From efd0c16becbf45e3b0215e124fde75fee8fcbce4 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 17 Aug 2022 11:12:35 -0400 Subject: Avoid using list_length() to test for empty list. The standard way to check for list emptiness is to compare the List pointer to NIL; our list code goes out of its way to ensure that that is the only representation of an empty list. (An acceptable alternative is a plain boolean test for non-null pointer, but explicit mention of NIL is usually preferable.) Various places didn't get that memo and expressed the condition with list_length(), which might not be so bad except that there were such a variety of ways to check it exactly: equal to zero, less than or equal to zero, less than one, yadda yadda. In the name of code readability, let's standardize all those spellings as "list == NIL" or "list != NIL". (There's probably some microscopic efficiency gain too, though few of these look to be at all performance-critical.) A very small number of cases were left as-is because they seemed more consistent with other adjacent list_length tests that way. Peter Smith, with bikeshedding from a number of us Discussion: https://postgr.es/m/CAHut+PtQYe+ENX5KrONMfugf0q6NHg4hR5dAhqEXEc2eefFeig@mail.gmail.com --- src/backend/utils/adt/jsonpath_exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/backend/utils/adt/jsonpath_exec.c') diff --git a/src/backend/utils/adt/jsonpath_exec.c b/src/backend/utils/adt/jsonpath_exec.c index 10c7e64aab3..5b6a4805721 100644 --- a/src/backend/utils/adt/jsonpath_exec.c +++ b/src/backend/utils/adt/jsonpath_exec.c @@ -2552,7 +2552,7 @@ JsonValueListLength(const JsonValueList *jvl) static bool JsonValueListIsEmpty(JsonValueList *jvl) { - return !jvl->singleton && list_length(jvl->list) <= 0; + return !jvl->singleton && (jvl->list == NIL); } static JsonbValue * -- cgit v1.2.3