1# Copyright 2015 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"""Helpers to manipulate a tensor graph in python. 16""" 17 18from __future__ import absolute_import 19from __future__ import division 20from __future__ import print_function 21import copy 22import re 23 24import six 25 26from tensorflow.core.framework import graph_pb2 27from tensorflow.core.framework import node_def_pb2 28from tensorflow.python.framework import _proto_comparators 29from tensorflow.python.framework import dtypes 30from tensorflow.python.framework import ops 31from tensorflow.python.util import deprecation 32from tensorflow.python.util import lazy_loader 33from tensorflow.python.util.tf_export import tf_export 34 35tf_export(v1=["GraphDef"])(graph_pb2.GraphDef) 36 37# A normal import here would generate circular dependencies. 38convert_to_constants = lazy_loader.LazyLoader( 39 "convert_to_constants", globals(), 40 "tensorflow.python.framework.convert_to_constants") 41 42_VARIABLE_OPS = { 43 "Assign", 44 "AssignAdd", 45 "AssignSub", 46 "Queue", 47 "ScatterAdd", 48 "ScatterSub", 49 "ScatterUpdate", 50 "TruncatedNormal", 51 "Variable", 52 "VariableV2", 53} 54 55_CONTROL_FLOW_OP_NAMES_OR_IDENTITY = [ 56 "Switch", 57 "Enter", 58 "Exit", 59 "Identity", 60 "Merge", 61 "NextIteration", 62] 63 64 65def _is_variable_op(op): 66 """Returns true if 'op' refers to a Variable node.""" 67 return op in _VARIABLE_OPS 68 69# GraphDef protobuf docstring. 70graph_pb2.GraphDef.__doc__ = """\ 71A protobuf containing the graph of operations. 72 73@compatibility(TF2) 74This API is not available in TensorFlow 2.x. 75 76You should not need to use `GraphDef`s directly in TF2. To load `GraphDef`s in 77TF2, use SavedModel. The SavedModel contains the `GraphDef`. 78 79Before: 80 81```python 82with tf.io.gfile.GFile('/tmp/graph.pb', 'rb') as f: 83 graph_def = tf.compat.v1.GraphDef() 84 graph_def.ParseFromString(f.read()) 85``` 86 87After: 88 89```python 90tf.saved_model.load('/tmp/saved_model') 91``` 92 93If you would like to create a `GraphDef` in TF2, use `tf.function` and 94`get_concrete_function`. 95 96>>> @tf.function 97>>> def f(x): 98>>> return x 99>>> 100>>> graph_def = f.get_concrete_function(1.).graph.as_graph_def() 101>>> print(graph_def) 102 103@end_compatibility 104 105""" 106 107 108@deprecation.deprecated( 109 date=None, 110 instructions="Use `tf.compat.v1.graph_util.must_run_on_cpu`") 111@tf_export(v1=["graph_util.must_run_on_cpu"]) 112def must_run_on_cpu(node, pin_variables_on_cpu=False): 113 """Returns True if the given node_def must run on CPU, otherwise False. 114 115 Args: 116 node: The node to be assigned to a device. Could be either an ops.Operation 117 or NodeDef. 118 pin_variables_on_cpu: If True, this function will return False if node_def 119 represents a variable-related op. 120 121 Returns: 122 True if the given node must run on CPU, otherwise False. 123 """ 124 125 if isinstance(node, ops.Operation): 126 node_def = node.node_def 127 else: 128 assert isinstance(node, node_def_pb2.NodeDef) 129 node_def = node 130 131 # If the op is a variable-related op, should we pin it on CPU? 132 if pin_variables_on_cpu and _is_variable_op(node_def.op): 133 return True 134 135 # Constant operations producing a string or int32 must run on CPU. 136 if node_def.op == "Const": 137 # Get the value of the 'dtype' attr 138 dtype = node_def.attr["dtype"].type 139 if dtype == dtypes.string or dtype == dtypes.int32: 140 return True 141 142 if node_def.op in ["DynamicStitch", "ParallelDynamicStitch"]: 143 dtype = node_def.attr["T"].type 144 if dtype == dtypes.int32: 145 # DynamicStitch on GPU only works for int32 values. 146 return True 147 148 if node_def.op in ["Cast"]: 149 dtype = node_def.attr["SrcT"].type 150 if dtype == dtypes.int32: 151 # Cast on GPU does not works for int32 values. 152 return True 153 return False 154 155 156################################################################################ 157# 158# device functions for use in with g.device(...) 