laywerrobot/lib/python3.6/site-packages/tensorflow/python/training/checkpoint_utils.py
2020-08-27 21:55:39 +02:00

349 lines
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Python

# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Tools to work with checkpoints."""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import six
from tensorflow.python import pywrap_tensorflow
from tensorflow.python.framework import ops
from tensorflow.python.ops import io_ops
from tensorflow.python.ops import resource_variable_ops
from tensorflow.python.ops import state_ops
from tensorflow.python.ops import variable_scope as vs
from tensorflow.python.ops import variables
from tensorflow.python.platform import gfile
from tensorflow.python.platform import tf_logging as logging
from tensorflow.python.training import saver
from tensorflow.python.util.tf_export import tf_export
__all__ = [
"load_checkpoint", "load_variable", "list_variables", "init_from_checkpoint"
]
@tf_export("train.load_checkpoint")
def load_checkpoint(ckpt_dir_or_file):
"""Returns `CheckpointReader` for checkpoint found in `ckpt_dir_or_file`.
If `ckpt_dir_or_file` resolves to a directory with multiple checkpoints,
reader for the latest checkpoint is returned.
Args:
ckpt_dir_or_file: Directory with checkpoints file or path to checkpoint
file.
Returns:
`CheckpointReader` object.
Raises:
ValueError: If `ckpt_dir_or_file` resolves to a directory with no
checkpoints.
"""
filename = _get_checkpoint_filename(ckpt_dir_or_file)
if filename is None:
raise ValueError("Couldn't find 'checkpoint' file or checkpoints in "
"given directory %s" % ckpt_dir_or_file)
return pywrap_tensorflow.NewCheckpointReader(filename)
@tf_export("train.load_variable")
def load_variable(ckpt_dir_or_file, name):
"""Returns the tensor value of the given variable in the checkpoint.
Args:
ckpt_dir_or_file: Directory with checkpoints file or path to checkpoint.
name: Name of the variable to return.
Returns:
A numpy `ndarray` with a copy of the value of this variable.
"""
# TODO(b/29227106): Fix this in the right place and remove this.
if name.endswith(":0"):
name = name[:-2]
reader = load_checkpoint(ckpt_dir_or_file)
return reader.get_tensor(name)
@tf_export("train.list_variables")
def list_variables(ckpt_dir_or_file):
"""Returns list of all variables in the checkpoint.
Args:
ckpt_dir_or_file: Directory with checkpoints file or path to checkpoint.
Returns:
List of tuples `(name, shape)`.
"""
reader = load_checkpoint(ckpt_dir_or_file)
variable_map = reader.get_variable_to_shape_map()
names = sorted(variable_map.keys())
result = []
for name in names:
result.append((name, variable_map[name]))
return result
@tf_export("train.init_from_checkpoint")
def init_from_checkpoint(ckpt_dir_or_file, assignment_map):
"""Initializes current variables with tensors loaded from given checkpoint.
Note: This overrides default initialization ops of specified variables and
redefines dtype.
Assignment map supports following syntax:
* `'checkpoint_scope_name/': 'scope_name/'` - will load all variables in
current `scope_name` from `checkpoint_scope_name` with matching tensor
names.
* `'checkpoint_scope_name/some_other_variable': 'scope_name/variable_name'` -
will initialize `scope_name/variable_name` variable
from `checkpoint_scope_name/some_other_variable`.
* `'scope_variable_name': variable` - will initialize given `tf.Variable`
object with tensor 'scope_variable_name' from the checkpoint.
* `'scope_variable_name': list(variable)` - will initialize list of
partitioned variables with tensor 'scope_variable_name' from the checkpoint.
* `'/': 'scope_name/'` - will load all variables in current `scope_name` from
checkpoint's root (e.g. no scope).
Supports loading into partitioned variables, which are represented as
`'<variable>/part_<part #>'`.
