private static PerformanceRecorder DownloadTest <T>(bool useManager = true, bool useRecorder = true, bool useMD5Validation = false) where T : Stream, new()
{
var tasks = new List <Task <PerformanceRecorder> >();
foreach (var n in Enumerable.Range(0, numFiles))
{
var blobName = $"{n}.dat";
var hash = File.ReadAllBytes(Path.Combine(TempFolderPath, $"{n}-md5.dat"));
tasks.Add(DownloadBlob <T>(blobName, hash, useManager: useManager, useRecorder: useRecorder, useMD5Validation: useMD5Validation));
}
PerformanceRecorder recorder = null;
foreach (var result in Task.WhenAll(tasks).Result)
{
if (recorder == null)
{
recorder = result;
}
else
{
recorder.Merge(result);
}
}
Console.WriteLine($"Total time was {recorder.Seconds} seconds at {recorder.AvgMbps} Mbps for {recorder.MBits * 1000 * 1000 / 1024 / 1024 / 8} MB");
return(recorder);
}
/// <summary>
/// Download a file, verify the hash, and return a throughput record of the transfer
/// </summary>
private static async Task <PerformanceRecorder> DownloadBlob <T>(string blobName, byte[] hash, bool useManager = true, bool useRecorder = true, bool useMD5Validation = false) where T : Stream, new()
{
Console.WriteLine($"Starting download of {blobName}");
// Create the source CloudBlob instances
var blob = await Util.GetCloudBlobAsync(ContainerName, blobName, BlobType.BlockBlob);
PerformanceRecorder recorder = null;
using (var stream = new T())
{
recorder = new PerformanceRecorder(useRecorder ? stream : null);
// Start the blob download
recorder.Start();
if (useManager)
{
await TransferManager.DownloadAsync(blob, stream, new DownloadOptions { DisableContentMD5Validation = !useMD5Validation, UseTransactionalMD5 = false }, new SingleTransferContext());
}
else
{
await blob.DownloadToStreamAsync(stream);
}
recorder.Stop();
recorder.Bytes = stream.Length;
if (VerifyStream(stream, hash))
{
Console.WriteLine($"Downloaded {blobName}: Average speed {recorder.AvgMbps} Mbps");
}
else
{
Console.WriteLine($"Failed to download {blobName}: Invalid hash");
}
}
return(recorder);
}