Tortuga.Chain.SQLiteDataSource.ExecuteAsync C# (CSharp) Method

        protected override async Task<int?> ExecuteAsync(CommandExecutionToken<SQLiteCommand, SQLiteParameter> executionToken, CommandImplementationAsync<SQLiteCommand> implementation, CancellationToken cancellationToken, object state)
        {
            if (executionToken == null)
                throw new ArgumentNullException("executionToken", "executionToken is null.");
            if (implementation == null)
                throw new ArgumentNullException("implementation", "implementation is null.");

            var mode = DisableLocks ? LockType.None : (executionToken as SQLiteCommandExecutionToken)?.LockType ?? LockType.Write;

            var startTime = DateTimeOffset.Now;
            OnExecutionStarted(executionToken, startTime, state);

            IDisposable lockToken = null;
            try
            {
                switch (mode)
                {
                    case LockType.Read: lockToken = await SyncLock.ReaderLockAsync().ConfigureAwait(false); break;
                    case LockType.Write: lockToken = await SyncLock.WriterLockAsync().ConfigureAwait(false); break;
                }

                using (var con = await CreateConnectionAsync(cancellationToken).ConfigureAwait(false))
                {
                    using (var cmd = new SQLiteCommand())
                    {
                        cmd.Connection = con;
                        if (DefaultCommandTimeout.HasValue)
                            cmd.CommandTimeout = (int)DefaultCommandTimeout.Value.TotalSeconds;
                        cmd.CommandText = executionToken.CommandText;
                        cmd.CommandType = executionToken.CommandType;
                        foreach (var param in executionToken.Parameters)
                            cmd.Parameters.Add(param);

                        executionToken.ApplyCommandOverrides(cmd);

                        var rows = await implementation(cmd).ConfigureAwait(false);
                        executionToken.RaiseCommandExecuted(cmd, rows);
                        OnExecutionFinished(executionToken, startTime, DateTimeOffset.Now, rows, state);
                        return rows;
                    }
                }
            }
            catch (Exception ex)
            {
                if (cancellationToken.IsCancellationRequested) //convert SQLiteException into a OperationCanceledException 
                {
                    var ex2 = new OperationCanceledException("Operation was canceled.", ex, cancellationToken);
                    OnExecutionError(executionToken, startTime, DateTimeOffset.Now, ex2, state);
                    throw ex2;
                }
                else
                {
                    OnExecutionError(executionToken, startTime, DateTimeOffset.Now, ex, state);
                    throw;
                }
            }
            finally
            {
                if (lockToken != null)
                    lockToken.Dispose();
            }
        }