private static void CreateForTest(CloudBlockBlob blob, int blockCount, int blockSize, bool isAsync, bool commit = true)
{
byte[] buffer = GetRandomBuffer(blockSize);
List<string> blocks = GetBlockIdList(blockCount);
using (AutoResetEvent waitHandle = new AutoResetEvent(false))
{
foreach (string block in blocks)
{
using (MemoryStream stream = new MemoryStream(buffer))
{
if (isAsync)
{
IAsyncResult result = blob.BeginPutBlock(block, stream, null,
ar => waitHandle.Set(),
null);
waitHandle.WaitOne();
blob.EndPutBlock(result);
}
else
{
blob.PutBlock(block, stream, null);
}
}
}
if (commit)
{
if (isAsync)
{
IAsyncResult result = blob.BeginPutBlockList(blocks,
ar => waitHandle.Set(),
null);
waitHandle.WaitOne();
blob.EndPutBlockList(result);
}
else
{
blob.PutBlockList(blocks);
}
}
}
}
/// <summary>
/// Test block blob creation (set block list), expecting success.
/// </summary>
/// <param name="testBlob">The block blob.</param>
/// <param name="blockList">The block list to set.</param>
/// <param name="testAccessCondition">The access condition to use.</param>
private void BlockBlobWriteExpectSuccess(CloudBlockBlob testBlob, IEnumerable<string> blockList, AccessCondition testAccessCondition)
{
testBlob.PutBlockList(blockList, testAccessCondition, null /* options */);
}
static void UploadBlobInChunks(FileInfo fileInfo, CloudBlockBlob packageBlob, CloudBlobClient blobClient)
{
var operationContext = new OperationContext();
operationContext.ResponseReceived += delegate(object sender, RequestEventArgs args)
{
var statusCode = (int) args.Response.StatusCode;
var statusDescription = args.Response.StatusDescription;
Log.Verbose("Uploading, response received: " + statusCode + " " + statusDescription);
if (statusCode >= 400)
{
Log.Error("Error when uploading the package. Azure returned a HTTP status code of: " +
statusCode + " " + statusDescription);
Log.Verbose("The upload will be retried");
}
};
blobClient.SetServiceProperties(blobClient.GetServiceProperties(), operationContext: operationContext);
Log.VerboseFormat("Uploading the package to blob storage. The package file is {0}.", fileInfo.Length.ToFileSizeString());
using (var fileReader = fileInfo.OpenRead())
{
var blocklist = new List<string>();
long uploadedSoFar = 0;
var data = new byte[1024 * 1024];
var id = 1;
while (true)
{
id++;
var read = fileReader.Read(data, 0, data.Length);
if (read == 0)
{
packageBlob.PutBlockList(blocklist);
break;
}
var blockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(id.ToString(CultureInfo.InvariantCulture).PadLeft(30, '0')));
packageBlob.PutBlock(blockId, new MemoryStream(data, 0, read, true), null);
blocklist.Add(blockId);
uploadedSoFar += read;
Log.VerboseFormat("Uploading package to blob storage: {0} of {1}", uploadedSoFar.ToFileSizeString(), fileInfo.Length.ToFileSizeString());
}
}
Log.Verbose("Upload complete");
}
/// <summary>
/// Test block blob creation (block list setting), expecting lease failure.
