private async Task ProcessTaskItemsAsync(EmailMassSendingTaskContext context,
ICollection <EmailMassSendingTaskItem> items, CancellationToken cancellationToken)
{
if (!items.Any())
{
return;
}
var delay = _configuration.DelayBetweenSendsInThread ?? TimeSpan.Zero;
var lastItem = items.Last();
foreach (var item in items)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
await ProcessTaskItemAsync(context, item, cancellationToken);
if (item != lastItem)
{
await Task.Delay(delay, cancellationToken);
}
}
}
private async Task ProcessTaskItemAsync(EmailMassSendingTaskContext context,
EmailMassSendingTaskItem item, CancellationToken cancellationToken)
{
item.AttemptsLeft--;
item.Attempt = DateTimeOffset.UtcNow;
var defaultEncoding = _configuration.Encoding == null
? Encoding.UTF8
: Encoding.GetEncoding(_configuration.Encoding);
var encoding = context.GroupConfiguration.Encoding == null
? defaultEncoding
: Encoding.GetEncoding(context.GroupConfiguration.Encoding);
//using var client = new SmtpClient()
var scope = _logger.BeginScope(context.TaskId);
if (_configuration.SmtpClient.Enable ?? true)
{
try
{
using var client = new SmtpClient();
client.Host = _configuration.SmtpClient.Host;
client.Port = _configuration.SmtpClient.Port ?? 25;
client.EnableSsl = _configuration.SmtpClient.UseSsl ?? true;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Credentials =
new NetworkCredential(_configuration.SmtpClient.Username, _configuration.SmtpClient.Password);
using var message = new MailMessage();
message.From = new MailAddress(_configuration.FromAddress, _configuration.FromTitle,
defaultEncoding);
message.BodyEncoding = encoding;
message.SubjectEncoding = encoding;
message.IsBodyHtml = false;
message.Body = encoding.GetString(context.Text);
message.Subject = context.GroupConfiguration.Subject;
message.To.Add(new MailAddress(item.Receiver));
var ts = DateTime.UtcNow;
await client.SendMailAsync(message, cancellationToken);
_logger.LogDebug(
$"Mail to `{item.Receiver}` sent ({DateTime.UtcNow.Subtract(ts).TotalSeconds} s).");
item.Failed = false;
item.Failure = null;
}
catch (Exception e)
{
_logger.LogError(e,
$"Email sending error (item receiver: `{item.Receiver}`)");
item.Failed = true;
item.Failure = e.Message;
item.WaitFor = DateTimeOffset.UtcNow.Add(_configuration.RollUpStrategy.Delay);
}
}
else
{
item.Failed = false;
item.Failure = "Not sent (disabled)";
}
}
private async Task <EmailMassSendingTaskContext> ProcessTaskAsync(EmailMassSendingTaskContext context, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
var buffer = new byte[context.File.Length];
context.File.Position = 0;
await context.File.ReadAsync(buffer, 0, buffer.Length, cancellationToken);
var taskList = JsonConvert.DeserializeObject <EmailMassSendingTask>(Encoding.UTF8.GetString(buffer));
var taskItems = taskList.Items ?? new List <EmailMassSendingTaskItem>();
var allTaskItems = taskItems;
taskItems = allTaskItems.Where(IsReadyToProcess).ToList();
if (!taskItems.Any())
{
_logger.LogDebug($"No task items to process.");
context.Success = true;
return(context);
}
var partedTaskItems = new List <EmailMassSendingTaskItem> [_configuration.Threads];
var threadsCount = _configuration.Threads;
for (var i = 0; i < threadsCount; i++)
{
partedTaskItems[i] = new List <EmailMassSendingTaskItem>();
}
var q = new Queue <EmailMassSendingTaskItem>(taskItems);
for (var i = 0; i < taskItems.Count; i++)
{
partedTaskItems[i % threadsCount].Add(q.Dequeue());
}
Parallel.ForEach(partedTaskItems, new ParallelOptions
{
MaxDegreeOfParallelism = threadsCount
},
(b) =>
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
ProcessTaskItemsAsync(context, b, cancellationToken).GetAwaiter().GetResult();
});
buffer = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(taskList, Formatting.Indented));
context.File.Position = 0;
context.File.SetLength(buffer.Length);
await context.File.WriteAsync(buffer, 0, buffer.Length, cancellationToken);
await context.File.FlushAsync(cancellationToken);
context.Success = allTaskItems.All(x => !IsNotObsolete(x) || (!x.Failed && x.Attempt != null));
context.Total = taskItems.Count;
context.Sent = taskItems.Count(x => x.Attempt != null && !x.Failed);
context.Failed = context.Total - context.Sent;
return(context);
}
