/** @file
* IPRT - File I/O.
*/
/*
* Copyright (C) 2006-2012 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* 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_file_h
#define ___iprt_file_h
/** @defgroup grp_rt_fileio RTFile - File I/O
* @ingroup grp_rt
* @{
*/
/** Platform specific text line break.
#if defined(RT_OS_OS2) || defined(RT_OS_WINDOWS)
#else
# define RTFILE_LINEFEED "\n"
#endif
/** Platform specific native standard input "handle". */
#ifdef RT_OS_WINDOWS
#else
# define RTFILE_NATIVE_STDIN 0
#endif
/** Platform specific native standard out "handle". */
#ifdef RT_OS_WINDOWS
#else
# define RTFILE_NATIVE_STDOUT 1
#endif
/** Platform specific native standard error "handle". */
#ifdef RT_OS_WINDOWS
#else
# define RTFILE_NATIVE_STDERR 2
#endif
/**
* Checks if the specified file name exists and is a regular file.
*
* Symbolic links will be resolved.
*
* @returns true if it's a regular file, false if it isn't.
* @param pszPath The path to the file.
*
* @sa RTDirExists, RTPathExists, RTSymlinkExists.
*/
/**
* Queries the size of a file, given the path to it.
*
* Symbolic links will be resolved.
*
* @returns IPRT status code.
* @param pszPath The path to the file.
* @param pcbFile Where to return the file size (bytes).
*
* @sa RTFileGetSize, RTPathQueryInfoEx.
*/
/** @name Open flags
* @{ */
/** Open the file with read access. */
/** Open the file with write access. */
/** Open the file with read & write access. */
/** The file access mask.
* @remarks The value 0 is invalid. */
/** Open file in APPEND mode, so all writes to the file handle will
* append data at the end of the file.
* @remarks It is ignored if write access is not requested, that is
* RTFILE_O_WRITE is not set. */
/* UINT32_C(0x00000008) is unused atm. */
/** Sharing mode: deny none. */
/** Sharing mode: deny read. */
/** Sharing mode: deny write. */
/** Sharing mode: deny read and write. */
/** Sharing mode: deny all. */
/** Sharing mode: do NOT deny delete (NT).
* @remarks This might not be implemented on all platforms, and will be
* defaulted & ignored on those.
*/
/** Sharing mode mask. */
/** Action: Open an existing file (the default action). */
/** Action: Create a new file or open an existing one. */
/** Action: Create a new a file. */
/** Action: Create a new file or replace an existing one. */
/** Action mask. */
/** Turns off indexing of files on Windows hosts, *CREATE* only.
* @remarks Window only. */
/** Truncate the file.
* @remarks This will not truncate files opened for read-only.
* @remarks The truncation doesn't have to be atomically, so anyone else opening
* the file may be racing us. The caller is responsible for not causing
* this race. */
/** Make the handle inheritable on RTProcessCreate(/exec). */
/** Open file in non-blocking mode - non-portable.
* @remarks This flag may not be supported on all platforms, in which case it's
* considered an invalid parameter. */
/** Write through directly to disk. Workaround to avoid iSCSI
* initiator deadlocks on Windows hosts.
* @remarks This might not be implemented on all platforms, and will be ignored
* on those. */
/** Attribute access: Attributes can be read if the file is being opened with
* read access, and can be written with write access. */
/** Attribute access: Attributes can be read.
* @remarks Windows only. */
/** Attribute access: Attributes can be written.
* @remarks Windows only. */
/** Attribute access: Attributes can be both read & written.
* @remarks Windows only. */
/** Attribute access: The file attributes access mask.
* @remarks Windows only. */
/** Open file for async I/O
* @remarks This flag may not be needed on all platforms, and will be ignored on
* those. */
/** Disables caching.
*
* Useful when using very big files which might bring the host I/O scheduler to
* its knees during high I/O load.
*
* @remarks This flag might impose restrictions
*
* On Linux the buffer needs to be aligned to the 512 sector
* boundary.
*
* On Windows the FILE_FLAG_NO_BUFFERING is used (see
* http://msdn.microsoft.com/en-us/library/cc644950(VS.85).aspx ).
* The buffer address, the transfer size and offset needs to be aligned
* to the sector size of the volume. Furthermore FILE_APPEND_DATA is
* disabled. To write beyond the size of file use RTFileSetSize prior
* writing the data to the file.
*
* This flag does not work on Solaris if the target filesystem is ZFS.
* RTFileOpen will return an error with that configuration. When used
* with UFS the same alginment restrictions apply like Linux and
* Windows.
*
* @remarks This might not be implemented on all platforms, and will be ignored
* on those.
*/
/** Don't allow symbolic links as part of the path.
* @remarks this flag is currently not implemented and will be ignored. */
/** Unix file mode mask for use when creating files. */
/** The number of bits to shift to get the file mode mask.
* To extract it: (fFlags & RTFILE_O_CREATE_MODE_MASK) >> RTFILE_O_CREATE_MODE_SHIFT.
*/
/* UINT32_C(0x40000000)
and UINT32_C(0x80000000) are unused atm. */
/** Mask of all valid flags.
* @remark This doesn't validate the access mode properly.
*/
/** @} */
#ifdef IN_RING3
/**
* Force the use of open flags for all files opened after the setting is
* changed. The caller is responsible for not causing races with RTFileOpen().
*
* @returns iprt status code.
