internal async Task EnsurePartitionSwitchedAsync(string partitionKey, TableRequestOptions requestOptions, OperationContext operationContext)
{
var metaQuery = new TableQuery <MTableEntity>
{
FilterString = ChainTableUtils.GeneratePointRetrievalFilterCondition(
new PrimaryKey(partitionKey, ROW_KEY_PARTITION_META))
};
Recheck:
MTablePartitionState? state;
if (IsBugEnabled(MTableOptionalBug.EnsurePartitionSwitchedFromPopulated))
{
state = null;
}
else
{
state =
(from r in (await oldTable.ExecuteQueryAtomicAsync(metaQuery, requestOptions, operationContext))
select r.partitionState).SingleOrDefault();
await monitor.AnnotateLastBackendCallAsync();
}
switch (state)
{
case null:
try
{
await oldTable.ExecuteAsync(TableOperation.Insert(new MTableEntity
{
PartitionKey = partitionKey,
RowKey = ROW_KEY_PARTITION_META,
partitionState = MTablePartitionState.SWITCHED
}), requestOptions, operationContext);
}
catch (StorageException ex)
{
if (ex.GetHttpStatusCode() != HttpStatusCode.Conflict)
{
throw ChainTableUtils.GenerateInternalException(ex);
}
if (!IsBugEnabled(MTableOptionalBug.EnsurePartitionSwitchedFromPopulated))
{
await monitor.AnnotateLastBackendCallAsync();
// We could now be in POPULATED or SWITCHED.
// XXX: In production, what's more likely? Is it faster
// to recheck first or just try the case below?
goto Recheck;
}
}
await monitor.AnnotateLastBackendCallAsync();
return;
case MTablePartitionState.POPULATED:
try
{
var batch = new TableBatchOperation();
batch.Replace(new MTableEntity
{
PartitionKey = partitionKey,
RowKey = ROW_KEY_PARTITION_META,
ETag = ChainTable2Constants.ETAG_ANY,
partitionState = MTablePartitionState.SWITCHED
});
batch.Delete(new MTableEntity
{
PartitionKey = partitionKey,
RowKey = ROW_KEY_PARTITION_POPULATED_ASSERTION,
ETag = ChainTable2Constants.ETAG_ANY,
});
await oldTable.ExecuteBatchAsync(batch, requestOptions, operationContext);
}
catch (ChainTableBatchException ex)
{
// The only way this can fail (within the semantics) is
// if someone else moved the partition to SWITCHED.
if (!(ex.FailedOpIndex == 1 && ex.GetHttpStatusCode() == HttpStatusCode.NotFound))
{
throw ChainTableUtils.GenerateInternalException(ex);
}
}
await monitor.AnnotateLastBackendCallAsync();
return;
case MTablePartitionState.SWITCHED:
// Nothing to do
return;
}
}
