/***************************************************************************** Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved. 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; version 2 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *****************************************************************************/ /*********************************************************************** Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved. Copyright (c) 2009, Percona Inc. Portions of this file contain modifications contributed and copyrighted by Percona Inc.. Those modifications are gratefully acknowledged and are described briefly in the InnoDB documentation. The contributions by Percona Inc. are incorporated with their permission, and subject to the conditions contained in the file COPYING.Percona. 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; version 2 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ***********************************************************************/ /**************************************************//** @file include/os0file.h The interface to the operating system file io Created 10/21/1995 Heikki Tuuri *******************************************************/ #ifndef os0file_h #define os0file_h #include "univ.i" #ifndef __WIN__ #include #include #include #endif /** File node of a tablespace or the log data space */ typedef struct fil_node_struct fil_node_t; #ifdef UNIV_DO_FLUSH extern ibool os_do_not_call_flush_at_each_write; #endif /* UNIV_DO_FLUSH */ extern ibool os_has_said_disk_full; /** Flag: enable debug printout for asynchronous i/o */ extern ibool os_aio_print_debug; /** Number of pending os_file_pread() operations */ extern ulint os_file_n_pending_preads; /** Number of pending os_file_pwrite() operations */ extern ulint os_file_n_pending_pwrites; /** Number of pending read operations */ extern ulint os_n_pending_reads; /** Number of pending write operations */ extern ulint os_n_pending_writes; #ifdef __WIN__ /** We define always WIN_ASYNC_IO, and check at run-time whether the OS actually supports it: Win 95 does not, NT does. */ #define WIN_ASYNC_IO /** Use unbuffered I/O */ #define UNIV_NON_BUFFERED_IO #endif #ifdef __WIN__ /** File handle */ #define os_file_t HANDLE /** Convert a C file descriptor to a native file handle @param fd file descriptor @return native file handle */ #define OS_FILE_FROM_FD(fd) (HANDLE) _get_osfhandle(fd) #else /** File handle */ typedef int os_file_t; /** Convert a C file descriptor to a native file handle @param fd file descriptor @return native file handle */ #define OS_FILE_FROM_FD(fd) fd #endif /** Umask for creating files */ extern ulint os_innodb_umask; /** If this flag is TRUE, then we will use the native aio of the OS (provided we compiled Innobase with it in), otherwise we will use simulated aio we build below with threads */ extern ibool os_aio_use_native_aio; /** The next value should be smaller or equal to the smallest sector size used on any disk. A log block is required to be a portion of disk which is written so that if the start and the end of a block get written to disk, then the whole block gets written. This should be true even in most cases of a crash: if this fails for a log block, then it is equivalent to a media failure in the log. */ #define OS_FILE_LOG_BLOCK_SIZE 512 /** Options for file_create @{ */ #define OS_FILE_OPEN 51 #define OS_FILE_CREATE 52 #define OS_FILE_OVERWRITE 53 #define OS_FILE_OPEN_RAW 54 #define OS_FILE_CREATE_PATH 55 #define OS_FILE_OPEN_RETRY 56 /* for os_file_create() on the first ibdata file */ #define OS_FILE_READ_ONLY 333 #define OS_FILE_READ_WRITE 444 #define OS_FILE_READ_ALLOW_DELETE 555 /* for ibbackup */ /* Options for file_create */ #define OS_FILE_AIO 61 #define OS_FILE_NORMAL 62 /* @} */ /** Types for file create @{ */ #define OS_DATA_FILE 100 #define OS_LOG_FILE 101 /* @} */ /** Error codes from os_file_get_last_error @{ */ #define OS_FILE_NOT_FOUND 71 #define OS_FILE_DISK_FULL 72 #define OS_FILE_ALREADY_EXISTS 73 #define OS_FILE_PATH_ERROR 74 #define OS_FILE_AIO_RESOURCES_RESERVED 75 /* wait for OS aio resources to become available again */ #define OS_FILE_SHARING_VIOLATION 76 #define OS_FILE_ERROR_NOT_SPECIFIED 77 #define OS_FILE_INSUFFICIENT_RESOURCE 78 /* @} */ /** Types for aio operations @{ */ #define OS_FILE_READ 10 #define OS_FILE_WRITE 11 #define OS_FILE_LOG 256 /* This can be ORed to type */ /* @} */ #define OS_AIO_N_PENDING_IOS_PER_THREAD 32 /*!