VDIfVfs.cpp revision 2698330926679dd315ebf905a0996726d3c31d28
/* $Id$ */
/** @file
* Virtual Disk Image (VDI), I/O interface to IPRT VFS I/O stream glue.
*/
/*
* Copyright (C) 2012-2013 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.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#include <iprt/types.h>
#include <iprt/assert.h>
#include <iprt/mem.h>
#include <iprt/err.h>
#include <iprt/asm.h>
#include <iprt/string.h>
#include <iprt/file.h>
#include <iprt/sg.h>
#include <iprt/vfslowlevel.h>
#include <iprt/poll.h>
#include <VBox/vd.h>
/*******************************************************************************
* Structures and Typedefs *
*******************************************************************************/
/**
* The internal data of a DVM volume I/O stream.
*/
typedef struct VDIFVFSIOS
{
/** The VD I/O interface we wrap. */
PVDINTERFACEIO pVDIfsIo;
/** User pointer to pass to the VD I/O interface methods. */
void *pvStorage;
/** The current stream position relative to the VDIfCreateVfsStream call. */
uint64_t offCurPos;
} VDIFVFSIOS;
/** Pointer to a the internal data of a DVM volume file. */
typedef VDIFVFSIOS *PVDIFVFSIOS;
/**
* @interface_method_impl{RTVFSOBJOPS,pfnClose}
*/
static DECLCALLBACK(int) vdIfVfsIos_Close(void *pvThis)
{
/* We don't close anything. */
return VINF_SUCCESS;
}
/**
* @interface_method_impl{RTVFSOBJOPS,pfnQueryInfo}
*/
static DECLCALLBACK(int) vdIfVfsIos_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr)
{
NOREF(pvThis);
NOREF(pObjInfo);
NOREF(enmAddAttr);
return VERR_NOT_SUPPORTED;
}
/**
* @interface_method_impl{RTVFSIOSTREAMOPS,pfnRead}
*/
static DECLCALLBACK(int) vdIfVfsIos_Read(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbRead)
{
PVDIFVFSIOS pThis = (PVDIFVFSIOS)pvThis;
Assert(pSgBuf->cSegs == 1); NOREF(fBlocking);
/*
* This may end up being a little more complicated, esp. wrt VERR_EOF.
*/
int rc = vdIfIoFileReadSync(pThis->pVDIfsIo, pThis->pvStorage, off, pSgBuf[0].pvSegCur, pSgBuf->paSegs[0].cbSeg, pcbRead);
if (RT_SUCCESS(rc))
pThis->offCurPos = off + (pcbRead ? *pcbRead : pSgBuf->paSegs[0].cbSeg);
return rc;
}
/**
* @interface_method_impl{RTVFSIOSTREAMOPS,pfnWrite}
*/
static DECLCALLBACK(int) vdIfVfsIos_Write(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbWritten)
{
PVDIFVFSIOS pThis = (PVDIFVFSIOS)pvThis;
Assert(pSgBuf->cSegs == 1); NOREF(fBlocking);
/*
* This may end up being a little more complicated, esp. wrt VERR_EOF.
*/
int rc = vdIfIoFileWriteSync(pThis->pVDIfsIo, pThis->pvStorage, off, pSgBuf[0].pvSegCur, pSgBuf->paSegs[0].cbSeg, pcbWritten);
if (RT_SUCCESS(rc))
pThis->offCurPos = off + (pcbWritten ? *pcbWritten : pSgBuf->paSegs[0].cbSeg);
return rc;
}
/**
* @interface_method_impl{RTVFSIOSTREAMOPS,pfnFlush}
*/
static DECLCALLBACK(int) vdIfVfsIos_Flush(void *pvThis)
{
PVDIFVFSIOS pThis = (PVDIFVFSIOS)pvThis;
return vdIfIoFileFlushSync(pThis->pVDIfsIo, pThis->pvStorage);
}
/**
* @interface_method_impl{RTVFSIOSTREAMOPS,pfnPollOne}
*/
static DECLCALLBACK(int) vdIfVfsIos_PollOne(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
uint32_t *pfRetEvents)
{
NOREF(pvThis);
int rc;
if (fEvents != RTPOLL_EVT_ERROR)
{
*pfRetEvents = fEvents & ~RTPOLL_EVT_ERROR;
rc = VINF_SUCCESS;
}
else
rc = RTVfsUtilDummyPollOne(fEvents, cMillies, fIntr, pfRetEvents);
return rc;
}
/**
* @interface_method_impl{RTVFSIOSTREAMOPS,pfnTell}
*/
static DECLCALLBACK(int) vdIfVfsIos_Tell(void *pvThis, PRTFOFF poffActual)
{
PVDIFVFSIOS pThis = (PVDIFVFSIOS)pvThis;
*poffActual = pThis->offCurPos;
return VINF_SUCCESS;
}
/**
* Standard file operations.
*/
DECL_HIDDEN_CONST(const RTVFSIOSTREAMOPS) g_vdIfVfsStdIosOps =
{
{ /* Obj */
RTVFSOBJOPS_VERSION,
RTVFSOBJTYPE_FILE,
"VDIfIos",
vdIfVfsIos_Close,
vdIfVfsIos_QueryInfo,
RTVFSOBJOPS_VERSION
},
RTVFSIOSTREAMOPS_VERSION,
RTVFSIOSTREAMOPS_FEAT_NO_SG,
vdIfVfsIos_Read,
vdIfVfsIos_Write,
vdIfVfsIos_Flush,
vdIfVfsIos_PollOne,
vdIfVfsIos_Tell,
NULL /*Skip*/,
NULL /*ZeroFill*/,
RTVFSIOSTREAMOPS_VERSION,
};
VBOXDDU_DECL(int) VDIfCreateVfsStream(PVDINTERFACEIO pVDIfsIo, void *pvStorage, uint32_t fFlags, PRTVFSIOSTREAM phVfsIos)
{
AssertPtrReturn(pVDIfsIo, VERR_INVALID_HANDLE);
AssertPtrReturn(phVfsIos, VERR_INVALID_POINTER);
/*
* Create the volume file.
*/
RTVFSIOSTREAM hVfsIos;
PVDIFVFSIOS pThis;
int rc = RTVfsNewIoStream(&g_vdIfVfsStdIosOps, sizeof(*pThis), fFlags,
NIL_RTVFS, NIL_RTVFSLOCK, &hVfsIos, (void **)&pThis);
if (RT_SUCCESS(rc))
{
pThis->pVDIfsIo = pVDIfsIo;
pThis->pvStorage = pvStorage;
pThis->offCurPos = 0;
*phVfsIos = hVfsIos;
return VINF_SUCCESS;
}
return rc;
}