vfslowlevel.h revision d6c4b5eecea7735227dc41255d4e742543ddc86f
/** @file
* IPRT - Virtual Filesystem.
*/
/*
* Copyright (C) 2010 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 ___iprt_vfslowlevel_h
#define ___iprt_vfslowlevel_h
#include <iprt/vfs.h>
#include <iprt/param.h>
RT_C_DECLS_BEGIN
/** @defgroup grp_rt_vfs_lowlevel RTVfs - Low-level Interface.
* @ingroup grp_rt_vfs
* @{
*/
/**
* The VFS operations.
*/
typedef struct RTVFSOPS
{
/** The structure version (RTVFSOPS_VERSION). */
uint32_t uVersion;
/** The virtual file system feature mask. */
uint32_t fFeatures;
/** The name of the operations. */
const char *pszName;
/**
* Destructor.
*
* @param pvThis The implementation specific data.
*/
DECLCALLBACKMEMBER(void, pfnDestroy)(void *pvThis);
/**
* 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);
/** @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
/** 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)
/** @} */
/**
* The object type.
*/
typedef enum RTVFSOBJTYPE
{
/** Invalid type. */
RTVFSOBJTYPE_INVALID = 0,
/** Directory. */
RTVFSOBJTYPE_DIR,
/** Pure I/O stream. */
RTVFSOBJTYPE_IOSTREAM,
/** File. */
RTVFSOBJTYPE_FILE,
/** Symbolic link. */
RTVFSOBJTYPE_SYMLINK,
/** End of valid object types. */
RTVFSOBJTYPE_END,
/** Pure I/O stream. */
RTVFSOBJTYPE_32BIT_HACK = 0x7fffffff
} RTVFSOBJTYPE;
/**
* The basis for all virtual file system objects except RTVFS.
*/
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.
* @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 RTFileQueryInfo
*/
DECLCALLBACKMEMBER(int, pfnQueryInfo)(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr);
/** 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,1,0)
/**
* Additional operations for setting object attributes.
*/
typedef struct RTVFSOBJSETOPS
{
/** The structure version (RTVFSOBJSETOPS_VERSION). */
uint32_t uVersion;
/** The offset to the RTVFSOBJOPS structure. */
int32_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.
* @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.
* @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.
* @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 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;
/**
* Opens a directory entry for traversal purposes.
*
* Method which sole purpose is helping the path traversal. Only one of
* the three output variables will be set, the others will left untouched
* (caller sets them to NIL).
*
* @returns IPRT status code.
* @retval VERR_PATH_NOT_FOUND if @a pszEntry was not found.
* @param pvThis The implementation specific directory data.
* @param pszEntry The name of the directory entry to remove.
* @param phVfsDir If not NULL and it is a directory, open it and
* return the handle here.
* @param phVfsSymlink If not NULL and it is a symbolic link, open it
* and return the handle here.
* @param phVfsMounted If not NULL and it is a mounted VFS directory,
* reference it and return the handle here.
* @todo Should com dir, symlinks and mount points using some common
* ancestor "class".
*/
DECLCALLBACKMEMBER(int, pfnTraversalOpen)(void *pvThis, const char *pszEntry, PRTVFSDIR phVfsDir,
PRTVFSSYMLINK phVfsSymlink, PRTVFS phVfsMounted);
/**
* 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 thandle to the opened file.
* @sa RTFileOpen.
*/
DECLCALLBACKMEMBER(int, pfnOpenFile)(void *pvThis, const char *pszFilename, uint32_t fOpen, PRTVFSFILE phVfsFile);
/**
* Open an existing subdirectory.
*
* @returns IPRT status code.
* @param pvThis The implementation specific directory data.
* @param pszSubDir The name of the immediate subdirectory to open.
* @param phVfsDir Where to return the handle to the opened directory.
* @sa RTDirOpen.
*/
DECLCALLBACKMEMBER(int, pfnOpenDir)(void *pvThis, const char *pszSubDir, 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.
* @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.
* @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);
/**
* 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, PRTVFSDIR phVfsDir);
/**
* 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,0x3f,1,0)
/**
* 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,0x4f,1,0)
/**
* 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;
/** Reserved field, MBZ. */
uint32_t fReserved;
/**
* Reads from the file/stream.
*
* @returns IPRT status code.
* @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. If
* NULL, try read all and fail if incomplete.
* @sa 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 pcbWrite Where to return the number of bytes actually
* written. If NULL, try write it all and fail if
* incomplete.
* @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.
* @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,0x5f,1,0)
/**
* 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/stream size.
*
* @returns IPRT status code.
* @param pvThis The implementation specific file data.
* @param pcbFile Where to store the current file size.
* @sa RTFileGetSize
*/
DECLCALLBACKMEMBER(int, pfnQuerySize)(void *pvThis, uint64_t *pcbFile);
/** @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,0x6f,1,0)
/**
* 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 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,
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;
/** 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 - 4U)
/**
* 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);
/** @} */
/** @} */
RT_C_DECLS_END
#endif /* !___iprt_vfslowlevel_h */