Support cascade deletion

api/s26_labels.py

@@ -1,4 +1,4 @@
-from .operation import *
+from .database import *
 
 
 def get_label_schema(name: str) -> dict[str, dict[str, Any]]:
@@ -43,7 +43,7 @@ class Label(object):
         return { 'type': self.type, 'x': self.x, 'y': self.y }
 
 
-def set_label_cache(name: str, cs: ChangeSet) -> DbChangeSet:
+def set_label_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
     old = Label(get_label(name, cs.operations[0]['x'], cs.operations[0]['y']))
     raw_new = get_label(name, cs.operations[0]['x'], cs.operations[0]['y'])
 
@@ -64,10 +64,10 @@ def set_label_cache(name: str, cs: ChangeSet) -> DbChangeSet:
 
 
 def set_label(name: str, cs: ChangeSet) -> ChangeSet:
-    return execute_command(name, set_label_cache(name, cs))
+    return execute_command(name, set_label_cmd(name, cs))
 
 
-def add_label_cache(name: str, cs: ChangeSet) -> DbChangeSet:
+def add_label_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
     new = Label(cs.operations[0])
 
     redo_sql = f"insert into labels (x, y, label, node) values ({new.f_x}, {new.f_y}, {new.f_label}, {new.f_node});"
@@ -80,10 +80,10 @@ def add_label_cache(name: str, cs: ChangeSet) -> DbChangeSet:
 
 
 def add_label(name: str, cs: ChangeSet) -> ChangeSet:
-    return execute_command(name, add_label_cache(name, cs))
+    return execute_command(name, add_label_cmd(name, cs))
 
 
-def delete_label_cache(name: str, cs: ChangeSet) -> DbChangeSet:
+def delete_label_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
     old = Label(get_label(name, cs.operations[0]['x'], cs.operations[0]['y']))
 
     redo_sql = f"delete from labels where x = {old.f_x} and y = {old.f_y};"
@@ -96,7 +96,7 @@ def delete_label_cache(name: str, cs: ChangeSet) -> DbChangeSet:
 
 
 def delete_label(name: str, cs: ChangeSet) -> ChangeSet:
-    return execute_command(name, delete_label_cache(name, cs))
+    return execute_command(name, delete_label_cmd(name, cs))
 
 
 class InpLabel:
@@ -134,3 +134,13 @@ def inp_out_label(name: str) -> list[str]:
         node = obj['node'] if obj['node'] != None else ''
         lines.append(f'{x} {y} {label} {node}')
     return lines
+
+
+def unset_label_by_node(name: str, node: str) -> ChangeSet:
+    cs = ChangeSet()
+
+    rows = read_all(name, f"select x, y from labels where node = '{node}'")
+    for row in rows:
+        cs.append(g_update_prefix | {'type': 'label', 'x': row['x'], 'y': row['y'], 'node': None})
+
+    return cs