private async Task <ShardWriteOperation> GetOrPopulateOperationCache(Guid shardId)
{
if (!_shardLastOperationCache.ContainsKey(shardId))
{
var totalOperations = _shardRepository.GetTotalShardWriteOperationsCount(shardId);
if (totalOperations != 0)
{
var lastOperation = await _shardRepository.GetShardWriteOperationAsync(shardId, totalOperations);
_shardLastOperationCache.TryAdd(shardId, lastOperation);
}
else
{
return(null);
}
}
return(_shardLastOperationCache[shardId]);
}
/// <summary>
/// Apply all unapplied operations
/// </summary>
public async void ResyncShardWriteOperations()
{
_logger.LogDebug("Resyncing Operations");
foreach (var shard in await _shardRepository.GetAllShardMetadataAsync())
{
_logger.LogInformation("Checking shard " + shard.ShardId);
var unappliedShardOperations = await _shardRepository.GetAllUnappliedOperationsAsync(shard.ShardId);
foreach (var unappliedShardOperation in unappliedShardOperations)
{
ShardWriteOperation lastOperation;
//If the previous operation exists and has been applied
if ((lastOperation = await _shardRepository.GetShardWriteOperationAsync(unappliedShardOperation.Value.Data.ShardId.Value, unappliedShardOperation.Value.Pos - 1)) != null && lastOperation.Applied)
{
string newHash;
//Run shard operation
_writer.ApplyOperationToDatastore(unappliedShardOperation.Value);
await _shardRepository.MarkShardWriteOperationAppliedAsync(unappliedShardOperation.Value.Id);
}
//Reverse all the last operations
else
{
var removeFrom = unappliedShardOperation.Value.Pos;
for (var i = _shardRepository.GetTotalShardWriteOperationsCount(shard.ShardId); i >= removeFrom; i--)
{
_logger.LogWarning("Detected out of order operations from " + removeFrom + ", removing operations onwards.");
_writer.ReverseLocalTransaction(unappliedShardOperation.Value.Data.ShardId.Value, unappliedShardOperation.Value.Data.ShardType, i);
}
//Break out of loop
break;
}
}
}
_logger.LogDebug("Finished Resyncing Operations");
}