1 /*-------------------------------------------------------------------------
2  *
3  * visibilitymap.h
4  *		visibility map interface
5  *
6  *
7  * Portions Copyright (c) 2007-2016, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/access/visibilitymap.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef VISIBILITYMAP_H
15 #define VISIBILITYMAP_H
16 
17 #include "access/xlogdefs.h"
18 #include "storage/block.h"
19 #include "storage/buf.h"
20 #include "utils/relcache.h"
21 
22 /* Number of bits for one heap page */
23 #define BITS_PER_HEAPBLOCK 2
24 
25 /* Flags for bit map */
26 #define VISIBILITYMAP_ALL_VISIBLE	0x01
27 #define VISIBILITYMAP_ALL_FROZEN	0x02
28 #define VISIBILITYMAP_VALID_BITS	0x03		/* OR of all valid
29 												 * visibilitymap flags bits */
30 
31 /* Macros for visibilitymap test */
32 #define VM_ALL_VISIBLE(r, b, v) \
33 	((visibilitymap_get_status((r), (b), (v)) & VISIBILITYMAP_ALL_VISIBLE) != 0)
34 #define VM_ALL_FROZEN(r, b, v) \
35 	((visibilitymap_get_status((r), (b), (v)) & VISIBILITYMAP_ALL_FROZEN) != 0)
36 
37 extern bool visibilitymap_clear(Relation rel, BlockNumber heapBlk,
38 					Buffer vmbuf, uint8 flags);
39 extern void visibilitymap_pin(Relation rel, BlockNumber heapBlk,
40 				  Buffer *vmbuf);
41 extern bool visibilitymap_pin_ok(BlockNumber heapBlk, Buffer vmbuf);
42 extern void visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
43 				  XLogRecPtr recptr, Buffer vmBuf, TransactionId cutoff_xid,
44 				  uint8 flags);
45 extern uint8 visibilitymap_get_status(Relation rel, BlockNumber heapBlk, Buffer *vmbuf);
46 extern void visibilitymap_count(Relation rel, BlockNumber *all_visible, BlockNumber *all_frozen);
47 extern void visibilitymap_truncate(Relation rel, BlockNumber nheapblocks);
48 
49 #endif   /* VISIBILITYMAP_H */
50