public async Task Read(string path, Stream toStream, CancellationToken token = default)
{
path = WithBasePath(path);
toStream.VerifyNotNull(nameof(toStream));
_logger.LogTrace($"Reading {path} to stream");
DataLakeFileClient file = _fileSystem.GetFileClient(path);
await file.ReadToAsync(toStream, cancellationToken : token);
}
public async Task Download(string path, Stream toStream, CancellationToken token)
{
path.VerifyNotEmpty(nameof(path));
toStream.VerifyNotNull(nameof(toStream));
_logger.LogTrace($"{nameof(Download)} downloading {path} to stream");
DataLakeFileClient file = _fileSystem.GetFileClient(path);
await file.ReadToAsync(toStream, cancellationToken : token);
}
public async Task ReadToAsync()
{
// Create a temporary Lorem Ipsum file on disk that we can upload
string originalPath = CreateTempFile(SampleFileContent);
// Get a temporary path on disk where we can download the file
string downloadPath = CreateTempPath();
// Make StorageSharedKeyCredential to pass to the serviceClient
string storageAccountName = StorageAccountName;
string storageAccountKey = StorageAccountKey;
Uri serviceUri = StorageAccountBlobUri;
StorageSharedKeyCredential sharedKeyCredential = new StorageSharedKeyCredential(storageAccountName, storageAccountKey);
// Create DataLakeServiceClient using StorageSharedKeyCredentials
DataLakeServiceClient serviceClient = new DataLakeServiceClient(serviceUri, sharedKeyCredential);
// Get a reference to a filesystem named "sample-filesystem-readasync" and then create it
DataLakeFileSystemClient filesystem = serviceClient.GetFileSystemClient(Randomize("sample-filesystem-read"));
await filesystem.CreateAsync();
try
{
// Get a reference to a file named "sample-file" in a filesystem
DataLakeFileClient file = filesystem.GetFileClient(Randomize("sample-file"));
// First upload something the DataLake file so we have something to download
await file.UploadAsync(File.OpenRead(originalPath));
// Download the DataLake file's contents directly to a file.
// For larger files, ReadToAsync() will download the file in multiple parallel requests.
await file.ReadToAsync(downloadPath);
// Verify the contents
Assert.AreEqual(SampleFileContent, File.ReadAllText(downloadPath));
}
finally
{
// Clean up after the test when we're finished
await filesystem.DeleteAsync();
}
}