Android 网络流量监听开源项目-ConnectionClass源码分析

 1  /**
 2      * AsyncTask for handling downloading and making calls to the timer.
 3      */
 4     private class DownloadImage extends AsyncTask<String, Void, Void> {
 5 
 6         @Override
 7         protected void onPreExecute() {
 8             mDeviceBandwidthSampler.startSampling();
 9             mRunningBar.setVisibility(View.VISIBLE);
10         }
11 
12         @Override
13         protected Void doInBackground(String... url) {
14             String imageURL = url[0];
15             try {
16                 // Open a stream to download the image from our URL.
17                 InputStream input = new URL(imageURL).openStream();
18                 try {
19                     byte[] buffer = new byte[1024];
20 
21                     // Do some busy waiting while the stream is open.
22                     while (input.read(buffer) != -1) {
23                     }
24                 } finally {
25                     input.close();
26                 }
27             } catch (IOException e) {
28                 Log.e(TAG, "Error while downloading image.");
29             }
30             return null;
31         }
32 
33         @Override
34         protected void onPostExecute(Void v) {
35             mDeviceBandwidthSampler.stopSampling();
36             // Retry for up to 10 times until we find a ConnectionClass.
37             if (mConnectionClass == ConnectionQuality.UNKNOWN && mTries < 10) {
38                 mTries++;
39                 new DownloadImage().execute(mURL);
40             }
41             if (!mDeviceBandwidthSampler.isSampling()) {
42                 mRunningBar.setVisibility(View.GONE);
43             }
44         }
45     }

 1  /**
 2      * Method call to start sampling for download bandwidth.
 3      */
 4     public void startSampling() {
 5         if (mSamplingCounter.getAndIncrement() == 0) {
 6             mHandler.sendEmptyMessage(SamplingHandler.MSG_START);
 7             long lastTimeReading = SystemClock.elapsedRealtime();
 8             mLastTimeReading = lastTimeReading;
 9         }
10     }

 1 private class SamplingHandler extends Handler {
 2         static final int MSG_START = 1;
 3         static final int MSG_STOP = 2;
 4 
 5         public SamplingHandler(Looper looper) {
 6             super(looper);
 7         }
 8 
 9         @Override
10         public void handleMessage(Message msg) {
11             switch (msg.what) {
12                 case MSG_START:
13                     addSample();
14                     sendEmptyMessageDelayed(MSG_START, SAMPLE_TIME);
15                     break;
16                 case MSG_STOP:
17                     addFinalSample();
18                     removeMessages(MSG_START);
19                     break;
20                 default:
21                     throw new IllegalArgumentException("Unknown what=" + msg.what);
22             }
23         }

 1 /**
 2          * Method for polling for the change in total bytes since last update and
 3          * adding it to the BandwidthManager.
 4          */
 5         private void addSample() {
 6             long byteDiff = QTagParser.getInstance().parseDataUsageForUidAndTag(Process.myUid());
 7             synchronized (this) {
 8                 long curTimeReading = SystemClock.elapsedRealtime();
 9                 if (byteDiff != -1) {
10                     mConnectionClassManager.addBandwidth(byteDiff, curTimeReading - mLastTimeReading);
11                 }
12                 mLastTimeReading = curTimeReading;
13             }
14         }

 1 /**
 2      * Reads the qtaguid file and returns a difference from the previous read.
 3      *
 4      * @param uid The target uid to read bytes downloaded for.
 5      * @return The difference between the current number of bytes downloaded and
 6      */
 7     public long parseDataUsageForUidAndTag(int uid) {
 8         // The format of each line is
 9         // idx iface acct_tag_hex uid_tag_int cnt_set rx_bytes rx_packets tx_bytes
10         // (There are many more fields but we are not interested in them)
11         // For us parts: 1, 2, 3 are to see if the line is relevant
12         // and part 5 is the received bytes
13         // (part numbers start from 0)
14 
15         // Permit disk reads here, as /proc/net/xt_qtaguid/stats isn‘t really "on
16         // disk" and should be fast.
17         StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
18         try {
19             long tagRxBytes = 0;
20 
21             FileInputStream fis = new FileInputStream(mPath);
22             //sStatsReader.setFileStream(fis);
23             // writeFileToSD(sStatsReader);
24             sStatsReader.setFileStream(fis);
25             byte[] buffer = sLineBuffer.get();
26             try {
27                 int length;
28                 sStatsReader.readLine(buffer);
29                 sStatsReader.skipLine(); // skip first line (headers)
30 
31                 int line = 2;
32                 while ((length = sStatsReader.readLine(buffer)) != -1) {
33                     try {
34 
35                         // Content is arranged in terms of:
36                         // idx iface acct_tag_hex uid_tag_int cnt_set rx_bytes rx_packets tx_bytes tx_packets rx_tcp_bytes
37                         // rx_tcp_packets rx_udp_bytes rx_udp_packets rx_other_bytes rx_other_packets tx_tcp_bytes tx_tcp_packets
38                         // tx_udp_bytes tx_udp_packets tx_other_bytes tx_other_packets
39 
40                         // The ones we‘re interested in are:
41                         // idx - ignore
42                         // interface, filter out local interface ("lo")
43                         // tag - ignore
44                         // uid_tag_int, match it with the UID of interest
45                         // cnt_set - ignore
46                         // rx_bytes
47                         //Log.v("burning", "buffer==" + new String(buffer));
48                         sScanner.reset(buffer, length);
49                         sScanner.useDelimiter(‘ ‘);
50 
51                         sScanner.skip();
52                         if (sScanner.nextStringEquals("lo")) {
53                             continue;
54                         }
55                         sScanner.skip();
56                         if (sScanner.nextInt() != uid) {
57                             continue;
58                         }
59                         sScanner.skip();
60                         int rxBytes = sScanner.nextInt();
61                         tagRxBytes += rxBytes;
62                         line++;
63 
64                         // If the line is incorrectly formatted, ignore the line.
65                     } catch (NumberFormatException e) {
66                         Log.e(TAG, "Cannot parse byte count at line" + line + ".");
67                         continue;
68                     } catch (NoSuchElementException e) {
69                         Log.e(TAG, "Invalid number of tokens on line " + line + ".");
70                         continue;
71                     }
72                 }
73             } finally {
74                 fis.close();
75             }
76 
77             if (sPreviousBytes == -1) {
78                 sPreviousBytes = tagRxBytes;
79                 return -1;
80             }
81             long diff = tagRxBytes - sPreviousBytes;
82             sPreviousBytes = tagRxBytes;
83             return diff;
84 
85         } catch (IOException e) {
86             Log.e(TAG, "Error reading from /proc/net/xt_qtaguid/stats. Please check if this file exists.");
87         } finally {
88             StrictMode.setThreadPolicy(savedPolicy);
89         }
90 
91         // Return -1 upon error.
92         return -1;
93     }