private async Task <TAutoNrData> UpdateAutoNrWithRetries <TSequenceData, TAutoNrData>(string sequence, string aggregateId, AutoNrUpdater <TSequenceData, TAutoNrData> updater, int retries)
where TSequenceData : class
where TAutoNrData : class
{
var sequenceRow = await GetSequenceRow(sequence); // or null
if (sequenceRow == null)
{
throw new Exception($"Sequence not found: {sequence}");
}
var idRow = await GetIdRow(sequence, aggregateId);
if (idRow == null)
{
throw new Exception($"Agreggate with id {aggregateId} not found in sequence {sequence}");
}
var nrRow = await GetNrRow(sequence, idRow.Nr);
if (nrRow == null)
{
throw new Exception($"Agreggate with id {aggregateId} not found in sequence {sequence}");
}
var prevNrRow = await GetNrRow(sequence, idRow.Nr - 1);
var nextNrRow = await GetNrRow(sequence, idRow.Nr + 1);
var result = updater(
nrRow.GetData <TAutoNrData>(),
sequenceRow.GetData <TSequenceData>(),
prevNrRow != null ? prevNrRow.GetData <TAutoNrData>() : null,
nextNrRow != null ? nextNrRow.GetData <TAutoNrData>() : null);
sequenceRow.SetData(result.SequenceData);
nrRow.SetData(result.NrData);
var batch = new TableBatchOperation();
batch.Add(TableOperation.Replace(sequenceRow)); // OperationIndex 0
batch.Add(TableOperation.Replace(nrRow)); // OperationIndex 1
if (prevNrRow != null)
{
batch.Add(TableOperation.Merge(prevNrRow)); // OperationIndex 2
}
if (nextNrRow != null)
{
batch.Add(TableOperation.Merge(nextNrRow)); // OperationIndex 2 or 3
}
try
{
await table.ExecuteBatchAsync(batch);
}
catch (StorageException storageException)
{
int operationIndex;
string errorCode;
if (!TryParseStorageException(storageException, out operationIndex, out errorCode))
{
throw;
}
if (errorCode == "UpdateConditionNotSatisfied")
{
if (retries >= 0)
{
return(await UpdateAutoNrWithRetries(sequence, aggregateId, updater, retries - 1));
}
var rowName = new string[] { "sequence", "auto-nr", "prev-auto-nr", "next-auto-nr" }[operationIndex];
throw new AutoNrOptimisticException($"Optimistic lock failed because {rowName} has changed. Sequence: {sequence}, nr:{idRow.Nr}.");
}
throw;
}
return(result.NrData);
}
public async Task <TAutoNrData> UpdateAutoNr <TSequenceData, TAutoNrData>(string sequence, string aggregateId, AutoNrUpdater <TSequenceData, TAutoNrData> updater)
where TSequenceData : class
where TAutoNrData : class
{
return(await UpdateAutoNrWithRetries(sequence, aggregateId, updater, MaxRetries));
}
public Task <TNrData> UpdateAutoNr <TSequenceData, TNrData>(string sequence, string aggregateId, AutoNrUpdater <TSequenceData, TNrData> updater)
where TSequenceData : class
where TNrData : class
{
Sequence contextLock = sequences[sequence];
if (contextLock == null)
{
throw new Exception($"Sequence not found: {sequence}");
}
lock (contextLock) // only one thread per context
{
var context = sequences[sequence];
if (context == null)
{
throw new Exception($"Sequence not found: {sequence}");
}
long seqNr;
if (!context.TryGet(aggregateId, out seqNr))
{
throw new Exception($"Agreggate with id {aggregateId} not found in sequence {sequence}");
}
var data = context.GetAutoNrDataByNr <TNrData>(seqNr);
var prev = context.GetAutoNrDataByNr <TNrData>(seqNr - 1);
var next = context.GetAutoNrDataByNr <TNrData>(seqNr + 1);
var result = updater(data, context.GetConfig <TSequenceData>(), prev, next);
context.SetData(aggregateId, seqNr, result.NrData);
context.SetConfig(result.SequenceData);
return(Task.FromResult(result.NrData));
}
}
