public static async Task <CloudBlockBlob> DownloadBlob(this CloudBlobContainer self, string path, string destinationFileName)
{
CloudBlockBlob blob = null;
try
{
blob = self.GetBlockBlobReference(path);
await blob.DownloadToFileAsync(destinationFileName, FileMode.Create);
}
catch (StorageException stex)
{
if (stex.RequestInformation != null &&
stex.RequestInformation.ExtendedErrorInformation != null &&
(stex.RequestInformation.ExtendedErrorInformation.ErrorCode == BlobErrorCodeStrings.ContainerNotFound ||
stex.RequestInformation.ExtendedErrorInformation.ErrorCode == BlobErrorCodeStrings.BlobNotFound))
{
// Ignore the error
}
else
{
throw;
}
}
return(blob);
}
public async Task CloudBlockBlobUploadDownloadFileWithFailures()
{
CloudBlockBlob blob = this.testContainer.GetBlockBlobReference("blob1");
CloudBlockBlob nullBlob = this.testContainer.GetBlockBlobReference("null");
await this.DoUploadDownloadFileAsync(blob, 0);
await this.DoUploadDownloadFileAsync(blob, 4096);
await this.DoUploadDownloadFileAsync(blob, 4097);
await TestHelper.ExpectedExceptionAsync <IOException>(
async() => await blob.UploadFromFileAsync("non_existentCloudBlockBlobUploadDownloadFileWithFailures.file"),
"UploadFromFileAsync requires an existing file");
await TestHelper.ExpectedExceptionAsync <StorageException>(
async() => await nullBlob.DownloadToFileAsync("garbageCloudBlockBlobUploadDownloadFileWithFailures.file", FileMode.Create),
"DownloadToFileAsync should not leave an empty file behind after failing.");
Assert.IsFalse(System.IO.File.Exists("garbageCloudBlockBlobUploadDownloadFileWithFailures.file"));
await TestHelper.ExpectedExceptionAsync <StorageException>(
async() => await nullBlob.DownloadToFileAsync("garbageCloudBlockBlobUploadDownloadFileWithFailures.file", FileMode.CreateNew),
"DownloadToFileAsync should not leave an empty file behind after failing.");
Assert.IsFalse(System.IO.File.Exists("garbageCloudBlockBlobUploadDownloadFileWithFailures.file"));
byte[] buffer = GetRandomBuffer(100);
using (FileStream file = new FileStream("garbageCloudBlockBlobUploadDownloadFileWithFailures.file", FileMode.Create, FileAccess.Write))
{
await file.WriteAsync(buffer, 0, buffer.Length);
}
await TestHelper.ExpectedExceptionAsync <IOException>(
async() => await nullBlob.DownloadToFileAsync("garbageCloudBlockBlobUploadDownloadFileWithFailures.file", FileMode.CreateNew),
"DownloadToFileAsync should leave an empty file behind after failing, depending on the mode.");
Assert.IsTrue(System.IO.File.Exists("garbageCloudBlockBlobUploadDownloadFileWithFailures.file"));
System.IO.File.Delete("garbageCloudBlockBlobUploadDownloadFileWithFailures.file");
await TestHelper.ExpectedExceptionAsync <StorageException>(
async() => await nullBlob.DownloadToFileAsync("garbageCloudBlockBlobUploadDownloadFileWithFailures.file", FileMode.Append),
"DownloadToFileAsync should leave an empty file behind after failing depending on file mode.");
Assert.IsTrue(System.IO.File.Exists("garbageCloudBlockBlobUploadDownloadFileWithFailures.file"));
System.IO.File.Delete("garbageCloudBlockBlobUploadDownloadFileWithFailures.file");
}