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virtualbox/include/iprt/vfslowlevel.h
Daniel Baumann df1bda4fe9
Adding upstream version 7.0.20-dfsg.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-22 09:56:04 +02:00

1588 lines
62 KiB
C++

/** @file
* IPRT - Virtual Filesystem.
*/
/*
* Copyright (C) 2010-2023 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
* in the VirtualBox 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.
*
* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
*/
#ifndef IPRT_INCLUDED_vfslowlevel_h
#define IPRT_INCLUDED_vfslowlevel_h
#ifndef RT_WITHOUT_PRAGMA_ONCE
# pragma once
#endif
#include <iprt/vfs.h>
#include <iprt/errcore.h>
#include <iprt/list.h>
#include <iprt/param.h>
RT_C_DECLS_BEGIN
/** @defgroup grp_rt_vfs_lowlevel RTVfs - Low-level Interface.
* @ingroup grp_rt_vfs
* @{
*/
/** @name VFS Lock Abstraction
* @todo This should be moved somewhere else as it is of general use.
* @{ */
/**
* VFS lock types.
*/
typedef enum RTVFSLOCKTYPE
{
/** Invalid lock type. */
RTVFSLOCKTYPE_INVALID = 0,
/** Read write semaphore. */
RTVFSLOCKTYPE_RW,
/** Fast mutex semaphore (critical section in ring-3). */
RTVFSLOCKTYPE_FASTMUTEX,
/** Full fledged mutex semaphore. */
RTVFSLOCKTYPE_MUTEX,
/** The end of valid lock types. */
RTVFSLOCKTYPE_END,
/** The customary 32-bit type hack. */
RTVFSLOCKTYPE_32BIT_HACK = 0x7fffffff
} RTVFSLOCKTYPE;
/** VFS lock handle. */
typedef struct RTVFSLOCKINTERNAL *RTVFSLOCK;
/** Pointer to a VFS lock handle. */
typedef RTVFSLOCK *PRTVFSLOCK;
/** Nil VFS lock handle. */
#define NIL_RTVFSLOCK ((RTVFSLOCK)~(uintptr_t)0)
/** Special handle value for creating a new read/write semaphore based lock. */
#define RTVFSLOCK_CREATE_RW ((RTVFSLOCK)~(uintptr_t)1)
/** Special handle value for creating a new fast mutex semaphore based lock. */
#define RTVFSLOCK_CREATE_FASTMUTEX ((RTVFSLOCK)~(uintptr_t)2)
/** Special handle value for creating a new mutex semaphore based lock. */
#define RTVFSLOCK_CREATE_MUTEX ((RTVFSLOCK)~(uintptr_t)3)
/**
* Retains a reference to the VFS lock handle.
*
* @returns New reference count on success, UINT32_MAX on failure.
* @param hLock The VFS lock handle.
*/
RTDECL(uint32_t) RTVfsLockRetain(RTVFSLOCK hLock);
/**
* Releases a reference to the VFS lock handle.
*
* @returns New reference count on success (0 if closed), UINT32_MAX on failure.
* @param hLock The VFS lock handle.
*/
RTDECL(uint32_t) RTVfsLockRelease(RTVFSLOCK hLock);
/**
* Gets the lock type.
*
* @returns The lock type on success, RTVFSLOCKTYPE_INVALID if the handle is
* not valid.
* @param hLock The lock handle.
*/
RTDECL(RTVFSLOCKTYPE) RTVfsLockGetType(RTVFSLOCK hLock);
RTDECL(void) RTVfsLockAcquireReadSlow(RTVFSLOCK hLock);
RTDECL(void) RTVfsLockReleaseReadSlow(RTVFSLOCK hLock);
RTDECL(void) RTVfsLockAcquireWriteSlow(RTVFSLOCK hLock);
RTDECL(void) RTVfsLockReleaseWriteSlow(RTVFSLOCK hLock);
/**
* Acquire a read lock.
*
* @param hLock The lock handle, can be NIL.
*/
DECLINLINE(void) RTVfsLockAcquireRead(RTVFSLOCK hLock)
{
if (hLock != NIL_RTVFSLOCK)
RTVfsLockAcquireReadSlow(hLock);
}
/**
* Release a read lock.
*
* @param hLock The lock handle, can be NIL.
*/
DECLINLINE(void) RTVfsLockReleaseRead(RTVFSLOCK hLock)
{
if (hLock != NIL_RTVFSLOCK)
RTVfsLockReleaseReadSlow(hLock);
}
/**
* Acquire a write lock.
*
* @param hLock The lock handle, can be NIL.
*/
DECLINLINE(void) RTVfsLockAcquireWrite(RTVFSLOCK hLock)
{
if (hLock != NIL_RTVFSLOCK)
RTVfsLockAcquireWriteSlow(hLock);
}
/**
* Release a write lock.
*
* @param hLock The lock handle, can be NIL.
*/
DECLINLINE(void) RTVfsLockReleaseWrite(RTVFSLOCK hLock)
{
if (hLock != NIL_RTVFSLOCK)
RTVfsLockReleaseWriteSlow(hLock);
}
/** @} */
/**
* Info queried via RTVFSOBJOPS::pfnQueryInfoEx, ++.
*/
typedef enum RTVFSQIEX
{
/** Invalid zero value. */
RTVFSQIEX_INVALID = 0,
/** Volume label.
* Returns a UTF-8 string. */
RTVFSQIEX_VOL_LABEL,
/** Alternative volume label, the primary one for ISOs, otherwise treated same
* as RTVFSQIEX_VOL_LABEL. */
RTVFSQIEX_VOL_LABEL_ALT,
/** Volume serial number.
* Returns a uint32_t, uint64_t or RTUUID. */
RTVFSQIEX_VOL_SERIAL,
/** End of valid queries. */
RTVFSQIEX_END,
/** The usual 32-bit hack. */
RTVFSQIEX_32BIT_SIZE_HACK = 0x7fffffff
} RTVFSQIEX;
/**
* The basis for all virtual file system objects.
*/
typedef struct RTVFSOBJOPS
{
/** The structure version (RTVFSOBJOPS_VERSION). */
uint32_t uVersion;
/** The object type for type introspection. */
RTVFSOBJTYPE enmType;
/** The name of the operations. */
const char *pszName;
/**
* Close the object.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
*/
DECLCALLBACKMEMBER(int, pfnClose,(void *pvThis));
/**
* Get information about the file.
*
* @returns IPRT status code. See RTVfsObjQueryInfo.
* @retval VERR_WRONG_TYPE if file system or file system stream.
*
* @param pvThis The implementation specific file data.