< Win NT does not allow more than 64 */ /** Modes for aio operations @{ */ #define OS_AIO_NORMAL 21 /*!< Normal asynchronous i/o not for ibuf pages or ibuf bitmap pages */ #define OS_AIO_IBUF 22 /*!< Asynchronous i/o for ibuf pages or ibuf bitmap pages */ #define OS_AIO_LOG 23 /*!< Asynchronous i/o for the log */ #define OS_AIO_SYNC 24 /*!< Asynchronous i/o where the calling thread will itself wait for the i/o to complete, doing also the job of the i/o-handler thread; can be used for any pages, ibuf or non-ibuf. This is used to save CPU time, as we can do with fewer thread switches. Plain synchronous i/o is not as good, because it must serialize the file seek and read or write, causing a bottleneck for parallelism. */ #define OS_AIO_SIMULATED_WAKE_LATER 512 /*!< This can be ORed to mode in the call of os_aio(...), if the caller wants to post several i/o requests in a batch, and only after that wake the i/o-handler thread; this has effect only in simulated aio */ /* @} */ #define OS_WIN31 1 /*!< Microsoft Windows 3.x */ #define OS_WIN95 2 /*!< Microsoft Windows 95 */ #define OS_WINNT 3 /*!< Microsoft Windows NT 3.x */ #define OS_WIN2000 4 /*!< Microsoft Windows 2000 */ extern ulint os_n_file_reads; extern ulint os_n_file_writes; extern ulint os_n_fsyncs; /* File types for directory entry data type */ enum os_file_type_enum{ OS_FILE_TYPE_UNKNOWN = 0, OS_FILE_TYPE_FILE, /* regular file */ OS_FILE_TYPE_DIR, /* directory */ OS_FILE_TYPE_LINK /* symbolic link */ }; typedef enum os_file_type_enum os_file_type_t; /* Maximum path string length in bytes when referring to tables with in the './databasename/tablename.ibd' path format; we can allocate at least 2 buffers of this size from the thread stack; that is why this should not be made much bigger than 4000 bytes */ #define OS_FILE_MAX_PATH 4000 /* Struct used in fetching information of a file in a directory */ struct os_file_stat_struct{ char name[OS_FILE_MAX_PATH]; /*!< path to a file */ os_file_type_t type; /*!< file type */ ib_int64_t size; /*!< file size */ time_t ctime; /*!< creation time */ time_t mtime; /*!< modification time */ time_t atime; /*!< access time */ }; typedef struct os_file_stat_struct os_file_stat_t; #ifdef __WIN__ typedef HANDLE os_file_dir_t; /*!< directory stream */ #else typedef DIR* os_file_dir_t; /*!< directory stream */ #endif /***********************************************************************//** Gets the operating system version. Currently works only on Windows. @return OS_WIN95, OS_WIN31, OS_WINNT, or OS_WIN2000 */ UNIV_INTERN ulint os_get_os_version(void); /*===================*/ #ifndef UNIV_HOTBACKUP /****************************************************************//** Creates the seek mutexes used in positioned reads and writes. */ UNIV_INTERN void os_io_init_simple(void); /*===================*/ /***********************************************************************//** Creates a temporary file. This function is like tmpfile(3), but the temporary file is created in the MySQL temporary directory. On Netware, this function is like tmpfile(3), because the C run-time library of Netware does not expose the delete-on-close flag. @return temporary file handle, or NULL on error */ FILE* os_file_create_tmpfile(void); /*========================*/ #endif /* !UNIV_HOTBACKUP */ /***********************************************************************//** The os_file_opendir() function opens a directory stream corresponding to the directory named by the dirname argument. The directory stream is positioned at the first entry. In both Unix and Windows we automatically skip the '.' and '..' items at the start of the directory listing. @return directory stream, NULL if error */ UNIV_INTERN os_file_dir_t os_file_opendir( /*============*/ const char* dirname, /*!< in: directory name; it must not contain a trailing '\' or '/' */ ibool error_is_fatal);/*!