/// <summary>
/// Listen database on selected channels
/// </summary>
/// <param name="stoppingToken">Cancellation</param>
/// <returns></returns>
public async Task ListenDb(CancellationToken stoppingToken)
{
await ParallelHelper.Run(() =>
{
Log.Info($"Listening started for DB: {_dbName}");
while (!stoppingToken.IsCancellationRequested)
{
try
{
using (PgSqlDbConnect connect = new PgSqlDbConnect(_connectionString))
{
connect.Open();
connect.UnderlyingConnection.Notification += OnNotification;
connect.Execute($"LISTEN {PgSqlDbConnect.CHANNEL_GENESIS_REQUEST};");
connect.Execute($"LISTEN {PgSqlDbConnect.CHANNEL_GENESIS_DELETE};");
connect.Execute($"LISTEN {PgSqlDbConnect.CHANNEL_BACKUP_REQUEST};");
while (!stoppingToken.IsCancellationRequested && connect.UnderlyingConnection.State == ConnectionState.Open)
{
connect.UnderlyingConnection.Wait(100);
}
}
}
catch (Exception e)
{
Log.Error(e);
Thread.Sleep(1000);
}
}
});
}
/// <summary>
/// Event on DB notification on listened channels occurs
/// </summary>
/// <param name="sender">Sender of event</param>
/// <param name="args">Event arguments</param>
private void OnNotification(object sender, NpgsqlNotificationEventArgs args)
{
try
{
switch (args.Channel)
{
case PgSqlDbConnect.CHANNEL_GENESIS_REQUEST:
{
if (string.IsNullOrEmpty(args.Payload))
{
throw new ArgumentException("Payload is empty");
}
string filePath = Path.Combine(_config["GenesisOutputDir"], args.Payload + ".sql");
FileHelper.DirectoryEnsure(filePath);
string exePath = _config["PgDumpPath"];
string argsText = $"{_config["GenesisArgs"]} --file=\"{filePath}\" {_dbName}";
Log.Info($"RUN {exePath} {argsText}");
Process pgsql = Process.Start(exePath, argsText);
pgsql?.WaitForExit();
using (PgSqlDbConnect connect2 = new PgSqlDbConnect(_connectionString))
{
connect2.Open();
connect2.Execute($"SELECT pg_notify('{PgSqlDbConnect.CHANNEL_GENESIS_RESPOND}', '{filePath}'::TEXT);");
}
break;
}
case PgSqlDbConnect.CHANNEL_GENESIS_DELETE:
{
File.Delete(args.Payload);
break;
}
case PgSqlDbConnect.CHANNEL_BACKUP_REQUEST:
{
string exePath = _config["PgDumpAllPath"];
string filePath = Path.Combine(_config["BackupOutputDir"],
_config["BackupFilePrefix"] + DateTimeHelper.Now.ToString(DateTimeHelper.FORMAT_FULL).Replace(".", "_").Replace(":", "_").Replace(" ", "_") + ".pgbak");
string argsText = $"{_config["BackupArgs"]} --file=\"{filePath}\"";
Log.Info($"RUN {exePath} {argsText}");
Process pgsql = Process.Start(exePath, argsText);
pgsql?.WaitForExit();
break;
}
}
}
catch (Exception ex)
{
Log.Error(ex, $"{args.Channel} [{args.Payload}]");
}
}