/// <summary>
/// Copy data between Azure storage.
/// 1. Copy a CloudBlobDirectory
/// 2. Cancel the transfer before it finishes with a CancellationToken
/// 3. Store the transfer checkpoint into a file after transfer being cancelled
/// 4. Reload checkpoint from the file
/// 4. Resume the transfer with the loaded checkpoint
/// </summary>
private static async Task BlobDirectoryCopySample()
{
CloudBlobDirectory sourceBlobDir = Util.GetCloudBlobDirectory(ContainerName, "blobdir");
CloudBlobDirectory destBlobDir = Util.GetCloudBlobDirectory(ContainerName, "blobdir2");
// When source is CloudBlobDirectory:
// 1. If recursive is set to true, data movement library matches the source blob name against SearchPattern as prefix.
// 2. Otherwise, data movement library matches the blob with the exact name specified by SearchPattern.
//
// You can also replace the source directory with a CloudFileDirectory instance to copy data from Azure File Storage. If so:
// 1. If recursive is set to true, SearchPattern is not supported. Data movement library simply transfer all azure files
// under the source CloudFileDirectory and its sub-directories.
// 2. Otherwise, data movement library matches the azure file with the exact name specified by SearchPattern.
//
// In the following case, data movement library will copy all blobs with the prefix "azure" in source blob directory.
CopyDirectoryOptions options = new CopyDirectoryOptions()
{
SearchPattern = "azure",
Recursive = true,
};
TransferContext context = new TransferContext();
context.FileTransferred += FileTransferredCallback;
context.FileFailed += FileFailedCallback;
context.FileSkipped += FileSkippedCallback;
// Create CancellationTokenSource used to cancel the transfer
CancellationTokenSource cancellationSource = new CancellationTokenSource();
TransferCheckpoint checkpoint = null;
try
{
Task task = TransferManager.CopyDirectoryAsync(sourceBlobDir, destBlobDir, false /* isServiceCopy */, options, context, cancellationSource.Token);
// Sleep for 1 seconds and cancel the transfer.
// It may fail to cancel the transfer if transfer is done in 1 second. If so, no file will be copied after resume.
Thread.Sleep(1000);
Console.WriteLine("Cancel the transfer.");
cancellationSource.Cancel();
await task;
}
catch (Exception e)
{
Console.WriteLine("The transfer is cancelled: {0}", e.Message);
}
// Store the transfer checkpoint
checkpoint = context.LastCheckpoint;
// Serialize the checkpoint into a file
IFormatter formatter = new BinaryFormatter();
string tempFileName = Guid.NewGuid().ToString();
using (var stream = new FileStream(tempFileName, FileMode.Create, FileAccess.Write, FileShare.None))
{
formatter.Serialize(stream, checkpoint);
}
// Deserialize the checkpoint from the file
using (var stream = new FileStream(tempFileName, FileMode.Open, FileAccess.Read, FileShare.None))
{
checkpoint = formatter.Deserialize(stream) as TransferCheckpoint;
}
File.Delete(tempFileName);
// Create a new TransferContext with the store checkpoint
TransferContext resumeContext = new TransferContext(checkpoint);
resumeContext.FileTransferred += FileTransferredCallback;
resumeContext.FileFailed += FileFailedCallback;
resumeContext.FileSkipped += FileSkippedCallback;
// Record the overall progress
ProgressRecorder recorder = new ProgressRecorder();
resumeContext.ProgressHandler = recorder;
// Resume transfer from the stored checkpoint
Console.WriteLine("Resume the cancelled transfer.");
await TransferManager.CopyDirectoryAsync(sourceBlobDir, destBlobDir, false /* isServiceCopy */, options, resumeContext);
// Print out the final transfer state
Console.WriteLine("Final transfer state: {0}", recorder.ToString());
}
/// <summary>
/// Download data from Azure storage.
/// 1. Download a CloudBlob to an exsiting local file
/// 2. Query the user to overwrite the local file or not in the OverwriteCallback
/// 3. Download another CloudBlob to local with content MD5 validation disabled
/// 4. Show the overall progress of both transfers
/// </summary>
private static async Task BlobDownloadSample()
{
string sourceBlobName1 = "azure_blockblob.png";
string sourceBlobName2 = "azure_blockblob2.png";
string destinationFileName1 = "azure.png";
string destinationFileName2 = "azure_new.png";
// Create the source CloudBlob instances
CloudBlob sourceBlob1 = Util.GetCloudBlob(ContainerName, sourceBlobName1, BlobType.BlockBlob);
CloudBlob sourceBlob2 = Util.GetCloudBlob(ContainerName, sourceBlobName2, BlobType.BlockBlob);
// Create a TransferContext shared by both transfers
TransferContext sharedTransferContext = new TransferContext();
// Show overwrite prompt in console when OverwriteCallback is triggered
sharedTransferContext.OverwriteCallback = (source, destination) =>
{
Console.WriteLine("{0} already exists. Do you want to overwrite it with {1}? (Y/N)", destination, source);
while (true)
{
ConsoleKeyInfo keyInfo = Console.ReadKey(true);
char key = keyInfo.KeyChar;
if (key == 'y' || key == 'Y')
{
Console.WriteLine("User choose to overwrite the destination.");
return(true);
}
else if (key == 'n' || key == 'N')
{
Console.WriteLine("User choose NOT to overwrite the destination.");
return(false);
}
Console.WriteLine("Please press 'y' or 'n'.");
}
};
// Record the overall progress
ProgressRecorder recorder = new ProgressRecorder();
sharedTransferContext.ProgressHandler = recorder;
// Start the blob download
Task task1 = TransferManager.DownloadAsync(sourceBlob1, destinationFileName1, null /* options */, sharedTransferContext);
// Create a DownloadOptions to disable md5 check after data is downloaded. Otherwise, data movement
// library will check the md5 checksum stored in the ContentMD5 property of the source CloudFile/CloudBlob
// You can uncomment following codes, enable ContentMD5Validation and have a try.
// sourceBlob2.Properties.ContentMD5 = "WrongMD5";
// sourceBlob2.SetProperties();
DownloadOptions options = new DownloadOptions();
options.DisableContentMD5Validation = true;
// Start the download
Task task2 = TransferManager.DownloadAsync(sourceBlob2, destinationFileName2, options, sharedTransferContext);
// Wait for both transfers to finish
try
{
await task1;
}
catch (Exception e)
{
// Data movement library will throw a TransferException when user choose to not overwrite the existing destination
Console.WriteLine(e.Message);
}
await task2;
// Print out the final transfer state
Console.WriteLine("Final transfer state: {0}", recorder.ToString());
}