txid_snapshot_out: 1 less alloc, use PG_FREE_IF_COPY

diff --git a/sql/txid/txid.c b/sql/txid/txid.c
index 6f85f1285347a1858680c49edb589a0c1ade3724..5cc7a26626f410966d6d3f98bd51850b210b80cf 100644 (file)
--- a/sql/txid/txid.c
+++ b/sql/txid/txid.c
@@ -207,7 +207,7 @@ txid_current_snapshot(PG_FUNCTION_ARGS)
        for (i = 0; i < num; i++)
                snap->xip[i] = txid_convert_xid(SerializableSnapshot->xip[i], &state);
 
-       /* we want then guaranteed ascending order */
+       /* we want them guaranteed ascending order */
        sort_snapshot(snap);
 
        PG_RETURN_POINTER(snap);
@@ -232,22 +232,26 @@ txid_snapshot_in(PG_FUNCTION_ARGS)
 Datum
 txid_snapshot_out(PG_FUNCTION_ARGS)
 {
-       TxidSnapshot *snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(0);
-       StringInfo      str;
-       int                     i;
+       TxidSnapshot   *snap;
+       StringInfoData  str;
+       int                             i;
+
+       snap = (TxidSnapshot *) PG_GETARG_VARLENA_P(0);
 
-       str = makeStringInfo();
+       initStringInfo(&str);
 
-       appendStringInfo(str, "%llu:", (unsigned long long)snap->xmin);
-       appendStringInfo(str, "%llu:", (unsigned long long)snap->xmax);
+       appendStringInfo(&str, "%llu:", (unsigned long long)snap->xmin);
+       appendStringInfo(&str, "%llu:", (unsigned long long)snap->xmax);
 
        for (i = 0; i < snap->nxip; i++)
        {
-               appendStringInfo(str, "%s%llu", ((i > 0) ? "," : ""),
+               appendStringInfo(&str, "%s%llu", ((i > 0) ? "," : ""),
                                                 (unsigned long long)snap->xip[i]);
        }
 
-       PG_RETURN_CSTRING(str->data);
+       PG_FREE_IF_COPY(snap, 0);
+
+       PG_RETURN_CSTRING(str.data);
 }