* @param pObjInfo Where to return the object info on success.
* @param enmAddAttr Which set of additional attributes to request.
* @sa RTVfsObjQueryInfo, RTFileQueryInfo, RTPathQueryInfo
*/
DECLCALLBACKMEMBER(int, pfnQueryInfo,(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr));
/**
* Query arbritray information about the file, volume, or whatever.
*
* @returns IPRT status code.
* @retval VERR_BUFFER_OVERFLOW sets pcbRet.
*
* @param pvThis The implementation specific file data.
* @param enmInfo The information being queried.
* @param pvInfo Where to return the info.
* @param cbInfo The size of the @a pvInfo buffer.
* @param pcbRet The size of the returned data. In case of
* VERR_BUFFER_OVERFLOW this will be set to the required
* buffer size.
*/
DECLCALLBACKMEMBER(int, pfnQueryInfoEx,(void *pvThis, RTVFSQIEX enmInfo, void *pvInfo, size_t cbInfo, size_t *pcbRet));
/** Marks the end of the structure (RTVFSOBJOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSOBJOPS;
/** Pointer to constant VFS object operations. */
typedef RTVFSOBJOPS const *PCRTVFSOBJOPS;
/** The RTVFSOBJOPS structure version. */
#define RTVFSOBJOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x1f,2,0)
/**
* The VFS operations.
*/
typedef struct RTVFSOPS
{
/** The basic object operation. */
RTVFSOBJOPS Obj;
/** The structure version (RTVFSOPS_VERSION). */
uint32_t uVersion;
/** The virtual file system feature mask. */
uint32_t fFeatures;
/**
* Opens the root directory.
*
* @returns IPRT status code.
* @param pvThis The implementation specific data.
* @param phVfsDir Where to return the handle to the root directory.
*/
DECLCALLBACKMEMBER(int, pfnOpenRoot,(void *pvThis, PRTVFSDIR phVfsDir));
/**
* Query the status of the given storage range (optional).
*
* This can be used by the image compaction utilites to evict non-zero blocks
* that aren't currently being used by the file system.
*
* @returns IPRT status code.
* @param pvThis The implementation specific data.
* @param off Start offset to check.
* @param cb Number of bytes to check.
* @param pfUsed Where to store whether the given range is in use.
*/
DECLCALLBACKMEMBER(int, pfnQueryRangeState,(void *pvThis, uint64_t off, size_t cb, bool *pfUsed));
/** @todo There will be more methods here to optimize opening and
* querying. */
#if 0
/**
* Optional entry point for optimizing path traversal within the file system.
*
* @returns IPRT status code.
* @param pvThis The implementation specific data.
* @param pszPath The path to resolve.
* @param poffPath The current path offset on input, what we've
* traversed to on successful return.
* @param phVfs??? Return handle to what we've traversed.
* @param p??? Return other stuff...
*/
DECLCALLBACKMEMBER(int, pfnTraverse,(void *pvThis, const char *pszPath, size_t *poffPath, PRTVFS??? phVfs?, ???* p???));
#endif
/** @todo need rename API */
/** Marks the end of the structure (RTVFSOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSOPS;
/** Pointer to constant VFS operations. */
typedef RTVFSOPS const *PCRTVFSOPS;
/** The RTVFSOPS structure version. */
#define RTVFSOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x0f,1,0)
/** @name RTVFSOPS::fFeatures
* @{ */
/** The VFS supports attaching other systems. */
#define RTVFSOPS_FEAT_ATTACH RT_BIT_32(0)
/** @} */
/**
* Creates a new VFS handle.
*
* @returns IPRT status code
* @param pVfsOps The VFS operations.
* @param cbInstance The size of the instance data.
* @param hVfs The VFS handle to associate this VFS with.
* NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param phVfs Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNew(PCRTVFSOPS pVfsOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
PRTVFS phVfs, void **ppvInstance);
/**
* Creates a new VFS base object handle.
*
* @returns IPRT status code
* @param pObjOps The base object operations.
* @param cbInstance The size of the instance data.
* @param hVfs The VFS handle to associate this base object
* with. NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param phVfsObj Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNewBaseObj(PCRTVFSOBJOPS pObjOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
PRTVFSOBJ phVfsObj, void **ppvInstance);
/**
* Gets the private data of a base object.
*
* @returns Pointer to the private data. NULL if the handle is invalid in some
* way.
* @param hVfsObj The I/O base object handle.
* @param pObjOps The base object operations. This servers as a
* sort of password.
*/
RTDECL(void *) RTVfsObjToPrivate(RTVFSOBJ hVfsObj, PCRTVFSOBJOPS pObjOps);
/**
* Additional operations for setting object attributes.
*/
typedef struct RTVFSOBJSETOPS
{
/** The structure version (RTVFSOBJSETOPS_VERSION). */
uint32_t uVersion;
/** The offset back to the RTVFSOBJOPS structure. */
uint32_t offObjOps;
/**
* Set the unix style owner and group.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param fMode The new mode bits.
* @param fMask The mask indicating which bits we are
* changing.
* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
* @sa RTFileSetMode
*/
DECLCALLBACKMEMBER(int, pfnSetMode,(void *pvThis, RTFMODE fMode, RTFMODE fMask));
/**
* Set the timestamps associated with the object.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param pAccessTime Pointer to the new access time. NULL if not
* to be changed.
* @param pModificationTime Pointer to the new modifcation time. NULL if
* not to be changed.
* @param pChangeTime Pointer to the new change time. NULL if not
* to be changed.
* @param pBirthTime Pointer to the new time of birth. NULL if
* not to be changed.
* @remarks See RTFileSetTimes for restrictions and behavior imposed by the
* host OS or underlying VFS provider.
* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
* @sa RTFileSetTimes
*/
DECLCALLBACKMEMBER(int, pfnSetTimes,(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime,
PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime));
/**
* Set the unix style owner and group.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param uid The user ID of the new owner. NIL_RTUID if
* unchanged.
* @param gid The group ID of the new owner group. NIL_RTGID if
* unchanged.
* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
* @sa RTFileSetOwner
*/
DECLCALLBACKMEMBER(int, pfnSetOwner,(void *pvThis, RTUID uid, RTGID gid));
/** Marks the end of the structure (RTVFSOBJSETOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSOBJSETOPS;
/** Pointer to const object attribute setter operations. */
typedef RTVFSOBJSETOPS const *PCRTVFSOBJSETOPS;
/** The RTVFSOBJSETOPS structure version. */
#define RTVFSOBJSETOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x2f,1,0)
/**
* The filesystem stream operations.
