public static void AcquireLeaseDuring(this CloudBlob blob, Action <string> action)
{
var leaseId = blob.AcquireLease();
action(leaseId);
blob.UploadText("text", "text");
blob.ReleaseLease(leaseId);
}
public static string TryAcquireLease(this CloudBlob blob)
{
try { return(blob.AcquireLease()); }
catch (WebException e)
{
if ((e.Response == null) || ((HttpWebResponse)e.Response).StatusCode != HttpStatusCode.Conflict) // 409, already leased
{
throw;
}
e.Response.Close();
return(null);
}
}
/// <summary>
/// Try to acquire a lease on the blob. If the acquire is successful the lease will be renewed at every 60 seconds.
/// In order to stop the renew task the <see cref="Stats.AzureCdnLogs.Common.AzureBlobLeaseManager.TryReleaseLease(CloudBlob)"/> needs to be invoked
/// or the token to be cancelled.
/// </summary>
/// <param name="blob">The blob to acquire the lease on.</param>
/// <param name="token">A token to cancel the operation.</param>
/// <param name="renewStatusTask">The renew task.</param>
/// <returns>True if the lease was acquired. </returns>
public bool AcquireLease(CloudBlob blob, CancellationToken token, out Task <bool> renewStatusTask)
{
renewStatusTask = null;
blob.FetchAttributes();
if (token.IsCancellationRequested || blob.Properties.LeaseStatus == LeaseStatus.Locked)
{
return(false);
}
var proposedLeaseId = Guid.NewGuid().ToString();
string leaseId;
leaseId = blob.AcquireLease(TimeSpan.FromSeconds(MaxRenewPeriodInSeconds), proposedLeaseId);
_leasedBlobs.AddOrUpdate(blob.Uri, leaseId, (uri, guid) => leaseId);
//start a task that will renew the lease until the token is cancelled or the Release methods was invoked
renewStatusTask =
Task.Run(() =>
{
if (!token.IsCancellationRequested)
{
//if the token was cancelled just try to release the lease as soon as possible
using (token.Register(() => { TryReleaseLease(blob); }))
{
while (!token.IsCancellationRequested)
{
string blobLeaseId = string.Empty;
//it will renew the lease only if the lease was not explicitelly released
if (_leasedBlobs.TryGetValue(blob.Uri, out blobLeaseId) && blobLeaseId == leaseId)
{
int sleepBeforeRenewInSeconds = MaxRenewPeriodInSeconds - 5 < 0 ? MaxRenewPeriodInSeconds : MaxRenewPeriodInSeconds - 5;
Thread.Sleep(sleepBeforeRenewInSeconds * 1000);
AccessCondition acc = new AccessCondition()
{
LeaseId = leaseId
};
blob.RenewLease(accessCondition: acc, options: _blobRequestOptions, operationContext: null);
}
else
{
break;
}
}
}
}
token.ThrowIfCancellationRequested();
return(false);
}, token);
return(true);
}
public static string TryAcquireLease(this CloudBlob blob, int leaseLengthSeconds)
{
try
{
return(blob.AcquireLease(leaseLengthSeconds));
}
catch (WebException ex)
{
if (ex.Response == null || ((HttpWebResponse)ex.Response).StatusCode != HttpStatusCode.Conflict)
{
throw;
}
ex.Response.Close();
return(null);
}
}
public void SnapshotLeaseBlobWithWrongLeaseID()
{
string containerName = Utility.GenNameString("container");
string blobName = Utility.GenNameString("blob");
CloudBlobContainer container = blobUtil.CreateContainer(containerName);
try
{
CloudBlob blob = blobUtil.CreateRandomBlob(container, blobName);
blob.AcquireLease(TimeSpan.FromMinutes(1), string.Empty);
string wrongLeaseId = Guid.NewGuid().ToString();
Test.Assert(!CommandAgent.SnapshotAzureStorageBlob(containerName, blobName, wrongLeaseId), Utility.GenComparisonData("Snapshot-AzureStorageBlob", false));
CommandAgent.ValidateErrorMessage(MethodBase.GetCurrentMethod().Name);
}
finally
{
blobUtil.RemoveContainer(containerName);
}
}
public void SnapshotLeasedBlob()
{
string containerName = Utility.GenNameString("container");
string blobName = Utility.GenNameString("blob");
CloudBlobContainer container = blobUtil.CreateContainer(containerName);
try
{
CloudBlob blob = blobUtil.CreateRandomBlob(container, blobName);
string leaseId = blob.AcquireLease(TimeSpan.FromMinutes(1), string.Empty);
Test.Assert(CommandAgent.SnapshotAzureStorageBlob(containerName, blobName, leaseId), Utility.GenComparisonData("Snapshot-AzureStorageBlob", true));
if (lang == Language.NodeJS)
{
try
{
string url = (CommandAgent as NodeJSAgent).Output[0]["url"] as string;
DateTimeOffset snapshot = new DateTimeOffset((DateTime)(CommandAgent as NodeJSAgent).Output[0]["snapshot"]);
CloudBlob snapshotBlob = blobUtil.GetBlobReference(container, blobName, blob.BlobType, snapshot);
Test.Assert(snapshotBlob.IsSnapshot, "Expect the the instance is a snapshot");
Test.Assert(snapshotBlob.SnapshotQualifiedUri.ToString() == url,
string.Format("Expect the URL to be {0} while get {1}", snapshotBlob.SnapshotQualifiedUri.AbsolutePath, url));
}
catch (Exception e)
{
Test.Error(string.Format("{0} error: {1}", MethodBase.GetCurrentMethod().Name, e.Message));
}
}
}
finally
{
blobUtil.RemoveContainer(containerName);
}
}
/// <summary>
/// Try to acquire a lease on the blob. If the acquire is successful the lease will be renewed at every 60 seconds.
