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Commitf4e031c

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Add bms_next_member(), and use it where appropriate.
This patch adds a way of iterating through the members of a bitmapsetnondestructively, unlike the old way with bms_first_member(). Whilebms_next_member() is very slightly slower than bms_first_member()(at least for typical-size bitmapsets), eliminating the need to pallocand pfree a temporary copy of the target bitmapset is a significant win.So this method should be preferred in all cases where a temporary copywould be necessary.Tom Lane, with suggestions from Dean Rasheed and David Rowley
1 parent96d66bc commitf4e031c

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13 files changed

+114
-76
lines changed

13 files changed

+114
-76
lines changed

‎contrib/postgres_fdw/postgres_fdw.c‎

Lines changed: 8 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -1198,15 +1198,17 @@ postgresPlanForeignModify(PlannerInfo *root,
11981198
}
11991199
elseif (operation==CMD_UPDATE)
12001200
{
1201-
Bitmapset*tmpset=bms_copy(rte->modifiedCols);
1202-
AttrNumbercol;
1201+
intcol;
12031202

1204-
while ((col=bms_first_member(tmpset)) >=0)
1203+
col=-1;
1204+
while ((col=bms_next_member(rte->modifiedCols,col)) >=0)
12051205
{
1206-
col+=FirstLowInvalidHeapAttributeNumber;
1207-
if (col <=InvalidAttrNumber)/* shouldn't happen */
1206+
/* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
1207+
AttrNumberattno=col+FirstLowInvalidHeapAttributeNumber;
1208+
1209+
if (attno <=InvalidAttrNumber)/* shouldn't happen */
12081210
elog(ERROR,"system-column update is not supported");
1209-
targetAttrs=lappend_int(targetAttrs,col);
1211+
targetAttrs=lappend_int(targetAttrs,attno);
12101212
}
12111213
}
12121214

‎contrib/sepgsql/dml.c‎

Lines changed: 7 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -93,10 +93,7 @@ fixup_whole_row_references(Oid relOid, Bitmapset *columns)
9393
staticBitmapset*
9494
fixup_inherited_columns(OidparentId,OidchildId,Bitmapset*columns)
9595
{
96-
AttrNumberattno;
97-
Bitmapset*tmpset;
9896
Bitmapset*result=NULL;
99-
char*attname;
10097
intindex;
10198

10299
/*
@@ -105,10 +102,12 @@ fixup_inherited_columns(Oid parentId, Oid childId, Bitmapset *columns)
105102
if (parentId==childId)
106103
returncolumns;
107104

108-
tmpset=bms_copy(columns);
109-
while ((index=bms_first_member(tmpset))>0)
105+
index=-1;
106+
while ((index=bms_next_member(columns,index)) >=0)
110107
{
111-
attno=index+FirstLowInvalidHeapAttributeNumber;
108+
/* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
109+
AttrNumberattno=index+FirstLowInvalidHeapAttributeNumber;
110+
char*attname;
112111

113112
/*
114113
* whole-row-reference shall be fixed-up later
@@ -128,12 +127,11 @@ fixup_inherited_columns(Oid parentId, Oid childId, Bitmapset *columns)
128127
elog(ERROR,"cache lookup failed for attribute %s of relation %u",
129128
attname,childId);
130129

131-
index=attno-FirstLowInvalidHeapAttributeNumber;
132-
result=bms_add_member(result,index);
130+
result=bms_add_member(result,
131+
attno-FirstLowInvalidHeapAttributeNumber);
133132

134133
pfree(attname);
135134
}
136-
bms_free(tmpset);
137135

138136
returnresult;
139137
}

‎src/backend/executor/execMain.c‎

Lines changed: 14 additions & 15 deletions
Original file line numberDiff line numberDiff line change
@@ -547,7 +547,6 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
547547
AclModeremainingPerms;
548548
OidrelOid;
549549
Oiduserid;
550-
Bitmapset*tmpset;
551550
intcol;
552551