*
* @extends RTVFSOBJOPS
*/
typedef struct RTVFSFSSTREAMOPS
{
/** The basic object operation. */
RTVFSOBJOPS Obj;
/** The structure version (RTVFSFSSTREAMOPS_VERSION). */
uint32_t uVersion;
/** Reserved field, MBZ. */
uint32_t fReserved;
/**
* Gets the next object in the stream.
*
* Readable streams only.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS if a new object was retrieved.
* @retval VERR_EOF when there are no more objects.
* @param pvThis The implementation specific directory data.
* @param ppszName Where to return the object name. Must be freed by
* calling RTStrFree.
* @param penmType Where to return the object type.
* @param phVfsObj Where to return the object handle (referenced). This
* must be cast to the desired type before use.
* @sa RTVfsFsStrmNext
*
* @note Setting this member to NULL is okay for write-only streams.
*/
DECLCALLBACKMEMBER(int, pfnNext,(void *pvThis, char **ppszName, RTVFSOBJTYPE *penmType, PRTVFSOBJ phVfsObj));
/**
* Adds another object into the stream.
*
* Writable streams only.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszPath The path to the object.
* @param hVfsObj The object to add.
* @param fFlags Reserved for the future, MBZ.
* @sa RTVfsFsStrmAdd
*
* @note Setting this member to NULL is okay for read-only streams.
*/
DECLCALLBACKMEMBER(int, pfnAdd,(void *pvThis, const char *pszPath, RTVFSOBJ hVfsObj, uint32_t fFlags));
/**
* Pushes an byte stream onto the stream (optional).
*
* Writable streams only.
*
* This differs from RTVFSFSSTREAMOPS::pfnAdd() in that it will create a regular
* file in the output file system stream and provide the actual content bytes
* via the returned I/O stream object.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszPath The path to the file.
* @param cbFile The file size. This can also be set to UINT64_MAX if
* the file system stream is backed by a file.
* @param paObjInfo Array of zero or more RTFSOBJINFO structures containing
* different pieces of information about the file. If any
* provided, the first one should be a RTFSOBJATTRADD_UNIX
* one, additional can be supplied if wanted. What exactly
* is needed depends on the underlying FS stream
* implementation.
* @param cObjInfo Number of items in the array @a paObjInfo points at.
* @param fFlags RTVFSFSSTRM_PUSH_F_XXX.
* @param phVfsIos Where to return the I/O stream to feed the file content
* to. If the FS stream is backed by a file, the returned
* handle can be cast to a file if necessary.
*/
DECLCALLBACKMEMBER(int, pfnPushFile,(void *pvThis, const char *pszPath, uint64_t cbFile,
PCRTFSOBJINFO paObjInfo, uint32_t cObjInfo, uint32_t fFlags, PRTVFSIOSTREAM phVfsIos));
/**
* Marks the end of the stream.
*
* Writable streams only.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @sa RTVfsFsStrmEnd
*
* @note Setting this member to NULL is okay for read-only streams.
*/
DECLCALLBACKMEMBER(int, pfnEnd,(void *pvThis));
/** Marks the end of the structure (RTVFSFSSTREAMOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSFSSTREAMOPS;
/** Pointer to const object attribute setter operations. */
typedef RTVFSFSSTREAMOPS const *PCRTVFSFSSTREAMOPS;
/** The RTVFSFSSTREAMOPS structure version. */
#define RTVFSFSSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x3f,2,0)
/**
* Creates a new VFS filesystem stream handle.
*
* @returns IPRT status code
* @param pFsStreamOps The filesystem stream operations.
* @param cbInstance The size of the instance data.
* @param hVfs The VFS handle to associate this filesystem
* stream with. NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param fAccess RTFILE_O_READ and/or RTFILE_O_WRITE.
* @param phVfsFss Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNewFsStream(PCRTVFSFSSTREAMOPS pFsStreamOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock, uint32_t fAccess,
PRTVFSFSSTREAM phVfsFss, void **ppvInstance);
/**
* Gets the private data of an filesystem stream.
*
* @returns Pointer to the private data. NULL if the handle is invalid in some
* way.
* @param hVfsFss The FS stream handle.
* @param pFsStreamOps The FS stream operations. This servers as a
* sort of password.
*/
RTDECL(void *) RTVfsFsStreamToPrivate(RTVFSFSSTREAM hVfsFss, PCRTVFSFSSTREAMOPS pFsStreamOps);
/**
* The directory operations.
*
* @extends RTVFSOBJOPS
* @extends RTVFSOBJSETOPS
*/
typedef struct RTVFSDIROPS
{
/** The basic object operation. */
RTVFSOBJOPS Obj;
/** The structure version (RTVFSDIROPS_VERSION). */
uint32_t uVersion;
/** Reserved field, MBZ. */
uint32_t fReserved;
/** The object setter operations. */
RTVFSOBJSETOPS ObjSet;
/**
* Generic method for opening any kind of file system object.
*
* Can also create files and directories. Symbolic links, devices and such
* needs to be created using special methods or this would end up being way more
* complicated than it already is.
*
* There are optional specializations available.
*
* @returns IPRT status code.
* @retval VERR_PATH_NOT_FOUND or VERR_FILE_NOT_FOUND if @a pszEntry was not
* found.
* @retval VERR_IS_A_FILE if @a pszEntry is a file or similar but @a fFlags
* indicates that the type of object should not be opened.
* @retval VERR_IS_A_DIRECTORY if @a pszEntry is a directory but @a fFlags
* indicates that directories should not be opened.
* @retval VERR_IS_A_SYMLINK if @a pszEntry is a symbolic link but @a fFlags
* indicates that symbolic links should not be opened (or followed).
* @retval VERR_IS_A_FIFO if @a pszEntry is a FIFO but @a fFlags indicates that
* FIFOs should not be opened.
* @retval VERR_IS_A_SOCKET if @a pszEntry is a socket but @a fFlags indicates
* that sockets should not be opened.
* @retval VERR_IS_A_BLOCK_DEVICE if @a pszEntry is a block device but
* @a fFlags indicates that block devices should not be opened, or vice
* versa.
*
* @param pvThis The implementation specific directory data.
* @param pszEntry The name of the immediate file to open or create.
* @param fOpenFile RTFILE_O_XXX combination.
* @param fObjFlags More flags: RTVFSOBJ_F_XXX, RTPATH_F_XXX.
* The meaning of RTPATH_F_FOLLOW_LINK differs here, if
* @a pszEntry is a symlink it should be opened for
* traversal rather than according to @a fOpenFile.
* @param phVfsObj Where to return the handle to the opened object.
