refactor: split ATExecAlterConstrRecurse()

This splits out a couple of subroutines from
ATExecAlterConstrRecurse().  This makes the main function a bit
smaller, and a future patch (NOT ENFORCED foreign-key constraints)
will also want to call some of the pieces separately.

Author: Amul Sul <[email protected]>
Reviewed-by: jian he <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b962c5AcYW9KUt_R_ER5qs3fUGbe4az-SP-vuwPS-w-AGA%40mail.gmail.com

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index d02d564883ae2a00366855098df2a52b38f7b1f5..c42a740ccef845b7d85b796d83610fd7011d4b86 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -394,6 +394,12 @@ static ObjectAddress ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
 static bool ATExecAlterConstrRecurse(Constraint *cmdcon, Relation conrel, Relation tgrel,
                                                                         Relation rel, HeapTuple contuple, List **otherrelids,
                                                                         LOCKMODE lockmode);
+static void AlterConstrTriggerDeferrability(Oid conoid, Relation tgrel, Relation rel,
+                                                                                       bool deferrable, bool initdeferred,
+                                                                                       List **otherrelids);
+static void ATExecAlterChildConstr(Constraint *cmdcon, Relation conrel, Relation tgrel,
+                                                                  Relation rel, HeapTuple contuple, List **otherrelids,
+                                                                  LOCKMODE lockmode);
 static ObjectAddress ATExecValidateConstraint(List **wqueue,
                                                                                          Relation rel, char *constrName,
                                                                                          bool recurse, bool recursing, LOCKMODE lockmode);
@@ -11861,9 +11867,6 @@ ATExecAlterConstrRecurse(Constraint *cmdcon, Relation conrel, Relation tgrel,
        {
                HeapTuple       copyTuple;
                Form_pg_constraint copy_con;
-               HeapTuple       tgtuple;
-               ScanKeyData tgkey;
-               SysScanDesc tgscan;
 
                copyTuple = heap_copytuple(contuple);
                copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
@@ -11884,53 +11887,8 @@ ATExecAlterConstrRecurse(Constraint *cmdcon, Relation conrel, Relation tgrel,
                 * Now we need to update the multiple entries in pg_trigger that
                 * implement the constraint.
                 */
-               ScanKeyInit(&tgkey,
-                                       Anum_pg_trigger_tgconstraint,
-                                       BTEqualStrategyNumber, F_OIDEQ,
-                                       ObjectIdGetDatum(conoid));
-               tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
-                                                                       NULL, 1, &tgkey);
-               while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan)))
-               {
-                       Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple);
-                       Form_pg_trigger copy_tg;
-                       HeapTuple       tgCopyTuple;
-
-                       /*
-                        * Remember OIDs of other relation(s) involved in FK constraint.
-                        * (Note: it's likely that we could skip forcing a relcache inval
-                        * for other rels that don't have a trigger whose properties
-                        * change, but let's be conservative.)
-                        */
-                       if (tgform->tgrelid != RelationGetRelid(rel))
-                               *otherrelids = list_append_unique_oid(*otherrelids,
-                                                                                                         tgform->tgrelid);
-
-                       /*
-                        * Update deferrability of RI_FKey_noaction_del,
-                        * RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd
-                        * triggers, but not others; see createForeignKeyActionTriggers
-                        * and CreateFKCheckTrigger.
-                        */
-                       if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL &&
-                               tgform->tgfoid != F_RI_FKEY_NOACTION_UPD &&
-                               tgform->tgfoid != F_RI_FKEY_CHECK_INS &&
-                               tgform->tgfoid != F_RI_FKEY_CHECK_UPD)
-                               continue;
-
-                       tgCopyTuple = heap_copytuple(tgtuple);
-                       copy_tg = (Form_pg_trigger) GETSTRUCT(tgCopyTuple);
-
-                       copy_tg->tgdeferrable = cmdcon->deferrable;
-                       copy_tg->tginitdeferred = cmdcon->initdeferred;
-                       CatalogTupleUpdate(tgrel, &tgCopyTuple->t_self, tgCopyTuple);
-
-                       InvokeObjectPostAlterHook(TriggerRelationId, tgform->oid, 0);
-
-                       heap_freetuple(tgCopyTuple);
-               }
-
-               systable_endscan(tgscan);
+               AlterConstrTriggerDeferrability(conoid, tgrel, rel, cmdcon->deferrable,
+                                                                               cmdcon->initdeferred, otherrelids);
        }
 