* @param fSet Open flags to be forced set.
* @param fMask Open flags to be masked out.
*/
#endif /* IN_RING3 */
/**
* Open a file.
*
* @returns iprt status code.
* @param pFile Where to store the handle to the opened file.
* @param pszFilename Path to the file which is to be opened. (UTF-8)
* @param fOpen Open flags, i.e a combination of the RTFILE_O_* defines.
* The ACCESS, ACTION and DENY flags are mandatory!
*/
/**
* Open a file given as a format string.
*
* @returns iprt status code.
* @param pFile Where to store the handle to the opened file.
* @param fOpen Open flags, i.e a combination of the RTFILE_O_* defines.
* The ACCESS, ACTION and DENY flags are mandatory!
* @param pszFilenameFmt Format string givin the path to the file which is to
* be opened. (UTF-8)
* @param ... Arguments to the format string.
*/
/**
* Open a file given as a format string.
*
* @returns iprt status code.
* @param pFile Where to store the handle to the opened file.
* @param fOpen Open flags, i.e a combination of the RTFILE_O_* defines.
* The ACCESS, ACTION and DENY flags are mandatory!
* @param pszFilenameFmt Format string givin the path to the file which is to
* be opened. (UTF-8)
* @param va Arguments to the format string.
*/
/**
*
* @returns IPRT status code.
* @param phFile Where to store the handle to the opened file.
* @param fAccess The desired access only, i.e. read, write or both.
*/
/**
* Close a file opened by RTFileOpen().
*
* @returns iprt status code.
* @param File The file handle to close.
*/
/**
* Creates an IPRT file handle from a native one.
*
* @returns IPRT status code.
* @param pFile Where to store the IPRT file handle.
* @param uNative The native handle.
*/
/**
* Gets the native handle for an IPRT file handle.
*
* @return The native handle.
* @param File The IPRT file handle.
*/
/**
* Delete a file.
*
* @returns iprt status code.
* @param pszFilename Path to the file which is to be deleted. (UTF-8)
* @todo This is a RTPath api!
*/
/** @name Seek flags.
* @{ */
/** Seek from the start of the file. */
/** Seek from the current file position. */
/** Seek from the end of the file. */
/** @internal */
/** @internal */
/** @} */
/**
* Changes the read & write position in a file.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param offSeek Offset to seek.
* @param uMethod Seek method, i.e. one of the RTFILE_SEEK_* defines.
* @param poffActual Where to store the new file position.
* NULL is allowed.
*/
/**
* Read bytes from a file.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param pvBuf Where to put the bytes we read.
* @param cbToRead How much to read.
* @param *pcbRead How much we actually read .
* If NULL an error will be returned for a partial read.
*/
/**
* Read bytes from a file at a given offset.
* This function may modify the file position.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param off Where to read.
* @param pvBuf Where to put the bytes we read.
* @param cbToRead How much to read.
* @param *pcbRead How much we actually read .
* If NULL an error will be returned for a partial read.
*/
/**
* Read bytes from a file at a given offset into a S/G buffer.
* This function may modify the file position.
*
* @returns iprt status code.
* @param hFile Handle to the file.
* @param off Where to read.
* @param pSgBuf Pointer to the S/G buffer to read into.
* @param cbToRead How much to read.
* @param *pcbRead How much we actually read .
* If NULL an error will be returned for a partial read.
*/
RTDECL(int) RTFileSgReadAt(RTFILE hFile, RTFOFF off, PRTSGBUF pSgBuf, size_t cbToRead, size_t *pcbRead);
/**
* Write bytes to a file.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param pvBuf What to write.
* @param cbToWrite How much to write.
* @param *pcbWritten How much we actually wrote.
* If NULL an error will be returned for a partial write.
*/
/**
* Write bytes to a file at a given offset.
* This function may modify the file position.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param off Where to write.
* @param pvBuf What to write.
* @param cbToWrite How much to write.
* @param *pcbWritten How much we actually wrote.
* If NULL an error will be returned for a partial write.
*/
RTDECL(int) RTFileWriteAt(RTFILE File, RTFOFF off, const void *pvBuf, size_t cbToWrite, size_t *pcbWritten);
/**
* Write bytes from a S/G buffer to a file at a given offset.
* This function may modify the file position.
*
* @returns iprt status code.
* @param hFile Handle to the file.
* @param off Where to write.
* @param pSgBuf What to write.
* @param cbToWrite How much to write.
* @param *pcbWritten How much we actually wrote.
* If NULL an error will be returned for a partial write.
*/
RTDECL(int) RTFileSgWriteAt(RTFILE hFile, RTFOFF off, PRTSGBUF pSgBuf, size_t cbToWrite, size_t *pcbWritten);
/**
* Flushes the buffers for the specified file.
*
* @returns iprt status code.
* @param File Handle to the file.
*/
/**
* Set the size of the file.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param cbSize The new file size.
*/
/**
* Query the size of the file.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param pcbSize Where to store the filesize.
*/
/**
* Determine the maximum file size.
*
* @returns The max size of the file.
* -1 on failure, the file position is undefined.
* @param File Handle to the file.
* @see RTFileGetMaxSizeEx.
*/
/**
* Determine the maximum file size.
*
* @returns IPRT status code.
* @param File Handle to the file.
* @param pcbMax Where to store the max file size.
* @see RTFileGetMaxSize.
*/
/**
* Determine the maximum file size depending on the file system the file is stored on.