553552
/*
@@ -614,12 +613,13 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
614613
return false;
615614
}
616615

617-
tmpset=bms_copy(rte->selectedCols);
618-
while ((col=bms_first_member(tmpset)) >=0)
616+
col=-1;
617+
while ((col=bms_next_member(rte->selectedCols,col)) >=0)
619618
{
620-
/* remove the column number offset */
621-
col+=FirstLowInvalidHeapAttributeNumber;
622-
if (col==InvalidAttrNumber)
619+
/* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
620+
AttrNumberattno=col+FirstLowInvalidHeapAttributeNumber;
621+
622+
if (attno==InvalidAttrNumber)
623623
{
624624
/* Whole-row reference, must have priv on all cols */
625625
if (pg_attribute_aclcheck_all(relOid,userid,ACL_SELECT,
@@ -628,12 +628,11 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
628628
}
629629
else
630630
{
631-
if (pg_attribute_aclcheck(relOid,col,userid,
631+
if (pg_attribute_aclcheck(relOid,attno,userid,
632632
ACL_SELECT)!=ACLCHECK_OK)
633633
return false;
634634
}
635635
}
636-
bms_free(tmpset);
637636
}
638637

639638
/*
@@ -656,24 +655,24 @@ ExecCheckRTEPerms(RangeTblEntry *rte)
656655
return false;
657656
}
658657

659-
tmpset=bms_copy(rte->modifiedCols);
660-
while ((col=bms_first_member(tmpset)) >=0)
658+
col=-1;
659+
while ((col=bms_next_member(rte->modifiedCols,col)) >=0)
661660
{
662-
/* remove the column number offset */
663-
col+=FirstLowInvalidHeapAttributeNumber;
664-
if (col==InvalidAttrNumber)
661+
/* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
662+
AttrNumberattno=col+FirstLowInvalidHeapAttributeNumber;
663+
664+
if (attno==InvalidAttrNumber)
665665
{
666666
/* whole-row reference can't happen here */
667667
elog(ERROR,"whole-row update is not implemented");
668668
}
669669
else
670670
{
671-
if (pg_attribute_aclcheck(relOid,col,userid,
671+
if (pg_attribute_aclcheck(relOid,attno,userid,
672672
remainingPerms)!=ACLCHECK_OK)
673673
return false;
674674
}
675675
}
676-
bms_free(tmpset);
677676
}
678677
}
679678
return true;

‎src/backend/nodes/bitmapset.c‎

Lines changed: 63 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -793,19 +793,19 @@ bms_join(Bitmapset *a, Bitmapset *b)
793793
returnresult;
794794
}
795795

796-
/*----------
796+
/*
797797
* bms_first_member - find and remove first member of a set
798798
*
799799
* Returns -1 if set is empty. NB: set is destructively modified!
800800
*
801801
* This is intended as support for iterating through the members of a set.
802802
* The typical pattern is
803803
*
804-
*tmpset = bms_copy(inputset);
805-
*while ((x = bms_first_member(tmpset)) >= 0)
804+
*while ((x = bms_first_member(inputset)) >= 0)
806805
*process member x;
807-
*bms_free(tmpset);
808-
*----------
806+
*
807+
* CAUTION: this destroys the content of "inputset". If the set must
808+
* not be modified, use bms_next_member instead.
809809
*/
810810
int
811811
bms_first_member(Bitmapset*a)
@@ -840,6 +840,64 @@ bms_first_member(Bitmapset *a)
840840
return-1;
841841
}
842842

