-extern File FileNameOpenFile(FileName fileName, int fileFlags, int fileMode);
-extern File PathNameOpenFile(FileName fileName, int fileFlags, int fileMode);
-extern void FileClose(File file);
-extern void FileUnlink(File file);
-extern int FileRead(File file, char *buffer, int amount);
-extern int FileWrite(File file, char *buffer, int amount);
-extern long FileSeek(File file, long offset, int whence);
-extern int FileTruncate(File file, int offset);
-extern int FileSync(File file);
-extern int FileNameUnlink(char *filename);
-extern FILE *AllocateFile(char *name, char *mode);
-extern void FreeFile(FILE *);
-extern void closeAllVfds(void);
-extern int pg_fsync(int fd);
-
-#endif /* FD_H */
+
+/* Operations on virtual Files --- equivalent to Unix kernel file ops */
+extern File PathNameOpenFile(FileName fileName, int fileFlags, int fileMode);
+extern File OpenTemporaryFile(bool interXact);
+extern void FileClose(File file);
+extern int FileRead(File file, char *buffer, int amount);
+extern int FileWrite(File file, char *buffer, int amount);
+extern int FileSync(File file);
+extern off_t FileSeek(File file, off_t offset, int whence);
+extern int FileTruncate(File file, off_t offset);
+
+/* 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 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 int FreeDir(DIR *dir);
+
+/* If you've really really gotta have a plain kernel FD, use this */
+extern int BasicOpenFile(FileName fileName, int fileFlags, int fileMode);
+
+/* Miscellaneous support routines */
+extern void InitFileAccess(void);
+extern void set_max_safe_fds(void);
+extern void closeAllVfds(void);
+extern void SetTempTablespaces(Oid *tableSpaces, int numSpaces);
+extern bool TempTablespacesAreSet(void);
+extern Oid GetNextTempTableSpace(void);
+extern void AtEOXact_Files(void);
+extern void AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
+ SubTransactionId parentSubid);
+extern void RemovePgTempFiles(void);
+
+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);
+
+/* Filename components for OpenTemporaryFile */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
+#endif /* FD_H */