159# 160################################################################################ 161 162 163def _node_name(n): 164 if n.startswith("^"): 165 return n[1:] 166 else: 167 return n.split(":")[0] 168 169 170def _get_colocated_node_name(colocated_node_name): 171 """Decodes colocated node name and returns it without loc:@ prepended.""" 172 colocated_node_decoded = colocated_node_name.decode("utf-8") 173 if colocated_node_decoded.startswith("loc:@"): 174 return colocated_node_decoded[5:] 175 return colocated_node_decoded 176 177 178def _extract_graph_summary(graph_def): 179 """Extracts useful information from the graph and returns them.""" 180 name_to_input_name = {} # Keyed by the dest node name. 181 name_to_node = {} # Keyed by node name. 182 183 # Keeps track of node sequences. It is important to still output the 184 # operations in the original order. 185 name_to_seq_num = {} # Keyed by node name. 186 seq = 0 187 for node in graph_def.node: 188 n = _node_name(node.name) 189 name_to_node[n] = node 190 name_to_input_name[n] = [_node_name(x) for x in node.input] 191 # Prevent colocated nodes from being lost. 192 if "_class" in node.attr: 193 for colocated_node_name in node.attr["_class"].list.s: 194 name_to_input_name[n].append( 195 _get_colocated_node_name(colocated_node_name)) 196 name_to_seq_num[n] = seq 197 seq += 1 198 return name_to_input_name, name_to_node, name_to_seq_num 199 200 201def _assert_nodes_are_present(name_to_node, nodes): 202 """Assert that nodes are present in the graph.""" 203 for d in nodes: 204 assert d in name_to_node, "%s is not in graph" % d 205 206 207def _bfs_for_reachable_nodes(target_nodes, name_to_input_name): 208 """Breadth first search for reachable nodes from target nodes.""" 209 nodes_to_keep = set() 210 # Breadth first search to find all the nodes that we should keep. 211 next_to_visit = list(target_nodes) 212 while next_to_visit: 213 node = next_to_visit[0] 214 del next_to_visit[0] 215 if node in nodes_to_keep: 216 # Already visited this node. 217 continue 218 nodes_to_keep.add(node) 219 if node in name_to_input_name: 220 next_to_visit += name_to_input_name[node] 221 return nodes_to_keep 222 223 224@deprecation.deprecated( 225 date=None, 226 instructions="Use `tf.compat.v1.graph_util.extract_sub_graph`") 227@tf_export(v1=["graph_util.extract_sub_graph"]) 228def extract_sub_graph(graph_def, dest_nodes): 229 """Extract the subgraph that can reach any of the nodes in 'dest_nodes'. 230 231 Args: 232 graph_def: A graph_pb2.GraphDef proto. 233 dest_nodes: An iterable of strings specifying the destination node names. 234 Returns: 235 The GraphDef of the sub-graph. 236 237 Raises: 238 TypeError: If 'graph_def' is not a graph_pb2.GraphDef proto. 239 """ 240 241 if not isinstance(graph_def, graph_pb2.GraphDef): 242 raise TypeError("graph_def must be a graph_pb2.GraphDef proto.") 243 244 if isinstance(dest_nodes, six.string_types): 245 raise TypeError("dest_nodes must be an iterable of strings.") 246 247 name_to_input_name, name_to_node, name_to_seq_num = _extract_graph_summary( 248 graph_def) 249 _assert_nodes_are_present(name_to_node, dest_nodes) 250 251 nodes_to_keep = _bfs_for_reachable_nodes(dest_nodes, name_to_input_name) 252 253 nodes_to_keep_list = sorted( 254 list(nodes_to_keep), key=lambda n: name_to_seq_num[n]) 255 # Now construct the output GraphDef 256 out = graph_pb2.GraphDef() 257 for n in nodes_to_keep_list: 258 out.node.extend([copy.deepcopy(name_to_node[n])]) 259 out.library.CopyFrom(graph_def.library) 260 out.versions.CopyFrom(graph_def.versions) 261 262 return out 263 264 265@deprecation.deprecated( 266 date=None, 267 instructions="Use `tf.compat.v1.graph_util.tensor_shape_from_node_def_name`" 268) 269@tf_export(v1=["graph_util.tensor_shape_from_node_def_name"]) 270def tensor_shape_from_node_def_name(graph, input_name): 271 """Convenience function to get a shape from a NodeDef's input string.""" 