*
* @returns The max size of the file.
* -1 on failure.
* @param File Handle to the file.
*/
/**
* Gets the current file position.
*
* @returns File offset.
* @returns ~0UUL on failure.
* @param File Handle to the file.
*/
/**
* Checks if the supplied handle is valid.
*
* @returns true if valid.
* @returns false if invalid.
* @param File The file handle
*/
/**
* Copies a file.
*
* @returns IPRT status code
* @retval VERR_ALREADY_EXISTS if the destination file exists.
*
* @param pszSrc The path to the source file.
* @param pszDst The path to the destination file.
* This file will be created.
*/
/**
* Copies a file given the handles to both files.
*
* @returns IPRT status code
*
* @param FileSrc The source file. The file position is unaltered.
* @param FileDst The destination file.
* On successful returns the file position is at the end of the file.
* On failures the file position and size is undefined.
*/
/** Flags for RTFileCopyEx().
* @{ */
/** Do not use RTFILE_O_DENY_WRITE on the source file to allow for copying files opened for writing. */
/** Do not use RTFILE_O_DENY_WRITE on the target file. */
/** Do not use RTFILE_O_DENY_WRITE on either of the two files. */
#define RTFILECOPY_FLAGS_NO_DENY_WRITE ( RTFILECOPY_FLAGS_NO_SRC_DENY_WRITE | RTFILECOPY_FLAGS_NO_DST_DENY_WRITE )
/** */
/** @} */
/**
* Copies a file.
*
* @returns IPRT status code
* @retval VERR_ALREADY_EXISTS if the destination file exists.
*
* @param pszSrc The path to the source file.
* @param pszDst The path to the destination file.
* This file will be created.
* @param fFlags Flags (RTFILECOPY_*).
* @param pfnProgress Pointer to callback function for reporting progress.
* @param pvUser User argument to pass to pfnProgress along with the completion percentage.
*/
RTDECL(int) RTFileCopyEx(const char *pszSrc, const char *pszDst, uint32_t fFlags, PFNRTPROGRESS pfnProgress, void *pvUser);
/**
* Copies a file given the handles to both files and
* provide progress callbacks.
*
* @returns IPRT status code.
*
* @param FileSrc The source file. The file position is unaltered.
* @param FileDst The destination file.
* On successful returns the file position is at the end of the file.
* On failures the file position and size is undefined.
* @param pfnProgress Pointer to callback function for reporting progress.
* @param pvUser User argument to pass to pfnProgress along with the completion percentage.
*/
RTDECL(int) RTFileCopyByHandlesEx(RTFILE FileSrc, RTFILE FileDst, PFNRTPROGRESS pfnProgress, void *pvUser);
/**
* Compares two file given the paths to both files.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS if equal.
* @retval VERR_NOT_EQUAL if not equal.
*
* @param pszFile1 The path to the first file.
* @param pszFile2 The path to the second file.
*/
/**
* Compares two file given the handles to both files.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS if equal.
* @retval VERR_NOT_EQUAL if not equal.
*
* @param hFile1 The first file. Undefined return position.
* @param hFile2 The second file. Undefined return position.
*/
/** Flags for RTFileCompareEx().
* @{ */
/** Do not use RTFILE_O_DENY_WRITE on the first file. */
/** Do not use RTFILE_O_DENY_WRITE on the second file. */
/** Do not use RTFILE_O_DENY_WRITE on either of the two files. */
#define RTFILECOMP_FLAGS_NO_DENY_WRITE ( RTFILECOMP_FLAGS_NO_DENY_WRITE_FILE1 | RTFILECOMP_FLAGS_NO_DENY_WRITE_FILE2 )
/** */
/** @} */
/**
* Compares two files, extended version with progress callback.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS if equal.
* @retval VERR_NOT_EQUAL if not equal.
*
* @param pszFile1 The path to the source file.
* @param pszFile2 The path to the destination file. This file will be
* created.
* @param fFlags Flags, any of the RTFILECOMP_FLAGS_ \#defines.
* @param pfnProgress Pointer to callback function for reporting progress.
* @param pvUser User argument to pass to pfnProgress along with the completion percentage.
*/
RTDECL(int) RTFileCompareEx(const char *pszFile1, const char *pszFile2, uint32_t fFlags, PFNRTPROGRESS pfnProgress, void *pvUser);
/**
* Compares two files given their handles, extended version with progress
* callback.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS if equal.
* @retval VERR_NOT_EQUAL if not equal.
*
* @param hFile1 The first file. Undefined return position.
* @param hFile2 The second file. Undefined return position.
*
* @param fFlags Flags, any of the RTFILECOMP_FLAGS_ \#defines, flags
* related to opening of the files will be ignored.
* @param pfnProgress Pointer to callback function for reporting progress.
* @param pvUser User argument to pass to pfnProgress along with the completion percentage.
*/
RTDECL(int) RTFileCompareByHandlesEx(RTFILE hFile1, RTFILE hFile2, uint32_t fFlags, PFNRTPROGRESS pfnProgress, void *pvUser);
/**
* Renames a file.
*
* Identical to RTPathRename except that it will ensure that the source is not a directory.
*
* @returns IPRT status code.
* @returns VERR_ALREADY_EXISTS if the destination file exists.
*
* @param pszSrc The path to the source file.
* @param pszDst The path to the destination file.
* This file will be created.
* @param fRename See RTPathRename.
