193 lines
7.4 KiB
C
193 lines
7.4 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* fd.h
|
|
* Virtual file descriptor definitions.
|
|
*
|
|
*
|
|
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
* src/include/storage/fd.h
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* calls:
|
|
*
|
|
* File {Close, Read, Write, Size, Sync}
|
|
* {Path Name Open, Allocate, Free} File
|
|
*
|
|
* These are NOT JUST RENAMINGS OF THE UNIX ROUTINES.
|
|
* Use them for all file activity...
|
|
*
|
|
* File fd;
|
|
* fd = PathNameOpenFile("foo", O_RDONLY);
|
|
*
|
|
* AllocateFile();
|
|
* FreeFile();
|
|
*
|
|
* Use AllocateFile, not fopen, if you need a stdio file (FILE*); then
|
|
* use FreeFile, not fclose, to close it. AVOID using stdio for files
|
|
* that you intend to hold open for any length of time, since there is
|
|
* no way for them to share kernel file descriptors with other files.
|
|
*
|
|
* Likewise, use AllocateDir/FreeDir, not opendir/closedir, to allocate
|
|
* open directories (DIR*), and OpenTransientFile/CloseTransientFile for an
|
|
* unbuffered file descriptor.
|
|
*
|
|
* If you really can't use any of the above, at least call AcquireExternalFD
|
|
* or ReserveExternalFD to report any file descriptors that are held for any
|
|
* length of time. Failure to do so risks unnecessary EMFILE errors.
|
|
*/
|
|
#ifndef FD_H
|
|
#define FD_H
|
|
|
|
#include <dirent.h>
|
|
#include <fcntl.h>
|
|
|
|
typedef int File;
|
|
|
|
|
|
#define IO_DIRECT_DATA 0x01
|
|
#define IO_DIRECT_WAL 0x02
|
|
#define IO_DIRECT_WAL_INIT 0x04
|
|
|
|
|
|
/* GUC parameter */
|
|
extern PGDLLIMPORT int max_files_per_process;
|
|
extern PGDLLIMPORT bool data_sync_retry;
|
|
extern PGDLLIMPORT int recovery_init_sync_method;
|
|
extern PGDLLIMPORT int io_direct_flags;
|
|
|
|
/*
|
|
* This is private to fd.c, but exported for save/restore_backend_variables()
|
|
*/
|
|
extern PGDLLIMPORT int max_safe_fds;
|
|
|
|
/*
|
|
* On Windows, we have to interpret EACCES as possibly meaning the same as
|
|
* ENOENT, because if a file is unlinked-but-not-yet-gone on that platform,
|
|
* that's what you get. Ugh. This code is designed so that we don't
|
|
* actually believe these cases are okay without further evidence (namely,
|
|
* a pending fsync request getting canceled ... see ProcessSyncRequests).
|
|
*/
|
|
#ifndef WIN32
|
|
#define FILE_POSSIBLY_DELETED(err) ((err) == ENOENT)
|
|
#else
|
|
#define FILE_POSSIBLY_DELETED(err) ((err) == ENOENT || (err) == EACCES)
|
|
#endif
|
|
|
|
/*
|
|
* O_DIRECT is not standard, but almost every Unix has it. We translate it
|
|
* to the appropriate Windows flag in src/port/open.c. We simulate it with
|
|
* fcntl(F_NOCACHE) on macOS inside fd.c's open() wrapper. We use the name
|
|
* PG_O_DIRECT rather than defining O_DIRECT in that case (probably not a good
|
|
* idea on a Unix). We can only use it if the compiler will correctly align
|
|
* PGIOAlignedBlock for us, though.
