First Commit

db/intent_admission.go

@@ -0,0 +1,32 @@
+package db
+
+import "fmt"
+
+// DiscardOpenIntent compensates a follow-up creation when task admission fails.
+// The task execution gate must still be held by the caller, so the intent cannot
+// be claimed between this check and deletion. Edges and anchors cascade with the
+// node; activity is deleted explicitly because its node FK otherwise becomes NULL.
+func (s *ExplorationStore) DiscardOpenIntent(id int64) error {
+	tx, err := s.db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	if _, err := tx.Exec(`DELETE FROM activity WHERE exploration_id=$1 AND node_id=$2`, s.expID, id); err != nil {
+		return err
+	}
+	res, err := tx.Exec(`DELETE FROM exploration_nodes
+		WHERE id=$1 AND exploration_id=$2 AND kind='intent' AND state='open'`, id, s.expID)
+	if err != nil {
+		return err
+	}
+	removed, err := res.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if removed != 1 {
+		return fmt.Errorf("open intent %d was not available for admission rollback", id)
+	}
+	return tx.Commit()
+}