public static DashClientCapabilities DetectClient(IHttpRequestWrapper requestWrapper)
{
DashClientCapabilities retval = DashClientCapabilities.None;
string agent = requestWrapper.Headers.Value("User-Agent", String.Empty).ToLower();
bool expect100 = requestWrapper.Headers.Contains("Expect");
if (expect100)
{
// Expect: 100-Continue trumps everything
retval = DashClientCapabilities.FullSupport;
}
else if (agent.Contains("dash"))
{
// Modified client
retval = DashClientCapabilities.FullSupport;
}
else if (agent.StartsWith("wa-storage/2.0.6") ||
agent.Contains(".net") ||
agent.Contains("windowspowershell"))
{
// .NET clients can handle redirects seamlessly (they omit the Authorization header as they follow the redirect)
retval = DashClientCapabilities.FollowRedirects;
}
return(retval);
}
public static async Task <HandlerResult> HandlePrePipelineOperationAsync(IHttpRequestWrapper requestWrapper)
{
string containerName = requestWrapper.UriParts.Container;
string blobName = requestWrapper.UriParts.BlobName;
StorageOperationTypes requestOperation = StorageOperations.GetBlobOperation(requestWrapper);
DashClientCapabilities client = DashClientDetector.DetectClient(requestWrapper);
HandlerResult result = null;
bool servePrimaryOnly = false;
switch (requestOperation)
{
case StorageOperationTypes.GetBlobProperties:
case StorageOperationTypes.SetBlobProperties:
case StorageOperationTypes.GetBlobMetadata:
case StorageOperationTypes.SetBlobMetadata:
case StorageOperationTypes.LeaseBlob:
case StorageOperationTypes.GetBlockList:
servePrimaryOnly = true;
// Fall through
goto case StorageOperationTypes.GetBlob;
case StorageOperationTypes.GetBlob:
case StorageOperationTypes.SnapshotBlob:
case StorageOperationTypes.GetPageRanges:
if (client.HasFlag(DashClientCapabilities.FollowRedirects))
{
// If the client has specified a concurrent operation, then we always serve the primary account
// as that is where the concurrency controls exist
if (!servePrimaryOnly && requestWrapper.Headers.IsConcurrentRequest())
{
servePrimaryOnly = true;
}
result = await BlobHandler.BasicBlobAsync(requestWrapper,
containerName,
blobName,
servePrimaryOnly,
BlobReplicationOperations.DoesOperationTriggerReplication(requestOperation));
}
break;
case StorageOperationTypes.PutPage:
if (client.HasFlag(DashClientCapabilities.NoPayloadToDash))
{
result = await BlobHandler.BasicBlobAsync(requestWrapper,
containerName,
blobName,
true,
BlobReplicationOperations.DoesOperationTriggerReplication(requestOperation));
}
break;
case StorageOperationTypes.PutBlob:
case StorageOperationTypes.PutBlock:
case StorageOperationTypes.PutBlockList:
if (client.HasFlag(DashClientCapabilities.NoPayloadToDash))
{
result = await BlobHandler.PutBlobAsync(requestWrapper,
containerName,
blobName,
BlobReplicationOperations.DoesOperationTriggerReplication(requestOperation));
}
break;
default:
// All other operations flow through to the controller action
break;
}
DashTrace.TraceInformation("Operation: {0}, client capability: {1}, action: {2}",
requestOperation,
client,
result == null ? "Forward" : "Redirect");
return(result);
}
