static async Task<string> AquireAsync(CloudBlockBlob blob, TimeSpan timeStamp)
{
bool retry = false;
do
{
try
{
return await blob.AcquireLeaseAsync(timeStamp, null);
}
catch (StorageException e)
{
WebException webException = e.InnerException as WebException;
if (webException != null)
{
HttpStatusCode statusCode = ((HttpWebResponse)webException.Response).StatusCode;
if (statusCode == HttpStatusCode.Conflict)
{
Thread.Sleep(500);
retry = true;
}
else if (statusCode == HttpStatusCode.NotFound)
{
blob.UploadText(string.Empty);
retry = true;
}
}
else
{
throw;
}
}
}
while (retry);
return null;
}
private static async Task AppendToBlob(CloudBlockBlob blockBlob, string content, string md5)
{
var leaseId = await blockBlob.AcquireLeaseAsync(TimeSpan.FromSeconds(30), null);
var access = AccessCondition.GenerateLeaseCondition(leaseId);
var options = new BlobRequestOptions();
var context = new OperationContext();
try
{
var blockId = Convert.ToBase64String(Guid.NewGuid().ToByteArray());
using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(content)))
{
stream.Position = 0;
await blockBlob.PutBlockAsync(blockId, stream, md5, access, options, context);
}
var blockList = await blockBlob.DownloadBlockListAsync(BlockListingFilter.Committed, access, options, context);
var blockIds = blockList.Select(x => x.Name).ToList();
blockIds.Add(blockId);
await blockBlob.PutBlockListAsync(blockIds, access, options, context);
}
catch(Exception ex)
{
//TODO - logging
}
finally
{
await blockBlob.ReleaseLeaseAsync(access);
}
}
async Task<string> TakeOutSagaLease(CloudBlockBlob dataBlob)
{
return await dataBlob.AcquireLeaseAsync(null);
}
