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 package com.android.car.storagemonitoring;
17 
18 import android.annotation.Nullable;
19 import android.car.storagemonitoring.UidIoRecord;
20 import android.util.Slog;
21 import android.util.SparseArray;
22 
23 import com.android.car.CarLog;
24 import com.android.internal.annotations.VisibleForTesting;
25 
26 import java.io.File;
27 import java.io.IOException;
28 import java.nio.file.Files;
29 import java.nio.file.Path;
30 import java.util.List;
31 import java.util.Objects;
32 import java.util.StringTokenizer;
33 
34 /**
35  * Loads I/O stats from procfs
36  *
37  * The Android kernel can be configured to provide uid I/O stats in /proc/uid_io/stats.
38  */
39 public class ProcfsUidIoStatsProvider implements UidIoStatsProvider {
40     private static Path DEFAULT_STATS_FILE = new File("/proc/uid_io/stats").toPath();
41 
42     private final Path mStatsFile;
43 
ProcfsUidIoStatsProvider()44     public ProcfsUidIoStatsProvider() {
45         this(DEFAULT_STATS_FILE);
46     }
47 
48     @VisibleForTesting
ProcfsUidIoStatsProvider(Path statsFile)49     ProcfsUidIoStatsProvider(Path statsFile) {
50         mStatsFile = Objects.requireNonNull(statsFile);
51     }
52 
53     @Nullable
54     @Override
load()55     public SparseArray<UidIoRecord> load() {
56         List<String> lines;
57         SparseArray<UidIoRecord> result = new SparseArray<>();
58         try {
59             lines = Files.readAllLines(mStatsFile);
60         } catch (IOException e) {
61             Slog.w(CarLog.TAG_STORAGE, "can't read I/O stats from " + mStatsFile, e);
62             return null;
63         }
64 
65         for (String line : lines) {
66             StringTokenizer tokenizer = new StringTokenizer(line);
67             if (tokenizer.countTokens() != 11) {
68                 Slog.w(CarLog.TAG_STORAGE, "malformed I/O stats entry: " + line);
69                 return null;
70             }
71 
72             try {
73                 int uid = Integer.valueOf(tokenizer.nextToken());
74                 long foreground_rchar = Long.valueOf(tokenizer.nextToken());
75                 long foreground_wchar = Long.valueOf(tokenizer.nextToken());
76                 long foreground_read_bytes = Long.valueOf(tokenizer.nextToken());
77                 long foreground_write_bytes = Long.valueOf(tokenizer.nextToken());
78                 long background_rchar = Long.valueOf(tokenizer.nextToken());
79                 long background_wchar = Long.valueOf(tokenizer.nextToken());
80                 long background_read_bytes = Long.valueOf(tokenizer.nextToken());
81                 long background_write_bytes = Long.valueOf(tokenizer.nextToken());
82                 long foreground_fsync = Long.valueOf(tokenizer.nextToken());
83                 long background_fsync = Long.valueOf(tokenizer.nextToken());
84 
85                 result.append(uid, new UidIoRecord(uid,
86                             foreground_rchar,
87                             foreground_wchar,
88                             foreground_read_bytes,
89                             foreground_write_bytes,
90                             foreground_fsync,
91                             background_rchar,
92                             background_wchar,
93                             background_read_bytes,
94                             background_write_bytes,
95                             background_fsync));
96 
97             } catch (NumberFormatException e) {
98                 Slog.w(CarLog.TAG_STORAGE, "malformed I/O stats entry: " + line, e);
99                 return null;
100             }
101         }
102 
103         return result;
104     }
105 }
106 
107 
108