1syntax = "proto3";
2
3package tensorflow;
4
5import "tensorflow/core/framework/tensor_shape.proto";
6import "tensorflow/core/framework/types.proto";
7import "tensorflow/core/framework/variable.proto";
8import "tensorflow/core/framework/versions.proto";
9import "tensorflow/core/protobuf/struct.proto";
10import "tensorflow/core/protobuf/trackable_object_graph.proto";
11
12option cc_enable_arenas = true;
13option go_package = "github.com/tensorflow/tensorflow/tensorflow/go/core/protobuf/for_core_protos_go_proto";
14
15// A SavedObjectGraph is part of object-based SavedModels in TF 2.0. It
16// describes the directed graph of Python objects (or equivalent in other
17// languages) that make up a model, with nodes[0] at the root.
18
19// SavedObjectGraph shares some structure with TrackableObjectGraph, but
20// SavedObjectGraph belongs to the MetaGraph and contains pointers to functions
21// and type information, while TrackableObjectGraph lives in the checkpoint
22// and contains pointers only to variable values.
23
24message SavedObjectGraph {
25  // Flattened list of objects in the object graph.
26  //
27  // The position of the object in this list indicates its id.
28  // Nodes[0] is considered the root node.
29  repeated SavedObject nodes = 1;
30
31  // Information about captures and output structures in concrete functions.
32  // Referenced from SavedBareConcreteFunction and SavedFunction.
33  map<string, SavedConcreteFunction> concrete_functions = 2;
34}
35
36message SavedObject {
37  // Objects which this object depends on: named edges in the dependency
38  // graph.
39  //
40  // Note: currently only valid if kind == "user_object".
41  repeated TrackableObjectGraph.TrackableObject.ObjectReference children = 1;
42
43  // Removed when forking SavedObject from TrackableObjectGraph.
44  reserved "attributes";
45  reserved 2;
46
47  // Slot variables owned by this object. This describes the three-way
48  // (optimizer, variable, slot variable) relationship; none of the three
49  // depend on the others directly.
50  //
51  // Note: currently only valid if kind == "user_object".
52  repeated TrackableObjectGraph.TrackableObject.SlotVariableReference
53      slot_variables = 3;
54
55  oneof kind {
56    SavedUserObject user_object = 4;
57    SavedAsset asset = 5;
58    SavedFunction function = 6;
59    SavedVariable variable = 7;
60    SavedBareConcreteFunction bare_concrete_function = 8;
61    SavedConstant constant = 9;
62    SavedResource resource = 10;
63  }
64
65  map<string, SaveableObject> saveable_objects = 11;
66}
67
68// A SavedUserObject is an object (in the object-oriented language of the
69// TensorFlow program) of some user- or framework-defined class other than
70// those handled specifically by the other kinds of SavedObjects.
71//
72// This object cannot be evaluated as a tensor, and therefore cannot be bound
73// to an input of a function.
74message SavedUserObject {
75  // Corresponds to a registration of the type to use in the loading program.
76  string identifier = 1;
77  // Version information from the producer of this SavedUserObject.
78  VersionDef version = 2;
79  // Deprecated! At the time of deprecation, Keras was the only user of this
80  // field, and its saving and loading code will be updated shortly.
81  // Please save your application-specific metadata to separate file
82  // Initialization-related metadata.
83  string metadata = 3;
84}
85
86// A SavedAsset points to an asset in the MetaGraph.
87//
88// When bound to a function this object evaluates to a tensor with the absolute
89// filename. Users should not depend on a particular part of the filename to
90// remain stable (e.g. basename could be changed).
91message SavedAsset {
92  // Index into `MetaGraphDef.asset_file_def[]` that describes the Asset.
93  //
94  // Only the field `AssetFileDef.filename` is used. Other fields, such as
95  // `AssetFileDef.tensor_info`, MUST be ignored.
96  int32 asset_file_def_index = 1;
97}
98
99// A function with multiple signatures, possibly with non-Tensor arguments.