        /*
@@ -11943,34 +11901,118 @@ ATExecAlterConstrRecurse(Constraint *cmdcon, Relation conrel, Relation tgrel,
         */
        if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ||
                get_rel_relkind(refrelid) == RELKIND_PARTITIONED_TABLE)
+               ATExecAlterChildConstr(cmdcon, conrel, tgrel, rel, contuple,
+                                                          otherrelids, lockmode);
+
+       return changed;
+}
+
+/*
+ * A subroutine of ATExecAlterConstrRecurse that updated constraint trigger's
+ * deferrability.
+ *
+ * The arguments to this function have the same meaning as the arguments to
+ * ATExecAlterConstrRecurse.
+ */
+static void
+AlterConstrTriggerDeferrability(Oid conoid, Relation tgrel, Relation rel,
+                                                               bool deferrable, bool initdeferred,
+                                                               List **otherrelids)
+{
+       HeapTuple       tgtuple;
+       ScanKeyData tgkey;
+       SysScanDesc tgscan;
+
+       ScanKeyInit(&tgkey,
+                               Anum_pg_trigger_tgconstraint,
+                               BTEqualStrategyNumber, F_OIDEQ,
+                               ObjectIdGetDatum(conoid));
+       tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
+                                                               NULL, 1, &tgkey);
+       while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan)))
        {
-               ScanKeyData pkey;
-               SysScanDesc pscan;
-               HeapTuple       childtup;
+               Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple);
+               Form_pg_trigger copy_tg;
+               HeapTuple       tgCopyTuple;
 
-               ScanKeyInit(&pkey,
-                                       Anum_pg_constraint_conparentid,
-                                       BTEqualStrategyNumber, F_OIDEQ,
-                                       ObjectIdGetDatum(conoid));
+               /*
+                * Remember OIDs of other relation(s) involved in FK constraint.
+                * (Note: it's likely that we could skip forcing a relcache inval for
+                * other rels that don't have a trigger whose properties change, but
+                * let's be conservative.)
+                */
+               if (tgform->tgrelid != RelationGetRelid(rel))
+                       *otherrelids = list_append_unique_oid(*otherrelids,
+                                                                                                 tgform->tgrelid);
 
-               pscan = systable_beginscan(conrel, ConstraintParentIndexId,
-                                                                  true, NULL, 1, &pkey);
+               /*
+                * Update enable status and deferrability of RI_FKey_noaction_del,
+                * RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd
+                * triggers, but not others; see createForeignKeyActionTriggers and
+                * CreateFKCheckTrigger.
+                */
+               if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL &&
+                       tgform->tgfoid != F_RI_FKEY_NOACTION_UPD &&
+                       tgform->tgfoid != F_RI_FKEY_CHECK_INS &&
+                       tgform->tgfoid != F_RI_FKEY_CHECK_UPD)
+                       continue;
 
-               while (HeapTupleIsValid(childtup = systable_getnext(pscan)))
-               {
-                       Form_pg_constraint childcon = (Form_pg_constraint) GETSTRUCT(childtup);
-                       Relation        childrel;
+               tgCopyTuple = heap_copytuple(tgtuple);
+               copy_tg = (Form_pg_trigger) GETSTRUCT(tgCopyTuple);
 
-                       childrel = table_open(childcon->conrelid, lockmode);
-                       ATExecAlterConstrRecurse(cmdcon, conrel, tgrel, childrel, childtup,
-                                                                        otherrelids, lockmode);
-                       table_close(childrel, NoLock);
-               }
+               copy_tg->tgdeferrable = deferrable;
+               copy_tg->tginitdeferred = initdeferred;
+               CatalogTupleUpdate(tgrel, &tgCopyTuple->t_self, tgCopyTuple);
+
+               InvokeObjectPostAlterHook(TriggerRelationId, tgform->oid, 0);
 
-               systable_endscan(pscan);
+               heap_freetuple(tgCopyTuple);
        }
 
-       return changed;
+       systable_endscan(tgscan);
+}
+
+/*
+ * Invokes ATExecAlterConstrRecurse for each constraint that is a child of the
+ * specified constraint.
+ *
+ * The arguments to this function have the same meaning as the arguments to
+ * ATExecAlterConstrRecurse.
+ */
+static void
+ATExecAlterChildConstr(Constraint *cmdcon, Relation conrel, Relation tgrel,
+                                          Relation rel, HeapTuple contuple, List **otherrelids,
+                                          LOCKMODE lockmode)
+{
+       Form_pg_constraint currcon;
+       Oid                     conoid;
+       ScanKeyData pkey;
+       SysScanDesc pscan;
+       HeapTuple       childtup;
+
+       currcon = (Form_pg_constraint) GETSTRUCT(contuple);
+       conoid = currcon->oid;
+
+       ScanKeyInit(&pkey,
+                               Anum_pg_constraint_conparentid,
+                               BTEqualStrategyNumber, F_OIDEQ,
+                               ObjectIdGetDatum(conoid));
+
+       pscan = systable_beginscan(conrel, ConstraintParentIndexId,
+                                                          true, NULL, 1, &pkey);
+
+       while (HeapTupleIsValid(childtup = systable_getnext(pscan)))
+       {
+               Form_pg_constraint childcon = (Form_pg_constraint) GETSTRUCT(childtup);
+               Relation        childrel;
+
+               childrel = table_open(childcon->conrelid, lockmode);
+               ATExecAlterConstrRecurse(cmdcon, conrel, tgrel, childrel, childtup,
+                                                                otherrelids, lockmode);
+               table_close(childrel, NoLock);
+       }
+
+       systable_endscan(pscan);
 }
 
 /*