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Beef/BeefySysLib/sound/Win32/AkDefaultIOHookDeferred.h

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2019-08-23 11:56:54 -07:00
//////////////////////////////////////////////////////////////////////
//
// AkDefaultIOHookDeferred.h
//
// Default deferred low level IO hook (AK::StreamMgr::IAkIOHookDeferred)
// and file system (AK::StreamMgr::IAkFileLocationResolver) implementation
// on Windows.
//
// AK::StreamMgr::IAkFileLocationResolver:
// Resolves file location using simple path concatenation logic
// (implemented in ../Common/CAkFileLocationBase). It can be used as a
// standalone Low-Level IO system, or as part of a multi device system.
// In the latter case, you should manage multiple devices by implementing
// AK::StreamMgr::IAkFileLocationResolver elsewhere (you may take a look
// at class CAkDefaultLowLevelIODispatcher).
//
// AK::StreamMgr::IAkIOHookDeferred:
// Uses platform API for I/O. Calls to ::ReadFile() and ::WriteFile()
// do not block because files are opened with the FILE_FLAG_OVERLAPPED flag.
// Transfer completion is handled by internal FileIOCompletionRoutine function,
// which then calls the AkAIOCallback.
// The AK::StreamMgr::IAkIOHookDeferred interface is meant to be used with
// AK_SCHEDULER_DEFERRED_LINED_UP streaming devices.
//
// Init() creates a streaming device (by calling AK::StreamMgr::CreateDevice()).
// AkDeviceSettings::uSchedulerTypeFlags is set inside to AK_SCHEDULER_DEFERRED_LINED_UP.
// If there was no AK::StreamMgr::IAkFileLocationResolver previously registered
// to the Stream Manager, this object registers itself as the File Location Resolver.
//
// Examples of streaming initialization:
//
// Standalone (registered as the one and only File Location Resolver):
/*
// Create Stream Manager.
AkStreamMgrSettings stmSettings;
AK::StreamMgr::GetDefaultSettings( stmSettings );
AK:IAkStreamMgr * pStreamMgr = AK::StreamMgr::Create( stmSettings );
AKASSERT( pStreamMgr );
// Create deferred device.
AkDeviceSettings deviceSettings;
AK::StreamMgr::GetDefaultDeviceSettings( deviceSettings );
CAkDefaultIOHookDeferred hookIODeferred;
AKRESULT eResult = hookIODeferred.Init( deviceSettings );
AKASSERT( AK_SUCCESS == eResult );
*/
//
// As part of a system with multiple devices (the File Location Resolver is
// implemented by CAkDefaultLowLevelIODispatcher):
/*
// Create Stream Manager.
AkStreamMgrSettings stmSettings;
AK::StreamMgr::GetDefaultSettings( stmSettings );
AK:IAkStreamMgr * pStreamMgr = AK::StreamMgr::Create( stmSettings );
AKASSERT( pStreamMgr );
// Create and register the File Location Resolver.
CAkDefaultLowLevelIODispatcher lowLevelIODispatcher;
AK::StreamMgr::SetFileLocationResolver( &lowLevelIODispatcher );
// Create deferred device.
AkDeviceSettings deviceSettings;
AK::StreamMgr::GetDefaultDeviceSettings( deviceSettings );
CAkDefaultIOHookDeferred hookIODeferred;
AKRESULT eResult = hookIODeferred.Init( deviceSettings );
AKASSERT( AK_SUCCESS == eResult );
// Add it to the global File Location Resolver.
lowLevelIODispatcher.AddDevice( hookIODeferred );
// Create more devices.
// ...
*/
//
// Copyright (c) 2006 Audiokinetic Inc. / All Rights Reserved
//
//////////////////////////////////////////////////////////////////////
#ifndef _AK_DEFAULT_IO_HOOK_DEFERRED_H_
#define _AK_DEFAULT_IO_HOOK_DEFERRED_H_
#include <AK/SoundEngine/Common/AkStreamMgrModule.h>
#include "../Common/AkFileLocationBase.h"
#include <AK/Tools/Common/AkAssert.h>
//-----------------------------------------------------------------------------
// Name: class CAkDefaultIOHookDeferred.
// Desc: Implements IAkIOHookDeferred low-level I/O hook, and
// IAkFileLocationResolver. Can be used as a standalone Low-Level I/O
// system, or as part of a system with multiple devices.
// File location is resolved using simple path concatenation logic
// (implemented in CAkFileLocationBase).