272 # To get a tensor, the name must be in the form <input>:<port>, for example 273 # 'Mul:0'. The GraphDef input strings don't always have the port specified 274 # though, so if there isn't a colon we need to add a default ':0' to the end. 275 if ":" not in input_name: 276 canonical_name = input_name + ":0" 277 else: 278 canonical_name = input_name 279 tensor = graph.get_tensor_by_name(canonical_name) 280 shape = tensor.get_shape() 281 return shape 282 283 284@deprecation.deprecated( 285 date=None, 286 instructions="Use `tf.compat.v1.graph_util.convert_variables_to_constants`") 287@tf_export(v1=["graph_util.convert_variables_to_constants"]) 288def convert_variables_to_constants(sess, 289 input_graph_def, 290 output_node_names, 291 variable_names_whitelist=None, 292 variable_names_blacklist=None): 293 """Replaces all the variables in a graph with constants of the same values. 294 295 If you have a trained graph containing Variable ops, it can be convenient to 296 convert them all to Const ops holding the same values. This makes it possible 297 to describe the network fully with a single GraphDef file, and allows the 298 removal of a lot of ops related to loading and saving the variables. 299 300 Args: 301 sess: Active TensorFlow session containing the variables. 302 input_graph_def: GraphDef object holding the network. 303 output_node_names: List of name strings for the result nodes of the graph. 304 variable_names_whitelist: The set of variable names to convert (by default, 305 all variables are converted). 306 variable_names_blacklist: The set of variable names to omit converting 307 to constants. 308 309 Returns: 310 GraphDef containing a simplified version of the original. 311 312 Raises: 313 RuntimeError: if a DT_RESOURCE op is found whose ancestor Variables are both 314 denylisted AND whitelisted for freezing. 315 """ 316 ret = convert_to_constants.convert_variables_to_constants_from_session_graph( 317 session=sess, 318 graph_def=input_graph_def, 319 output_node_names=output_node_names, 320 variable_names_allowlist=variable_names_whitelist, 321 variable_names_denylist=variable_names_blacklist) 322 # The previous code logic generated an empty versions field, we clear it here 323 # to maintain backwards compatibility. 324 ret.versions.Clear() 325 return ret 326 327 328@deprecation.deprecated( 329 date=None, 330 instructions="Use `tf.compat.v1.graph_util.remove_training_nodes`") 331@tf_export(v1=["graph_util.remove_training_nodes"]) 332def remove_training_nodes(input_graph, protected_nodes=None): 333 """Prunes out nodes that aren't needed for inference. 334 335 There are nodes like Identity and CheckNumerics that are only useful 336 during training, and can be removed in graphs that will be used for 337 nothing but inference. Here we identify and remove them, returning an 338 equivalent graph. To be specific, CheckNumerics nodes are always removed, and 339 Identity nodes that aren't involved in control edges are spliced out so that 340 their input and outputs are directly connected. 341 342 Args: 343 input_graph: Model to analyze and prune. 344 protected_nodes: An optional list of names of nodes to be kept 345 unconditionally. This is for example useful to preserve Identity output 346 nodes. 347 348 Returns: 349 A list of nodes with the unnecessary ones removed. 