1 /*
2  * Copyright (C) 2015 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 
17 package com.android.tools.build.apkzlib.zip.utils;
18 
19 import java.io.IOException;
20 import java.io.RandomAccessFile;
21 import javax.annotation.Nonnull;
22 
23 /**
24  * Utility class with utility methods for random access files.
25  */
26 public final class RandomAccessFileUtils {
27 
RandomAccessFileUtils()28     private RandomAccessFileUtils() {}
29 
30     /**
31      * Reads from an random access file until the provided array is filled. Data is read from the
32      * current position in the file.
33      *
34      * @param raf the file to read data from
35      * @param data the array that will receive the data
36      * @throws IOException failed to read the data
37      */
fullyRead(@onnull RandomAccessFile raf, @Nonnull byte[] data)38     public static void fullyRead(@Nonnull RandomAccessFile raf, @Nonnull byte[] data)
39             throws IOException {
40         int r;
41         int p = 0;
42 
43         while ((r = raf.read(data, p, data.length - p)) > 0) {
44             p += r;
45             if (p == data.length) {
46                 break;
47             }
48         }
49 
50         if (p < data.length) {
51             throw new IOException(
52                     "Failed to read "
53                             + data.length
54                             + " bytes from file. Only "
55                             + p
56                             + " bytes could be read.");
57         }
58     }
59 }
60