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fd.h
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1 /*-------------------------------------------------------------------------
2  *
3  * fd.h
4  * Virtual file descriptor definitions.
5  *
6  *
7  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/storage/fd.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 
15 /*
16  * calls:
17  *
18  * File {Close, Read, Write, Seek, Tell, Sync}
19  * {Path Name Open, Allocate, Free} File
20  *
21  * These are NOT JUST RENAMINGS OF THE UNIX ROUTINES.
22  * Use them for all file activity...
23  *
24  * File fd;
25  * fd = PathNameOpenFile("foo", O_RDONLY);
26  *
27  * AllocateFile();
28  * FreeFile();
29  *
30  * Use AllocateFile, not fopen, if you need a stdio file (FILE*); then
31  * use FreeFile, not fclose, to close it. AVOID using stdio for files
32  * that you intend to hold open for any length of time, since there is
33  * no way for them to share kernel file descriptors with other files.
34  *
35  * Likewise, use AllocateDir/FreeDir, not opendir/closedir, to allocate
36  * open directories (DIR*), and OpenTransientFile/CloseTransient File for an
37  * unbuffered file descriptor.
38  */
39 #ifndef FD_H
40 #define FD_H
41 
42 #include <dirent.h>
43 
44 
45 /*
46  * FileSeek uses the standard UNIX lseek(2) flags.
47  */
48 
49 typedef int File;
50 
51 
52 /* GUC parameter */
53 extern int max_files_per_process;
54 
55 /*
56  * This is private to fd.c, but exported for save/restore_backend_variables()
57  */
58 extern int max_safe_fds;
59 
60 
61 /*
62  * prototypes for functions in fd.c
63  */
64 
65 /* Operations on virtual Files --- equivalent to Unix kernel file ops */
66 extern File PathNameOpenFile(const char *fileName, int fileFlags);
67 extern File PathNameOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode);
68 extern File OpenTemporaryFile(bool interXact);
69 extern void FileClose(File file);
70 extern int FilePrefetch(File file, off_t offset, int amount, uint32 wait_event_info);
71 extern int FileRead(File file, char *buffer, int amount, uint32 wait_event_info);
72 extern int FileWrite(File file, char *buffer, int amount, uint32 wait_event_info);
73 extern int FileSync(File file, uint32 wait_event_info);
74 extern off_t FileSeek(File file, off_t offset, int whence);
75 extern int FileTruncate(File file, off_t offset, uint32 wait_event_info);
76 extern void FileWriteback(File file, off_t offset, off_t nbytes, uint32 wait_event_info);
77 extern char *FilePathName(File file);
78 extern int FileGetRawDesc(File file);
79 extern int FileGetRawFlags(File file);
80 extern mode_t FileGetRawMode(File file);
81 
82 /* Operations that allow use of regular stdio --- USE WITH CAUTION */
83 extern FILE *AllocateFile(const char *name, const char *mode);
84 extern int FreeFile(FILE *file);
85 
86 /* Operations that allow use of pipe streams (popen/pclose) */
87 extern FILE *OpenPipeStream(const char *command, const char *mode);
88 extern int ClosePipeStream(FILE *file);
89 
90 /* Operations to allow use of the <dirent.h> library routines */
91 extern DIR *AllocateDir(const char *dirname);
92 extern struct dirent *ReadDir(DIR *dir, const char *dirname);
93 extern int FreeDir(DIR *dir);
94 
95 /* Operations to allow use of a plain kernel FD, with automatic cleanup */
96 extern int OpenTransientFile(const char *fileName, int fileFlags);
97 extern int OpenTransientFilePerm(const char *fileName, int fileFlags, mode_t fileMode);
98 extern int CloseTransientFile(int fd);
99 
100 /* If you've really really gotta have a plain kernel FD, use this */
101 extern int BasicOpenFile(const char *fileName, int fileFlags);
102 extern int BasicOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode);
103 
104 /* Miscellaneous support routines */
105 extern void InitFileAccess(void);
106 extern void set_max_safe_fds(void);
107 extern void closeAllVfds(void);
108 extern void SetTempTablespaces(Oid *tableSpaces, int numSpaces);
109 extern bool TempTablespacesAreSet(void);
110 extern Oid GetNextTempTableSpace(void);
111 extern void AtEOXact_Files(void);
112 extern void AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
113  SubTransactionId parentSubid);
114 extern void RemovePgTempFiles(void);
115 
116 extern int pg_fsync(int fd);