350 """ 351 if not protected_nodes: 352 protected_nodes = [] 353 354 types_to_remove = {"CheckNumerics": True} 355 356 input_nodes = input_graph.node 357 names_to_remove = {} 358 for node in input_nodes: 359 if node.op in types_to_remove and node.name not in protected_nodes: 360 names_to_remove[node.name] = True 361 362 nodes_after_removal = [] 363 for node in input_nodes: 364 if node.name in names_to_remove: 365 continue 366 new_node = node_def_pb2.NodeDef() 367 new_node.CopyFrom(node) 368 input_before_removal = node.input 369 del new_node.input[:] 370 for full_input_name in input_before_removal: 371 input_name = re.sub(r"^\^", "", full_input_name) 372 if input_name in names_to_remove: 373 continue 374 new_node.input.append(full_input_name) 375 nodes_after_removal.append(new_node) 376 377 types_to_splice = {"Identity": True} 378 control_input_names = set() 379 node_names_with_control_input = set() 380 for node in nodes_after_removal: 381 for node_input in node.input: 382 if "^" in node_input: 383 control_input_names.add(node_input.replace("^", "")) 384 node_names_with_control_input.add(node.name) 385 386 names_to_splice = {} 387 for node in nodes_after_removal: 388 if node.op in types_to_splice and node.name not in protected_nodes: 389 # We don't want to remove nodes that have control edge inputs, because 390 # they might be involved in subtle dependency issues that removing them 391 # will jeopardize. 392 if node.name not in node_names_with_control_input: 393 names_to_splice[node.name] = node.input[0] 394 395 # We also don't want to remove nodes which are used as control edge inputs. 396 names_to_splice = {name: value for name, value in names_to_splice.items() 397 if name not in control_input_names} 398 399 nodes_after_splicing = [] 400 for node in nodes_after_removal: 401 if node.name in names_to_splice: 402 continue 403 new_node = node_def_pb2.NodeDef() 404 new_node.CopyFrom(node) 405 input_before_removal = node.input 406 del new_node.input[:] 407 for full_input_name in input_before_removal: 408 input_name = re.sub(r"^\^", "", full_input_name) 409 while input_name in names_to_splice: 410 full_input_name = names_to_splice[input_name] 411 input_name = re.sub(r"^\^", "", full_input_name) 412 new_node.input.append(full_input_name) 413 nodes_after_splicing.append(new_node) 414 415 output_graph = graph_pb2.GraphDef() 416 output_graph.node.extend(nodes_after_splicing) 417 return output_graph 418 419 420@tf_export("__internal__.graph_util.graph_defs_equal", v1=[]) 421def graph_defs_equal(graph_def_1: graph_pb2.GraphDef, 422 graph_def_2: graph_pb2.GraphDef, 423 treat_nan_as_equal: bool = False) -> bool: 424 """Returns True iff the graph def arguments are structurally equivalent. 425 426 The notion of equivalence encoded here checks that the set of NodeDefs in 427 the GraphDef's function library and main graph body are identical. 428 Additionally, it checks that the functions in the function library are equal 429 as sets. 430 431 Example usage: 432 433 ``` 434 with tf.Graph().as_default() as g1: 435 tf.constant(1) 436 437 with tf.Graph().as_default() as g2: 438 tf.constant(2) 439 440 with tf.Graph().as_default() as g3: 441 tf.constant(1) 442 443 assert tf.__internal__.graph_util.graph_defs_equal(g1.as_graph_def(), 444 g3.as_graph_def()) 445 446 assert not tf.__internal__.graph_util.graph_defs_equal(g1.as_graph_def(), 447 g2.as_graph_def()) 448 ``` 449 450 Args: 451 graph_def_1: Instance of `graph_pb2.GraphDef` to compare. 452 graph_def_2: Instance of `graph_pb2.GraphDef` to compare. 453 treat_nan_as_equal: Boolean indicating whether or not to treat nan 454 floating-point values as equal. This is crucial for any equivalence 455 relation defined over GraphDefs, to ensure symmetry. 456 457 Returns: 458 Boolean indicating structural equivalence as described above. 459 460 Raises: 461 TypeError: If either of the GraphDefs are not instances of 462 `graph_pb2.GraphDef`. 463 """ 464 if not isinstance(graph_def_1, graph_pb2.GraphDef): 465 raise TypeError("graph_def_1 must be a graph_pb2.GraphDef proto.") 466 if not isinstance(graph_def_2, graph_pb2.GraphDef): 467 raise TypeError("graph_def_2 must be a graph_pb2.GraphDef proto.") 468 options = _proto_comparators.ProtoComparisonOptions(treat_nan_as_equal) 469 return _proto_comparators.EqualsGraphDef(graph_def_1.SerializeToString(), 470 graph_def_2.SerializeToString(), 471 options) 472