Example:
```python
# Say, '/tmp/model.ckpt' has the following tensors:
# -- name='old_scope_1/var1', shape=[20, 2]
# -- name='old_scope_1/var2', shape=[50, 4]
# -- name='old_scope_2/var3', shape=[100, 100]
# Create new model's variables
with tf.variable_scope('new_scope_1'):
var1 = tf.get_variable('var1', shape=[20, 2],
initializer=tf.zeros_initializer())
with tf.variable_scope('new_scope_2'):
var2 = tf.get_variable('var2', shape=[50, 4],
initializer=tf.zeros_initializer())
# Partition into 5 variables along the first axis.
var3 = tf.get_variable(name='var3', shape=[100, 100],
initializer=tf.zeros_initializer(),
partitioner=lambda shape, dtype: [5, 1])
# Initialize all variables in `new_scope_1` from `old_scope_1`.
init_from_checkpoint('/tmp/model.ckpt', {'old_scope_1/': 'new_scope_1'})
# Use names to specify which variables to initialize from checkpoint.
init_from_checkpoint('/tmp/model.ckpt',
{'old_scope_1/var1': 'new_scope_1/var1',
'old_scope_1/var2': 'new_scope_2/var2'})
# Or use tf.Variable objects to identify what to initialize.
init_from_checkpoint('/tmp/model.ckpt',
{'old_scope_1/var1': var1,
'old_scope_1/var2': var2})
# Initialize partitioned variables using variable's name
init_from_checkpoint('/tmp/model.ckpt',
{'old_scope_2/var3': 'new_scope_2/var3'})
# Or specify the list of tf.Variable objects.
init_from_checkpoint('/tmp/model.ckpt',
{'old_scope_2/var3': var3._get_variable_list()})
```
Args:
ckpt_dir_or_file: Directory with checkpoints file or path to checkpoint.
assignment_map: Dict, where keys are names of the variables in the
checkpoint and values are current variables or names of current variables
(in default graph).
Raises:
tf.errors.OpError: If missing checkpoints or tensors in checkpoints.
ValueError: If missing variables in current graph.
"""
ckpt_file = _get_checkpoint_filename(ckpt_dir_or_file)
reader = load_checkpoint(ckpt_dir_or_file)
variable_map = reader.get_variable_to_shape_map()
for tensor_name_in_ckpt, current_var_or_name in sorted(
six.iteritems(assignment_map)):
var = None
# Check if this is Variable object or list of Variable objects (in case of
# partitioned variables).
is_var = lambda x: isinstance(x, variables.Variable)
if is_var(current_var_or_name) or (
isinstance(current_var_or_name, list)
and all(is_var(v) for v in current_var_or_name)):
var = current_var_or_name
else:
store_vars = vs._get_default_variable_store()._vars # pylint:disable=protected-access
# Check if this variable is in var_store.
var = store_vars.get(current_var_or_name, None)
# Also check if variable is partitioned as list.
if var is None:
var = _collect_partitioned_variable(current_var_or_name, store_vars)
if var is not None:
# If 1 to 1 mapping was provided, find variable in the checkpoint.
if tensor_name_in_ckpt not in variable_map:
raise ValueError("Tensor %s is not found in %s checkpoint %s" % (
tensor_name_in_ckpt, ckpt_dir_or_file, variable_map
))
if is_var(var):
# Additional at-call-time checks.
if not var.get_shape().is_compatible_with(
variable_map[tensor_name_in_ckpt]):
raise ValueError(
"Shape of variable %s (%s) doesn't match with shape of "
"tensor %s (%s) from checkpoint reader." % (
var.name, str(var.get_shape()),
tensor_name_in_ckpt, str(variable_map[tensor_name_in_ckpt])
))
var_name = var.name
else:
var_name = ",".join([v.name for v in var])
_set_variable_or_list_initializer(var, ckpt_file, tensor_name_in_ckpt)
logging.debug("Initialize variable %s from checkpoint %s with %s",
var_name, ckpt_dir_or_file, tensor_name_in_ckpt)
else:
scopes = ""
# TODO(vihanjain): Support list of 'current_var_or_name' here.
if "/" in current_var_or_name:
scopes = current_var_or_name[:current_var_or_name.rindex("/")]
if not tensor_name_in_ckpt.endswith("/"):
raise ValueError(
"Assignment map with scope only name {} should map to scope only "
"{}. Should be 'scope/': 'other_scope/'.".format(
scopes, tensor_name_in_ckpt))
# If scope to scope mapping was provided, find all variables in the scope
# and create variable to variable mapping.
scope_variables = set()
for var_name in store_vars:
if not scopes or var_name.startswith(scopes + "/"):
# Consume /part_ if partitioned variable.
if "/part_" in var_name:
var_name = var_name[:var_name.index("/part_")]
scope_variables.add(var_name)
for var_name in sorted(scope_variables):