/// </summary>
/// <param name="testBlob">The block blob.</param>
/// <param name="blockList">An appropriate block list to set.</param>
/// <param name="testAccessCondition">The failing access condition to use.</param>
/// <param name="expectedErrorCode">The expected error code.</param>
/// <param name="description">The reason why these calls should fail.</param>
private void BlockBlobWriteExpectLeaseFailure(CloudBlockBlob testBlob, IEnumerable<string> blockList, AccessCondition testAccessCondition, HttpStatusCode expectedStatusCode, string expectedErrorCode, string description)
{
TestHelper.ExpectedException(
() => testBlob.PutBlockList(blockList, testAccessCondition, null /* options */),
description + " (Put Block List)",
expectedStatusCode,
expectedErrorCode);
}
public void CloudBlobSASApiVersionQueryParam()
{
CloudBlobContainer container = GetRandomContainerReference();
try
{
container.Create();
CloudBlob blob;
SharedAccessBlobPolicy policy = new SharedAccessBlobPolicy()
{
Permissions = SharedAccessBlobPermissions.Read,
SharedAccessStartTime = DateTimeOffset.UtcNow.AddMinutes(-5),
SharedAccessExpiryTime = DateTimeOffset.UtcNow.AddMinutes(30),
};
CloudBlockBlob blockBlob = container.GetBlockBlobReference("bb");
blockBlob.PutBlockList(new string[] { });
CloudPageBlob pageBlob = container.GetPageBlobReference("pb");
pageBlob.Create(0);
CloudAppendBlob appendBlob = container.GetAppendBlobReference("ab");
appendBlob.CreateOrReplace();
string blockBlobToken = blockBlob.GetSharedAccessSignature(policy);
StorageCredentials blockBlobSAS = new StorageCredentials(blockBlobToken);
Uri blockBlobSASUri = blockBlobSAS.TransformUri(blockBlob.Uri);
StorageUri blockBlobSASStorageUri = blockBlobSAS.TransformUri(blockBlob.StorageUri);
string pageBlobToken = pageBlob.GetSharedAccessSignature(policy);
StorageCredentials pageBlobSAS = new StorageCredentials(pageBlobToken);
Uri pageBlobSASUri = pageBlobSAS.TransformUri(pageBlob.Uri);
StorageUri pageBlobSASStorageUri = pageBlobSAS.TransformUri(pageBlob.StorageUri);
string appendBlobToken = appendBlob.GetSharedAccessSignature(policy);
StorageCredentials appendBlobSAS = new StorageCredentials(appendBlobToken);
Uri appendBlobSASUri = appendBlobSAS.TransformUri(appendBlob.Uri);
StorageUri appendBlobSASStorageUri = appendBlobSAS.TransformUri(appendBlob.StorageUri);
OperationContext apiVersionCheckContext = new OperationContext();
apiVersionCheckContext.SendingRequest += (sender, e) =>
{
Assert.IsTrue(e.Request.RequestUri.Query.Contains("api-version"));
};
blob = new CloudBlob(blockBlobSASUri);
blob.FetchAttributes(operationContext: apiVersionCheckContext);
Assert.AreEqual(blob.BlobType, BlobType.BlockBlob);
Assert.IsTrue(blob.StorageUri.PrimaryUri.Equals(blockBlob.Uri));
Assert.IsNull(blob.StorageUri.SecondaryUri);
blob = new CloudBlob(pageBlobSASUri);
blob.FetchAttributes(operationContext: apiVersionCheckContext);
Assert.AreEqual(blob.BlobType, BlobType.PageBlob);
Assert.IsTrue(blob.StorageUri.PrimaryUri.Equals(pageBlob.Uri));
Assert.IsNull(blob.StorageUri.SecondaryUri);
blob = new CloudBlob(blockBlobSASStorageUri, null, null);
blob.FetchAttributes(operationContext: apiVersionCheckContext);
Assert.AreEqual(blob.BlobType, BlobType.BlockBlob);
Assert.IsTrue(blob.StorageUri.Equals(blockBlob.StorageUri));
blob = new CloudBlob(pageBlobSASStorageUri, null, null);
blob.FetchAttributes(operationContext: apiVersionCheckContext);
Assert.AreEqual(blob.BlobType, BlobType.PageBlob);
Assert.IsTrue(blob.StorageUri.Equals(pageBlob.StorageUri));
}
finally
{
container.DeleteIfExists();
}
}
public void CloudBlobSASSharedProtocolsQueryParam()
{
CloudBlobContainer container = GetRandomContainerReference();
try
{
container.Create();
CloudBlob blob;
SharedAccessBlobPolicy policy = new SharedAccessBlobPolicy()
{
Permissions = SharedAccessBlobPermissions.Read,
