Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitfdfaccf

Browse files
committed
Cosmetic improvements to freeze map code.
Per post-commit review comments from Andres Freund, improve variablenames, comments, and in one place, slightly improve the code structure.Masahiko Sawada
1 parenta3b3076 commitfdfaccf

File tree

3 files changed

+31
-31
lines changed

3 files changed

+31
-31
lines changed

‎src/backend/access/heap/visibilitymap.c

Lines changed: 19 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -33,7 +33,7 @@
3333
* is set, we know the condition is true, but if a bit is not set, it might or
3434
* might not be true.
3535
*
36-
* Clearingbothvisibility map bits is not separately WAL-logged. The callers
36+
* Clearing visibility map bits is not separately WAL-logged. The callers
3737
* must make sure that whenever a bit is cleared, the bit is cleared on WAL
3838
* replay of the updating operation as well.
3939
*
@@ -104,13 +104,16 @@
104104
*/
105105
#defineMAPSIZE (BLCKSZ - MAXALIGN(SizeOfPageHeaderData))
106106

107+
/* Number of heap blocks we can represent in one byte */
108+
#defineHEAPBLOCKS_PER_BYTE (BITS_PER_BYTE / BITS_PER_HEAPBLOCK)
109+
107110
/* Number of heap blocks we can represent in one visibility map page. */
108111
#defineHEAPBLOCKS_PER_PAGE (MAPSIZE * HEAPBLOCKS_PER_BYTE)
109112

110113
/* Mapping from heap block number to the right bit in the visibility map */
111114
#defineHEAPBLK_TO_MAPBLOCK(x) ((x) / HEAPBLOCKS_PER_PAGE)
112115
#defineHEAPBLK_TO_MAPBYTE(x) (((x) % HEAPBLOCKS_PER_PAGE) / HEAPBLOCKS_PER_BYTE)
113-
#defineHEAPBLK_TO_MAPBIT(x) (((x) % HEAPBLOCKS_PER_BYTE) * BITS_PER_HEAPBLOCK)
116+
#defineHEAPBLK_TO_OFFSET(x) (((x) % HEAPBLOCKS_PER_BYTE) * BITS_PER_HEAPBLOCK)
114117

115118
/* tables for fast counting of set bits for visible and frozen */
116119
staticconstuint8number_of_ones_for_visible[256]= {
@@ -156,7 +159,7 @@ static void vm_extend(Relation rel, BlockNumber nvmblocks);
156159

157160

158161
/*
159-
*visibilitymap_clear - clear all bits in visibility map
162+
*visibilitymap_clear - clear all bitsfor one pagein visibility map
160163
*
161164
* You must pass a buffer containing the correct map page to this function.
162165
* Call visibilitymap_pin first to pin the right one. This function doesn't do
@@ -167,8 +170,8 @@ visibilitymap_clear(Relation rel, BlockNumber heapBlk, Buffer buf)
167170
{
168171
BlockNumbermapBlock=HEAPBLK_TO_MAPBLOCK(heapBlk);
169172
intmapByte=HEAPBLK_TO_MAPBYTE(heapBlk);
170-
intmapBit=HEAPBLK_TO_MAPBIT(heapBlk);
171-
uint8mask=VISIBILITYMAP_VALID_BITS <<mapBit;
173+
intmapOffset=HEAPBLK_TO_OFFSET(heapBlk);
174+
uint8mask=VISIBILITYMAP_VALID_BITS <<mapOffset;
172175
char*map;
173176

174177
#ifdefTRACE_VISIBILITYMAP
@@ -267,7 +270,7 @@ visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
267270
{
268271
BlockNumbermapBlock=HEAPBLK_TO_MAPBLOCK(heapBlk);
269272
uint32mapByte=HEAPBLK_TO_MAPBYTE(heapBlk);
270-
uint8mapBit=HEAPBLK_TO_MAPBIT(heapBlk);
273+
uint8mapOffset=HEAPBLK_TO_OFFSET(heapBlk);
271274
Pagepage;
272275
uint8*map;
273276

@@ -291,11 +294,11 @@ visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
291294
map= (uint8*)PageGetContents(page);
292295
LockBuffer(vmBuf,BUFFER_LOCK_EXCLUSIVE);
293296

294-
if (flags!= (map[mapByte] >>mapBit&VISIBILITYMAP_VALID_BITS))
297+
if (flags!= (map[mapByte] >>mapOffset&VISIBILITYMAP_VALID_BITS))
295298
{
296299
START_CRIT_SECTION();
297300

298-
map[mapByte] |= (flags <<mapBit);
301+
map[mapByte] |= (flags <<mapOffset);
299302
MarkBufferDirty(vmBuf);
300303

301304
if (RelationNeedsWAL(rel))
@@ -338,8 +341,7 @@ visibilitymap_set(Relation rel, BlockNumber heapBlk, Buffer heapBuf,
338341
* earlier call to visibilitymap_pin or visibilitymap_get_status on the same
339342
* relation. On return, *buf is a valid buffer with the map page containing
340343
* the bit for heapBlk, or InvalidBuffer. The caller is responsible for
341-
* releasing *buf after it's done testing and setting bits, and must pass flags
342-
* for which it needs to check the value in visibility map.
344+
* releasing *buf after it's done testing and setting bits.
343345
*
344346
* NOTE: This function is typically called without a lock on the heap page,
345347
* so somebody else could change the bit just after we look at it. In fact,
@@ -353,8 +355,9 @@ visibilitymap_get_status(Relation rel, BlockNumber heapBlk, Buffer *buf)
353355
{
354356
BlockNumbermapBlock=HEAPBLK_TO_MAPBLOCK(heapBlk);
355357
uint32mapByte=HEAPBLK_TO_MAPBYTE(heapBlk);
356-
uint8mapBit=HEAPBLK_TO_MAPBIT(heapBlk);
358+
uint8mapOffset=HEAPBLK_TO_OFFSET(heapBlk);
357359
char*map;
360+
uint8result;
358361

