private async Task AddConversationForUser(string username, Conversation conversation)
{
var conversationOrderEntity = new OrderedConversationEntity(username, conversation.Id, conversation.Participants, conversation.LastModifiedDateUtc);
var conversationEntity = new ConversationEntity(username, conversation.Id, conversation.Participants,
conversationOrderEntity.RowKey);
TableBatchOperation batchInsert = new TableBatchOperation
{
TableOperation.Insert(conversationEntity),
TableOperation.Insert(conversationOrderEntity)
};
try
{
await table.ExecuteBatchAsync(batchInsert);
}
catch (StorageException e)
{
// Do nothing if the conversation already exists.
// The client should list all conversations periodically or based on events and will get
// the latest list of conversations.
if (e.RequestInformation.HttpStatusCode != 409)
{
throw new StorageErrorException("Failed to reach storage", e);
}
}
}
private async Task UpdateConversationModifiedDateForUser(string username, string conversationId, Message message)
{
ConversationEntity conversationEntity = await RetrieveConversationEntity(username, conversationId);
var newOrderedConversationEntity = new OrderedConversationEntity(
username, conversationId, conversationEntity.GetParticipants(), message.UtcTime);
string oldTicksRowKey = conversationEntity.TicksRowKey;
string newTicksRowKey = newOrderedConversationEntity.RowKey;
conversationEntity.TicksRowKey = newTicksRowKey;
TableBatchOperation batchOperation = new TableBatchOperation
{
TableOperation.Replace(conversationEntity), // will fail if entity has changed since we retrieved it (ETAG)
TableOperation.Delete(new TableEntity(partitionKey: username, rowKey: oldTicksRowKey)
{
ETag = "*"
}), // delete old conversation order entity
TableOperation.Insert(newOrderedConversationEntity) // will fail if another entity with the same ticks exists
};
try
{
await table.ExecuteBatchAsync(batchOperation);
}
catch (StorageException e)
{
throw new StorageErrorException("Failed to update conversation modified time", e);
}
}
public async Task AddMessage(string conversationId, string messageId, Message message)
{
if (message == null)
{
throw new ArgumentNullException(nameof(message));
}
if (string.IsNullOrWhiteSpace(conversationId))
{
throw new ArgumentNullException(nameof(conversationId));
}
if (string.IsNullOrWhiteSpace(messageId))
{
throw new ArgumentNullException(nameof(messageId));
}
if (string.IsNullOrWhiteSpace(message.SenderUsername))
{
throw new ArgumentNullException(nameof(message.SenderUsername));
}
// Add the message first
await messagesStore.AddMessage(conversationId, messageId, message);
// Then update the conversations modified date for each user
ConversationEntity conversationEntity = await RetrieveConversationEntity(message.SenderUsername, conversationId);
var tasks = new List <Task>();
foreach (var participant in conversationEntity.Participants.Split(ParticipantsSeparator))
{
tasks.Add(UpdateConversationModifiedDateForUser(participant, conversationId, message));
}
await Task.WhenAll(tasks);
}
private async Task <ConversationEntity> RetrieveConversationEntity(string username, string conversationId)
{
TableOperation retrieveOperation = TableOperation.Retrieve <ConversationEntity>(partitionKey: username, rowkey: ConversationEntity.ToRowKey(conversationId));
try
{
TableResult tableResult = await table.ExecuteAsync(retrieveOperation);
var entity = (ConversationEntity)tableResult.Result;
if (entity == null)
{
throw new ConversationNotFoundException($"Could not find a conversation with id {conversationId}");
}
return(entity);
}
catch (StorageException e)
{
throw new StorageErrorException($"Could not retrieve conversation {conversationId} from storage", e);
}
}