* @sa RTFileOpen, RTDirOpen
*/
DECLCALLBACKMEMBER(int, pfnOpen,(void *pvThis, const char *pszEntry, uint64_t fOpenFile,
uint32_t fObjFlags, PRTVFSOBJ phVfsObj));
/**
* Optional method for symbolic link handling in the vfsstddir.cpp.
*
* This is really just a hack to make symbolic link handling work when working
* with directory objects that doesn't have an associated VFS. It also helps
* deal with drive letters in symbolic links on Windows and OS/2.
*
* @returns IPRT status code.
* @retval VERR_PATH_IS_RELATIVE if @a pszPath isn't absolute and should be
* handled using pfnOpen().
*
* @param pvThis The implementation specific directory data.
* @param pszRoot Path to the alleged root.
* @param phVfsDir Where to return the handle to the specified root
* directory (or may current dir on a drive letter).
*/
DECLCALLBACKMEMBER(int, pfnFollowAbsoluteSymlink,(void *pvThis, const char *pszRoot, PRTVFSDIR phVfsDir));
/**
* Open or create a file.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszFilename The name of the immediate file to open or create.
* @param fOpen The open flags (RTFILE_O_XXX).
* @param phVfsFile Where to return the handle to the opened file.
* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
* @sa RTFileOpen.
*/
DECLCALLBACKMEMBER(int, pfnOpenFile,(void *pvThis, const char *pszFilename, uint64_t fOpen, PRTVFSFILE phVfsFile));
/**
* Open an existing subdirectory.
*
* @returns IPRT status code.
* @retval VERR_IS_A_SYMLINK if @a pszSubDir is a symbolic link.
* @retval VERR_NOT_A_DIRECTORY is okay for symbolic links too.
*
* @param pvThis The implementation specific directory data.
* @param pszSubDir The name of the immediate subdirectory to open.
* @param fFlags RTDIR_F_XXX.
* @param phVfsDir Where to return the handle to the opened directory.
* Optional.
* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
* @sa RTDirOpen.
*/
DECLCALLBACKMEMBER(int, pfnOpenDir,(void *pvThis, const char *pszSubDir, uint32_t fFlags, PRTVFSDIR phVfsDir));
/**
* Creates a new subdirectory.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszSubDir The name of the immediate subdirectory to create.
* @param fMode The mode mask of the new directory.
* @param phVfsDir Where to optionally return the handle to the newly
* create directory.
* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
* @sa RTDirCreate.
*/
DECLCALLBACKMEMBER(int, pfnCreateDir,(void *pvThis, const char *pszSubDir, RTFMODE fMode, PRTVFSDIR phVfsDir));
/**
* Opens an existing symbolic link.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszSymlink The name of the immediate symbolic link to open.
* @param phVfsSymlink Where to optionally return the handle to the
* newly create symbolic link.
* @note Optional. RTVFSDIROPS::pfnOpenObj will be used if NULL.
* @sa RTSymlinkCreate.
*/
DECLCALLBACKMEMBER(int, pfnOpenSymlink,(void *pvThis, const char *pszSymlink, PRTVFSSYMLINK phVfsSymlink));
/**
* Creates a new symbolic link.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszSymlink The name of the immediate symbolic link to create.
* @param pszTarget The symbolic link target.
* @param enmType The symbolic link type.
* @param phVfsSymlink Where to optionally return the handle to the
* newly create symbolic link.
* @sa RTSymlinkCreate.
*/
DECLCALLBACKMEMBER(int, pfnCreateSymlink,(void *pvThis, const char *pszSymlink, const char *pszTarget,
RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink));
/**
* Query information about an entry.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszEntry The name of the directory entry to remove.
* @param pObjInfo Where to return the info on success.
* @param enmAddAttr Which set of additional attributes to request.
* @note Optional. RTVFSDIROPS::pfnOpenObj and RTVFSOBJOPS::pfnQueryInfo
* will be used if NULL.
* @sa RTPathQueryInfo, RTVFSOBJOPS::pfnQueryInfo
*/
DECLCALLBACKMEMBER(int, pfnQueryEntryInfo,(void *pvThis, const char *pszEntry,
PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr));
/**
* Removes a directory entry.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszEntry The name of the directory entry to remove.
* @param fType If non-zero, this restricts the type of the entry to
* the object type indicated by the mask
* (RTFS_TYPE_XXX).
* @sa RTFileRemove, RTDirRemove, RTSymlinkRemove.
*/
DECLCALLBACKMEMBER(int, pfnUnlinkEntry,(void *pvThis, const char *pszEntry, RTFMODE fType));
/**
* Renames a directory entry.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszEntry The name of the directory entry to rename.
* @param fType If non-zero, this restricts the type of the entry to
* the object type indicated by the mask
* (RTFS_TYPE_XXX).
* @param pszNewName The new entry name.
* @sa RTPathRename
*
* @todo This API is not flexible enough, must be able to rename between
* directories within a file system.
*/
DECLCALLBACKMEMBER(int, pfnRenameEntry,(void *pvThis, const char *pszEntry, RTFMODE fType, const char *pszNewName));
/**
* Rewind the directory stream so that the next read returns the first
* entry.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
*/
DECLCALLBACKMEMBER(int, pfnRewindDir,(void *pvThis));
/**
* Rewind the directory stream so that the next read returns the first
* entry.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pDirEntry Output buffer.
* @param pcbDirEntry Complicated, see RTDirReadEx.
* @param enmAddAttr Which set of additional attributes to request.
* @sa RTDirReadEx
*/
DECLCALLBACKMEMBER(int, pfnReadDir,(void *pvThis, PRTDIRENTRYEX pDirEntry, size_t *pcbDirEntry, RTFSOBJATTRADD enmAddAttr));
/** Marks the end of the structure (RTVFSDIROPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSDIROPS;
/** Pointer to const directory operations. */
typedef RTVFSDIROPS const *PCRTVFSDIROPS;
/** The RTVFSDIROPS structure version. */
#define RTVFSDIROPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x4f,1,0)
/**
* Creates a new VFS directory handle.
*
* @returns IPRT status code
* @param pDirOps The directory operations.
* @param cbInstance The size of the instance data.
* @param fFlags RTVFSDIR_F_XXX
* @param hVfs The VFS handle to associate this directory with.
* NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param phVfsDir Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNewDir(PCRTVFSDIROPS pDirOps, size_t cbInstance, uint32_t fFlags, RTVFS hVfs, RTVFSLOCK hLock,
PRTVFSDIR phVfsDir, void **ppvInstance);
/** @name RTVFSDIR_F_XXX
* @{ */
/** Don't reference the @a hVfs parameter passed to RTVfsNewDir.