*/
/** @name RTFileMove flags (bit masks).
* @{ */
/** Replace destination file if present. */
/** Don't allow symbolic links as part of the path.
* @remarks this flag is currently not implemented and will be ignored. */
/** @} */
/**
* Converts file opening modes (used by fopen, for example) to IPRT
* compatible flags, which then can be used with RTFileOpen* APIs.
*
* Note: Handling sharing modes is not supported yet, so RTFILE_O_DENY_NONE
* will be used by default.
*
* @return IPRT status code.
* @param pszMode Mode string to convert.
* @param puMode Where to store the converted mode flags
* on success.
*/
/**
* Converts file opening modes along with a separate disposition command
* to IPRT compatible flags, which then can be used with RTFileOpen* APIs.
*
* Access modes:
* "r" - Opens a file for reading.
* "r+" - Opens a file for reading and writing.
* "w" - Opens a file for writing.
* "w+" - Opens a file for writing and reading.
*
* Disposition modes:
* "ca" - Creates a new file, always. Overwrites an existing file.
* "ce" - Creates a new file if it does not exist. Fail if exist.
* "oa" - Opens an existing file and places the file pointer at
* the end of the file, if opened with write access.
* Create the file if it does not exist.
* "oc" - Opens an existing file or create it if it does not exist.
* "oe" - Opens an existing file or fail if it does not exist.
* "ot" - Opens and truncate an existing file or fail if it does not exist.
*
* Sharing modes:
* Not implemented yet. RTFILE_O_DENY_NONE will be
* used by default.
*
* @return IPRT status code.
* @param pszAccess Access mode string to convert.
* @param pszDisposition Disposition mode string to convert.
* @param pszSharing Sharing mode string to convert. Not
* implemented yet.
* @param puMode Where to store the converted mode flags
* on success.
*/
RTDECL(int) RTFileModeToFlagsEx(const char *pszAccess, const char *pszDisposition, const char *pszSharing, uint64_t *puMode);
/**
* Moves a file.
*
* RTFileMove differs from RTFileRename in that it works across volumes.
*
* @returns IPRT status code.
* @returns VERR_ALREADY_EXISTS if the destination file exists.
*
* @param pszSrc The path to the source file.
* @param pszDst The path to the destination file.
* This file will be created.
* @param fMove A combination of the RTFILEMOVE_* flags.
*/
/**
* Creates a new file with a unique name using the given template.
*
* One or more trailing X'es in the template will be replaced by random alpha
* numeric characters until a RTFileOpen with RTFILE_O_CREATE succeeds or we
* run out of patience.
* For instance:
* "/tmp/myprog-XXXXXX"
*
* As an alternative to trailing X'es, it is possible to put 3 or more X'es
* somewhere inside the file name. In the following string only the last
* bunch of X'es will be modified:
* "/tmp/myprog-XXX-XXX.tmp"
*
* @returns iprt status code.
* @param pszTemplate The file name template on input. The actual file
* name on success. Empty string on failure.
* @param fMode The mode to create the file with. Use 0600 unless
* you have reason not to.
*/
/**
* Secure version of @a RTFileCreateTemp with a fixed mode of 0600.
*
* This function behaves in the same way as @a RTFileCreateTemp with two
* additional points. Firstly the mode is fixed to 0600. Secondly it will
* fail if it is not possible to perform the operation securely. Possible
* reasons include that the file could be removed by another unprivileged
* user before it is used (e.g. if is created in a non-sticky /tmp directory)
* or that the path contains symbolic links which another unprivileged user
* could manipulate; however the exact criteria will be specified on a
* platform-by-platform basis as platform support is added.
* @see RTPathIsSecure for the current list of criteria.
* @returns iprt status code.
* @returns VERR_NOT_SUPPORTED if the interface can not be supported on the
* current platform at this time.
* @returns VERR_INSECURE if the file could not be created securely.
* @param pszTemplate The file name template on input. The actual
* file name on success. Empty string on failure.
*/
/** @page pg_rt_filelock RT File locking API description
*
* File locking general rules:
*
* Region to lock or unlock can be located beyond the end of file, this can be used for
* growing files.
* Read (or Shared) locks can be acquired held by an unlimited number of processes at the
* same time, but a Write (or Exclusive) lock can only be acquired by one process, and
* cannot coexist with a Shared lock. To acquire a Read lock, a process must wait until
* there are no processes holding any Write locks. To acquire a Write lock, a process must
* wait until there are no processes holding either kind of lock.
* By default, RTFileLock and RTFileChangeLock calls returns error immediately if the lock
* can't be acquired due to conflict with other locks, however they can be called in wait mode.
*
* Differences in implementation:
*
* Win32, OS/2: Locking is mandatory, since locks are enforced by the operating system.
* I.e. when file region is locked in Read mode, any write in it will fail; in case of Write
* lock - region can be read and writed only by lock's owner.
*
* Win32: File size change (RTFileSetSize) is not controlled by locking at all (!) in the
* operation system. Also see comments to RTFileChangeLock API call.
*
* may use locks to coordinate access to a file between themselves, but programs are also free
* to ignore locks and access the file in any way they choose to.
*
* Additional reading:
*/
/** @name Lock flags (bit masks).
* @{ */
/** Read access, can be shared with others. */
/** Write access, one at a time. */
/** Don't wait for other locks to be released. */
/** Wait till conflicting locks have been released. */
/** Valid flags mask */
/** @} */
/**
* Locks a region of file for read (shared) or write (exclusive) access.
