1# Copyright 2019 The TensorFlow Authors. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14# ============================================================================== 15# pylint: disable=protected-access 16"""Utilities for Keras classes with v1 and v2 versions.""" 17 18from tensorflow.python.eager import context 19from tensorflow.python.framework import ops 20from tensorflow.python.keras.utils.generic_utils import LazyLoader 21 22# TODO(b/134426265): Switch back to single-quotes once the issue 23# with copybara is fixed. 24# pylint: disable=g-inconsistent-quotes 25training = LazyLoader( 26 "training", globals(), 27 "tensorflow.python.keras.engine.training") 28training_v1 = LazyLoader( 29 "training_v1", globals(), 30 "tensorflow.python.keras.engine.training_v1") 31base_layer = LazyLoader( 32 "base_layer", globals(), 33 "tensorflow.python.keras.engine.base_layer") 34base_layer_v1 = LazyLoader( 35 "base_layer_v1", globals(), 36 "tensorflow.python.keras.engine.base_layer_v1") 37callbacks = LazyLoader( 38 "callbacks", globals(), 39 "tensorflow.python.keras.callbacks") 40callbacks_v1 = LazyLoader( 41 "callbacks_v1", globals(), 42 "tensorflow.python.keras.callbacks_v1") 43 44 45# pylint: enable=g-inconsistent-quotes 46 47 48class ModelVersionSelector(object): 49 """Chooses between Keras v1 and v2 Model class.""" 50 51 def __new__(cls, *args, **kwargs): # pylint: disable=unused-argument 52 use_v2 = should_use_v2() 53 cls = swap_class(cls, training.Model, training_v1.Model, use_v2) # pylint: disable=self-cls-assignment 54 return super(ModelVersionSelector, cls).__new__(cls) 55 56 57class LayerVersionSelector(object): 58 """Chooses between Keras v1 and v2 Layer class.""" 59 60 def __new__(cls, *args, **kwargs): # pylint: disable=unused-argument 61 use_v2 = should_use_v2() 62 cls = swap_class(cls, base_layer.Layer, base_layer_v1.Layer, use_v2) # pylint: disable=self-cls-assignment 63 return super(LayerVersionSelector, cls).__new__(cls) 64 65 66class TensorBoardVersionSelector(object): 67 """Chooses between Keras v1 and v2 TensorBoard callback class.""" 68 69 def __new__(cls, *args, **kwargs): # pylint: disable=unused-argument 70 use_v2 = should_use_v2() 71 start_cls = cls 72 cls = swap_class(start_cls, callbacks.TensorBoard, callbacks_v1.TensorBoard, 73 use_v2) 74 if start_cls == callbacks_v1.TensorBoard and cls == callbacks.TensorBoard: 75 # Since the v2 class is not a subclass of the v1 class, __init__ has to 76 # be called manually. 77 return cls(*args, **kwargs) 78 return super(TensorBoardVersionSelector, cls).__new__(cls) 79 80 81def should_use_v2(): 82 """Determine if v1 or v2 version should be used.""" 83 if context.executing_eagerly(): 84 return True 85 elif ops.executing_eagerly_outside_functions(): 86 # Check for a v1 `wrap_function` FuncGraph. 87 # Code inside a `wrap_function` is treated like v1 code. 88 graph = ops.get_default_graph() 89 if (getattr(graph, "name", False) and 90 graph.name.startswith("wrapped_function")): 91 return False 92 return True 93 else: 94 return False 95 96 97def swap_class(cls, v2_cls, v1_cls, use_v2): 98 """Swaps in v2_cls or v1_cls depending on graph mode.""" 99 if cls == object: 100 return cls 101 if cls in (v2_cls, v1_cls): 102 return v2_cls if use_v2 else v1_cls 103 104 # Recursively search superclasses to swap in the right Keras class. 105 new_bases = [] 106 for base in cls.__bases__: 107 if ((use_v2 and issubclass(base, v1_cls) 108 # `v1_cls` often extends `v2_cls`, so it may still call `swap_class` 109 # even if it doesn't need to. That being said, it may be the safest 110 # not to over optimize this logic for the sake of correctness, 111 # especially if we swap v1 & v2 classes that don't extend each other, 112 # or when the inheritance order is different. 113 or (not use_v2 and issubclass(base, v2_cls)))): 114 new_base = swap_class(base, v2_cls, v1_cls, use_v2) 115 else: 116 new_base = base 117 new_bases.append(new_base) 118 cls.__bases__ = tuple(new_bases) 119 return cls 120 121 122def disallow_legacy_graph(cls_name, method_name): 123 if not ops.executing_eagerly_outside_functions(): 124 error_msg = ( 125 "Calling `{cls_name}.{method_name}` in graph mode is not supported " 126 "when the `{cls_name}` instance was constructed with eager mode " 127 "enabled. Please construct your `{cls_name}` instance in graph mode or" 128 " call `{cls_name}.{method_name}` with eager mode enabled.") 129 error_msg = error_msg.format(cls_name=cls_name, method_name=method_name) 130 raise ValueError(error_msg) 131 132 133def is_v1_layer_or_model(obj): 134 return isinstance(obj, (base_layer_v1.Layer, training_v1.Model)) 135