Add bms_next_member(), and use it where appropriate.

This patch adds a way of iterating through the members of a bitmapset
nondestructively, unlike the old way with bms_first_member().  While
bms_next_member() is very slightly slower than bms_first_member()
(at least for typical-size bitmapsets), eliminating the need to palloc
and pfree a temporary copy of the target bitmapset is a significant win.
So this method should be preferred in all cases where a temporary copy
would be necessary.

Tom Lane, with suggestions from Dean Rasheed and David Rowley

1 files changed, 4 insertions, 8 deletions

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 11cb47b522..d1feef78b7 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -5263,7 +5263,6 @@ setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr)
 	 */
 	if (!bms_is_empty(expr->paramnos))
 	{
-		Bitmapset  *tmpset;
 		int			dno;
 
 		paramLI = (ParamListInfo)
@@ -5276,8 +5275,8 @@ setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr)
 		paramLI->numParams = estate->ndatums;
 
 		/* Instantiate values for "safe" parameters of the expression */
-		tmpset = bms_copy(expr->paramnos);
-		while ((dno = bms_first_member(tmpset)) >= 0)
+		dno = -1;
+		while ((dno = bms_next_member(expr->paramnos, dno)) >= 0)
 		{
 			PLpgSQL_datum *datum = estate->datums[dno];
 
@@ -5292,7 +5291,6 @@ setup_param_list(PLpgSQL_execstate *estate, PLpgSQL_expr *expr)
 				prm->ptype = var->datatype->typoid;
 			}
 		}
-		bms_free(tmpset);
 
 		/*
 		 * Set up link to active expr where the hook functions can find it.
@@ -6528,15 +6526,14 @@ format_expr_params(PLpgSQL_execstate *estate,
 	int			paramno;
 	int			dno;
 	StringInfoData paramstr;
-	Bitmapset  *tmpset;
 
 	if (!expr->paramnos)
 		return NULL;
 
 	initStringInfo(&paramstr);
-	tmpset = bms_copy(expr->paramnos);
 	paramno = 0;
-	while ((dno = bms_first_member(tmpset)) >= 0)
+	dno = -1;
+	while ((dno = bms_next_member(expr->paramnos, dno)) >= 0)
 	{
 		Datum		paramdatum;
 		Oid			paramtypeid;
@@ -6572,7 +6569,6 @@ format_expr_params(PLpgSQL_execstate *estate,
 
 		paramno++;
 	}
-	bms_free(tmpset);
 
 	return paramstr.data;
 }