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

1# Copyright 2017 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"""Asset-type Trackable object.""" 

16import os 

17 

18from tensorflow.python.eager import context 

19from tensorflow.python.framework import dtypes 

20from tensorflow.python.framework import ops 

21from tensorflow.python.framework import tensor_conversion_registry 

22from tensorflow.python.lib.io import file_io 

23from tensorflow.python.ops import array_ops 

24from tensorflow.python.ops import resource_variable_ops 

25from tensorflow.python.saved_model import path_helpers 

26from tensorflow.python.trackable import base 

27from tensorflow.python.util.tf_export import tf_export 

28 

29 

30@tf_export("saved_model.Asset") 

31class Asset(base.Trackable): 

32 """Represents a file asset to hermetically include in a SavedModel. 

33 

34 A SavedModel can include arbitrary files, called assets, that are needed 

35 for its use. For example a vocabulary file used initialize a lookup table. 

36 

37 When a trackable object is exported via `tf.saved_model.save()`, all the 

38 `Asset`s reachable from it are copied into the SavedModel assets directory. 

39 Upon loading, the assets and the serialized functions that depend on them 

40 will refer to the correct filepaths inside the SavedModel directory. 

41 

42 Example: 

43 

44 ``` 

45 filename = tf.saved_model.Asset("file.txt") 

46 

47 @tf.function(input_signature=[]) 

48 def func(): 

49 return tf.io.read_file(filename) 

50 

51 trackable_obj = tf.train.Checkpoint() 

52 trackable_obj.func = func 

53 trackable_obj.filename = filename 

54 tf.saved_model.save(trackable_obj, "/tmp/saved_model") 

55 

56 # The created SavedModel is hermetic, it does not depend on 

57 # the original file and can be moved to another path. 

58 tf.io.gfile.remove("file.txt") 

59 tf.io.gfile.rename("/tmp/saved_model", "/tmp/new_location") 

60 

61 reloaded_obj = tf.saved_model.load("/tmp/new_location") 

62 print(reloaded_obj.func()) 

63 ``` 

64 

65 Attributes: 

66 asset_path: A path, or a 0-D `tf.string` tensor with path to the asset. 

67 """ 

68 

69 def __init__(self, path): 

70 """Record the full path to the asset.""" 

71 if isinstance(path, os.PathLike): 

72 path = os.fspath(path) 

73 # The init_scope prevents functions from capturing `path` in an 

74 # initialization graph, since it is transient and should not end up in a 

75 # serialized function body. 

76 with ops.init_scope(), ops.device("CPU"): 

77 self._path = ops.convert_to_tensor( 

78 path, dtype=dtypes.string, name="asset_path") 

79 

80 @property 

81 def asset_path(self): 

82 """Fetch the current asset path.""" 

83 return self._path 

84 

85 @classmethod 

86 def _deserialize_from_proto(cls, object_proto, export_dir, asset_file_def, 

87 **unused_kwargs): 

88 proto = object_proto.asset 

89 filename = file_io.join( 

90 path_helpers.get_assets_dir(export_dir), 

91 asset_file_def[proto.asset_file_def_index].filename) 

92 asset = cls(filename) 

93 if not context.executing_eagerly(): 

94 ops.add_to_collection(ops.GraphKeys.ASSET_FILEPATHS, asset.asset_path) 

95 return asset 

96 

97 def _add_trackable_child(self, name, value): 

98 setattr(self, name, value) 

99 

100 def _export_to_saved_model_graph(self, tensor_map, **unused_kwargs): 

101 # TODO(b/205008097): Instead of mapping 1-1 between trackable asset 

102 # and asset in the graph def consider deduping the assets that 

103 # point to the same file. 

104 asset_path_initializer = array_ops.placeholder( 

105 shape=self.asset_path.shape, 

106 dtype=dtypes.string, 

107 name="asset_path_initializer") 

108 asset_variable = resource_variable_ops.ResourceVariable( 

109 asset_path_initializer) 

110 

111 tensor_map[self.asset_path] = asset_variable 

112 return [self.asset_path] 

113 

114 

115tensor_conversion_registry.register_tensor_conversion_function( 

116 Asset, lambda asset, **kw: ops.convert_to_tensor(asset.asset_path, **kw))