< in: TRUE if we should treat an error as a fatal error; if we try to open symlinks then we do not wish a fatal error if it happens not to be a directory */ /***********************************************************************//** Closes a directory stream. @return 0 if success, -1 if failure */ UNIV_INTERN int os_file_closedir( /*=============*/ os_file_dir_t dir); /*!< in: directory stream */ /***********************************************************************//** This function returns information of the next file in the directory. We jump over the '.' and '..' entries in the directory. @return 0 if ok, -1 if error, 1 if at the end of the directory */ UNIV_INTERN int os_file_readdir_next_file( /*======================*/ const char* dirname,/*!< in: directory name or path */ os_file_dir_t dir, /*!< in: directory stream */ os_file_stat_t* info); /*!< in/out: buffer where the info is returned */ /*****************************************************************//** This function attempts to create a directory named pathname. The new directory gets default permissions. On Unix, the permissions are (0770 & ~umask). If the directory exists already, nothing is done and the call succeeds, unless the fail_if_exists arguments is true. @return TRUE if call succeeds, FALSE on error */ UNIV_INTERN ibool os_file_create_directory( /*=====================*/ const char* pathname, /*!< in: directory name as null-terminated string */ ibool fail_if_exists);/*!< in: if TRUE, pre-existing directory is treated as an error. */ /****************************************************************//** A simple function to open or create a file. @return own: handle to the file, not defined if error, error number can be retrieved with os_file_get_last_error */ UNIV_INTERN os_file_t os_file_create_simple( /*==================*/ const char* name, /*!< in: name of the file or path as a null-terminated string */ ulint create_mode,/*!< in: OS_FILE_OPEN if an existing file is opened (if does not exist, error), or OS_FILE_CREATE if a new file is created (if exists, error), or OS_FILE_CREATE_PATH if new file (if exists, error) and subdirectories along its path are created (if needed)*/ ulint access_type,/*!< in: OS_FILE_READ_ONLY or OS_FILE_READ_WRITE */ ibool* success);/*!< out: TRUE if succeed, FALSE if error */ /****************************************************************//** A simple function to open or create a file. @return own: handle to the file, not defined if error, error number can be retrieved with os_file_get_last_error */ UNIV_INTERN os_file_t os_file_create_simple_no_error_handling( /*====================================*/ const char* name, /*!< in: name of the file or path as a null-terminated string */ ulint create_mode,/*!< in: OS_FILE_OPEN if an existing file is opened (if does not exist, error), or OS_FILE_CREATE if a new file is created (if exists, error) */ ulint access_type,/*!< in: OS_FILE_READ_ONLY, OS_FILE_READ_WRITE, or OS_FILE_READ_ALLOW_DELETE; the last option is used by a backup program reading the file */ ibool* success);/*!< out: TRUE if succeed, FALSE if error */ /****************************************************************//** Tries to disable OS caching on an opened file descriptor. */ UNIV_INTERN void os_file_set_nocache( /*================*/ int fd, /*!< in: file descriptor to alter */ const char* file_name, /*!< in: file name, used in the diagnostic message */ const char* operation_name);/*!< in: "open" or "create"; used in the diagnostic message */ /****************************************************************//** Opens an existing file or creates a new. @return own: handle to the file, not defined if error, error number can be retrieved with os_file_get_last_error */ UNIV_INTERN os_file_t os_file_create( /*===========*/ const char* name, /*!< in: name of the file or path as a null-terminated string */ ulint create_mode,/*!< in: OS_FILE_OPEN if an existing file is opened (if does not exist, error), or OS_FILE_CREATE if a new file is created (if exists, error), OS_FILE_OVERWRITE if a new file is created or an old overwritten; OS_FILE_OPEN_RAW, if a raw device or disk partition should be opened */ ulint purpose,/*!< in: OS_FILE_AIO, if asynchronous, non-buffered i/o is desired, OS_FILE_NORMAL, if any normal file; NOTE that it also depends on type, os_aio_.. and srv_.. variables whether we really use async i/o or unbuffered i/o: look in the function source code for the exact rules */ ulint type, /*!