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/replication/logical/tablesync.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'src/backend/replication/logical/tablesync.c') diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c index 6a01ffd273f..bfcb80b4955 100644 --- a/src/backend/replication/logical/tablesync.c +++ b/src/backend/replication/logical/tablesync.c @@ -383,7 +383,7 @@ process_syncing_tables_for_apply(XLogRecPtr current_lsn) * immediate restarts. We don't need it if there are no tables that need * syncing. */ - if (table_states_not_ready && !last_start_times) + if (table_states_not_ready != NIL && !last_start_times) { HASHCTL ctl; @@ -397,7 +397,7 @@ process_syncing_tables_for_apply(XLogRecPtr current_lsn) * Clean up the hash table when we're done with all tables (just to * release the bit of memory). */ - else if (!table_states_not_ready && last_start_times) + else if (table_states_not_ready == NIL && last_start_times) { hash_destroy(last_start_times); last_start_times = NULL; @@ -1498,7 +1498,7 @@ FetchTableStates(bool *started_tx) * if table_state_not_ready was empty we still need to check again to * see if there are 0 tables. */ - has_subrels = (list_length(table_states_not_ready) > 0) || + has_subrels = (table_states_not_ready != NIL) || HasSubscriptionRelations(MySubscription->oid); table_states_valid = true; @@ -1534,7 +1534,7 @@ AllTablesyncsReady(void) * Return false when there are no tables in subscription or not all tables * are in ready state; true otherwise. */ - return has_subrels && list_length(table_states_not_ready) == 0; + return has_subrels && (table_states_not_ready == NIL); } /* -- cgit v1.2.3