# Lookup name with specified prefix and suffix from current variable.
# If tensor_name given is '/' (root), don't use it for full name.
full_tensor_name = var_name[len(scopes):]
if current_var_or_name != "/":
full_tensor_name = full_tensor_name[1:]
if tensor_name_in_ckpt != "/":
full_tensor_name = tensor_name_in_ckpt + full_tensor_name
# Remove trailing '/', if any, in the full_tensor_name
if full_tensor_name.endswith("/"):
full_tensor_name = full_tensor_name[:-1]
if full_tensor_name not in variable_map:
raise ValueError(
"Tensor %s (%s in %s) is not found in %s checkpoint" % (
full_tensor_name, var_name[len(scopes) + 1:],
tensor_name_in_ckpt, ckpt_dir_or_file
))
var = store_vars.get(var_name, None)
if var is None:
var = _collect_partitioned_variable(var_name, store_vars)
_set_variable_or_list_initializer(var, ckpt_file, full_tensor_name)
logging.debug("Initialize variable %s from checkpoint %s with %s",
var_name, ckpt_dir_or_file, full_tensor_name)
def _get_checkpoint_filename(ckpt_dir_or_file):
"""Returns checkpoint filename given directory or specific checkpoint file."""
if gfile.IsDirectory(ckpt_dir_or_file):
return saver.latest_checkpoint(ckpt_dir_or_file)
return ckpt_dir_or_file
def _set_checkpoint_initializer(variable,
ckpt_file,
tensor_name,
slice_spec,
name="checkpoint_initializer"):
"""Overrides given variable's initialization op.
Sets variable initializer to assign op that initializes variable from tensor's
value in the checkpoint.
Args:
variable: `tf.Variable` object.
ckpt_file: string, full path of the checkpoint.
tensor_name: Name of the tensor to load from the checkpoint.
slice_spec: Slice specification for loading partitioned tensors.
name: Name of the operation.
"""
base_type = variable.dtype.base_dtype
# Do not colocate with variable since RestoreV2 op only runs on CPU and
# colocation will force variable (and other ops that colocate with variable)
# to be on CPU as well. It is okay to place the variable's initializer op on
# CPU since it will only be run once at the start.
with ops.device(variable.device), ops.device("/cpu:0"):
restore_op = io_ops.restore_v2(
ckpt_file, [tensor_name], [slice_spec], [base_type], name=name)[0]
if isinstance(variable, resource_variable_ops.ResourceVariable):
init_op = variable.assign(restore_op, read_value=False)
else:
init_op = state_ops.assign(variable, restore_op)
variable._initializer_op = init_op # pylint:disable=protected-access
restore_op.set_shape(variable.shape)
variable._initial_value = restore_op # pylint:disable=protected-access
def _set_variable_or_list_initializer(variable_or_list, ckpt_file,
tensor_name):
"""Overrides initialization op of given variable or list of variables.
Calls `_set_checkpoint_initializer` for each variable in the given list of
variables.
Args:
variable_or_list: `tf.Variable` object or a list of `tf.Variable` objects.
ckpt_file: string, full path of the checkpoint.
tensor_name: Name of the tensor to load from the checkpoint.
Raises:
ValueError: if all objects in `variable_or_list` are not partitions of the
same large variable.
"""
if isinstance(variable_or_list, (list, tuple)):
# A set of slices.
slice_name = None
for v in variable_or_list:
slice_info = v._save_slice_info # pylint:disable=protected-access
if slice_name is None:
slice_name = slice_info.full_name
elif slice_name != slice_info.full_name:
raise ValueError("Slices must all be from the same tensor: %s != %s" %
(slice_name, slice_info.full_name))
_set_checkpoint_initializer(v, ckpt_file, tensor_name, slice_info.spec)
else:
_set_checkpoint_initializer(variable_or_list, ckpt_file, tensor_name, "")
def _collect_partitioned_variable(name, all_vars):
"""Returns list of `tf.Variable` that comprise the partitioned variable."""
if name + "/part_0" in all_vars:
var = []
i = 0
while name + "/part_%d" % i in all_vars:
var.append(all_vars[name + "/part_%d" % i])
i += 1
return var
return None