", and are used for simple equality checks (matches
40 * or not matches the checksum), and are also persisted in this form (locally to file system but also uploaded as
41 * checksum files). Resolver itself never tries to "decode" or "interpret" this string in any other way.
42 */
43 String checksum();
44 }