/// In order to stop the renew task the <see cref="Stats.AzureCdnLogs.Common.AzureBlobLeaseManager.TryReleaseLease(CloudBlob)"/> needs to be invoked
/// or the token to be cancelled.
/// </summary>
/// <param name="blob">The blob to acquire the lease on.</param>
/// <param name="token">A token to cancel the operation.</param>
/// <param name="renewStatusTask">The renew task.</param>
/// <returns>True if the lease was acquired. </returns>
public AzureBlobLockResult AcquireLease(CloudBlob blob, CancellationToken token)
{
blob.FetchAttributes();
if (token.IsCancellationRequested || blob.Properties.LeaseStatus == LeaseStatus.Locked)
{
_logger.LogInformation("AcquireLease: The operation was cancelled or the blob lease is already taken. Blob {BlobUri}, Cancellation status {IsCancellationRequested}, BlobLeaseStatus {BlobLeaseStatus}.",
blob.Uri.AbsoluteUri,
token.IsCancellationRequested,
blob.Properties.LeaseStatus);
return(AzureBlobLockResult.FailedLockResult(blob));
}
var proposedLeaseId = Guid.NewGuid().ToString();
var leaseId = blob.AcquireLease(TimeSpan.FromSeconds(MaxRenewPeriodInSeconds), proposedLeaseId);
var lockResult = new AzureBlobLockResult(blob: blob, lockIsTaken: true, leaseId: leaseId, linkToken: token);
//start a task that will renew the lease until the token is cancelled or the Release methods was invoked
var renewStatusTask = new Task((lockresult) =>
{
var blobLockResult = (AzureBlobLockResult)lockresult;
_logger.LogInformation("RenewLeaseTask: Started for BlobUri {BlobUri}. ThreadId {ThreadId}. IsCancellationRequested {IsCancellationRequested}. LeaseId {LeaseId}",
blob.Uri.AbsoluteUri,
Thread.CurrentThread.ManagedThreadId,
blobLockResult.BlobOperationToken.IsCancellationRequested,
blobLockResult.LeaseId);
int sleepBeforeRenewInSeconds = MaxRenewPeriodInSeconds - OverlapRenewPeriodInSeconds < 0 ? MaxRenewPeriodInSeconds : MaxRenewPeriodInSeconds - OverlapRenewPeriodInSeconds;
if (!blobLockResult.BlobOperationToken.IsCancellationRequested)
{
while (!blobLockResult.BlobOperationToken.Token.IsCancellationRequested)
{
Thread.Sleep(sleepBeforeRenewInSeconds * 1000);
//it will renew the lease only if the lease was not explicitly released
try
{
if (!blobLockResult.Blob.Exists())
{
blobLockResult.BlobOperationToken.Cancel();
break;
}
AccessCondition acc = new AccessCondition {
LeaseId = blobLockResult.LeaseId
};
blob.RenewLease(accessCondition: acc, options: _blobRequestOptions, operationContext: null);
_logger.LogInformation("RenewLeaseTask: Lease was renewed for BlobUri {BlobUri} and LeaseId {LeaseId}.",
blob.Uri.AbsoluteUri,
blobLockResult.LeaseId);
}
catch (StorageException exception)
{
_logger.LogWarning(LogEvents.FailedBlobLease, exception, "RenewLeaseTask: The Lease could not be renewed for BlobUri {BlobUri}. ExpectedLeaseId {LeaseId}. CurrentLeaseId {CurrentLeaseId}.",
blob.Uri.AbsoluteUri,
leaseId,
blobLockResult.LeaseId);
blobLockResult.BlobOperationToken.Cancel();
break;
}
}
}
}, lockResult, TaskCreationOptions.LongRunning);
renewStatusTask.Start();
return(lockResult);
}