SharedAccessStartTime = DateTimeOffset.UtcNow.AddMinutes(-5),
SharedAccessExpiryTime = DateTimeOffset.UtcNow.AddMinutes(30),
};
CloudBlockBlob blockBlob = container.GetBlockBlobReference("bb");
blockBlob.PutBlockList(new string[] { });
foreach (SharedAccessProtocol?protocol in new SharedAccessProtocol?[] { null, SharedAccessProtocol.HttpsOrHttp, SharedAccessProtocol.HttpsOnly })
{
string blockBlobToken = blockBlob.GetSharedAccessSignature(policy, null, null, protocol, null);
StorageCredentials blockBlobSAS = new StorageCredentials(blockBlobToken);
Uri blockBlobSASUri = new Uri(blockBlob.Uri + blockBlobSAS.SASToken);
StorageUri blockBlobSASStorageUri = new StorageUri(new Uri(blockBlob.StorageUri.PrimaryUri + blockBlobSAS.SASToken), new Uri(blockBlob.StorageUri.SecondaryUri + blockBlobSAS.SASToken));
int httpPort = blockBlobSASUri.Port;
int securePort = 443;
if (!string.IsNullOrEmpty(TestBase.TargetTenantConfig.BlobSecurePortOverride))
{
securePort = Int32.Parse(TestBase.TargetTenantConfig.BlobSecurePortOverride);
}
var schemesAndPorts = new[] {
new { scheme = Uri.UriSchemeHttp, port = httpPort },
new { scheme = Uri.UriSchemeHttps, port = securePort }
};
foreach (var item in schemesAndPorts)
{
blockBlobSASUri = TransformSchemeAndPort(blockBlobSASUri, item.scheme, item.port);
blockBlobSASStorageUri = new StorageUri(TransformSchemeAndPort(blockBlobSASStorageUri.PrimaryUri, item.scheme, item.port), TransformSchemeAndPort(blockBlobSASStorageUri.SecondaryUri, item.scheme, item.port));
if (protocol.HasValue && protocol.Value == SharedAccessProtocol.HttpsOnly && string.CompareOrdinal(item.scheme, Uri.UriSchemeHttp) == 0)
{
blob = new CloudBlob(blockBlobSASUri);
TestHelper.ExpectedException(() => blob.FetchAttributes(), "Access a blob using SAS with a shared protocols that does not match", HttpStatusCode.Unused);
blob = new CloudBlob(blockBlobSASStorageUri, null, null);
TestHelper.ExpectedException(() => blob.FetchAttributes(), "Access a blob using SAS with a shared protocols that does not match", HttpStatusCode.Unused);
}
else
{
blob = new CloudBlob(blockBlobSASUri);
blob.FetchAttributes();
Assert.AreEqual(blob.BlobType, BlobType.BlockBlob);
blob = new CloudBlob(blockBlobSASStorageUri, null, null);
blob.FetchAttributes();
Assert.AreEqual(blob.BlobType, BlobType.BlockBlob);
}
}
}
}
finally
{
container.DeleteIfExists();
}
}
public void CloudBlobSASApiVersionQueryParam()
{
CloudBlobContainer container = GetRandomContainerReference();
try
{
container.Create();
ICloudBlob blob;
SharedAccessBlobPolicy policy = new SharedAccessBlobPolicy()
{
Permissions = SharedAccessBlobPermissions.Read,
SharedAccessStartTime = DateTimeOffset.UtcNow.AddMinutes(-5),
SharedAccessExpiryTime = DateTimeOffset.UtcNow.AddMinutes(30),
};
CloudBlockBlob blockBlob = container.GetBlockBlobReference("bb");
blockBlob.PutBlockList(new string[] { });
CloudPageBlob pageBlob = container.GetPageBlobReference("pb");
pageBlob.Create(0);
string blockBlobToken = blockBlob.GetSharedAccessSignature(policy);
StorageCredentials blockBlobSAS = new StorageCredentials(blockBlobToken);
Uri blockBlobSASUri = blockBlobSAS.TransformUri(blockBlob.Uri);
StorageUri blockBlobSASStorageUri = blockBlobSAS.TransformUri(blockBlob.StorageUri);
string pageBlobToken = pageBlob.GetSharedAccessSignature(policy);
StorageCredentials pageBlobSAS = new StorageCredentials(pageBlobToken);
Uri pageBlobSASUri = pageBlobSAS.TransformUri(pageBlob.Uri);
StorageUri pageBlobSASStorageUri = pageBlobSAS.TransformUri(pageBlob.StorageUri);
OperationContext apiVersionCheckContext = new OperationContext();
apiVersionCheckContext.SendingRequest += (sender, e) =>
{
Assert.IsNull(e.Request.Headers.Get("x-ms-version"));
Assert.IsTrue(e.Request.RequestUri.Query.Contains("api-version"));
};
blob = container.ServiceClient.GetBlobReferenceFromServer(blockBlobSASUri, operationContext: apiVersionCheckContext);
