WifiNetworkScoreCache.java revision f6c6d3ccda924ad5f11883bc346b4eb4ada1bc06 
1/*
2 * Copyright (C) 2014 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.Manifest.permission;
20import android.content.Context;
21import android.net.INetworkScoreCache;
22import android.net.NetworkKey;
23import android.net.ScoredNetwork;
24import android.net.wifi.ScanResult;
25import android.net.wifi.WifiManager;
26import android.util.Log;
27
28import java.io.FileDescriptor;
29import java.io.PrintWriter;
30import java.util.HashMap;
31import java.util.List;
32import java.util.Map;
33
34public class WifiNetworkScoreCache extends INetworkScoreCache.Stub
35 {
36
37    private static String TAG = "WifiNetworkScoreCache";
38    private boolean DBG = true;
39    private final Context mContext;
40
41    // The key is of the form "<ssid>"<bssid>
42    // TODO: What about SSIDs that can't be encoded as UTF-8?
43    private final Map<String, ScoredNetwork> mNetworkCache;
44
45    public WifiNetworkScoreCache(Context context) {
46        mContext = context;
47        mNetworkCache = new HashMap<String, ScoredNetwork>();
48    }
49
50     @Override public final void updateScores(List<android.net.ScoredNetwork> networks) {
51        if (networks == null) {
52            return;
53        }
54        Log.e(TAG, "updateScores list size=" + networks.size());
55
56        synchronized(mNetworkCache) {
57            for (ScoredNetwork network : networks) {
58                String networkKey = buildNetworkKey(network);
59                if (networkKey == null) continue;
60                mNetworkCache.put(networkKey, network);
61            }
62        }
63     }
64
65     @Override public final void clearScores() {
66         synchronized (mNetworkCache) {
67             mNetworkCache.clear();
68         }
69     }
70
71    public boolean isScoredNetwork(ScanResult result) {
72        String key = buildNetworkKey(result);
73        if (key == null) return false;
74
75        //find it
76        synchronized(mNetworkCache) {
77            ScoredNetwork network = mNetworkCache.get(key);
78            if (network != null) {
79                return true;
80            }
81        }
82        return false;
83    }
84
85    public int getNetworkScore(ScanResult result) {
86
87        int score = -1;
88
89        String key = buildNetworkKey(result);
90        if (key == null) return score;
91
92        //find it
93        synchronized(mNetworkCache) {
94            ScoredNetwork network = mNetworkCache.get(key);
95            if (network != null && network.rssiCurve != null) {
96                score = network.rssiCurve.lookupScore(result.level);
97                if (DBG) {
98                    Log.e(TAG, "getNetworkScore found Herrevad network" + key
99                            + " score " + Integer.toString(score)
100                            + " RSSI " + result.level);
101                }
102            }
103        }
104        return score;
105    }
106
107    private String buildNetworkKey(ScoredNetwork network) {
108        if (network.networkKey == null) return null;
109        if (network.networkKey.wifiKey == null) return null;
110        if (network.networkKey.type == NetworkKey.TYPE_WIFI) {
111            String key = network.networkKey.wifiKey.ssid;
112            if (key == null) return null;
113            if (network.networkKey.wifiKey.bssid != null) {
114                key = key + network.networkKey.wifiKey.bssid;
115            }
116            return key;
117        }
118        return null;
119    }
120
121    private String buildNetworkKey(ScanResult result) {
122        if (result.SSID == null) {
123            return null;
124        }
125        StringBuilder key = new StringBuilder("\"");
126        key.append(result.SSID);
127        key.append("\"");
128        if (result.BSSID != null) {
129            key.append(result.BSSID);
130        }
131        return key.toString();
132    }
133
134    @Override protected final void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
135        mContext.enforceCallingOrSelfPermission(permission.DUMP, TAG);
136        writer.println("WifiNetworkScoreCache");
137        writer.println("  All score curves:");
138        for (Map.Entry<String, ScoredNetwork> entry : mNetworkCache.entrySet()) {
139            writer.println("    " + entry.getKey() + ": " + entry.getValue().rssiCurve);
140        }
141        writer.println("  Current network scores:");
142        WifiManager wifiManager = (WifiManager) mContext.getSystemService(Context.WIFI_SERVICE);
143        for (ScanResult scanResult : wifiManager.getScanResults()) {
144            writer.println("    " + buildNetworkKey(scanResult) + ": " + getNetworkScore(scanResult));
145        }
146    }
147
148}
149