100message SavedFunction {
101  repeated string concrete_functions = 1;
102  FunctionSpec function_spec = 2;
103}
104
105// Stores low-level information about a concrete function. Referenced in either
106// a SavedFunction or a SavedBareConcreteFunction.
107message SavedConcreteFunction {
108  // Bound inputs to the function. The SavedObjects identified by the node ids
109  // given here are appended as extra inputs to the caller-supplied inputs.
110  // The only types of SavedObjects valid here are SavedVariable, SavedResource
111  // and SavedAsset.
112  repeated int32 bound_inputs = 2;
113  // Input in canonicalized form that was received to create this concrete
114  // function.
115  StructuredValue canonicalized_input_signature = 3;
116  // Output that was the return value of this function after replacing all
117  // Tensors with TensorSpecs. This can be an arbitrary nested function and will
118  // be used to reconstruct the full structure from pure tensors.
119  StructuredValue output_signature = 4;
120}
121
122message SavedBareConcreteFunction {
123  // Identifies a SavedConcreteFunction.
124  string concrete_function_name = 1;
125
126  // A sequence of unique strings, one per Tensor argument.
127  repeated string argument_keywords = 2;
128  // The prefix of `argument_keywords` which may be identified by position.
129  int64 allowed_positional_arguments = 3;
130  // The spec of the function that this ConcreteFunction is traced from. This
131  // allows the ConcreteFunction to be called with nest structure inputs. This
132  // field may not be populated. If this field is absent, the concrete function
133  // can only be called with flat inputs.
134  // TODO(b/169361281): support calling saved ConcreteFunction with structured
135  // inputs in C++ SavedModel API.
136  FunctionSpec function_spec = 4;
137}
138
139message SavedConstant {
140  // An Operation name for a ConstantOp in this SavedObjectGraph's MetaGraph.
141  string operation = 1;
142}
143
144// Represents a Variable that is initialized by loading the contents from the
145// checkpoint.
146message SavedVariable {
147  DataType dtype = 1;
148  TensorShapeProto shape = 2;
149  bool trainable = 3;
150  VariableSynchronization synchronization = 4;
151  VariableAggregation aggregation = 5;
152  string name = 6;
153  string device = 7;
154  // List of component variables for a distributed variable.
155  //
156  // When this field is non-empty, the SavedVariable will be assumed
157  // to be a distributed variable defined by the components listed here.
158  //
159  // This is only supported by experimental loaders at the moment.
160  repeated SavedVariable experimental_distributed_variable_components = 8;
161}
162
163
164// Represents `FunctionSpec` used in `Function`. This represents a
165// function that has been wrapped as a TensorFlow `Function`.
166message FunctionSpec {
167  // Full arg spec from inspect.getfullargspec().
168  StructuredValue fullargspec = 1;
169  // Whether this represents a class method.
170  bool is_method = 2;
171  // The input signature, if specified.
172  StructuredValue input_signature = 5;
173
174  // Whether the function should be compiled by XLA.
175  //
176  // The public interface to `tf.function` uses an optional boolean to
177  // represent three distinct states for this field.  Unfortunately, proto3
178  // removes the ability to explicitly check for the presence or absence of a
179  // field, so we instead map to an enum.
180  //
181  // See `tf.function` for details.
182  enum JitCompile {
183    DEFAULT = 0;
184    ON = 1;
185    OFF = 2;
186  }
187  JitCompile jit_compile = 6;
188
189  reserved 3, 4;
190}
191
192// A SavedResource represents a TF object that holds state during its lifetime.
193// An object of this type can have a reference to a:
194// create_resource() and an initialize() function.
195message SavedResource {
196  // A device specification indicating a required placement for the resource
197  // creation function, e.g. "CPU". An empty string allows the user to select a
198  // device.
199  string device = 1;
200}
201
202message SaveableObject {
203  // Node ids of concrete functions for saving and loading from a checkpoint.
204  int32 save_function = 2;
205  int32 restore_function = 3;
206}
207