1 /*
2  * Copyright (C) 2020 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 android.util;
18 
19 import android.annotation.NonNull;
20 import android.annotation.SystemApi;
21 import android.annotation.UptimeMillisLong;
22 import android.os.SystemClock;
23 
24 import com.android.internal.annotations.VisibleForTesting;
25 
26 /**
27  * Writes an EventLog event capturing the performance of system config file writes.
28  * The event log entry is formatted like this:
29  * <code>525000 commit_sys_config_file (name|3),(time|2|3)</code>, where <code>name</code> is
30  * a short unique name representing the type of configuration file and <code>time</code> is
31  * duration in the {@link SystemClock#uptimeMillis()} time base.
32  *
33  * @hide
34  */
35 @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
36 public class SystemConfigFileCommitEventLogger {
37     private final String mName;
38     private long mStartTime;
39 
40     /**
41      * @param name The short name of the config file that is included in the event log event,
42      *             e.g. "jobs", "appops", "uri-grants" etc.
43      */
SystemConfigFileCommitEventLogger(@onNull String name)44     public SystemConfigFileCommitEventLogger(@NonNull String name) {
45         mName = name;
46     }
47 
48     /**
49      * Override the start timestamp.  Use this method when it's desired to include the time
50      * taken by the preparation of the configuration data in the overall duration of the
51      * "commitSysConfigFile" event.
52      *
53      * @param startTime Overridden start time, in system uptime milliseconds
54      */
setStartTime(@ptimeMillisLong long startTime)55     public void setStartTime(@UptimeMillisLong long startTime) {
56         mStartTime = startTime;
57     }
58 
59     /**
60      * Invoked just before the configuration file writing begins.
61      * @hide
62      */
onStartWrite()63     public void onStartWrite() {
64         if (mStartTime == 0) {
65             mStartTime = SystemClock.uptimeMillis();
66         }
67     }
68 
69     /**
70      * Invoked just after the configuration file writing ends.
71      * @hide
72      */
onFinishWrite()73     public void onFinishWrite() {
74         writeLogRecord(SystemClock.uptimeMillis() - mStartTime);
75     }
76 
77     /**
78      * The actual write of the log record.
79      * @hide
80      */
81     @VisibleForTesting
writeLogRecord(long durationMs)82     public void writeLogRecord(long durationMs) {
83         com.android.internal.logging.EventLogTags.writeCommitSysConfigFile(mName, durationMs);
84     }
85 }
86