*
* @returns iprt status code.
* @returns VERR_FILE_LOCK_VIOLATION if lock can't be acquired.
* @param File Handle to the file.
* @param fLock Lock method and flags, see RTFILE_LOCK_* defines.
* @param offLock Offset of lock start.
* @param cbLock Length of region to lock, may overlap the end of file.
*/
/**
* Changes a lock type from read to write or from write to read.
* The region to type change must correspond exactly to an existing locked region.
* If change can't be done due to locking conflict and non-blocking mode is used, error is
* returned and lock keeps its state (see next warning).
*
* WARNING: win32 implementation of this call is not atomic, it transforms to a pair of
* calls RTFileUnlock and RTFileLock. Potentially the previously acquired lock can be
* lost, i.e. function is called in non-blocking mode, previous lock is freed, new lock can't
* be acquired, and old lock (previous state) can't be acquired back too. This situation
* may occurs _only_ if the other process is acquiring a _write_ lock in blocking mode or
* in race condition with the current call.
* In this very bad case special error code VERR_FILE_LOCK_LOST will be returned.
*
* @returns iprt status code.
* @returns VERR_FILE_NOT_LOCKED if region was not locked.
* @returns VERR_FILE_LOCK_VIOLATION if lock type can't be changed, lock remains its type.
* @returns VERR_FILE_LOCK_LOST if lock was lost, we haven't this lock anymore :(
* @param File Handle to the file.
* @param fLock Lock method and flags, see RTFILE_LOCK_* defines.
* @param offLock Offset of lock start.
* @param cbLock Length of region to lock, may overlap the end of file.
*/
/**
* Unlocks previously locked region of file.
* The region to unlock must correspond exactly to an existing locked region.
*
* @returns iprt status code.
* @returns VERR_FILE_NOT_LOCKED if region was not locked.
* @param File Handle to the file.
* @param offLock Offset of lock start.
* @param cbLock Length of region to unlock, may overlap the end of file.
*/
/**
* Query information about an open file.
*
* @returns iprt status code.
*
* @param File Handle to the file.
* @param pObjInfo Object information structure to be filled on successful return.
* @param enmAdditionalAttribs Which set of additional attributes to request.
* Use RTFSOBJATTRADD_NOTHING if this doesn't matter.
*/
RTDECL(int) RTFileQueryInfo(RTFILE File, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAdditionalAttribs);
/**
* Changes one or more of the timestamps associated of file system object.
*
* @returns iprt status code.
* @retval VERR_NOT_SUPPORTED is returned if the operation isn't supported by
* the OS.
*
* @param File Handle to the file.
* @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.
*
* @remark The file system might not implement all these time attributes,
* the API will ignore the ones which aren't supported.
*
* @remark The file system might not implement the time resolution
* employed by this interface, the time will be chopped to fit.
*
* @remark The file system may update the change time even if it's
* not specified.
*
* @remark POSIX can only set Access & Modification and will always set both.
*/
/**
* Gets one or more of the timestamps associated of file system object.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param pAccessTime Where to store the access time. NULL is ok.
* @param pModificationTime Where to store the modifcation time. NULL is ok.
* @param pChangeTime Where to store the change time. NULL is ok.
* @param pBirthTime Where to store the time of birth. NULL is ok.
*
* @remark This is wrapper around RTFileQueryInfo() and exists to complement RTFileSetTimes().
*/
/**
* Changes the mode flags of an open file.
*
* be set. The type is ignored.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param fMode The new file mode, see @ref grp_rt_fs for details.
*/
/**
* Gets the mode flags of an open file.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param pfMode Where to store the file mode, see @ref grp_rt_fs for details.
*
* @remark This is wrapper around RTFileQueryInfo()
* and exists to complement RTFileSetMode().
*/
/**
*
* @returns iprt status code.
* @param File Handle to the file.
* @param uid The new file owner user id. Pass NIL_RTUID to leave
* this unchanged.
* @param gid The new group id. Pass NIL_RTGID to leave this
* unchanged.
*/
/**
*
* @returns iprt status code.
* @param File Handle to the file.
* @param pUid Where to store the owner user id. NULL is ok.
* @param pGid Where to store the group id. NULL is ok.
*
* @remark This is wrapper around RTFileQueryInfo() and exists to complement RTFileGetOwner().
*/
/**
* Executes an IOCTL on a file descriptor.
*
* This function is currently only available in L4 and posix environments.
* Attemps at calling it from code shared with any other platforms will break things!
*
* The rational for defining this API is to simplify L4 porting of audio drivers,
* and to remove some of the assumptions on RTFILE being a file descriptor on
* platforms using the posix file implementation.
*
* @returns iprt status code.
* @param File Handle to the file.
* @param iRequest IOCTL request to carry out.
* @param pvData IOCTL data.
* @param cbData Size of the IOCTL data.
* @param piRet Return value of the IOCTL request.
*/
RTDECL(int) RTFileIoCtl(RTFILE File, unsigned long ulRequest, void *pvData, unsigned cbData, int *piRet);
/**
* Query the sizes of a filesystem.
*
* @returns iprt status code.
* @retval VERR_NOT_SUPPORTED is returned if the operation isn't supported by
* the OS.
*
* @param hFile The file handle.
