fix uid duplicate and add type hint alias for edge endpoint (#3188)

nni/retiarii/graph.py

@@ -9,15 +9,19 @@ from collections import defaultdict
 from typing import (Any, Dict, List, Optional, Tuple, Union, overload)
 
 from .operation import Cell, Operation, _IOPseudoOperation
+from .utils import uid
 
 __all__ = ['Model', 'ModelStatus', 'Graph', 'Node', 'Edge', 'IllegalGraphError', 'MetricData']
 
 
 MetricData = Any
 """
-Graph metrics like loss, accuracy, etc.
+Type hint for graph metrics (loss, accuracy, etc).
+"""
 
-# Maybe we can assume this is a single float number for first iteration.
+EdgeEndpoint = Tuple['Node', Optional[int]]
+"""
+Type hint for edge's endpoint. The int indicates nodes' order.
 """
 
 
@@ -88,12 +92,10 @@ class Model:
     intermediate_metrics
         Intermediate training metrics. If the model is not trained, it's an empty list.
     """
-    _cur_model_id = 0
 
     def __init__(self, _internal=False):
         assert _internal, '`Model()` is private, use `model.fork()` instead'
-        Model._cur_model_id += 1
-        self.model_id = Model._cur_model_id
+        self.model_id: int = uid('model')
 
         self.status: ModelStatus = ModelStatus.Mutating
 
@@ -106,8 +108,6 @@ class Model:
         self.metric: Optional[MetricData] = None
         self.intermediate_metrics: List[MetricData] = []
 
-        self._last_uid: int = 0  # FIXME: this should be global, not model-wise
-
     def __repr__(self):
         return f'Model(model_id={self.model_id}, status={self.status}, graphs={list(self.graphs.keys())}, ' + \
             f'training_config={self.training_config}, metric={self.metric}, intermediate_metrics={self.intermediate_metrics})'
@@ -130,13 +130,8 @@ class Model:
         new_model.graphs = {name: graph._fork_to(new_model) for name, graph in self.graphs.items()}
         new_model.training_config = copy.deepcopy(self.training_config)
         new_model.history = self.history + [self]
-        new_model._last_uid = self._last_uid
         return new_model
 
-    def _uid(self) -> int:
-        self._last_uid += 1
-        return self._last_uid
-
     @staticmethod
     def _load(ir: Any) -> 'Model':
         model = Model(_internal=True)
@@ -295,7 +290,7 @@ class Graph:
             op = operation_or_type
         else:
             op = Operation.new(operation_or_type, parameters, name)
-        return Node(self, self.model._uid(), name, op, _internal=True)._register()
+        return Node(self, uid(), name, op, _internal=True)._register()
 
     @overload
     def insert_node_on_edge(self, edge: 'Edge', name: str, operation: Operation) -> 'Node': ...
@@ -307,7 +302,7 @@ class Graph:
             op = operation_or_type
         else:
             op = Operation.new(operation_or_type, parameters, name)
-        new_node = Node(self, self.model._uid(), name, op, _internal=True)._register()
+        new_node = Node(self, uid(), name, op, _internal=True)._register()
         # update edges
         self.add_edge((edge.head, edge.head_slot), (new_node, None))
         self.add_edge((new_node, None), (edge.tail, edge.tail_slot))
@@ -315,7 +310,7 @@ class Graph:
         return new_node
 
     # mutation
-    def add_edge(self, head: Tuple['Node', Optional[int]], tail: Tuple['Node', Optional[int]]) -> 'Edge':
+    def add_edge(self, head: EdgeEndpoint, tail: EdgeEndpoint) -> 'Edge':
         assert head[0].graph is self and tail[0].graph is self
         return Edge(head, tail, _internal=True)._register()
 
@@ -414,7 +409,7 @@ class Graph:
     def _copy(self) -> 'Graph':
         # Copy this graph inside the model.
         # The new graph will have identical topology, but its nodes' name and ID will be different.
-        new_graph = Graph(self.model, self.model._uid(), _internal=True)._register()
+        new_graph = Graph(self.model, uid(), _internal=True)._register()
         new_graph.input_node.operation.io_names = self.input_node.operation.io_names
         new_graph.output_node.operation.io_names = self.output_node.operation.io_names
         new_graph.input_node.update_label(self.input_node.label)
@@ -423,7 +418,7 @@ class Graph:
         id_to_new_node = {}  # old node ID -> new node object
 
         for old_node in self.hidden_nodes:
-            new_node = Node(new_graph, self.model._uid(), None, old_node.operation, _internal=True)._register()
+            new_node = Node(new_graph, uid(), None, old_node.operation, _internal=True)._register()
             new_node.update_label(old_node.label)
             id_to_new_node[old_node.id] = new_node
 
@@ -440,7 +435,7 @@ class Graph:
 
     @staticmethod
     def _load(model: Model, name: str, ir: Any) -> 'Graph':
-        graph = Graph(model, model._uid(), name, _internal=True)
+        graph = Graph(model, uid(), name, _internal=True)
         graph.input_node.operation.io_names = ir.get('inputs')
         graph.output_node.operation.io_names = ir.get('outputs')
         for node_name, node_data in ir['nodes'].items():
@@ -501,6 +496,8 @@ class Node:
         self.graph: Graph = graph
         self.id: int = node_id
         self.name: str = name or f'_generated_{node_id}'
+        # TODO: the operation is likely to be considered editable by end-user and it will be hard to debug
+        # maybe we should copy it here or make Operation class immutable, in next release
         self.operation: Operation = operation
         self.label: str = None
 
@@ -577,7 +574,7 @@ class Node:
             op = Cell(ir['operation']['cell_name'], ir['operation'].get('parameters', {}))
         else:
             op = Operation.new(ir['operation']['type'], ir['operation'].get('parameters', {}))
-        node = Node(graph, graph.model._uid(), name, op)
+        node = Node(graph, uid(), name, op)
         if 'label' in ir:
             node.update_label(ir['label'])
         return node
@@ -626,11 +623,7 @@ class Edge:
         If the node does not care about order, this can be `-1`.
     """
 
-    def __init__(
-            self,
-            head: Tuple[Node, Optional[int]],
-            tail: Tuple[Node, Optional[int]],
-            _internal: bool = False):
+    def __init__(self, head: EdgeEndpoint, tail: EdgeEndpoint, _internal: bool = False):
         assert _internal, '`Edge()` is private'
         self.graph: Graph = head[0].graph
         self.head: Node = head[0]

nni/retiarii/utils.py

+from collections import defaultdict
 import inspect
 
 def import_(target: str, allow_none: bool = False) -> 'Any':
@@ -7,7 +8,6 @@ def import_(target: str, allow_none: bool = False) -> 'Any':
     module = __import__(path, globals(), locals(), [identifier])
     return getattr(module, identifier)
 
-
 _records = {}
 
 def get_records():
@@ -83,3 +83,9 @@ def register_trainer():
         return m
 
     return _register
+
+_last_uid = defaultdict(int)
+
+def uid(namespace: str = 'default') -> int:
+    _last_uid[namespace] += 1
+    return _last_uid[namespace]