* This is a permanent root directory hack. */
#define RTVFSDIR_F_NO_VFS_REF RT_BIT_32(0)
/** @} */
/**
* Gets the private data of a directory.
*
* @returns Pointer to the private data. NULL if the handle is invalid in some
* way.
* @param hVfsDir The directory handle.
* @param pDirOps The directory operations. This servers as a
* sort of password.
*/
RTDECL(void *) RTVfsDirToPrivate(RTVFSDIR hVfsDir, PCRTVFSDIROPS pDirOps);
/**
* The symbolic link operations.
*
* @extends RTVFSOBJOPS
* @extends RTVFSOBJSETOPS
*/
typedef struct RTVFSSYMLINKOPS
{
/** The basic object operation. */
RTVFSOBJOPS Obj;
/** The structure version (RTVFSSYMLINKOPS_VERSION). */
uint32_t uVersion;
/** Reserved field, MBZ. */
uint32_t fReserved;
/** The object setter operations. */
RTVFSOBJSETOPS ObjSet;
/**
* Read the symbolic link target.
*
* @returns IPRT status code.
* @param pvThis The implementation specific symbolic link data.
* @param pszTarget The target buffer.
* @param cbTarget The size of the target buffer.
* @sa RTSymlinkRead
*/
DECLCALLBACKMEMBER(int, pfnRead,(void *pvThis, char *pszTarget, size_t cbTarget));
/** Marks the end of the structure (RTVFSSYMLINKOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSSYMLINKOPS;
/** Pointer to const symbolic link operations. */
typedef RTVFSSYMLINKOPS const *PCRTVFSSYMLINKOPS;
/** The RTVFSSYMLINKOPS structure version. */
#define RTVFSSYMLINKOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x5f,1,0)
/**
* Creates a new VFS symlink handle.
*
* @returns IPRT status code
* @param pSymlinkOps The symlink operations.
* @param cbInstance The size of the instance data.
* @param hVfs The VFS handle to associate this symlink object
* with. NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param phVfsSym Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNewSymlink(PCRTVFSSYMLINKOPS pSymlinkOps, size_t cbInstance, RTVFS hVfs, RTVFSLOCK hLock,
PRTVFSSYMLINK phVfsSym, void **ppvInstance);
/**
* Gets the private data of a symbolic link.
*
* @returns Pointer to the private data. NULL if the handle is invalid in some
* way.
* @param hVfsSym The symlink handle.
* @param pSymlinkOps The symlink operations. This servers as a sort
* of password.
*/
RTDECL(void *) RTVfsSymlinkToPrivate(RTVFSSYMLINK hVfsSym, PCRTVFSSYMLINKOPS pSymlinkOps);
/**
* The basis for all I/O objects (files, pipes, sockets, devices, ++).
*
* @extends RTVFSOBJOPS
*/
typedef struct RTVFSIOSTREAMOPS
{
/** The basic object operation. */
RTVFSOBJOPS Obj;
/** The structure version (RTVFSIOSTREAMOPS_VERSION). */
uint32_t uVersion;
/** Feature field. */
uint32_t fFeatures;
/**
* Reads from the file/stream.
*
* @returns IPRT status code. See RTVfsIoStrmRead.
* @param pvThis The implementation specific file data.
* @param off Where to read at, -1 for the current position.
* @param pSgBuf Gather buffer describing the bytes that are to be
* written.
* @param fBlocking If @c true, the call is blocking, if @c false it
* should not block.
* @param pcbRead Where return the number of bytes actually read.
* This is set it 0 by the caller. If NULL, try read
* all and fail if incomplete.
* @sa RTVfsIoStrmRead, RTVfsIoStrmSgRead, RTVfsFileRead,
* RTVfsFileReadAt, RTFileRead, RTFileReadAt.
*/
DECLCALLBACKMEMBER(int, pfnRead,(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbRead));
/**
* Writes to the file/stream.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param off Where to start wrinting, -1 for the current
* position.
* @param pSgBuf Gather buffers describing the bytes that are to be
* written.
* @param fBlocking If @c true, the call is blocking, if @c false it
* should not block.
* @param pcbWritten Where to return the number of bytes actually
* written. This is set it 0 by the caller. If
* NULL, try write it all and fail if incomplete.
* @note Optional, failing with VERR_WRITE_PROTECT if NULL.
* @sa RTFileWrite, RTFileWriteAt.
*/
DECLCALLBACKMEMBER(int, pfnWrite,(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbWritten));
/**
* Flushes any pending data writes to the stream.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @sa RTFileFlush.
*/
DECLCALLBACKMEMBER(int, pfnFlush,(void *pvThis));
/**
* Poll for events.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
* @param cMillies How long to wait for event to eventuate.
* @param fIntr Whether the wait is interruptible and can return
* VERR_INTERRUPTED (@c true) or if this condition
* should be hidden from the caller (@c false).
* @param pfRetEvents Where to return the event mask.
* @note Optional. If NULL, immediately return all requested non-error
* events, waiting for errors works like sleep.
* @sa RTPollSetAdd, RTPoll, RTPollNoResume.
*/
DECLCALLBACKMEMBER(int, pfnPollOne,(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr,
uint32_t *pfRetEvents));
/**
* Tells the current file/stream position.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param poffActual Where to return the actual offset.
* @sa RTFileTell
*/
DECLCALLBACKMEMBER(int, pfnTell,(void *pvThis, PRTFOFF poffActual));
/**
* Skips @a cb ahead in the stream.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param cb The number bytes to skip.
* @remarks This is optional and can be NULL.
*/
DECLCALLBACKMEMBER(int, pfnSkip,(void *pvThis, RTFOFF cb));
/**
* Fills the stream with @a cb zeros.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param cb The number of zero bytes to insert.
* @remarks This is optional and can be NULL.
*/
DECLCALLBACKMEMBER(int, pfnZeroFill,(void *pvThis, RTFOFF cb));
/** Marks the end of the structure (RTVFSIOSTREAMOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSIOSTREAMOPS;
/** Pointer to const I/O stream operations. */
typedef RTVFSIOSTREAMOPS const *PCRTVFSIOSTREAMOPS;
/** The RTVFSIOSTREAMOPS structure version. */
#define RTVFSIOSTREAMOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x6f,1,0)
/** @name RTVFSIOSTREAMOPS::fFeatures
* @{ */
/** No scatter gather lists, thank you. */
#define RTVFSIOSTREAMOPS_FEAT_NO_SG RT_BIT_32(0)
/** Mask of the valid I/O stream feature flags. */
#define RTVFSIOSTREAMOPS_FEAT_VALID_MASK UINT32_C(0x00000001)
/** @} */
/**
* Creates a new VFS I/O stream handle.