* @param pcbTotal Where to store the total filesystem space. (Optional)
* @param pcbFree Where to store the remaining free space in the filesystem. (Optional)
* @param pcbBlock Where to store the block size. (Optional)
* @param pcbSector Where to store the sector size. (Optional)
*
* @sa RTFsQuerySizes
*/
/**
* Reads the file into memory.
*
* The caller must free the memory using RTFileReadAllFree().
*
* @returns IPRT status code.
* @param pszFilename The name of the file.
* @param ppvFile Where to store the pointer to the memory on successful return.
* @param pcbFile Where to store the size of the returned memory.
*
* @remarks Note that this function may be implemented using memory mapping, which means
* that the file may remain open until RTFileReadAllFree() is called. It also
* means that the return memory may reflect the state of the file when it's
* accessed instead of when this call was done. So, in short, don't use this
* API for volatile files, then rather use the extended variant with a
* yet-to-be-defined flag.
*/
/**
* Reads the file into memory.
*
* The caller must free the memory using RTFileReadAllFree().
*
* @returns IPRT status code.
* @param pszFilename The name of the file.
* @param off The offset to start reading at.
* @param cbMax The maximum number of bytes to read into memory. Specify RTFOFF_MAX
* to read to the end of the file.
* @param fFlags See RTFILE_RDALL_*.
* @param ppvFile Where to store the pointer to the memory on successful return.
* @param pcbFile Where to store the size of the returned memory.
*
* @remarks See the remarks for RTFileReadAll.
*/
RTDECL(int) RTFileReadAllEx(const char *pszFilename, RTFOFF off, RTFOFF cbMax, uint32_t fFlags, void **ppvFile, size_t *pcbFile);
/**
* Reads the file into memory.
*
* The caller must free the memory using RTFileReadAllFree().
*
* @returns IPRT status code.
* @param File The handle to the file.
* @param ppvFile Where to store the pointer to the memory on successful return.
* @param pcbFile Where to store the size of the returned memory.
*
* @remarks See the remarks for RTFileReadAll.
*/
/**
* Reads the file into memory.
*
* The caller must free the memory using RTFileReadAllFree().
*
* @returns IPRT status code.
* @param File The handle to the file.
* @param off The offset to start reading at.
* @param cbMax The maximum number of bytes to read into memory. Specify RTFOFF_MAX
* to read to the end of the file.
* @param fFlags See RTFILE_RDALL_*.
* @param ppvFile Where to store the pointer to the memory on successful return.
* @param pcbFile Where to store the size of the returned memory.
*
* @remarks See the remarks for RTFileReadAll.
*/
RTDECL(int) RTFileReadAllByHandleEx(RTFILE File, RTFOFF off, RTFOFF cbMax, uint32_t fFlags, void **ppvFile, size_t *pcbFile);
/**
* Frees the memory returned by one of the RTFileReadAll(), RTFileReadAllEx(),
* RTFileReadAllByHandle() and RTFileReadAllByHandleEx() functions.
*
* @param pvFile Pointer to the memory.
* @param cbFile The size of the memory.
*/
/** @name RTFileReadAllEx and RTFileReadAllHandleEx flags
* The open flags are ignored by RTFileReadAllHandleEx.
* @{ */
/** Mask of valid flags. */
/** @} */
#ifdef IN_RING3
/** @page pg_rt_asyncio RT File async I/O API
*
* File operations are usually blocking the calling thread until
* they completed making it impossible to let the thread do anything
* else in-between.
* The RT File async I/O API provides an easy and efficient way to
* access files asynchronously using the native facilities provided
* by each operating system.
*
* @section sec_rt_asyncio_objects Objects
*
* There are two objects used in this API.
* The first object is the request. A request contains every information
* needed two complete the file operation successfully like the start offset
* and pointer to the source or destination buffer.
* Requests are created with RTFileAioReqCreate() and destroyed with
* RTFileAioReqDestroy().
* Because creating a request may require allocating various operating
* system dependent resources and may be quite expensive it is possible
* to use a request more than once to save CPU cycles.
* A request is constructed with either RTFileAioReqPrepareRead()
* which will set up a request to read from the given file or
* RTFileAioReqPrepareWrite() which will write to a given file.
*
* The second object is the context. A file is associated with a context
* and requests for this file may complete only on the context the file
* was associated with and not on the context given in RTFileAioCtxSubmit()
* (see below for further information).
* RTFileAioCtxWait() is used to wait for completion of requests which were
* associated with the context. While waiting for requests the thread can not
* respond to global state changes. That's why the API provides a way to let
* RTFileAioCtxWait() return immediately no matter how many requests
* have finished through RTFileAioCtxWakeup(). The return code is
* VERR_INTERRUPTED to let the thread know that he got interrupted.
*
* @section sec_rt_asyncio_request_states Request states
*
* Created:
* After a request was created with RTFileAioReqCreate() it is in the same state
* like it just completed successfully. RTFileAioReqGetRC() will return VINF_SUCCESS
* and a transfer size of 0. RTFileAioReqGetUser() will return NULL. The request can be
* destroyed RTFileAioReqDestroy(). It is also allowed to prepare a the request
* for a data transfer with the RTFileAioReqPrepare* methods.
* Calling any other method like RTFileAioCtxSubmit() will return VERR_FILE_AIO_NOT_PREPARED
* and RTFileAioReqCancel() returns VERR_FILE_AIO_NOT_SUBMITTED.
