This client library enables high-performance, multi-threaded uploading, downloading and copying Azure Storage blobs and containers.
The package depends on the Azure.Storage.DataMovement package and can be used in conjuction with other Data Movement sub-packages, such as Azure.Storage.DataMovement.Files.Shares to transfer data between services.
For this release see notes - https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/storage/Azure.Storage.DataMovement.Blobs/README.md and https://github.com/Azure/azure-sdk-for-net/blob/master/sdk/storage/Azure.Storage.DataMovement.Blobs/CHANGELOG.md
The Azure.Storage.DataMovement.Blobs library uses clients from the Azure.Storage.Blobs package to communicate with the Azure Blob Storage service. For more information see the Azure.Storage.Blobs .
The authenticated blob storage resource needs the following permissions to perform a transfer:
Read
List (for container transfers)
Write
Add (specific to append blobs)
Delete (for cleanup of a failed transfer item)
Create
Key concepts
The Azure Storage Common client library contains shared infrastructure like
[authentication credentials][auth_credentials] and RequestFailedException.
Thread safety
We guarantee that all client instance methods are thread-safe and independent of each other (guideline). This ensures that the recommendation of reusing client instances is always safe, even across threads.
This section demonstrates usage of Data Movement for interacting with blob storage.
Using the TransferManager for Blob Transfers
The TransferManager is the primary class for managing data transfers between storage resources. See Setup the TransferManager sample.
Initializing Blob Storage StorageResource
Azure.Storage.DataMovement.Blobs exposes BlobsStorageResourceProvider to create StorageResource instances for each type of blob (block, page, append) as well as a blob container. The resource provider should be initialized with a credential to properly authenticate the storage resources. The following demonstrates this using an Azure.Core token credential.
To create a blob StorageResource, use the methods FromBlob or FromContainer.
StorageResource container = await blobs.FromContainerAsync(
new Uri("https://myaccount.blob.core.windows.net/container"));
// Block blobs are the default if no options are specified
StorageResource blockBlob = await blobs.FromBlobAsync(
new Uri("https://myaccount.blob.core.windows.net/container/sample-blob-block"),
new BlockBlobStorageResourceOptions());
StorageResource pageBlob = await blobs.FromBlobAsync(
new Uri("https://myaccount.blob.core.windows.net/container/sample-blob-page"),
new PageBlobStorageResourceOptions());
StorageResource appendBlob = await blobs.FromBlobAsync(
new Uri("https://myaccount.blob.core.windows.net/container/sample-blob-append"),
new AppendBlobStorageResourceOptions());
Storage resources can also be initialized with the appropriate client object from Azure.Storage.Blobs. Since these resources will use the credential already present in the client object, no credential is required in the provider when using FromClient(). However, a BlobsStorageResourceProvider must still have a credential if it is to be used in TransferManagerOptions for resuming a transfer.
A copy takes place between two blob StorageResource instances. Copying between to Azure blobs uses PUT from URL REST APIs, which do not transfer data through the machine running DataMovement.
Copy a single blob. Note the destination blob is an append blob, regardless of the first blob's type.
TransferOperation transferOperation = await transferManager.StartTransferAsync(
sourceResource: await blobs.FromContainerAsync(
sourceContainerUri,
new BlobStorageResourceContainerOptions()
{
BlobPrefix = sourceDirectoryName
}),
destinationResource: await blobs.FromContainerAsync(
destinationContainerUri,
new BlobStorageResourceContainerOptions()
{
// all source blobs will be copied as a single type of destination blob
// defaults to block blobs if unspecified
BlobType = BlobType.Block,
BlobPrefix = downloadPath
}));
await transferOperation.WaitForCompletionAsync();
Resume using ShareFilesStorageResourceProvider
To resume a transfer with Blob(s), valid credentials must be provided. See the sample below.
TokenCredential tokenCredential = new DefaultAzureCredential();
BlobsStorageResourceProvider blobs = new(tokenCredential);
TransferManager transferManager = new TransferManager(new TransferManagerOptions()
{
ProvidersForResuming = new List<StorageResourceProvider>() { blobs }
});
// Get resumable transfers from transfer manager
await foreach (TransferProperties properties in transferManager.GetResumableTransfersAsync())
{
// Resume the transfer
if (properties.SourceUri.AbsoluteUri == "https://storageaccount.blob.core.windows.net/containername/blobpath")
{
await transferManager.ResumeTransferAsync(properties.TransferId);
}
}
For applications with preexisting code using Azure.Storage.Blobs, this package provides extension methods for BlobContainerClient to get some of the benefits of the TransferManager with minimal extra code.
Instantiate the BlobContainerClient
BlobServiceClient service = new BlobServiceClient(serviceUri, credential);
BlobContainerClient container = service.GetBlobContainerClient(containerName);
Upload a local directory to the root of the container
TransferOperation transfer = await container.UploadDirectoryAsync(WaitUntil.Started, localPath);
await transfer.WaitForCompletionAsync();
Upload a local directory to a virtual directory in the container by specifying a directory prefix
TransferOperation transfer = await container.UploadDirectoryAsync(WaitUntil.Started, localPath, blobDirectoryPrefix);
await transfer.WaitForCompletionAsync();
Upload a local directory to a virtual directory in the container specifying more advanced options
BlobContainerClientTransferOptions options = new BlobContainerClientTransferOptions
{
BlobContainerOptions = new BlobStorageResourceContainerOptions
{
BlobPrefix = blobDirectoryPrefix
},
TransferOptions = new TransferOptions()
{
CreationMode = StorageResourceCreationMode.OverwriteIfExists,
}
};
TransferOperation transfer = await container.UploadDirectoryAsync(WaitUntil.Started, localPath, options);
await transfer.WaitForCompletionAsync();
Download the entire container to a local directory
TransferOperation transfer = await container.DownloadToDirectoryAsync(WaitUntil.Started, localDirectoryPath);
await transfer.WaitForCompletionAsync();
Download a directory in the container by specifying a directory prefix
TransferOperation transfer = await container.DownloadToDirectoryAsync(WaitUntil.Started, localDirectoryPath2, blobDirectoryPrefix);
await transfer.WaitForCompletionAsync();
Download from the container specifying more advanced options
BlobContainerClientTransferOptions options = new BlobContainerClientTransferOptions
{
BlobContainerOptions = new BlobStorageResourceContainerOptions
{
BlobPrefix = blobDirectoryPrefix
},
TransferOptions = new TransferOptions()
{
CreationMode = StorageResourceCreationMode.OverwriteIfExists,
}
};
TransferOperation transfer = await container.DownloadToDirectoryAsync(WaitUntil.Started, localDirectoryPath2, options);
await transfer.WaitForCompletionAsync();
See the Storage CONTRIBUTING.md for details on building,
testing, and contributing to these libraries.
This project welcomes contributions and suggestions. Most contributions require
you to agree to a Contributor License Agreement (CLA) declaring that you have
the right to, and actually do, grant us the rights to use your contribution. For
details, visit cla.microsoft.com.