*
* @returns IPRT status code
* @param pIoStreamOps The I/O stream operations.
* @param cbInstance The size of the instance data.
* @param fOpen The open flags. The minimum is the access mask.
* @param hVfs The VFS handle to associate this I/O stream
* with. NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param phVfsIos Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNewIoStream(PCRTVFSIOSTREAMOPS pIoStreamOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
PRTVFSIOSTREAM phVfsIos, void **ppvInstance);
/**
* Gets the private data of an I/O stream.
*
* @returns Pointer to the private data. NULL if the handle is invalid in some
* way.
* @param hVfsIos The I/O stream handle.
* @param pIoStreamOps The I/O stream operations. This servers as a
* sort of password.
*/
RTDECL(void *) RTVfsIoStreamToPrivate(RTVFSIOSTREAM hVfsIos, PCRTVFSIOSTREAMOPS pIoStreamOps);
/**
* The file operations.
*
* @extends RTVFSIOSTREAMOPS
* @extends RTVFSOBJSETOPS
*/
typedef struct RTVFSFILEOPS
{
/** The I/O stream and basis object operations. */
RTVFSIOSTREAMOPS Stream;
/** The structure version (RTVFSFILEOPS_VERSION). */
uint32_t uVersion;
/** Reserved field, MBZ. */
uint32_t fReserved;
/** The object setter operations. */
RTVFSOBJSETOPS ObjSet;
/**
* Changes the current file position.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param offSeek The offset to seek.
* @param uMethod The seek method, i.e. what the seek is relative to.
* @param poffActual Where to return the actual offset.
* @sa RTFileSeek
*/
DECLCALLBACKMEMBER(int, pfnSeek,(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual));
/**
* Get the current file size.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param pcbFile Where to store the current file size.
* @sa RTFileQuerySize
*/
DECLCALLBACKMEMBER(int, pfnQuerySize,(void *pvThis, uint64_t *pcbFile));
/**
* Change the file size.
*
* @returns IPRT status code.
* @retval VERR_ACCESS_DENIED if handle isn't writable.
* @retval VERR_WRITE_PROTECT if read-only file system.
* @retval VERR_FILE_TOO_BIG if cbSize is larger than what the file system can
* theoretically deal with.
* @retval VERR_DISK_FULL if the file system if full.
* @retval VERR_NOT_SUPPORTED if fFlags indicates some operation that's not
* supported by the file system / host operating system.
*
* @param pvThis The implementation specific file data.
* @param pcbFile Where to store the current file size.
* @param fFlags RTVFSFILE_SET_SIZE_F_XXX.
* @note Optional. If NULL, VERR_WRITE_PROTECT will be returned.
* @sa RTFileSetSize, RTFileSetAllocationSize
*/
DECLCALLBACKMEMBER(int, pfnSetSize,(void *pvThis, uint64_t cbFile, uint32_t fFlags));
/**
* Determine the maximum file size.
*
* This won't take amount of freespace into account, just the limitations of the
* underlying file system / host operating system.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param pcbMax Where to return the max file size.
* @note Optional. If NULL, VERR_NOT_IMPLEMENTED will be returned.
* @sa RTFileQueryMaxSizeEx
*/
DECLCALLBACKMEMBER(int, pfnQueryMaxSize,(void *pvThis, uint64_t *pcbMax));
/** @todo There will be more methods here. */
/** Marks the end of the structure (RTVFSFILEOPS_VERSION). */
uintptr_t uEndMarker;
} RTVFSFILEOPS;
/** Pointer to const file operations. */
typedef RTVFSFILEOPS const *PCRTVFSFILEOPS;
/** The RTVFSFILEOPS structure version. */
#define RTVFSFILEOPS_VERSION RT_MAKE_U32_FROM_U8(0xff,0x7f,2,0)
/**
* Creates a new VFS file handle.
*
* @returns IPRT status code
* @param pFileOps The file operations.
* @param cbInstance The size of the instance data.
* @param fOpen The open flags. The minimum is the access mask.
* @param hVfs The VFS handle to associate this file with.
* NIL_VFS is ok.
* @param hLock Handle to a custom lock to be used with the new
* object. The reference is consumed. NIL and
* special lock handles are fine.
* @param phVfsFile Where to return the new handle.
* @param ppvInstance Where to return the pointer to the instance data
* (size is @a cbInstance).
*/
RTDECL(int) RTVfsNewFile(PCRTVFSFILEOPS pFileOps, size_t cbInstance, uint32_t fOpen, RTVFS hVfs, RTVFSLOCK hLock,
PRTVFSFILE phVfsFile, void **ppvInstance);
/** @defgroup grp_rt_vfs_ll_util VFS Utility APIs
* @{ */
/**
* Parsed path.
*/
typedef struct RTVFSPARSEDPATH
{
/** The length of the path in szCopy. */
uint16_t cch;
/** The number of path components. */
uint16_t cComponents;
/** Set if the path ends with slash, indicating that it's a directory
* reference and not a file reference. The slash has been removed from
* the copy. */
bool fDirSlash;
/** Set if absolute. */
bool fAbsolute;
/** The offset where each path component starts, i.e. the char after the
* slash. The array has cComponents + 1 entries, where the final one is
* cch + 1 so that one can always terminate the current component by
* szPath[aoffComponent[i] - 1] = '\0'. */
uint16_t aoffComponents[RTPATH_MAX / 2 + 1];
/** A normalized copy of the path.
* Reserve some extra space so we can be more relaxed about overflow
* checks and terminator paddings, especially when recursing. */
char szPath[RTPATH_MAX];
} RTVFSPARSEDPATH;
/** Pointer to a parsed path. */
typedef RTVFSPARSEDPATH *PRTVFSPARSEDPATH;
/** The max accepted path length.
* This must be a few chars shorter than RTVFSPARSEDPATH::szPath because we
* use two terminators and wish be a little bit lazy with checking. */
#define RTVFSPARSEDPATH_MAX (RTPATH_MAX - 4)
/**
* Appends @a pszPath (relative) to the already parsed path @a pPath.
*
* @retval VINF_SUCCESS
* @retval VERR_FILENAME_TOO_LONG
* @retval VERR_INTERNAL_ERROR_4
* @param pPath The parsed path to append @a pszPath onto.
* This is both input and output.
* @param pszPath The path to append. This must be relative.
* @param piRestartComp The component to restart parsing at. This is
* input/output. The input does not have to be
* within the valid range. Optional.
