From b60df906e9894d061f3f37025b92c6b258e9c8fc Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 1 Mar 2023 17:02:30 -0500 Subject: [PATCH v2 1/4] Remove bms_first_member(). This function has been semi-deprecated ever since we invented bms_next_member(). Its habit of scribbling on the input bitmapset isn't great, plus for sufficiently large bitmapsets it would take O(N^2) time to complete a loop. Now we have the additional problem that reducing the input to empty while leaving it still accessible would violate a proposed invariant. So let's just get rid of it, after updating the few extant callers to use bms_next_member(). Discussion: https://postgr.es/m/1159933.1677621588@sss.pgh.pa.us --- contrib/file_fdw/file_fdw.c | 9 ++--- contrib/sepgsql/dml.c | 3 +- src/backend/access/heap/heapam.c | 27 +++++--------- src/backend/executor/nodeAgg.c | 3 +- src/backend/nodes/bitmapset.c | 42 ---------------------- src/backend/optimizer/plan/subselect.c | 3 +- src/backend/parser/parse_expr.c | 2 +- src/backend/replication/logical/relation.c | 3 +- src/include/nodes/bitmapset.h | 1 - 9 files changed, 23 insertions(+), 70 deletions(-) diff --git a/contrib/file_fdw/file_fdw.c b/contrib/file_fdw/file_fdw.c index 8ccc167548..2d2b0b6a6b 100644 --- a/contrib/file_fdw/file_fdw.c +++ b/contrib/file_fdw/file_fdw.c @@ -858,7 +858,7 @@ check_selective_binary_conversion(RelOptInfo *baserel, ListCell *lc; Relation rel; TupleDesc tupleDesc; - AttrNumber attnum; + int attidx; Bitmapset *attrs_used = NULL; bool has_wholerow = false; int numattrs; @@ -901,10 +901,11 @@ check_selective_binary_conversion(RelOptInfo *baserel, rel = table_open(foreigntableid, AccessShareLock); tupleDesc = RelationGetDescr(rel); - while ((attnum = bms_first_member(attrs_used)) >= 0) + attidx = -1; + while ((attidx = bms_next_member(attrs_used, attidx)) >= 0) { - /* Adjust for system attributes. */ - attnum += FirstLowInvalidHeapAttributeNumber; + /* attidx is zero-based, attnum is the normal attribute number */ + AttrNumber attnum = attidx + FirstLowInvalidHeapAttributeNumber; if (attnum == 0) { diff --git a/contrib/sepgsql/dml.c b/contrib/sepgsql/dml.c index 3cc927c79e..8c8f6f1e3a 100644 --- a/contrib/sepgsql/dml.c +++ b/contrib/sepgsql/dml.c @@ -231,7 +231,8 @@ check_relation_privileges(Oid relOid, updated = fixup_whole_row_references(relOid, updated); columns = bms_union(selected, bms_union(inserted, updated)); - while ((index = bms_first_member(columns)) >= 0) + index = -1; + while ((index = bms_next_member(columns, index)) >= 0) { AttrNumber attnum; uint32 column_perms = 0; diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 7eb79cee58..a84290c434 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -3859,9 +3859,6 @@ heap_attr_equals(TupleDesc tupdesc, int attrnum, Datum value1, Datum value2, * has_external indicates if any of the unmodified attributes (from those * listed as interesting) of the old tuple is a member of external_cols and is * stored externally. - * - * The input interesting_cols bitmapset is destructively modified; that is OK - * since this is invoked at most once in heap_update. */ static Bitmapset * HeapDetermineColumnsInfo(Relation relation, @@ -3870,19 +3867,20 @@ HeapDetermineColumnsInfo(Relation relation, HeapTuple oldtup, HeapTuple newtup, bool *has_external) { - int attrnum; + int attidx; Bitmapset *modified = NULL; TupleDesc tupdesc = RelationGetDescr(relation); - while ((attrnum = bms_first_member(interesting_cols)) >= 0) + attidx = -1; + while ((attidx = bms_next_member(interesting_cols, attidx)) >= 0) { + /* attidx is zero-based, attrnum is the normal attribute number */ + int attrnum = attidx + FirstLowInvalidHeapAttributeNumber; Datum value1, value2; bool isnull1, isnull2; - attrnum += FirstLowInvalidHeapAttributeNumber; - /* * If it's a whole-tuple reference, say "not equal". It's not really * worth supporting this case, since it could only succeed after a @@ -3890,9 +3888,7 @@ HeapDetermineColumnsInfo(Relation relation, */ if (attrnum == 0) { - modified = bms_add_member(modified, - attrnum - - FirstLowInvalidHeapAttributeNumber); + modified = bms_add_member(modified, attidx); continue; } @@ -3905,9 +3901,7 @@ HeapDetermineColumnsInfo(Relation relation, { if (attrnum != TableOidAttributeNumber) { - modified = bms_add_member(modified, - attrnum - - FirstLowInvalidHeapAttributeNumber); + modified = bms_add_member(modified, attidx); continue; } } @@ -3924,9 +3918,7 @@ HeapDetermineColumnsInfo(Relation relation, if (!heap_attr_equals(tupdesc, attrnum, value1, value2, isnull1, isnull2)) { - modified = bms_add_member(modified, - attrnum - - FirstLowInvalidHeapAttributeNumber); + modified = bms_add_member(modified, attidx); continue; } @@ -3943,8 +3935,7 @@ HeapDetermineColumnsInfo(Relation relation, * member of external_cols. */ if (VARATT_IS_EXTERNAL((struct varlena *) DatumGetPointer(value1)) && - bms_is_member(attrnum - FirstLowInvalidHeapAttributeNumber, - external_cols)) + bms_is_member(attidx, external_cols)) *has_external = true; } diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c index 20d23696a5..5960e4a6c1 100644 --- a/src/backend/executor/nodeAgg.c +++ b/src/backend/executor/nodeAgg.c @@ -1646,7 +1646,8 @@ find_hash_columns(AggState *aggstate) } /* and add the remaining columns */ - while ((i = bms_first_member(colnos)) >= 0) + i = -1; + while ((i = bms_next_member(colnos, i)) >= 0) { perhash->hashGrpColIdxInput[perhash->numhashGrpCols] = i; perhash->numhashGrpCols++; diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c index 98660524ad..10dbbdddf5 100644 --- a/src/backend/nodes/bitmapset.c +++ b/src/backend/nodes/bitmapset.c @@ -982,48 +982,6 @@ bms_join(Bitmapset *a, Bitmapset *b) return result; } -/* - * bms_first_member - find and remove first member of a set - * - * Returns -1 if set is empty. NB: set is destructively modified! - * - * This is intended as support for iterating through the members of a set. - * The typical pattern is - * - * while ((x = bms_first_member(inputset)) >= 0) - * process member x; - * - * CAUTION: this destroys the content of "inputset". If the set must - * not be modified, use bms_next_member instead. - */ -int -bms_first_member(Bitmapset *a) -{ - int nwords; - int wordnum; - - if (a == NULL) - return -1; - nwords = a->nwords; - for (wordnum = 0; wordnum < nwords; wordnum++) - { - bitmapword w = a->words[wordnum]; - - if (w != 0) - { - int result; - - w = RIGHTMOST_ONE(w); - a->words[wordnum] &= ~w; - - result = wordnum * BITS_PER_BITMAPWORD; - result += bmw_rightmost_one_pos(w); - return result; - } - } - return -1; -} - /* * bms_next_member - find next member of a set * diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index 04eda4798e..22ffe4ca42 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -1481,7 +1481,8 @@ convert_EXISTS_sublink_to_join(PlannerInfo *root, SubLink *sublink, */ clause_varnos = pull_varnos(root, whereClause); upper_varnos = NULL; - while ((varno = bms_first_member(clause_varnos)) >= 0) + varno = -1; + while ((varno = bms_next_member(clause_varnos, varno)) >= 0) { if (varno <= rtoffset) upper_varnos = bms_add_member(upper_varnos, varno); diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 7ff41acb84..78221d2e0f 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -2759,7 +2759,7 @@ make_row_comparison_op(ParseState *pstate, List *opname, * them ... this coding arbitrarily picks the lowest btree strategy * number. */ - i = bms_first_member(strats); + i = bms_next_member(strats, -1); if (i < 0) { /* No common interpretation, so fail */ diff --git a/src/backend/replication/logical/relation.c b/src/backend/replication/logical/relation.c index 9f139c64db..55bfa07871 100644 --- a/src/backend/replication/logical/relation.c +++ b/src/backend/replication/logical/relation.c @@ -227,7 +227,8 @@ logicalrep_report_missing_attrs(LogicalRepRelation *remoterel, initStringInfo(&missingattsbuf); - while ((i = bms_first_member(missingatts)) >= 0) + i = -1; + while ((i = bms_next_member(missingatts, i)) >= 0) { missingattcnt++; if (missingattcnt == 1) diff --git a/src/include/nodes/bitmapset.h b/src/include/nodes/bitmapset.h index 3d2225e1ae..c344ac04be 100644 --- a/src/include/nodes/bitmapset.h +++ b/src/include/nodes/bitmapset.h @@ -115,7 +115,6 @@ extern Bitmapset *bms_del_members(Bitmapset *a, const Bitmapset *b); extern Bitmapset *bms_join(Bitmapset *a, Bitmapset *b); /* support for iterating through the integer elements of a set: */ -extern int bms_first_member(Bitmapset *a); extern int bms_next_member(const Bitmapset *a, int prevbit); extern int bms_prev_member(const Bitmapset *a, int prevbit); -- 2.31.1