Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/tensorflow/python/saved_model/load_options.py: 58%

1# Copyright 2020 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"""Options for saving SavedModels.""" 

16 

17from tensorflow.python.saved_model import save_options 

18from tensorflow.python.util.tf_export import tf_export 

19 

20 

21@tf_export("saved_model.LoadOptions", v1=[]) 

22class LoadOptions(object): 

23 """Options for loading a SavedModel. 

24 

25 This function may be used in the `options` argument in functions that 

26 load a SavedModel (`tf.saved_model.load`, `tf.keras.models.load_model`). 

27 """ 

28 

29 # Define object attributes in __slots__ for improved memory and performance. 

30 __slots__ = ("allow_partial_checkpoint", "experimental_io_device", 

31 "experimental_skip_checkpoint", "experimental_variable_policy", 

32 "experimental_load_function_aliases") 

33 

34 def __init__(self, 

35 allow_partial_checkpoint=False, 

36 experimental_io_device=None, 

37 experimental_skip_checkpoint=False, 

38 experimental_variable_policy=None, 

39 experimental_load_function_aliases=False): 

40 """Creates an object that stores options for SavedModel loading. 

41 

42 *When to set `allow_partial_checkpoint=True`?* 

43 

44 This can be used when loading a Keras model (`tf.keras.models.load_model`) 

45 with custom objects. When new variables are added to the custom object 

46 class, loading will fail the assertion check that all loaded variables have 

47 been restored, because the SavedModel checkpoint only contains the variables 

48 that were in original the custom object. 

49 See the following example: 

50 

51 ``` 

52 class Custom(tf.keras.Model): 

53 def __init__(self): 

54 super(Custom, self).__init__() 

55 self.v = tf.Variable(...) 

56 

57 def call(self, inputs): 

58 return ... 

59 

60 model = Custom() 

61 model.save(...) 

62 ``` 

63 

64 After saving, say that `Custom` is updated to include an additional 

65 variable. 

66 

67 ``` 

68 class Custom(tf.keras.Model): 

69 def __init__(self): 

70 super(Custom, self).__init__() 

71 self.v = tf.Variable(...) 

72 self.w = tf.Variable(...) 

73 

74 def call(self, inputs): 

75 return ... 

76 ``` 

77 

78 `tf.keras.models.load_model(path, custom_objects={'Custom': Custom})` fails 

79 to load since `Custom.w` does not exist in the SavedModel checkpoint. To 

80 acknowledge that there are variables that are not restored from the 

81 checkpoint and successfully load the model, call: 

82 

83 ``` 

84 tf.keras.models.load_model( 

85 path, custom_objects={'Custom': Custom}, 

86 options=tf.saved_model.LoadOptions(allow_partial_checkpoint=True)) 

87 ``` 

88 

89 Args: 

90 allow_partial_checkpoint: bool. Defaults to `False`. When enabled, allows 

91 the SavedModel checkpoint to not entirely match the loaded object. 

92 experimental_io_device: string. Applies in a distributed setting. 

93 Tensorflow device to use to access the filesystem. If `None` (default) 

94 then for each variable the filesystem is accessed from the CPU:0 device 

95 of the host where that variable is assigned. If specified, the 

96 filesystem is instead accessed from that device for all variables. 

97 This is for example useful if you want to load from a local directory, 

98 such as "/tmp" when running in a distributed setting. In that case 

99 pass a device for the host where the "/tmp" directory is accessible. 

100 experimental_skip_checkpoint: bool. Defaults to `False`. If set to `True`, 

101 checkpoints will not be restored. Note that this in the majority of 

102 cases will generate an unusable model. 

103 experimental_variable_policy: string. The policy to apply to variables 

104 when loading. This is either a `saved_model.experimental.VariablePolicy` 

105 enum instance or one of its value strings (case is not important). See 

106 that enum documentation for details. A value of `None` corresponds to 

107 the default policy. 

108 experimental_load_function_aliases: bool. Defaults to `False`. If set to 

109 `True`, a `function_aliases` attribute will be added to the loaded 

110 SavedModel object. 

111 

112 Example: 

113 

114 load_options = tf.saved_model.LoadOptions(experimental_io_device= 

115 '/job:localhost') 

116 restoredmodel = tf.keras.models.load_model(saved_model_path, 

117 options=load_options) 

118 

119 """ 

120 self.experimental_io_device = experimental_io_device 

121 self.allow_partial_checkpoint = allow_partial_checkpoint 

122 self.experimental_skip_checkpoint = experimental_skip_checkpoint 

123 self.experimental_variable_policy = ( 

124 save_options.VariablePolicy.from_obj(experimental_variable_policy)) 

125 self.experimental_load_function_aliases = experimental_load_function_aliases