< in: OS_DATA_FILE or OS_LOG_FILE */ ibool* success);/*!< out: TRUE if succeed, FALSE if error */ /***********************************************************************//** Deletes a file. The file has to be closed before calling this. @return TRUE if success */ UNIV_INTERN ibool os_file_delete( /*===========*/ const char* name); /*!< in: file path as a null-terminated string */ /***********************************************************************//** Deletes a file if it exists. The file has to be closed before calling this. @return TRUE if success */ UNIV_INTERN ibool os_file_delete_if_exists( /*=====================*/ const char* name); /*!< in: file path as a null-terminated string */ /***********************************************************************//** Renames a file (can also move it to another directory). It is safest that the file is closed before calling this function. @return TRUE if success */ UNIV_INTERN ibool os_file_rename( /*===========*/ const char* oldpath, /*!< in: old file path as a null-terminated string */ const char* newpath); /*!< in: new file path */ /***********************************************************************//** Closes a file handle. In case of error, error number can be retrieved with os_file_get_last_error. @return TRUE if success */ UNIV_INTERN ibool os_file_close( /*==========*/ os_file_t file); /*!< in, own: handle to a file */ #ifdef UNIV_HOTBACKUP /***********************************************************************//** Closes a file handle. @return TRUE if success */ UNIV_INTERN ibool os_file_close_no_error_handling( /*============================*/ os_file_t file); /*!< in, own: handle to a file */ #endif /* UNIV_HOTBACKUP */ /***********************************************************************//** Gets a file size. @return TRUE if success */ UNIV_INTERN ibool os_file_get_size( /*=============*/ os_file_t file, /*!< in: handle to a file */ ulint* size, /*!< out: least significant 32 bits of file size */ ulint* size_high);/*!< out: most significant 32 bits of size */ /***********************************************************************//** Gets file size as a 64-bit integer ib_int64_t. @return size in bytes, -1 if error */ UNIV_INTERN ib_int64_t os_file_get_size_as_iblonglong( /*===========================*/ os_file_t file); /*!< in: handle to a file */ /***********************************************************************//** Write the specified number of zeros to a newly created file. @return TRUE if success */ UNIV_INTERN ibool os_file_set_size( /*=============*/ const char* name, /*!< in: name of the file or path as a null-terminated string */ os_file_t file, /*!< in: handle to a file */ ulint size, /*!< in: least significant 32 bits of file size */ ulint size_high);/*!< in: most significant 32 bits of size */ /***********************************************************************//** Truncates a file at its current position. @return TRUE if success */ UNIV_INTERN ibool os_file_set_eof( /*============*/ FILE* file); /*!< in: file to be truncated */ /***********************************************************************//** Flushes the write buffers of a given file to the disk. @return TRUE if success */ UNIV_INTERN ibool os_file_flush( /*==========*/ os_file_t file); /*!< in, own: handle to a file */ /***********************************************************************//** Retrieves the last error number if an error occurs in a file io function. The number should be retrieved before any other OS calls (because they may overwrite the error number). If the number is not known to this program, the OS error number + 100 is returned. @return error number, or OS error number + 100 */ UNIV_INTERN ulint os_file_get_last_error( /*===================*/ ibool report_all_errors); /*!< in: TRUE if we want an error message printed of all errors */ /*******************************************************************//** Requests a synchronous read operation. @return TRUE if request was successful, FALSE if fail */ UNIV_INTERN ibool os_file_read( /*=========*/ os_file_t file, /*!