private Byte[] PublishMessages(Byte[] data, Queue <LogEntry> publishQueue, TimeSpan timeout)
{
LogBook logBook = DeserializeLogBook(data);
logBook.TrimStaleEntries(DateTime.UtcNow - _minMessageAge);
Int64 logSize = logBook.CalculateLogSize();
// Start slot timer after deserializing log so deserialization doesn't starve the slot time
Stopwatch slotTimer = Stopwatch.StartNew();
DateTime batchTime = DateTime.UtcNow;
// Try to exhaust the publish queue but don't keep a write lock forever
while (publishQueue.Count > 0 && slotTimer.Elapsed < timeout)
{
// Check if the next message will fit in the log
if (logSize + LogEntry.Overhead + publishQueue.Peek().Message.Length > _memoryMappedFile.MaxFileSize)
{
break;
}
// Write the entry to the log
LogEntry entry = publishQueue.Dequeue();
entry.Id = ++logBook.LastId;
entry.Timestamp = batchTime;
logBook.Entries.Add(entry);
logSize += LogEntry.Overhead + entry.Message.Length;
// Skip counting empty messages though, they are skipped on the receiving end anyway
if (entry.Message.Length == 0)
{
continue;
}
Interlocked.Increment(ref _messagesPublished);
}
// Flush the updated log to the memory mapped file
using MemoryStream memoryStream = new MemoryStream((Int32)logSize);
Serializer.Serialize(memoryStream, logBook);
return(memoryStream.ToArray());
}