//-----------------------------------------------------------------------------
class CAkDefaultIOHookDeferred : public AK::StreamMgr::IAkFileLocationResolver
,public AK::StreamMgr::IAkIOHookDeferred
,public CAkFileLocationBase
{
public:
CAkDefaultIOHookDeferred();
virtual ~CAkDefaultIOHookDeferred();
// Initialization/termination. Init() registers this object as the one and
// only File Location Resolver if none were registered before. Then
// it creates a streaming device with scheduler type AK_SCHEDULER_DEFERRED_LINED_UP.
AKRESULT Init(
const AkDeviceSettings & in_deviceSettings, // Device settings.
bool in_bAsyncOpen=false // If true, files are opened asynchronously when possible.
);
void Term();
//
// IAkFileLocationAware interface.
//-----------------------------------------------------------------------------
// 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.
);
//
// IAkIOHookDeferred interface.
//-----------------------------------------------------------------------------
/// Reads data from a file (asynchronous).
virtual AKRESULT Read(
AkFileDesc & in_fileDesc, // File descriptor.
const AkIoHeuristics & in_heuristics, // Heuristics for this data transfer.
AkAsyncIOTransferInfo & io_transferInfo // Asynchronous data transfer info.
);
// Writes data to a file (asynchronous).
virtual AKRESULT Write(
AkFileDesc & in_fileDesc, // File descriptor.
const AkIoHeuristics & in_heuristics, // Heuristics for this data transfer.
AkAsyncIOTransferInfo & io_transferInfo // Platform-specific asynchronous IO operation info.
);
// Notifies that a transfer request is cancelled. It will be flushed by the streaming device when completed.
virtual void Cancel(
AkFileDesc & in_fileDesc, // File descriptor.
AkAsyncIOTransferInfo & io_transferInfo, // Transfer info to cancel.
bool & io_bCancelAllTransfersForThisFile // Flag indicating whether all transfers should be cancelled for this file (see notes in function description).
);
// Cleans up a file.
virtual AKRESULT Close(
AkFileDesc & in_fileDesc // File descriptor.
);
// Returns the block size for the file or its storage device.
virtual AkUInt32 GetBlockSize(
AkFileDesc & in_fileDesc // File descriptor.
);
// Returns a description for the streaming device above this low-level hook.
virtual void GetDeviceDesc(
AkDeviceDesc & out_deviceDesc // Description of associated low-level I/O device.
);
// Returns custom profiling data: 1 if file opens are asynchronous, 0 otherwise.
virtual AkUInt32 GetDeviceData();
protected:
// Local callback for overlapped I/O.
static VOID CALLBACK FileIOCompletionRoutine(
DWORD dwErrorCode,
DWORD dwNumberOfBytesTransfered,
LPOVERLAPPED lpOverlapped
);
protected:
AkDeviceID m_deviceID;
bool m_bAsyncOpen; // If true, opens files asynchronously when it can.
// Structures for concurrent asynchronous transfers bookkeeping.
static AkMemPoolId m_poolID; // Memory pool for overlapped objects.
// Note 1: The pool is a fixed block size pool. It returns OVERLAPPED objects. Allocation is guaranteed
// because the pool size is MaxConcurrentIO * sizeof(OVERLAPPED).
// Note 2: accesses to memory pool are not locked, because we only use the platform SDK here,
// which is executed by the I/O thread when it is in an alertable state.
// If you release overlapped objects from your own thread, a lock is mandatory.
// Note 3: we use the hEvent field to store a pointer to the AkAsyncIOTransferInfo structure.
// Get a free slot for an OVERLAPPED I/O transfer.
OVERLAPPED * GetFreeOverlapped(
AkAsyncIOTransferInfo * in_pTransfer // Transfer that will use this OVERLAPPED. Its address is stored in OVERLAPPED::hEvent.
)
{
OVERLAPPED * pOverlapped = (OVERLAPPED*)AK::MemoryMgr::GetBlock( m_poolID );
AKASSERT( pOverlapped || !"Too many concurrent transfers in the Low-Level IO" );
pOverlapped->hEvent = in_pTransfer;
return pOverlapped;
}
// Release a slot after an OVERLAPPED I/O transfer.
static inline void ReleaseOverlapped(
OVERLAPPED * in_pOverlapped // OVERLAPPED structure to release.
)
{
AK::MemoryMgr::ReleaseBlock( m_poolID, in_pOverlapped );
}
};
#endif //_AK_DEFAULT_IO_HOOK_DEFERRED_H_