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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2022-08-17 11:12:35 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2022-08-17 11:12:35 -0400 |
| commit | efd0c16becbf45e3b0215e124fde75fee8fcbce4 (patch) | |
| tree | 4583c8e845ce18ae4a6c6b4c008a4989c514b3cb /src/backend/replication/logical/tablesync.c | |
| parent | 4a319fce7671ffbe2a730f79529b7a2ef3794d41 (diff) | |
| download | postgresql-efd0c16becbf45e3b0215e124fde75fee8fcbce4.tar.gz postgresql-efd0c16becbf45e3b0215e124fde75fee8fcbce4.zip | |
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
Diffstat (limited to 'src/backend/replication/logical/tablesync.c')
| -rw-r--r-- | src/backend/replication/logical/tablesync.c | 8 |
1 files changed, 4 insertions, 4 deletions
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); } /* |