1 /*-------------------------------------------------------------------------
4 * Management of large buffered files, primarily temporary files.
6 * The BufFile routines provide a partial replacement for stdio atop
7 * virtual file descriptors managed by fd.c. Currently they only support
8 * buffered access to a virtual file, without any of stdio's formatting
9 * features. That's enough for immediate needs, but the set of facilities
10 * could be expanded if necessary.
12 * BufFile also supports working with temporary files that exceed the OS
13 * file size limit and/or the largest offset representable in an int.
14 * It might be better to split that out as a separately accessible module,
15 * but currently we have no need for oversize temp files without buffered
18 * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
19 * Portions Copyright (c) 1994, Regents of the University of California
21 * $PostgreSQL: pgsql/src/include/storage/buffile.h,v 1.19 2006/03/05 15:58:59 momjian Exp $
23 *-------------------------------------------------------------------------
29 /* BufFile is an opaque type whose details are not known outside buffile.c. */
31 typedef struct BufFile BufFile;
34 * prototypes for functions in buffile.c
37 extern BufFile *BufFileCreateTemp(bool interXact);
38 extern void BufFileClose(BufFile *file);
39 extern size_t BufFileRead(BufFile *file, void *ptr, size_t size);
40 extern size_t BufFileWrite(BufFile *file, void *ptr, size_t size);
41 extern int BufFileSeek(BufFile *file, int fileno, long offset, int whence);
42 extern void BufFileTell(BufFile *file, int *fileno, long *offset);
43 extern int BufFileSeekBlock(BufFile *file, long blknum);
45 #endif /* BUFFILE_H */