// Called by AzureBlobSyncProvider.UpdateItem to help with writing item updates
internal SyncedBlobAttributes UpdateFile(string oldName, FileData fileData, string relativePath, Stream dataStream,
DateTime expectedLastModified)
{
var blob = Container.GetBlobReference(oldName);
try {
blob.FetchAttributes();
}
catch (StorageClientException e) {
// Someone may have deleted the blob in the mean time
if (e.ErrorCode == StorageErrorCode.BlobNotFound) {
throw new ApplicationException("Concurrency Violation", e);
}
throw;
}
var blobProperties = blob.Properties;
//
// For directories create an empty data stream
//
if (dataStream == null) {
dataStream = new MemoryStream();
}
SetupMetadata(blob.Metadata, fileData, relativePath);
blobProperties.ContentType = LookupMimeType(Path.GetExtension(fileData.Name));
// Specify an optimistic concurrency check to prevent races with other endpoints syncing at the same time.
var opts = new BlobRequestOptions();
opts.AccessCondition = AccessCondition.IfNotModifiedSince(expectedLastModified);
try {
blob.UploadFromStream(dataStream, opts);
}
catch (StorageClientException e) {
// Someone must have modified the file in the mean time
if (e.ErrorCode == StorageErrorCode.BlobNotFound || e.ErrorCode == StorageErrorCode.ConditionFailed) {
throw new ApplicationException("Storage Error", e);
}
throw;
}
blobProperties = blob.Properties;
var attributes = new SyncedBlobAttributes(blob.Uri.ToString(), blobProperties.LastModifiedUtc);
return attributes;
}
// Called by AzureBlobSyncProvider.InsertItem.
internal SyncedBlobAttributes InsertFile(FileData fileData, string relativePath, Stream dataStream)
{
if (fileData.Name.Length > MaxFileNameLength) {
throw new ApplicationException("Name Too Long");
}
var blob = Container.GetBlobReference(fileData.RelativePath);
var blobProperties = blob.Properties;
var uninitTime = blobProperties.LastModifiedUtc;
SetupMetadata(blob.Metadata, fileData, relativePath);
blobProperties.ContentType = LookupMimeType(Path.GetExtension(fileData.Name));
if (fileData.IsDirectory) {
// Directories have no stream
dataStream = new MemoryStream();
}
// Specify an optimistic concurrency check to prevent races with other endpoints syncing at the same time.
var opts = new BlobRequestOptions();
opts.AccessCondition = AccessCondition.IfNotModifiedSince(uninitTime);
try {
blob.UploadFromStream(dataStream, opts);
}
catch (StorageException e) {
if (e.ErrorCode == StorageErrorCode.BlobAlreadyExists || e.ErrorCode == StorageErrorCode.ConditionFailed) {
throw new ApplicationException("Concurrency Violation", e);
}
throw;
}
blobProperties = blob.Properties;
var attributes = new SyncedBlobAttributes(blob.Uri.ToString(), blobProperties.LastModifiedUtc);
return attributes;
}
