import android.app.Fragment;
import android.os.Bundle;
+import android.os.FileObserver;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
private BufferedReader mReader;
private Thread mThread;
private volatile boolean mRunning;
+ private FileObserver mDirectoryObserver;
@Override
public void onCreate(Bundle savedInstanceState)
mLogFilePath = getActivity().getFilesDir() + File.separator + CharonVpnService.LOG_FILE;
/* use a handler to update the log view */
mLogHandler = new Handler();
+
+ mDirectoryObserver = new LogDirectoryObserver(getActivity().getFilesDir().getAbsolutePath());
}
@Override
public void onStart()
{
super.onStart();
- mLogView.setText("");
+ startLogReader();
+ mDirectoryObserver.startWatching();
+ }
+
+ @Override
+ public void onStop()
+ {
+ super.onStop();
+ mDirectoryObserver.stopWatching();
+ stopLogReader();
+ }
+
+ /**
+ * Start reading from the log file
+ */
+ private void startLogReader()
+ {
try
{
mReader = new BufferedReader(new FileReader(mLogFilePath));
{
mReader = new BufferedReader(new StringReader(""));
}
+
+ mLogView.setText("");
mRunning = true;
mThread = new Thread(this);
mThread.start();
}
- @Override
- public void onStop()
+ /**
+ * Stop reading from the log file
+ */
+ private void stopLogReader()
{
- super.onStop();
try
{
mRunning = false;
/**
* Write the given log line to the TextView. We strip the prefix off to save
* some space (it is not that helpful for regular users anyway).
+ *
* @param line log line to log
*/
public void logLine(final String line)
while (mRunning)
{
try
- {
+ { /* this works as long as the file is not truncated */
String line = mReader.readLine();
if (line == null)
{ /* wait until there is more to log */
}
}
}
+
+ /**
+ * FileObserver that checks for changes regarding the log file. Since charon
+ * truncates it (for which there is no explicit event) we check for any modification
+ * to the file, keep track of the file size and reopen it if it got smaller.
+ */
+ private class LogDirectoryObserver extends FileObserver
+ {
+ private final File mFile;
+ private long mSize;
+
+ public LogDirectoryObserver(String path)
+ {
+ super(path, FileObserver.CREATE | FileObserver.MODIFY | FileObserver.DELETE);
+ mFile = new File(mLogFilePath);
+ mSize = mFile.length();
+ }
+
+ @Override
+ public void onEvent(int event, String path)
+ {
+ if (path == null || !path.equals(CharonVpnService.LOG_FILE))
+ {
+ return;
+ }
+ switch (event)
+ { /* even though we only subscribed for these we check them,
+ * as strange events are sometimes received */
+ case FileObserver.CREATE:
+ case FileObserver.DELETE:
+ restartLogReader();
+ break;
+ case FileObserver.MODIFY:
+ /* if the size got smaller reopen the log file, as it was probably truncated */
+ long size = mFile.length();
+ if (size < mSize)
+ {
+ restartLogReader();
+ }
+ mSize = size;
+ break;
+ }
+ }
+
+ private void restartLogReader()
+ {
+ /* we are called from a separate thread, so we use the handler */
+ mLogHandler.post(new Runnable() {
+ @Override
+ public void run()
+ {
+ stopLogReader();
+ startLogReader();
+ }
+ });
+ }
+ }
}