843+
/*
844+
* bms_next_member - find next member of a set
845+
*
846+
* Returns smallest member greater than "prevbit", or -2 if there is none.
847+
* "prevbit" must NOT be less than -1, or the behavior is unpredictable.
848+
*
849+
* This is intended as support for iterating through the members of a set.
850+
* The typical pattern is
851+
*
852+
*x = -1;
853+
*while ((x = bms_next_member(inputset, x)) >= 0)
854+
*process member x;
855+
*
856+
* Notice that when there are no more members, we return -2, not -1 as you
857+
* might expect. The rationale for that is to allow distinguishing the
858+
* loop-not-started state (x == -1) from the loop-completed state (x == -2).
859+
* It makes no difference in simple loop usage, but complex iteration logic
860+
* might need such an ability.
861+
*/
862+
int
863+
bms_next_member(constBitmapset*a,intprevbit)
864+
{
865+
intnwords;
866+
intwordnum;
867+
bitmapwordmask;
868+
869+
if (a==NULL)
870+
return-2;
871+
nwords=a->nwords;
872+
prevbit++;
873+
mask= (~(bitmapword)0) <<BITNUM(prevbit);
874+
for (wordnum=WORDNUM(prevbit);wordnum<nwords;wordnum++)
875+
{
876+
bitmapwordw=a->words[wordnum];
877+
878+
/* ignore bits before prevbit */
879+
w &=mask;
880+
881+
if (w!=0)
882+
{
883+
intresult;
884+
885+
result=wordnum*BITS_PER_BITMAPWORD;
886+
while ((w&255)==0)
887+
{
888+
w >>=8;
889+
result+=8;
890+
}
891+
result+=rightmost_one_pos[w&255];
892+
returnresult;
893+
}
894+
895+
/* in subsequent words, consider all bits */
896+
mask= (~(bitmapword)0);
897+
}
898+
return-2;
899+
}
900+
843901
/*
844902
* bms_hash_value - compute a hash key for a Bitmapset
845903
*

‎src/backend/nodes/outfuncs.c‎

Lines changed: 2 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -184,15 +184,13 @@ _outList(StringInfo str, const List *node)
184184
staticvoid
185185
_outBitmapset(StringInfostr,constBitmapset*bms)
186186
{
187-
Bitmapset*tmpset;
188187
intx;
189188

190189
appendStringInfoChar(str,'(');
191190
appendStringInfoChar(str,'b');
192-
tmpset=bms_copy(bms);
193-
while ((x=bms_first_member(tmpset)) >=0)
191+
x=-1;
192+
while ((x=bms_next_member(bms,x)) >=0)
194193
appendStringInfo(str," %d",x);
195-
bms_free(tmpset);
196194
appendStringInfoChar(str,')');
197195
}
198196

‎src/backend/optimizer/path/allpaths.c‎

Lines changed: 2 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -2272,19 +2272,17 @@ remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel)
22722272
staticvoid
22732273
print_relids(Relidsrelids)
22742274
{
2275-
Relidstmprelids;
22762275
intx;
22772276
boolfirst= true;
22782277

2279-
tmprelids=bms_copy(relids);
2280-
while ((x=bms_first_member(tmprelids)) >=0)
2278+
x=-1;
2279+
while ((x=bms_next_member(relids,x)) >=0)
22812280
{
22822281
if (!first)
22832282
printf(" ");
22842283
printf("%d",x);
22852284
first= false;
22862285
}
2287-
bms_free(tmprelids);
22882286
}
22892287

22902288
staticvoid

‎src/backend/optimizer/path/indxpath.c‎

Lines changed: 2 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -1875,9 +1875,8 @@ get_loop_count(PlannerInfo *root, Relids outer_relids)
18751875
{
18761876
intrelid;
18771877

1878-
/* Need a working copy since bms_first_member is destructive */
1879-
outer_relids=bms_copy(outer_relids);
1880-
while ((relid=bms_first_member(outer_relids)) >=0)
1878+
relid=-1;
1879+
while ((relid=bms_next_member(outer_relids,relid)) >=0)
18811880
{
18821881
RelOptInfo*outer_rel;
18831882

@@ -1900,7 +1899,6 @@ get_loop_count(PlannerInfo *root, Relids outer_relids)
19001899
if (result==1.0||result>outer_rel->rows)
19011900
result=outer_rel->rows;
19021901
}
1903-
bms_free(outer_relids);
19041902
}
19051903
returnresult;
19061904
}