359362
#ifdefTRACE_VISIBILITYMAP
360363
elog(DEBUG1,"vm_get_status %s %d",RelationGetRelationName(rel),heapBlk);
@@ -384,7 +387,8 @@ visibilitymap_get_status(Relation rel, BlockNumber heapBlk, Buffer *buf)
384387
* here, but for performance reasons we make it the caller's job to worry
385388
* about that.
386389
*/
387-
return ((map[mapByte] >>mapBit)&VISIBILITYMAP_VALID_BITS);
390+
result= ((map[mapByte] >>mapOffset)&VISIBILITYMAP_VALID_BITS);
391+
returnresult;
388392
}
389393

390394
/*
@@ -456,7 +460,7 @@ visibilitymap_truncate(Relation rel, BlockNumber nheapblocks)
456460
/* last remaining block, byte, and bit */
457461
BlockNumbertruncBlock=HEAPBLK_TO_MAPBLOCK(nheapblocks);
458462
uint32truncByte=HEAPBLK_TO_MAPBYTE(nheapblocks);
459-
uint8truncBit=HEAPBLK_TO_MAPBIT(nheapblocks);
463+
uint8truncOffset=HEAPBLK_TO_OFFSET(nheapblocks);
460464

461465
#ifdefTRACE_VISIBILITYMAP
462466
elog(DEBUG1,"vm_truncate %s %d",RelationGetRelationName(rel),nheapblocks);
@@ -478,7 +482,7 @@ visibilitymap_truncate(Relation rel, BlockNumber nheapblocks)
478482
* because we don't get a chance to clear the bits if the heap is extended
479483
* again.
480484
*/
481-
if (truncByte!=0||truncBit!=0)
485+
if (truncByte!=0||truncOffset!=0)
482486
{
483487
BuffermapBuffer;
484488
Pagepage;
@@ -511,7 +515,7 @@ visibilitymap_truncate(Relation rel, BlockNumber nheapblocks)
511515
* ((1 << 7) - 1) = 01111111
512516
*----
513517
*/
514-
map[truncByte] &= (1 <<truncBit)-1;
518+
map[truncByte] &= (1 <<truncOffset)-1;
515519

516520
MarkBufferDirty(mapBuffer);
517521
UnlockReleaseBuffer(mapBuffer);

‎src/backend/commands/vacuumlazy.c

Lines changed: 11 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -1192,9 +1192,9 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
11921192
}
11931193

11941194
/*
1195-
* If the page ismarked asall-visible but notall-frozen, we should
1196-
* so mark it. Note that all_frozen is only valid if all_visible is
1197-
* true, so we must check both.
1195+
* If theall-visiblepage isturned out to beall-frozen but notmarked,
1196+
*we shouldso mark it. Note that all_frozen is only valid if all_visible
1197+
*istrue, so we must check both.
11981198
*/
11991199
elseif (all_visible_according_to_vm&&all_visible&&all_frozen&&
12001200
!VM_ALL_FROZEN(onerel,blkno,&vmbuffer))
@@ -2068,6 +2068,7 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
20682068
if (ItemIdIsDead(itemid))
20692069
{
20702070
all_visible= false;
2071+
*all_frozen= false;
20712072
break;
20722073
}
20732074

@@ -2087,6 +2088,7 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
20872088
if (!HeapTupleHeaderXminCommitted(tuple.t_data))
20882089
{
20892090
all_visible= false;
2091+
*all_frozen= false;
20902092
break;
20912093
}
20922094

@@ -2098,6 +2100,7 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
20982100
if (!TransactionIdPrecedes(xmin,OldestXmin))
20992101
{
21002102
all_visible= false;
2103+
*all_frozen= false;
21012104
break;
21022105
}
21032106

@@ -2116,23 +2119,16 @@ heap_page_is_all_visible(Relation rel, Buffer buf,
21162119
caseHEAPTUPLE_RECENTLY_DEAD:
21172120
caseHEAPTUPLE_INSERT_IN_PROGRESS:
21182121
caseHEAPTUPLE_DELETE_IN_PROGRESS:
2119-
all_visible= false;
2120-
break;
2121-
2122+
{
2123+
all_visible= false;
2124+
*all_frozen= false;
2125+
break;
2126+
}
21222127
default:
21232128
elog(ERROR,"unexpected HeapTupleSatisfiesVacuum result");
21242129
break;
21252130
}
21262131
}/* scan along page */
21272132

2128-
/*
2129-
* We don't bother clearing *all_frozen when the page is discovered not to
2130-
* be all-visible, so do that now if necessary. The page might fail to be
2131-
* all-frozen for other reasons anyway, but if it's not all-visible, then
2132-
* it definitely isn't all-frozen.
2133-
*/
2134-
if (!all_visible)
2135-
*all_frozen= false;
2136-
21372133
returnall_visible;
21382134
}

‎src/include/access/visibilitymap.h

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -19,8 +19,8 @@
1919
#include"storage/buf.h"
2020
#include"utils/relcache.h"
2121

22+
/* Number of bits for one heap page */
2223
#defineBITS_PER_HEAPBLOCK 2
23-
#defineHEAPBLOCKS_PER_BYTE (BITS_PER_BYTE / BITS_PER_HEAPBLOCK)
2424

2525
/* Flags for bit map */
2626
#defineVISIBILITYMAP_ALL_VISIBLE0x01

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp