Initial release

engine/vendor/vst3sdk/public.sdk/source/vst/hosting/hostdataexchangehandler.h

@@ -0,0 +1,120 @@
+//-----------------------------------------------------------------------------
+// Project     : VST SDK
+// Flags       : clang-format SMTGSequencer
+// Category    : Helpers
+// Filename    : public.sdk/source/vst/hosting/hostdataexchangehandler.h
+// Created by  : Steinberg, 06/2023
+// Description : VST Data Exchange API Host Helper
+//
+//-----------------------------------------------------------------------------
+// This file is part of a Steinberg SDK. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this distribution
+// and at www.steinberg.net/sdklicenses.
+// No part of the SDK, including this file, may be copied, modified, propagated,
+// or distributed except according to the terms contained in the LICENSE file.
+//-----------------------------------------------------------------------------
+
+#pragma once
+
+#include "pluginterfaces/vst/ivstdataexchange.h"
+
+#include <memory>
+
+//------------------------------------------------------------------------
+namespace Steinberg {
+namespace Vst {
+
+//------------------------------------------------------------------------
+struct IDataExchangeHandlerHost
+{
+	virtual ~IDataExchangeHandlerHost () noexcept = default;
+
+	/** return if the audioprocessor is in an inactive state
+	 *	[main thread]
+	 */
+	virtual bool isProcessorInactive (IAudioProcessor* processor) = 0;
+	/** return the data exchange receiver (most likely the edit controller) for the processor
+	 *	[main thread]
+	 */
+	virtual IPtr<IDataExchangeReceiver> findDataExchangeReceiver (IAudioProcessor* processor) = 0;
+	/** check if the requested queue size should be allowed
+	 *	[main thread]
+	 */
+	virtual bool allowAllocateSize (uint32 blockSize, uint32 numBlocks, uint32 alignment) = 0;
+	/** check if this call is made on the main thread
+	 *	[any thread]
+	 */
+	virtual bool isMainThread () = 0;
+
+	/** check if the number of queues can be changed in this moment.
+	 *
+	 *	this is only allowed if no other thread can access the IDataExchangeManagerHost in this
+	 *	moment
+	 *	[main thread]
+	 */
+	virtual bool allowQueueListResize (uint32 newNumQueues) = 0;
+
+	/** notification that the number of open queues changed
+	 *	[main thread]
+	 */
+	virtual void numberOfQueuesChanged (uint32 openMainThreadQueues,
+	                                    uint32 openBackgroundThreadQueues) = 0;
+
+	/** notification that a new queue was opened */
+	virtual void onQueueOpened (IAudioProcessor* processor, DataExchangeQueueID queueID,
+	                            bool dispatchOnMainThread) = 0;
+	/** notification that a queue was closed */
+	virtual void onQueueClosed (IAudioProcessor* processor, DataExchangeQueueID queueID,
+	                            bool dispatchOnMainThread) = 0;
+
+	/** notification that a new block is ready to be send
+	 *	[process thread]
+	 */
+	virtual void newBlockReadyToBeSend (DataExchangeQueueID queueID) = 0;
+};
+
+//------------------------------------------------------------------------
+struct HostDataExchangeHandler
+{
+	/** Constructor
+	 *
+	 *	allocate and deallocate this object on the main thread
+	 *
+	 *	the number of queues is constant
+	 *
+	 *	@param host the managing host
+	 *	@param maxQueues number of maximal allowed open queues
+	 */
+	HostDataExchangeHandler (IDataExchangeHandlerHost& host, uint32 maxQueues = 64);
+	~HostDataExchangeHandler () noexcept;
+
+	/** get the IHostDataExchangeManager interface
+	 *
+	 *	the interface you must provide to the IAudioProcessor
+	 */
+	IDataExchangeHandler* getInterface () const;
+
+	/** send blocks
+	 *
+	 *	the host should periodically call this method on the main thread to send all queued blocks
+	 *	which should be send on the main thread
+	 */
+	uint32 sendMainThreadBlocks ();
+	/** send blocks
+	 *
+	 *	the host should call this on a dedicated background thread
+	 *	inside a mutex is used, so don't delete this object while calling this
+	 *
+	 *	@param queueId	only send blocks from the specified queue. If queueId is equal to
+	 *					InvalidDataExchangeQueueID all blocks from all queues are send.
+	 */
+	uint32 sendBackgroundBlocks (DataExchangeQueueID queueId = InvalidDataExchangeQueueID);
+
+private:
+	struct Impl;
+	std::unique_ptr<Impl> impl;
+};
+
+//------------------------------------------------------------------------
+} // Vst
+} // Steinberg