*/
RTDECL(int) RTVfsParsePathAppend(PRTVFSPARSEDPATH pPath, const char *pszPath, uint16_t *piRestartComp);
/**
* Parses a path.
*
* @retval VINF_SUCCESS
* @retval VERR_FILENAME_TOO_LONG
* @param pPath Where to store the parsed path.
* @param pszPath The path to parse. Absolute or relative to @a
* pszCwd.
* @param pszCwd The current working directory. Must be
* absolute.
*/
RTDECL(int) RTVfsParsePath(PRTVFSPARSEDPATH pPath, const char *pszPath, const char *pszCwd);
/**
* Same as RTVfsParsePath except that it allocates a temporary buffer.
*
* @retval VINF_SUCCESS
* @retval VERR_NO_TMP_MEMORY
* @retval VERR_FILENAME_TOO_LONG
* @param pszPath The path to parse. Absolute or relative to @a
* pszCwd.
* @param pszCwd The current working directory. Must be
* absolute.
* @param ppPath Where to store the pointer to the allocated
* buffer containing the parsed path. This must
* be freed by calling RTVfsParsePathFree. NULL
* will be stored on failured.
*/
RTDECL(int) RTVfsParsePathA(const char *pszPath, const char *pszCwd, PRTVFSPARSEDPATH *ppPath);
/**
* Frees a buffer returned by RTVfsParsePathA.
*
* @param pPath The parsed path buffer to free. NULL is fine.
*/
RTDECL(void) RTVfsParsePathFree(PRTVFSPARSEDPATH pPath);
/**
* Dummy implementation of RTVFSIOSTREAMOPS::pfnPollOne.
*
* This handles the case where there is no chance any events my be raised and
* all that is required is to wait according to the parameters.
*
* @returns IPRT status code.
* @param fEvents The events to poll for (RTPOLL_EVT_XXX).
* @param cMillies How long to wait for event to eventuate.
* @param fIntr Whether the wait is interruptible and can return
* VERR_INTERRUPTED (@c true) or if this condition
* should be hidden from the caller (@c false).
* @param pfRetEvents Where to return the event mask.
* @sa RTVFSIOSTREAMOPS::pfnPollOne, RTPollSetAdd, RTPoll, RTPollNoResume.
*/
RTDECL(int) RTVfsUtilDummyPollOne(uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, uint32_t *pfRetEvents);
/** @} */
/** @defgroup grp_rt_vfs_lowlevel_chain VFS Chains (Low Level)
* @ref grp_rt_vfs_chain
* @{
*/
/** Pointer to a VFS chain element registration record. */
typedef struct RTVFSCHAINELEMENTREG *PRTVFSCHAINELEMENTREG;
/** Pointer to a const VFS chain element registration record. */
typedef struct RTVFSCHAINELEMENTREG const *PCRTVFSCHAINELEMENTREG;
/**
* VFS chain element argument.
*/
typedef struct RTVFSCHAINELEMENTARG
{
/** The string argument value. */
char *psz;
/** The specification offset of this argument. */
uint16_t offSpec;
/** Provider specific value. */
uint64_t uProvider;
} RTVFSCHAINELEMENTARG;
/** Pointer to a VFS chain element argument. */
typedef RTVFSCHAINELEMENTARG *PRTVFSCHAINELEMENTARG;
/**
* VFS chain element specification.
*/
typedef struct RTVFSCHAINELEMSPEC
{
/** The provider name.
* This can be NULL if this is the final component and it's just a path. */
char *pszProvider;
/** The input type, RTVFSOBJTYPE_INVALID if first. */
RTVFSOBJTYPE enmTypeIn;
/** The element type.
* RTVFSOBJTYPE_END if this is the final component and it's just a path. */
RTVFSOBJTYPE enmType;
/** The input spec offset of this element. */
uint16_t offSpec;
/** The length of the input spec. */
uint16_t cchSpec;
/** The number of arguments. */
uint32_t cArgs;
/** Arguments. */
PRTVFSCHAINELEMENTARG paArgs;
/** The provider. */
PCRTVFSCHAINELEMENTREG pProvider;
/** Provider specific value. */
uint64_t uProvider;
/** The object (with reference). */
RTVFSOBJ hVfsObj;
} RTVFSCHAINELEMSPEC;
/** Pointer to a chain element specification. */
typedef RTVFSCHAINELEMSPEC *PRTVFSCHAINELEMSPEC;
/** Pointer to a const chain element specification. */
typedef RTVFSCHAINELEMSPEC const *PCRTVFSCHAINELEMSPEC;
/**
* Parsed VFS chain specification.
*/
typedef struct RTVFSCHAINSPEC
{
/** Open directory flags (RTFILE_O_XXX). */
uint64_t fOpenFile;
/** To be defined. */
uint32_t fOpenDir;
/** The type desired by the caller. */
RTVFSOBJTYPE enmDesiredType;
/** The number of elements. */
uint32_t cElements;
/** The elements. */
PRTVFSCHAINELEMSPEC paElements;
} RTVFSCHAINSPEC;
/** Pointer to a parsed VFS chain specification. */
typedef RTVFSCHAINSPEC *PRTVFSCHAINSPEC;
/** Pointer to a const, parsed VFS chain specification. */
typedef RTVFSCHAINSPEC const *PCRTVFSCHAINSPEC;
/**
* A chain element provider registration record.
*/
typedef struct RTVFSCHAINELEMENTREG
{
/** The version (RTVFSCHAINELEMENTREG_VERSION). */
uint32_t uVersion;
/** Reserved, MBZ. */
uint32_t fReserved;
/** The provider name (unique). */
const char *pszName;
/** For chaining the providers. */
RTLISTNODE ListEntry;
/** Help text. */
const char *pszHelp;
/**
* Checks the element specification.
*
* This is allowed to parse arguments and use pSpec->uProvider and
* pElement->paArgs[].uProvider to store information that pfnInstantiate and
* pfnCanReuseElement may use later on, thus avoiding duplicating work/code.
*
* @returns IPRT status code.
* @param pProviderReg Pointer to the element provider registration.
* @param pSpec The chain specification.
* @param pElement The chain element specification to validate.
* @param poffError Where to return error offset on failure. This is
* set to the pElement->offSpec on input, so it only
* needs to be adjusted if an argument is at fault.
* @param pErrInfo Where to return additional error information, if
* available. Optional.
*/
DECLCALLBACKMEMBER(int, pfnValidate,(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec,
PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo));
/**
* Create a VFS object according to the element specification.
*
* @returns IPRT status code.
* @param pProviderReg Pointer to the element provider registration.
* @param pSpec The chain specification.
* @param pElement The chain element specification to instantiate.