Assert.IsInstanceOfType(blob, typeof(CloudBlockBlob));
Assert.IsTrue(blob.StorageUri.PrimaryUri.Equals(blockBlob.Uri));
Assert.IsNull(blob.StorageUri.SecondaryUri);
blob = container.ServiceClient.GetBlobReferenceFromServer(pageBlobSASUri, operationContext: apiVersionCheckContext);
Assert.IsInstanceOfType(blob, typeof(CloudPageBlob));
Assert.IsTrue(blob.StorageUri.PrimaryUri.Equals(pageBlob.Uri));
Assert.IsNull(blob.StorageUri.SecondaryUri);
blob = container.ServiceClient.GetBlobReferenceFromServer(blockBlobSASStorageUri, operationContext: apiVersionCheckContext);
Assert.IsInstanceOfType(blob, typeof(CloudBlockBlob));
Assert.IsTrue(blob.StorageUri.Equals(blockBlob.StorageUri));
blob = container.ServiceClient.GetBlobReferenceFromServer(pageBlobSASStorageUri, operationContext: apiVersionCheckContext);
Assert.IsInstanceOfType(blob, typeof(CloudPageBlob));
Assert.IsTrue(blob.StorageUri.Equals(pageBlob.StorageUri));
}
finally
{
container.DeleteIfExists();
}
}
public void BlobIngressEgressCounters()
{
CloudBlobContainer container = GetRandomContainerReference();
container.CreateIfNotExists();
CloudBlockBlob blob = container.GetBlockBlobReference("blob1");
string[] blockIds = new string[] { Convert.ToBase64String(Guid.NewGuid().ToByteArray()), Convert.ToBase64String(Guid.NewGuid().ToByteArray()), Convert.ToBase64String(Guid.NewGuid().ToByteArray()) };
try
{
// 1 byte
TestHelper.ValidateIngressEgress(Selectors.IfUrlContains(blob.Uri.ToString()), () =>
{
OperationContext opContext = new OperationContext();
blob.PutBlock(blockIds[0], new MemoryStream(GetRandomBuffer(1)), null, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, opContext);
return(opContext.LastResult);
});
// 1024
TestHelper.ValidateIngressEgress(Selectors.IfUrlContains(blob.Uri.ToString()), () =>
{
OperationContext opContext = new OperationContext();
blob.PutBlock(blockIds[1], new MemoryStream(GetRandomBuffer(1024)), null, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, opContext);
return(opContext.LastResult);
});
// 98765
TestHelper.ValidateIngressEgress(Selectors.IfUrlContains(blob.Uri.ToString()), () =>
{
OperationContext opContext = new OperationContext();
blob.PutBlock(blockIds[2], new MemoryStream(GetRandomBuffer(98765)), null, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, opContext);
return(opContext.LastResult);
});
// PutBlockList
TestHelper.ValidateIngressEgress(Selectors.IfUrlContains(blob.Uri.ToString()), () =>
{
OperationContext opContext = new OperationContext();
blob.PutBlockList(blockIds, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, opContext);
return(opContext.LastResult);
});
// GetBlockList
TestHelper.ValidateIngressEgress(Selectors.IfUrlContains(blob.Uri.ToString()), () =>
{
OperationContext opContext = new OperationContext();
blob.DownloadBlockList(BlockListingFilter.All, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, opContext);
return(opContext.LastResult);
});
// Download
TestHelper.ValidateIngressEgress(Selectors.IfUrlContains(blob.Uri.ToString()), () =>
{
OperationContext opContext = new OperationContext();
blob.DownloadToStream(Stream.Null, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, opContext);
return(opContext.LastResult);
});
Assert.AreEqual(blob.Properties.Length, 98765 + 1024 + 1);
// Error Case
CloudBlockBlob nullBlob = container.GetBlockBlobReference("null");
OperationContext errorContext = new OperationContext();
try
{
nullBlob.DownloadToStream(Stream.Null, null, new BlobRequestOptions()
{
RetryPolicy = new RetryPolicies.NoRetry()
}, errorContext);
Assert.Fail("Null blob, null stream, no download possible.");
}
catch (StorageException)
{
Assert.IsTrue(errorContext.LastResult.IngressBytes > 0);
}
}
finally
{
container.DeleteIfExists();
}
}
/// <summary>
/// Adds the diagnostic message to block blob.