|
|
*/
|
|
#if defined(O_DIRECT) && defined(pg_attribute_aligned)
|
|
#define PG_O_DIRECT O_DIRECT
|
|
#elif defined(F_NOCACHE)
|
|
#define PG_O_DIRECT 0x80000000
|
|
#define PG_O_DIRECT_USE_F_NOCACHE
|
|
#else
|
|
#define PG_O_DIRECT 0
|
|
#endif
|
|
|
|
/*
|
|
* prototypes for functions in fd.c
|
|
*/
|
|
|
|
/* Operations on virtual Files --- equivalent to Unix kernel file ops */
|
|
extern File PathNameOpenFile(const char *fileName, int fileFlags);
|
|
extern File PathNameOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode);
|
|
extern File OpenTemporaryFile(bool interXact);
|
|
extern void FileClose(File file);
|
|
extern int FilePrefetch(File file, off_t offset, off_t amount, uint32 wait_event_info);
|
|
extern int FileRead(File file, void *buffer, size_t amount, off_t offset, uint32 wait_event_info);
|
|
extern int FileWrite(File file, const void *buffer, size_t amount, off_t offset, uint32 wait_event_info);
|
|
extern int FileSync(File file, uint32 wait_event_info);
|
|
extern int FileZero(File file, off_t offset, off_t amount, uint32 wait_event_info);
|
|
extern int FileFallocate(File file, off_t offset, off_t amount, uint32 wait_event_info);
|
|
|
|
extern off_t FileSize(File file);
|
|
extern int FileTruncate(File file, off_t offset, uint32 wait_event_info);
|
|
extern void FileWriteback(File file, off_t offset, off_t nbytes, uint32 wait_event_info);
|
|
extern char *FilePathName(File file);
|
|
extern int FileGetRawDesc(File file);
|
|
extern int FileGetRawFlags(File file);
|
|
extern mode_t FileGetRawMode(File file);
|
|
|
|
/* Operations used for sharing named temporary files */
|
|
extern File PathNameCreateTemporaryFile(const char *path, bool error_on_failure);
|
|
extern File PathNameOpenTemporaryFile(const char *path, int mode);
|
|
extern bool PathNameDeleteTemporaryFile(const char *path, bool error_on_failure);
|
|
extern void PathNameCreateTemporaryDir(const char *basedir, const char *directory);
|
|
extern void PathNameDeleteTemporaryDir(const char *dirname);
|
|
extern void TempTablespacePath(char *path, Oid tablespace);
|
|
|
|
/* Operations that allow use of regular stdio --- USE WITH CAUTION */
|
|
extern FILE *AllocateFile(const char *name, const char *mode);
|
|
extern int FreeFile(FILE *file);
|
|
|
|
/* Operations that allow use of pipe streams (popen/pclose) */
|
|
extern FILE *OpenPipeStream(const char *command, const char *mode);
|
|
extern int ClosePipeStream(FILE *file);
|
|
|
|
/* Operations to allow use of the <dirent.h> library routines */
|
|
extern DIR *AllocateDir(const char *dirname);
|
|
extern struct dirent *ReadDir(DIR *dir, const char *dirname);
|
|
extern struct dirent *ReadDirExtended(DIR *dir, const char *dirname,
|
|
int elevel);
|
|
extern int FreeDir(DIR *dir);
|
|
|
|
/* Operations to allow use of a plain kernel FD, with automatic cleanup */
|
|
extern int OpenTransientFile(const char *fileName, int fileFlags);
|
|
extern int OpenTransientFilePerm(const char *fileName, int fileFlags, mode_t fileMode);
|
|
extern int CloseTransientFile(int fd);
|
|
|
|
/* If you've really really gotta have a plain kernel FD, use this */
|
|
extern int BasicOpenFile(const char *fileName, int fileFlags);
|
|
extern int BasicOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode);
|
|
|
|
/* Use these for other cases, and also for long-lived BasicOpenFile FDs */
|
|
extern bool AcquireExternalFD(void);
|
|
extern void ReserveExternalFD(void);
|
|
extern void ReleaseExternalFD(void);
|
|
|
|
/* Make a directory with default permissions */
|
|
extern int MakePGDirectory(const char *directoryName);
|
|
|
|
/* Miscellaneous support routines */
|
|
extern void InitFileAccess(void);
|
|
extern void InitTemporaryFileAccess(void);
|
|
extern void set_max_safe_fds(void);
|
|
extern void closeAllVfds(void);
|
|
extern void SetTempTablespaces(Oid *tableSpaces, int numSpaces);
|
|
extern bool TempTablespacesAreSet(void);
|
|
extern int GetTempTablespaces(Oid *tableSpaces, int numSpaces);
|
|
extern Oid GetNextTempTableSpace(void);
|
|
extern void AtEOXact_Files(bool isCommit);
|
|
extern void AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
|
|
SubTransactionId parentSubid);
|
|
extern void RemovePgTempFiles(void);
|
|
extern void RemovePgTempFilesInDir(const char *tmpdirname, bool missing_ok,
|
|
bool unlink_all);
|
|
extern bool looks_like_temp_rel_name(const char *name);
|
|
|
|
extern int pg_fsync(int fd);
|
|
extern int pg_fsync_no_writethrough(int fd);
|
|
extern int pg_fsync_writethrough(int fd);
|
|
extern int pg_fdatasync(int fd);
|
|
extern void pg_flush_data(int fd, off_t offset, off_t nbytes);
|
|
extern int pg_truncate(const char *path, off_t length);
|
|
extern void fsync_fname(const char *fname, bool isdir);
|
|
extern int fsync_fname_ext(const char *fname, bool isdir, bool ignore_perm, int elevel);
|
|
extern int durable_rename(const char *oldfile, const char *newfile, int elevel);
|
|
extern int durable_unlink(const char *fname, int elevel);
|
|
extern void SyncDataDirectory(void);
|
|
extern int data_sync_elevel(int elevel);
|
|
|
|
#endif /* FD_H */
|