< in: handle to a file */ void* buf, /*!< in: buffer where to read */ ulint offset, /*!< in: least significant 32 bits of file offset where to read */ ulint offset_high,/*!< in: most significant 32 bits of offset */ ulint n); /*!< in: number of bytes to read */ /*******************************************************************//** Rewind file to its start, read at most size - 1 bytes from it to str, and NUL-terminate str. All errors are silently ignored. This function is mostly meant to be used with temporary files. */ UNIV_INTERN void os_file_read_string( /*================*/ FILE* file, /*!< in: file to read from */ char* str, /*!< in: buffer where to read */ ulint size); /*!< in: size of buffer */ /*******************************************************************//** Requests a synchronous positioned read operation. This function does not do any error handling. In case of error it returns FALSE. @return TRUE if request was successful, FALSE if fail */ UNIV_INTERN ibool os_file_read_no_error_handling( /*===========================*/ os_file_t file, /*!< in: handle to a file */ void* buf, /*!< in: buffer where to read */ ulint offset, /*!< in: least significant 32 bits of file offset where to read */ ulint offset_high,/*!< in: most significant 32 bits of offset */ ulint n); /*!< in: number of bytes to read */ /*******************************************************************//** Requests a synchronous write operation. @return TRUE if request was successful, FALSE if fail */ UNIV_INTERN ibool os_file_write( /*==========*/ const char* name, /*!< in: name of the file or path as a null-terminated string */ os_file_t file, /*!< in: handle to a file */ const void* buf, /*!< in: buffer from which to write */ ulint offset, /*!< in: least significant 32 bits of file offset where to write */ ulint offset_high,/*!< in: most significant 32 bits of offset */ ulint n); /*!< in: number of bytes to write */ /*******************************************************************//** Check the existence and type of the given file. @return TRUE if call succeeded */ UNIV_INTERN ibool os_file_status( /*===========*/ const char* path, /*!< in: pathname of the file */ ibool* exists, /*!< out: TRUE if file exists */ os_file_type_t* type); /*!< out: type of the file (if it exists) */ /****************************************************************//** The function os_file_dirname returns a directory component of a null-terminated pathname string. In the usual case, dirname returns the string up to, but not including, the final '/', and basename is the component following the final '/'. Trailing '/' charac­ ters are not counted as part of the pathname. If path does not contain a slash, dirname returns the string ".". Concatenating the string returned by dirname, a "/", and the basename yields a complete pathname. The return value is a copy of the directory component of the pathname. The copy is allocated from heap. It is the caller responsibility to free it after it is no longer needed. The following list of examples (taken from SUSv2) shows the strings returned by dirname and basename for different paths: path dirname basename "/usr/lib" "/usr" "lib" "/usr/" "/" "usr" "usr" "." "usr" "/" "/" "/" "." "." "." ".." "." ".." @return own: directory component of the pathname */ UNIV_INTERN char* os_file_dirname( /*============*/ const char* path); /*!< in: pathname */ /****************************************************************//** Creates all missing subdirectories along the given path. @return TRUE if call succeeded FALSE otherwise */ UNIV_INTERN ibool os_file_create_subdirs_if_needed( /*=============================*/ const char* path); /*!< in: path name */ /*********************************************************************** Initializes the asynchronous io system. Creates one array each for ibuf and log i/o. Also creates one array each for read and write where each array is divided logically into n_read_segs and n_write_segs respectively. The caller must create an i/o handler thread for each segment in these arrays. This function also creates the sync array. No i/o handler thread needs to be created for that */ UNIV_INTERN void os_aio_init( /*========*/ ulint n_per_seg, /*