/// </summary>
/// <param name="blob">The cloud blob.</param>
/// <param name="message">The message.</param>
protected virtual void AddMessageToBlock(CloudBlockBlob blob, string message)
{
Sitecore.Diagnostics.Assert.ArgumentNotNull(blob, "blob");
Sitecore.Diagnostics.Assert.ArgumentNotNull(message, "message");
var blockIds = new List<string>();
if (blob.Exists())
{
blockIds.AddRange(blob.DownloadBlockList().Select(b => b.Name));
}
string blockId = Guid.NewGuid().ToString().Replace("-", string.Empty);
blockIds.Add(blockId);
using (var blockData = new MemoryStream(LogStorageManager.DefaultTextEncoding.GetBytes(message), false))
{
blob.PutBlock(blockId, blockData, null);
blob.PutBlockList(blockIds);
}
}
private static void CloudBlockBlobCopy(bool sourceIsSas, bool destinationIsSas)
{
CloudBlobContainer container = GetRandomContainerReference();
try
{
container.Create();
// Create Source on server
CloudBlockBlob source = container.GetBlockBlobReference("source");
string data = "String data";
UploadText(source, data, Encoding.UTF8);
source.Metadata["Test"] = "value";
source.SetMetadata();
// Create Destination on server
CloudBlockBlob destination = container.GetBlockBlobReference("destination");
destination.PutBlockList(new string[] { });
CloudBlockBlob copySource = source;
CloudBlockBlob copyDestination = destination;
if (sourceIsSas)
{
// Source SAS must have read permissions
SharedAccessBlobPermissions permissions = SharedAccessBlobPermissions.Read;
SharedAccessBlobPolicy policy = new SharedAccessBlobPolicy()
{
SharedAccessStartTime = DateTimeOffset.UtcNow.AddMinutes(-5),
SharedAccessExpiryTime = DateTimeOffset.UtcNow.AddMinutes(30),
Permissions = permissions,
};
string sasToken = source.GetSharedAccessSignature(policy);
// Get source
StorageCredentials credentials = new StorageCredentials(sasToken);
copySource = new CloudBlockBlob(credentials.TransformUri(source.Uri));
}
if (destinationIsSas)
{
if (!sourceIsSas)
{
// Source container must be public if source is not SAS
BlobContainerPermissions containerPermissions = new BlobContainerPermissions
{
PublicAccess = BlobContainerPublicAccessType.Blob
};
container.SetPermissions(containerPermissions);
}
// Destination SAS must have write permissions
SharedAccessBlobPermissions permissions = SharedAccessBlobPermissions.Write;
SharedAccessBlobPolicy policy = new SharedAccessBlobPolicy()
{
SharedAccessStartTime = DateTimeOffset.UtcNow.AddMinutes(-5),
SharedAccessExpiryTime = DateTimeOffset.UtcNow.AddMinutes(30),
Permissions = permissions,
};
string sasToken = destination.GetSharedAccessSignature(policy);
// Get destination
StorageCredentials credentials = new StorageCredentials(sasToken);
copyDestination = new CloudBlockBlob(credentials.TransformUri(destination.Uri));
}
// Start copy and wait for completion
string copyId = copyDestination.StartCopyFromBlob(TestHelper.Defiddler(copySource));
WaitForCopy(destination);
// Check original blob references for equality
Assert.AreEqual(CopyStatus.Success, destination.CopyState.Status);
Assert.AreEqual(source.Uri.AbsolutePath, destination.CopyState.Source.AbsolutePath);
Assert.AreEqual(data.Length, destination.CopyState.TotalBytes);
Assert.AreEqual(data.Length, destination.CopyState.BytesCopied);
Assert.AreEqual(copyId, destination.CopyState.CopyId);
