Beef/BeefySysLib/sound/Common/AkDefaultLowLevelIODispatcher.h

//////////////////////////////////////////////////////////////////////
//
// AkDefaultLowLevelIODispatcher.h
//
// Canvas for implementation of the AK::StreamMgr::IAkFileLocationResolver,
// meant to be used in a multiple streaming devices system. It is this
// object that should be registered as the one and only 
// AK::StreamMgr::IAkFileLocationResolver of the Stream Manager
// (by calling AK::StreamMgr::SetFileLocationResolver()).
// 
// It forwards the calls to Open() to one of the low level I/O devices 
// that were added to it using AddDevice(). These devices must thus also 
// implement AK::StreamMgr::IAkFileLocationResolver.
// 
// The strategy for device dispatching is that of a chain of responsibility:
// the dispatcher asks the first file resolver hook to open the file. If it 
// fails, then it tries with the second, and so on, until a hook succeeds. 
// This is inefficient. In your game, you should implement a strategy of 
// your own (see CAkDefaultLowLevelIODispatcher::Open()). 
//
// Copyright (c) 2006 Audiokinetic Inc. / All Rights Reserved
//
//////////////////////////////////////////////////////////////////////

#ifndef _AK_DEFAULT_LOW_LEVEL_IO_DISPATCHER_H_
#define _AK_DEFAULT_LOW_LEVEL_IO_DISPATCHER_H_

#include <AK/SoundEngine/Common/AkStreamMgrModule.h>

#define AK_MAX_IO_DEVICES	(3)

//-----------------------------------------------------------------------------
// Name: class CAkDefaultLowLevelIODispatcher.
// Desc: Register this object to the Stream Manager as the File Location Resolver.
//		 You need to implement dispatching calls to Open() to separate devices,
//		 according to your specific requirements.
//-----------------------------------------------------------------------------
class CAkDefaultLowLevelIODispatcher : public AK::StreamMgr::IAkFileLocationResolver
{
public:

    CAkDefaultLowLevelIODispatcher( );
    virtual ~CAkDefaultLowLevelIODispatcher( );

    // Returns a file descriptor for a given file name (string).
    virtual AKRESULT Open( 
        const AkOSChar*			in_pszFileName,		// File name.
		AkOpenMode				in_eOpenMode,		// Open mode.
        AkFileSystemFlags *		in_pFlags,			// Special flags. Can pass NULL.
		bool &					io_bSyncOpen,		// If true, the file must be opened synchronously. Otherwise it is left at the File Location Resolver's discretion. Return false if Open needs to be deferred.
        AkFileDesc &			out_fileDesc        // Returned file descriptor.
        );

    // Returns a file descriptor for a given file ID.
    virtual AKRESULT Open( 
        AkFileID				in_fileID,          // File ID.
        AkOpenMode				in_eOpenMode,       // Open mode.
        AkFileSystemFlags *		in_pFlags,			// Special flags. Can pass NULL.
		bool &					io_bSyncOpen,		// If true, the file must be opened synchronously. Otherwise it is left at the File Location Resolver's discretion. Return false if Open needs to be deferred.
        AkFileDesc &			out_fileDesc        // Returned file descriptor.
        );


	// 
	// Default dispatcher services.
	//-----------------------------------------------------------------------------

	// Add a "device" (actually, a File Location Resolver) to the dispatcher's list. 
	// The first device added will be the first device queried.
    virtual AKRESULT AddDevice(
		AK::StreamMgr::IAkFileLocationResolver *	in_pHook
        );

	// Remove all devices from the dispatcher's array.
	virtual void RemoveAllDevices();
    
protected:

	// List of devices.
	AK::StreamMgr::IAkFileLocationResolver *	m_arDevices[AK_MAX_IO_DEVICES];
	AkUInt32									m_uNumDevices;
};

#endif //_AK_DEFAULT_LOW_LEVEL_IO_DISPATCHER_H_