vd-filter-backend.h revision 01ada958d2e36535af7048aadda8c0b4a8942f60
/** @file
* Internal VD filter backend interface.
*/
/*
* Copyright (C) 2014 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
#ifndef __vd_filter_backend_h__
#define __vd_filter_backend_h__
#include <VBox/vd.h>
#include <VBox/vd-ifs-internal.h>
/**
* VD filter backend interface.
*/
typedef struct VDFILTERBACKEND
{
/**
* The name of the backend (constant string).
*/
const char *pszBackendName;
/**
* The size of the structure.
*/
uint32_t cbSize;
/**
* Pointer to an array of structs describing each supported config key.
* Terminated by a NULL config key. Note that some backends do not support
* the configuration interface, so this pointer may just contain NULL.
* Mandatory if the backend sets VD_CAP_CONFIG.
*/
PCVDCONFIGINFO paConfigInfo;
/**
* Creates a new filter instance.
*
* @returns VBox status code.
* @param pVDIfsDisk Pointer to the per-disk VD interface list.
* @param fFlags Subset of VD_FILTER_FLAGS_*.
* @param pVDIfsFilter Pointer to the per-filter VD interface list.
* @param ppvBackendData Opaque state data for this filter instance.
*/
DECLR3CALLBACKMEMBER(int, pfnCreate, (PVDINTERFACE pVDIfsDisk, uint32_t fFlags,
PVDINTERFACE pVDIfsFilter,
void **ppvBackendData));
/**
* Destroys a filter instance.
*
* @returns VBox status code.
* @param pvBackendData Opaque state data for the filter instance to destroy.
*/
DECLR3CALLBACKMEMBER(int, pfnDestroy, (void *pvBackendData));
/**
* Filters the data of a read from the image chain. The filter is applied
* after everything was read.
*
* @returns VBox status code.
* @param pvBackendData Opaque state data for the filter instance.
* @param uOffset Start offset of the read.
* @param cbRead Number of bytes read.
* @param pIoCtx The I/O context holding the read data.
*/
DECLR3CALLBACKMEMBER(int, pfnFilterRead, (void *pvBackendData, uint64_t uOffset, size_t cbRead,
PVDIOCTX pIoCtx));
/**
* Filters the data of a write to the image chain. The filter is applied
* before everything is written.
*
* @returns VBox status code.
* @param pvBackendData Opaque state data for the filter instance.
* @param uOffset Start offset of the write.
* @param cbWrite Number of bytes to be written.
* @param pIoCtx The I/O context holding the data to write.
*/
DECLR3CALLBACKMEMBER(int, pfnFilterWrite, (void *pvBackendData, uint64_t uOffset, size_t cbWrite,
PVDIOCTX pIoCtx));
} VDFILTERBACKEND;
/** Pointer to VD filter backend. */
typedef VDFILTERBACKEND *PVDFILTERBACKEND;
/** Constant pointer to a VD filter backend. */
typedef const VDFILTERBACKEND *PCVDFILTERBACKEND;
#endif