*
* Prepared:
* A request will enter this state if one of the RTFileAioReqPrepare* methods
* is called. In this state you can still destroy and retrieve the user data
* associated with the request but trying to cancel the request or getting
* the result of the operation will return VERR_FILE_AIO_NOT_SUBMITTED.
*
* Submitted:
* A prepared request can be submitted with RTFileAioCtxSubmit(). If the operation
* succeeds it is not allowed to touch the request or free any resources until
* it completed through RTFileAioCtxWait(). The only allowed method is RTFileAioReqCancel()
* which tries to cancel the request. The request will go into the completed state
* and RTFileAioReqGetRC() will return VERR_FILE_AIO_CANCELED.
* If the request completes not matter if successfully or with an error it will
* switch into the completed state. RTFileReqDestroy() fails if the given request
* is in this state.
*
* Completed:
* The request will be in this state after it completed and returned through
* RTFileAioCtxWait(). RTFileAioReqGetRC() returns the final result code
* and the number of bytes transferred.
* The request can be used for new data transfers.
*
* @section sec_rt_asyncio_threading Threading
*
* The API is a thin wrapper around the specific host OS APIs and therefore
* relies on the thread safety of the underlying API.
* The interesting functions with regards to thread safety are RTFileAioCtxSubmit()
* and RTFileAioCtxWait(). RTFileAioCtxWait() must not be called from different
* threads at the same time with the same context handle. The same applies to
* RTFileAioCtxSubmit(). However it is possible to submit new requests from a different
* thread while waiting for completed requests on another thread with RTFileAioCtxWait().
*
* @section sec_rt_asyncio_implementations Differences in implementation
*
* Because the host APIs are quite different on every OS and every API has other limitations
* there are some things to consider to make the code as portable as possible.
*
* The first restriction at the moment is that every buffer has to be aligned to a 512 byte boundary.
* This limitation comes from the Linux io_* interface. To use the interface the file
* must be opened with O_DIRECT. This flag disables the kernel cache too which may
* degrade performance but is unfortunately the only way to make asynchronous
* I/O work till today (if O_DIRECT is omitted io_submit will revert to sychronous behavior
* and will return when the requests finished and when they are queued).
* It is mostly used by DBMS which do theire own caching.
* Furthermore there is no filesystem independent way to discover the restrictions at least
* for the 2.4 kernel series. Since 2.6 the 512 byte boundary seems to be used by all
* file systems. So Linus comment about this flag is comprehensible but Linux
* lacks an alternative at the moment.
*
* The next limitation applies only to Windows. Requests are not associated with the
* I/O context they are associated with but with the file the request is for.
* The file needs to be associated with exactly one I/O completion port and requests
* for this file will only arrive at that context after they completed and not on
* the context the request was submitted.
* To associate a file with a specific context RTFileAioCtxAssociateWithFile() is
* used. It is only implemented on Windows and does nothing on the other platforms.
* If the file needs to be associated with different context for some reason
* the file must be closed first. After it was opened again the new context
* can be associated with the other context.
* This can't be done by the API because there is no way to retrieve the flags
* the file was opened with.
*/
/**
* Global limits for the AIO API.
*/
typedef struct RTFILEAIOLIMITS
{
/** Global number of simultaneous outstanding requests allowed.
* RTFILEAIO_UNLIMITED_REQS means no limit. */
/** The alignment data buffers need to have.
* 0 means no alignment restrictions. */
/** A pointer to a AIO limits structure. */
/**
* Returns the global limits for the AIO API.
*
* @returns IPRT status code.
* @retval VERR_NOT_SUPPORTED if the host does not support the async I/O API.
*
* @param pAioLimits Where to store the global limit information.
*/
/**
* Creates an async I/O request handle.
*
* @returns IPRT status code.
* @param phReq Where to store the request handle.
*/
/**
* Destroys an async I/O request handle.
*
* @returns IPRT status code.
* @retval VERR_FILE_AIO_IN_PROGRESS if the request is still in progress.
*
* @param hReq The request handle.
*/
/**
* Prepares an async read request.
*
* @returns IPRT status code.
* @retval VERR_FILE_AIO_IN_PROGRESS if the request is still in progress.
*
* @param hReq The request handle.
* @param hFile The file to read from.
* @param off The offset to start reading at.
* @param pvBuf Where to store the read bits.
* @param cbRead Number of bytes to read.
* @param pvUser Opaque user data associated with this request which
* can be retrieved with RTFileAioReqGetUser().
*/
/**
* Prepares an async write request.
*
* @returns IPRT status code.
* @retval VERR_FILE_AIO_IN_PROGRESS if the request is still in progress.
*
* @param hReq The request handle.
* @param hFile The file to write to.
* @param off The offset to start writing at.
* @param pvBuf The bits to write.
* @param cbWrite Number of bytes to write.
* @param pvUser Opaque user data associated with this request which
* can be retrieved with RTFileAioReqGetUser().
*/
/**
* Prepares an async flush of all cached data associated with a file handle.
*
* @returns IPRT status code.
* @retval VERR_FILE_AIO_IN_PROGRESS if the request is still in progress.
*
* @param hReq The request handle.
* @param hFile The file to flush.
* @param pvUser Opaque user data associated with this request which
* can be retrieved with RTFileAioReqGetUser().
*
* @remarks May also flush other caches on some platforms.
*/
/**
* Gets the opaque user data associated with the given request.
*
* @returns Opaque user data.
* @retval NULL if the request hasn't been prepared yet.
