WifiScoreReport.java revision 33d55307b8e4a03b7ace877968585002ec37dbea 
1/*
2 * Copyright (C) 2016 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 com.android.server.wifi;
18
19import android.content.Context;
20import android.net.NetworkAgent;
21import android.net.wifi.WifiInfo;
22import android.util.Log;
23
24import java.io.FileDescriptor;
25import java.io.PrintWriter;
26import java.text.SimpleDateFormat;
27import java.util.Date;
28import java.util.LinkedList;
29import java.util.Locale;
30
31/**
32 * Class used to calculate scores for connected wifi networks and report it to the associated
33 * network agent.
34*/
35public class WifiScoreReport {
36    private static final String TAG = "WifiScoreReport";
37
38    private static final int DUMPSYS_ENTRY_COUNT_LIMIT = 14400; // 12 hours on 3 second poll
39
40    private boolean mVerboseLoggingEnabled = false;
41    private static final long FIRST_REASONABLE_WALL_CLOCK = 1490000000000L; // mid-December 2016
42
43    // Cache of the last score report.
44    private String mReport;
45    private boolean mReportValid = false;
46
47    private final Clock mClock;
48    private int mSessionNumber = 0;
49
50    ConnectedScore mConnectedScore;
51    ConnectedScore mAggressiveConnectedScore;
52
53    WifiScoreReport(Context context, WifiConfigManager wifiConfigManager, Clock clock) {
54        mClock = clock;
55        mConnectedScore = new LegacyConnectedScore(context, wifiConfigManager, clock);
56        mAggressiveConnectedScore = new AggressiveConnectedScore(context, clock);
57    }
58
59    /**
60     * Method returning the String representation of the last score report.
61     *
62     *  @return String score report
63     */
64    public String getLastReport() {
65        return mReport;
66    }
67
68    /**
69     * Reset the last calculated score.
70     */
71    public void reset() {
72        mReport = "";
73        if (mReportValid) {
74            mSessionNumber++;
75            mReportValid = false;
76        }
77        mConnectedScore.reset();
78        mAggressiveConnectedScore.reset();
79        if (mVerboseLoggingEnabled) Log.d(TAG, "reset");
80    }
81
82    /**
83     * Checks if the last report data is valid or not. This will be cleared when {@link #reset()} is
84     * invoked.
85     *
86     * @return true if valid, false otherwise.
87     */
88    public boolean isLastReportValid() {
89        return mReportValid;
90    }
91
92    /**
93     * Enable/Disable verbose logging in score report generation.
94     */
95    public void enableVerboseLogging(boolean enable) {
96        mVerboseLoggingEnabled = enable;
97    }
98
99    /**
100     * Calculate wifi network score based on updated link layer stats and send the score to
101     * the provided network agent.
102     *
103     * If the score has changed from the previous value, update the WifiNetworkAgent.
104     *
105     * Called periodically (POLL_RSSI_INTERVAL_MSECS) about every 3 seconds.
106     *
107     * @param wifiInfo WifiInfo instance pointing to the currently connected network.
108     * @param networkAgent NetworkAgent to be notified of new score.
109     * @param aggressiveHandover int current aggressiveHandover setting.
110     * @param wifiMetrics for reporting our scores.
111     */
112    public void calculateAndReportScore(WifiInfo wifiInfo, NetworkAgent networkAgent,
113                                        int aggressiveHandover, WifiMetrics wifiMetrics) {
114        int score;
115
116        long millis = mConnectedScore.getMillis();
117
118        mConnectedScore.updateUsingWifiInfo(wifiInfo, millis);
119        mAggressiveConnectedScore.updateUsingWifiInfo(wifiInfo, millis);
120
121        int s0 = mConnectedScore.generateScore();
122        int s1 = mAggressiveConnectedScore.generateScore();
123
124        if (aggressiveHandover == 0) {
125            score = s0;
126        } else {
127            score = s1;
128        }
129
130        //sanitize boundaries
131        if (score > NetworkAgent.WIFI_BASE_SCORE) {
132            score = NetworkAgent.WIFI_BASE_SCORE;
133        }
134        if (score < 0) {
135            score = 0;
136        }
137
138        logLinkMetrics(wifiInfo, s0, s1);
139
140        //report score
141        if (score != wifiInfo.score) {
142            if (mVerboseLoggingEnabled) {
143                Log.d(TAG, " report new wifi score " + score);
144            }
145            wifiInfo.score = score;
146            if (networkAgent != null) {
147                networkAgent.sendNetworkScore(score);
148            }
149        }
150
151        mReport = String.format(Locale.US, " score=%d", score);
152        mReportValid = true;
153        wifiMetrics.incrementWifiScoreCount(score);
154    }
155
156    /**
157     * Data for dumpsys
158     *
159     * These are stored as csv formatted lines
160     */
161    private LinkedList<String> mLinkMetricsHistory = new LinkedList<String>();
162
163    /**
164     * Data logging for dumpsys
165     */
166    private void logLinkMetrics(WifiInfo wifiInfo, int s0, int s1) {
167        long now = mClock.getWallClockMillis();
168        if (now < FIRST_REASONABLE_WALL_CLOCK) return;
169        double rssi = wifiInfo.getRssi();
170        int freq = wifiInfo.getFrequency();
171        int linkSpeed = wifiInfo.getLinkSpeed();
172        double txSuccessRate = wifiInfo.txSuccessRate;
173        double txRetriesRate = wifiInfo.txRetriesRate;
174        double txBadRate = wifiInfo.txBadRate;
175        double rxSuccessRate = wifiInfo.rxSuccessRate;
176        try {
177            String timestamp = new SimpleDateFormat("MM-dd HH:mm:ss.SSS").format(new Date(now));
178            String s = String.format(Locale.US, // Use US to avoid comma/decimal confusion
179                    "%s,%d,%.1f,%d,%d,%.2f,%.2f,%.2f,%.2f,%d,%d",
180                    timestamp, mSessionNumber, rssi, freq, linkSpeed,
181                    txSuccessRate, txRetriesRate, txBadRate, rxSuccessRate,
182                    s0, s1);
183            mLinkMetricsHistory.add(s);
184        } catch (Exception e) {
185            Log.e(TAG, "format problem", e);
186        }
187        while (mLinkMetricsHistory.size() > DUMPSYS_ENTRY_COUNT_LIMIT) {
188            mLinkMetricsHistory.removeFirst();
189        }
190    }
191
192    /**
193     * Tag to be used in dumpsys request
194     */
195    public static final String DUMP_ARG = "WifiScoreReport";
196
197    /**
198     * Dump logged signal strength and traffic measurements.
199     * @param fd unused
200     * @param pw PrintWriter for writing dump to
201     * @param args unused
202     */
203    public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
204        pw.println("time,session,rssi,freq,linkspeed,tx_good,tx_retry,tx_bad,rx,s0,s1");
205        for (String line : mLinkMetricsHistory) {
206            pw.println(line);
207        }
208    }
209}
210