117 extern int pg_fsync_no_writethrough(int fd);
118 extern int pg_fsync_writethrough(int fd);
119 extern int pg_fdatasync(int fd);
120 extern void pg_flush_data(int fd, off_t offset, off_t amount);
121 extern void fsync_fname(const char *fname, bool isdir);
122 extern int durable_rename(const char *oldfile, const char *newfile, int loglevel);
123 extern int durable_unlink(const char *fname, int loglevel);
124 extern int durable_link_or_rename(const char *oldfile, const char *newfile, int loglevel);
125 extern void SyncDataDirectory(void);
126 
127 /* Filename components for OpenTemporaryFile */
128 #define PG_TEMP_FILES_DIR "pgsql_tmp"
129 #define PG_TEMP_FILE_PREFIX "pgsql_tmp"
130 
131 #endif /* FD_H */
int FreeDir(DIR *dir)
Definition: fd.c:2482
int durable_unlink(const char *fname, int loglevel)
Definition: fd.c:681
File PathNameOpenFile(const char *fileName, int fileFlags)
Definition: fd.c:1315
void AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid, SubTransactionId parentSubid)
Definition: fd.c:2624
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2373
void FileClose(File file)
Definition: fd.c:1522
int max_safe_fds
Definition: fd.c:144
void FileWriteback(File file, off_t offset, off_t nbytes, uint32 wait_event_info)
Definition: fd.c:1647
File PathNameOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode)
Definition: fd.c:1328
int FileRead(File file, char *buffer, int amount, uint32 wait_event_info)
Definition: fd.c:1674
int CloseTransientFile(int fd)
Definition: fd.c:2343
int pg_fsync_writethrough(int fd)
Definition: fd.c:367
int FreeFile(FILE *file)
Definition: fd.c:2315
uint32 SubTransactionId
Definition: c.h:449
unsigned int Oid
Definition: postgres_ext.h:31
Definition: dirent.h:9
static int fd(const char *x, int i)
Definition: preproc-init.c:105
int max_files_per_process
Definition: fd.c:131
File OpenTemporaryFile(bool interXact)
Definition: fd.c:1396
off_t FileSeek(File file, off_t offset, int whence)
Definition: fd.c:1880
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2173
Definition: dirent.c:25
FILE * OpenPipeStream(const char *command, const char *mode)
Definition: fd.c:2222
int durable_rename(const char *oldfile, const char *newfile, int loglevel)
Definition: fd.c:598
int ClosePipeStream(FILE *file)
Definition: fd.c:2508
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2439
bool TempTablespacesAreSet(void)
Definition: fd.c:2591
char * FilePathName(File file)
Definition: fd.c:2003
unsigned int uint32
Definition: c.h:296
Oid GetNextTempTableSpace(void)
Definition: fd.c:2603
void pg_flush_data(int fd, off_t offset, off_t amount)
Definition: fd.c:412
FILE * AllocateFile(const char *name, const char *mode)
Definition: fd.c:2123
void SyncDataDirectory(void)
Definition: fd.c:2971
int FileSync(File file, uint32 wait_event_info)
Definition: fd.c:1859
void closeAllVfds(void)
Definition: fd.c:2537
int FileGetRawFlags(File file)
Definition: fd.c:2029
int pg_fsync_no_writethrough(int fd)
Definition: fd.c:355
void AtEOXact_Files(void)
Definition: fd.c:2655
int FileGetRawDesc(File file)
Definition: fd.c:2019
int durable_link_or_rename(const char *oldfile, const char *newfile, int loglevel)
Definition: fd.c:717
void set_max_safe_fds(void)
Definition: fd.c:886
int pg_fdatasync(int fd)
Definition: fd.c:390
int FileTruncate(File file, off_t offset, uint32 wait_event_info)
Definition: fd.c:1968
WalTimeSample buffer[LAG_TRACKER_BUFFER_SIZE]
Definition: walsender.c:214
void InitFileAccess(void)
Definition: fd.c:769
int FilePrefetch(File file, off_t offset, int amount, uint32 wait_event_info)
Definition: fd.c:1619
int pg_fsync(int fd)
Definition: fd.c:338
void fsync_fname(const char *fname, bool isdir)
Definition: fd.c:572
void RemovePgTempFiles(void)
Definition: fd.c:2744
void SetTempTablespaces(Oid *tableSpaces, int numSpaces)
Definition: fd.c:2563
const char * name
Definition: encode.c:521
mode_t FileGetRawMode(File file)
Definition: fd.c:2039
int BasicOpenFilePerm(const char *fileName, int fileFlags, mode_t fileMode)
Definition: fd.c:951
int BasicOpenFile(const char *fileName, int fileFlags)
Definition: fd.c:929
int FileWrite(File file, char *buffer, int amount, uint32 wait_event_info)
Definition: fd.c:1738
int File
Definition: fd.h:49
int OpenTransientFilePerm(const char *fileName, int fileFlags, mode_t fileMode)
Definition: fd.c:2182