// write given buffer to db
// displays form to user to please wait
// could make use of BackgroundWorker to prevent lockup, or async
public void Write(WatcherEventBuffer buffer)
{
// get lock on db
lock (lockObj) {
// ensure the connection is alive first
if (!AliveCheck())
{
return;
}
// get buffer as new queue (to avoid having to keep is locked during DB write)
Queue <WatcherEventArgs> queue = buffer.DequeueToQueue();
// form to display to user while writing to db
FormWriteWait waitForm = new FormWriteWait();
waitForm.Show();
waitForm.Refresh();
try {
// create command obj
SQLiteCommand com = sqlite_connection.CreateCommand();
while (queue.Count > 0)
{
// dequque
WatcherEventArgs args = queue.Dequeue();
// generate insert and execute
com.CommandText = GenerateInsert(args);
com.ExecuteNonQuery();
}
} catch (Exception e) {
// check if is an SQLite exception
// just to avoid having to do 2 of almost the same catch blocks
if (e is SQLiteException)
{
System.Windows.Forms.MessageBox.Show(string.Format("Failed to write to database\nSQLite Exception: {0}", e.Message));
}
else
{
System.Windows.Forms.MessageBox.Show(string.Format("Failed to write to database\nException: {0}", e.Message));
}
}
// close form
waitForm.Close();
// pass remaining queue back to buffer (if there was an error)
while (queue.Count > 0)
{
buffer.Enqueue(queue.Dequeue());
}
}
}
// Form constructor
public FormMonitor()
{
// Build GUI
InitializeComponent();
// setup event between Watcher and Form
Watcher.WatcherEvent = new WatcherEventHandler(EH_MonitorEvent);
// Create buffer
eventBuffer = new WatcherEventBuffer();
// create DB obj (not connected to anything)
eventDB = new EventDatabase();
}