* @param hPrevVfsObj Handle to the previous VFS object, NIL_RTVFSOBJ if
* first.
* @param phVfsObj Where to return the VFS object handle.
* @param poffError Where to return error offset on failure. This is
* set to the pElement->offSpec on input, so it only
* needs to be adjusted if an argument is at fault.
* @param pErrInfo Where to return additional error information, if
* available. Optional.
*/
DECLCALLBACKMEMBER(int, pfnInstantiate,(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec,
PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj,
PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo));
/**
* Determins whether the element can be reused.
*
* This is for handling situations accessing the same file system twice, like
* for both the source and destiation of a copy operation. This allows not only
* sharing resources and avoid doing things twice, but also helps avoid file
* sharing violations and inconsistencies araising from the image being updated
* and read independently.
*
* @returns true if the element from @a pReuseSpec an be reused, false if not.
* @param pProviderReg Pointer to the element provider registration.
* @param pSpec The chain specification.
* @param pElement The chain element specification.
* @param pReuseSpec The chain specification of the existing chain.
* @param pReuseElement The chain element specification of the existing
* element that is being considered for reuse.
*/
DECLCALLBACKMEMBER(bool, pfnCanReuseElement,(PCRTVFSCHAINELEMENTREG pProviderReg,
PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement,
PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement));
/** End marker (RTVFSCHAINELEMENTREG_VERSION). */
uintptr_t uEndMarker;
} RTVFSCHAINELEMENTREG;
/** The VFS chain element registration record version number. */
#define RTVFSCHAINELEMENTREG_VERSION RT_MAKE_U32_FROM_U8(0xff, 0x7f, 1, 0)
/**
* Parses the specification.
*
* @returns IPRT status code.
* @param pszSpec The specification string to parse.
* @param fFlags Flags, see RTVFSCHAIN_PF_XXX.
* @param enmDesiredType The object type the caller wants to interface with.
* @param ppSpec Where to return the pointer to the parsed
* specification. This must be freed by calling
* RTVfsChainSpecFree. Will always be set (unless
* invalid parameters.)
* @param poffError Where to return the offset into the input
* specification of what's causing trouble. Always
* set, unless this argument causes an invalid pointer
* error.
*/
RTDECL(int) RTVfsChainSpecParse(const char *pszSpec, uint32_t fFlags, RTVFSOBJTYPE enmDesiredType,
PRTVFSCHAINSPEC *ppSpec, uint32_t *poffError);
/** @name RTVfsChainSpecParse
* @{ */
/** Mask of valid flags. */
#define RTVFSCHAIN_PF_VALID_MASK UINT32_C(0x00000000)
/** @} */
/**
* Checks and setups the chain.
*
* @returns IPRT status code.
* @param pSpec The parsed specification.
* @param pReuseSpec Spec to reuse if applicable. Optional.
* @param phVfsObj Where to return the VFS object.
* @param ppszFinalPath Where to return the pointer to the final path if
* applicable. The caller needs to check whether this
* is NULL or a path, in the former case nothing more
* needs doing, whereas in the latter the caller must
* perform the desired operation(s) on *phVfsObj using
* the final path.
* @param poffError Where to return the offset into the input
* specification of what's causing trouble. Always
* set, unless this argument causes an invalid pointer
* error.
* @param pErrInfo Where to return additional error information, if
* available. Optional.
*/
RTDECL(int) RTVfsChainSpecCheckAndSetup(PRTVFSCHAINSPEC pSpec, PCRTVFSCHAINSPEC pReuseSpec,
PRTVFSOBJ phVfsObj, const char **ppszFinalPath, uint32_t *poffError, PRTERRINFO pErrInfo);
/**
* Frees a parsed chain specification.
*
* @param pSpec What RTVfsChainSpecParse returned. NULL is
* quietly ignored.
*/
RTDECL(void) RTVfsChainSpecFree(PRTVFSCHAINSPEC pSpec);
/**
* Registers a chain element provider.
*
* @returns IPRT status code
* @param pRegRec The registration record.
* @param fFromCtor Indicates where we're called from.
*/
RTDECL(int) RTVfsChainElementRegisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromCtor);
/**
* Deregisters a chain element provider.
*
* @returns IPRT status code
* @param pRegRec The registration record.
* @param fFromDtor Indicates where we're called from.
*/
RTDECL(int) RTVfsChainElementDeregisterProvider(PRTVFSCHAINELEMENTREG pRegRec, bool fFromDtor);
/** @def RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER
* Automatically registers a chain element provider using a global constructor
* and destructor hack.
*
* @param pRegRec Pointer to the registration record.
* @param name Some unique variable name prefix.
*/
#ifdef __cplusplus
/**
* Class used for registering a VFS chain element provider.
*/
class RTVfsChainElementAutoRegisterHack
{
private:
/** The registration record, NULL if registration failed. */
PRTVFSCHAINELEMENTREG m_pRegRec;
public:
RTVfsChainElementAutoRegisterHack(PRTVFSCHAINELEMENTREG a_pRegRec)
: m_pRegRec(a_pRegRec)
{
int rc = RTVfsChainElementRegisterProvider(m_pRegRec, true);
if (RT_FAILURE(rc))
m_pRegRec = NULL;
}
~RTVfsChainElementAutoRegisterHack()
{
RTVfsChainElementDeregisterProvider(m_pRegRec, true);
m_pRegRec = NULL;
}
};
# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
static RTVfsChainElementAutoRegisterHack name ## AutoRegistrationHack(pRegRec)
#else
# define RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(pRegRec, name) \
extern void *name ## AutoRegistrationHack = \
&Sorry_but_RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER_does_not_work_in_c_source_files
#endif
/**
* Common worker for the 'stdfile' and 'open' providers for implementing
* RTVFSCHAINELEMENTREG::pfnValidate.
*
* Stores the RTFILE_O_XXX flags in pSpec->uProvider.
*
* @returns IPRT status code.
* @param pSpec The chain specification.
* @param pElement The chain element specification to validate.
* @param poffError Where to return error offset on failure. This is set to
* the pElement->offSpec on input, so it only needs to be
* adjusted if an argument is at fault.
* @param pErrInfo Where to return additional error information, if
* available. Optional.
*/
RTDECL(int) RTVfsChainValidateOpenFileOrIoStream(PRTVFSCHAINSPEC pSpec, PRTVFSCHAINELEMSPEC pElement,
uint32_t *poffError, PRTERRINFO pErrInfo);
/** @} */
/** @} */
RT_C_DECLS_END
#endif /* !IPRT_INCLUDED_vfslowlevel_h */