‎src/backend/optimizer/util/joininfo.c‎

Lines changed: 4 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -96,17 +96,15 @@ add_join_clause_to_rels(PlannerInfo *root,
9696
RestrictInfo*restrictinfo,
9797
Relidsjoin_relids)
9898
{
99-
Relidstmprelids;
10099
intcur_relid;
101100

102-
tmprelids=bms_copy(join_relids);
103-
while ((cur_relid=bms_first_member(tmprelids)) >=0)
101+
cur_relid=-1;
102+
while ((cur_relid=bms_next_member(join_relids,cur_relid)) >=0)
104103
{
105104
RelOptInfo*rel=find_base_rel(root,cur_relid);
106105

107106
rel->joininfo=lappend(rel->joininfo,restrictinfo);
108107
}
109-
bms_free(tmprelids);
110108
}
111109

112110
/*
@@ -125,11 +123,10 @@ remove_join_clause_from_rels(PlannerInfo *root,
125123
RestrictInfo*restrictinfo,
126124
Relidsjoin_relids)
127125
{
128-
Relidstmprelids;
129126
intcur_relid;
130127

131-
tmprelids=bms_copy(join_relids);
132-
while ((cur_relid=bms_first_member(tmprelids)) >=0)
128+
cur_relid=-1;
129+
while ((cur_relid=bms_next_member(join_relids,cur_relid)) >=0)
133130
{
134131
RelOptInfo*rel=find_base_rel(root,cur_relid);
135132

@@ -140,5 +137,4 @@ remove_join_clause_from_rels(PlannerInfo *root,
140137
Assert(list_member_ptr(rel->joininfo,restrictinfo));
141138
rel->joininfo=list_delete_ptr(rel->joininfo,restrictinfo);
142139
}
143-
bms_free(tmprelids);
144140
}

‎src/backend/optimizer/util/var.c‎

Lines changed: 2 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -773,11 +773,10 @@ static Relids
773773
alias_relid_set(PlannerInfo*root,Relidsrelids)
774774
{
775775
Relidsresult=NULL;
776-
Relidstmprelids;
777776
intrtindex;
778777

779-
tmprelids=bms_copy(relids);
780-
while ((rtindex=bms_first_member(tmprelids)) >=0)
778+
rtindex=-1;
779+
while ((rtindex=bms_next_member(relids,rtindex)) >=0)
781780
{
782781
RangeTblEntry*rte=rt_fetch(rtindex,root->parse->rtable);
783782

@@ -786,6 +785,5 @@ alias_relid_set(PlannerInfo *root, Relids relids)
786785
else
787786
result=bms_add_member(result,rtindex);
788787
}
789-
bms_free(tmprelids);
790788
returnresult;
791789
}

‎src/backend/rewrite/rewriteHandler.c‎

Lines changed: 3 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -2456,11 +2456,10 @@ static Bitmapset *
24562456
adjust_view_column_set(Bitmapset*cols,List*targetlist)
24572457
{
24582458
Bitmapset*result=NULL;
2459-
Bitmapset*tmpcols;
2460-
AttrNumbercol;
2459+
intcol;
24612460

2462-
tmpcols=bms_copy(cols);
2463-
while ((col=bms_first_member(tmpcols)) >=0)
2461+
col=-1;
2462+
while ((col=bms_next_member(cols,col)) >=0)
24642463
{
24652464
/* bit numbers are offset by FirstLowInvalidHeapAttributeNumber */
24662465
AttrNumberattno=col+FirstLowInvalidHeapAttributeNumber;
@@ -2510,7 +2509,6 @@ adjust_view_column_set(Bitmapset *cols, List *targetlist)
25102509
attno);
25112510
}
25122511
}
2513-
bms_free(tmpcols);
25142512

25152513
returnresult;
25162514
}

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