Assert.IsTrue(destination.CopyState.CompletionTime > DateTimeOffset.UtcNow.Subtract(TimeSpan.FromMinutes(1)));
if (!destinationIsSas)
{
// Abort Copy is not supported for SAS destination
TestHelper.ExpectedException(
() => copyDestination.AbortCopy(copyId),
"Aborting a copy operation after completion should fail",
HttpStatusCode.Conflict,
"NoPendingCopyOperation");
}
source.FetchAttributes();
Assert.IsNotNull(destination.Properties.ETag);
Assert.AreNotEqual(source.Properties.ETag, destination.Properties.ETag);
Assert.IsTrue(destination.Properties.LastModified > DateTimeOffset.UtcNow.Subtract(TimeSpan.FromMinutes(1)));
string copyData = DownloadText(destination, Encoding.UTF8);
Assert.AreEqual(data, copyData, "Data inside copy of blob not equal.");
destination.FetchAttributes();
BlobProperties prop1 = destination.Properties;
BlobProperties prop2 = source.Properties;
Assert.AreEqual(prop1.CacheControl, prop2.CacheControl);
Assert.AreEqual(prop1.ContentEncoding, prop2.ContentEncoding);
Assert.AreEqual(prop1.ContentLanguage, prop2.ContentLanguage);
Assert.AreEqual(prop1.ContentMD5, prop2.ContentMD5);
Assert.AreEqual(prop1.ContentType, prop2.ContentType);
Assert.AreEqual("value", destination.Metadata["Test"], false, "Copied metadata not same");
destination.Delete();
source.Delete();
}
finally
{
container.DeleteIfExists();
}
}
/// <summary>
/// Upload in parallel.
/// If total size of file is smaller than chunkSize, then simply split length by parallel factor.
/// FIXME: Need to retest this!!!
/// </summary>
/// <param name="stream"></param>
/// <param name="blob"></param>
/// <param name="parallelFactor"></param>
/// <param name="chunkSizeInMB"></param>
private void ParallelWriteBlockBlob(Stream stream, CloudBlockBlob blob, int parallelFactor, int chunkSizeInMB)
{
long chunkSize = chunkSizeInMB * 1024 * 1024;
var length = stream.Length;
if (chunkSize > length)
{
chunkSize = length / parallelFactor;
}
var numberOfBlocks = (length / chunkSize) + 1;
var blockIdList = new string[numberOfBlocks];
var chunkSizeList = new int[numberOfBlocks];
var taskList = new List<Task>();
var count = numberOfBlocks - 1;
// read the data... spawn a task to launch... then wait for all.
while (count >= 0)
{
while (count >= 0 && taskList.Count < parallelFactor)
{
var index = (numberOfBlocks - count - 1);
var chunkSizeToUpload = (int)Math.Min(chunkSize, length - (index * chunkSize));
// only upload if we have data to give.
// edge case where we already have uploaded all the data.
if (chunkSizeToUpload > 0)
{
chunkSizeList[index] = chunkSizeToUpload;
var dataBuffer = new byte[chunkSizeToUpload];
stream.Seek(index * chunkSize, SeekOrigin.Begin);
stream.Read(dataBuffer, 0, chunkSizeToUpload);
var t = Task.Factory.StartNew(() =>
{
var tempCount = index;
var uploadSize = chunkSizeList[tempCount];
var newBuffer = new byte[uploadSize];
Array.Copy(dataBuffer, newBuffer, dataBuffer.Length);
var blockId = Convert.ToBase64String(Guid.NewGuid().ToByteArray());
using (var memStream = new MemoryStream(newBuffer, 0, uploadSize))
{
blob.PutBlock(blockId, memStream, null);
}
blockIdList[tempCount] = blockId;
});
taskList.Add(t);
}
count--;
}
var waitedIndex = Task.WaitAny(taskList.ToArray());
if (waitedIndex >= 0)
{
taskList.RemoveAt(waitedIndex);
}
}
Task.WaitAll(taskList.ToArray());
blob.PutBlockList(blockIdList.Where(t => t != null));
}