1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.util.apk;
18
19import java.io.IOException;
20import java.security.DigestException;
21
22/** Source of data to be digested. */
23interface DataSource {
24
25    /**
26     * Returns the size (in bytes) of the data offered by this source.
27     */
28    long size();
29
30    /**
31     * Feeds the specified region of this source's data into the provided digester.
32     *
33     * @param offset offset of the region inside this data source.
34     * @param size size (in bytes) of the region.
35     */
36    void feedIntoDataDigester(DataDigester md, long offset, int size)
37            throws IOException, DigestException;
38}
39