*
* @param hReq The request handle.
*/
/**
* Cancels a pending request.
*
* @returns IPRT status code.
* @retval VINF_SUCCESS If the request was canceled.
* @retval VERR_FILE_AIO_NOT_SUBMITTED If the request wasn't submitted yet.
* @retval VERR_FILE_AIO_IN_PROGRESS If the request could not be canceled because it is already processed.
* @retval VERR_FILE_AIO_COMPLETED If the request could not be canceled because it already completed.
*
* @param hReq The request to cancel.
*/
/**
* Gets the status of a completed request.
*
* @returns The IPRT status code of the given request.
* @retval VERR_FILE_AIO_NOT_SUBMITTED if the request wasn't submitted yet.
* @retval VERR_FILE_AIO_CANCELED if the request was canceled.
* @retval VERR_FILE_AIO_IN_PROGRESS if the request isn't yet completed.
*
* @param hReq The request handle.
* @param pcbTransferred Where to store the number of bytes transferred.
* Optional since it is not relevant for all kinds of
* requests.
*/
/**
* Creates an async I/O context.
*
* @todo briefly explain what an async context is here or in the page
* above.
*
* @returns IPRT status code.
* @param phAioCtx Where to store the async I/O context handle.
* @param cAioReqsMax How many async I/O requests the context should be capable
* to handle. Pass RTFILEAIO_UNLIMITED_REQS if the
* context should support an unlimited number of
* requests.
* @param fFlags Combination of RTFILEAIOCTX_FLAGS_*.
*/
/** Unlimited number of requests.
* Used with RTFileAioCtxCreate and RTFileAioCtxGetMaxReqCount. */
/** When set RTFileAioCtxWait() will always wait for completing requests,
* even when there is none waiting currently, instead of returning
* VERR_FILE_AIO_NO_REQUEST. */
/** mask of valid flags. */
/**
* Destroys an async I/O context.
*
* @returns IPRT status code.
* @param hAioCtx The async I/O context handle.
*/
/**
* Get the maximum number of requests one aio context can handle.
*
* @returns Maximum number of tasks the context can handle.
* RTFILEAIO_UNLIMITED_REQS if there is no limit.
*
* @param hAioCtx The async I/O context handle.
* If NIL_RTAIOCONTEXT is passed the maximum value
* which can be passed to RTFileAioCtxCreate()
* is returned.
*/
/**
* Associates a file with an async I/O context.
* Requests for this file will arrive at the completion port
* associated with the file.
*
* @returns IPRT status code.
*
* @param hAioCtx The async I/O context handle.
* @param hFile The file handle.
*/
/**
* Submits a set of requests to an async I/O context for processing.
*
* @returns IPRT status code.
* @returns VERR_FILE_AIO_INSUFFICIENT_RESSOURCES if the maximum number of
* simultaneous outstanding requests would be exceeded.
*
* @param hAioCtx The async I/O context handle.
* @param pahReqs Pointer to an array of request handles.
* @param cReqs The number of entries in the array.
*
* @remarks It is possible that some requests could be submitted successfully
* even if the method returns an error code. In that case RTFileAioReqGetRC()
* can be used to determine the status of a request.
* If it returns VERR_FILE_AIO_IN_PROGRESS it was submitted successfully.
* Any other error code may indicate why the request failed.
* VERR_FILE_AIO_NOT_SUBMITTED indicates that a request wasn't submitted
* probably because the previous request encountered an error.
*
* @remarks @a cReqs uses the type size_t while it really is a uint32_t, this is
* to avoid annoying warnings when using RT_ELEMENTS and similar
* macros.
*/
/**
* Waits for request completion.
*
* Only one thread at a time may call this API on a context.
*
* @returns IPRT status code.
* @retval VERR_INVALID_HANDLE If hAioCtx is invalid.
* @retval VERR_OUT_OF_RANGE If cMinReqs is larger than cReqs.
* @retval VERR_INVALID_PARAMETER If cReqs is 0.
* @retval VERR_TIMEOUT If cMinReqs didn't complete before the
* timeout expired.
* @retval VERR_INTERRUPTED If the completion context was interrupted
* by RTFileAioCtxWakeup().
* @retval VERR_FILE_AIO_NO_REQUEST If there are no pending request.
*
* @param hAioCtx The async I/O context handle to wait and get
* completed requests from.
* @param cMinReqs The minimum number of requests which have to
* complete before this function returns.
* @param cMillies The number of milliseconds to wait before returning
* VERR_TIMEOUT. Use RT_INDEFINITE_WAIT to wait
* forever.
* @param pahReqs Pointer to an array where the handles of the
* completed requests will be stored on success.
* @param cReqs The number of entries @a pahReqs can hold.
* @param pcReqs Where to store the number of returned (complete)
* requests. This will always be set.
*
* @remarks The wait will be resume if interrupted by a signal. An
* RTFileAioCtxWaitNoResume variant can be added later if it becomes
* necessary.
*
* @remarks @a cMinReqs and @a cReqs use the type size_t while they really are
* uint32_t's, this is to avoid annoying warnings when using
* RT_ELEMENTS and similar macros.
*/
/**
* Forces any RTFileAioCtxWait() call on another thread to return immediately.
*
* @returns IPRT status code.
*
* @param hAioCtx The handle of the async I/O context to wakeup.
*/
#endif /* IN_RING3 */
/** @} */
#endif