Implement GraphRegularization.save().

PiperOrigin-RevId: 458086350

Author: csferng

neural_structured_learning/keras/adversarial_regularization_test.py

@@ -18,6 +18,7 @@
 from __future__ import print_function
 
 import collections
+import os
 
 from absl.testing import parameterized
 import neural_structured_learning.configs as configs
@@ -64,10 +65,12 @@ def build_linear_keras_functional_model(input_shape,
 def build_linear_keras_subclassed_model(input_shape, weights, dynamic=False):
   del input_shape
 
-  class LinearModel(tf.keras.Model):
+  class CustomLinearModel(tf.keras.Model):
 
-    def __init__(self):
-      super(LinearModel, self).__init__(dynamic=dynamic)
+    def __init__(self, weights, name=None, dynamic=False):
+      super(CustomLinearModel, self).__init__(name=name, dynamic=dynamic)
+      self.init_weights = weights
+      self.init_dynamic = dynamic
       self.dense = tf.keras.layers.Dense(
           weights.shape[-1],
           use_bias=False,
@@ -77,7 +80,14 @@ def __init__(self):
     def call(self, inputs):
       return self.dense(inputs['feature'])
 
-  return LinearModel()
+    def get_config(self):
+      return {
+          'name': self.name,
+          'weights': self.init_weights,
+          'dynamic': self.init_dynamic
+      }
+
+  return CustomLinearModel(weights, dynamic=dynamic)
 
 
 def build_linear_keras_dynamic_model(input_shape, weights):
@@ -728,6 +738,42 @@ def test_perturb_on_batch_pgd(self, model_fn):
     self.assertAllClose(x_adv, adv_inputs['feature'])
     self.assertAllClose(y0, adv_inputs['label'])
 
+  def _test_adv_model_save(self, model_fn):
+    """Template for testing model saving and loading."""
+    w, x0, y0, lr, adv_config, _ = self._set_up_linear_regression()
+    model = model_fn(input_shape=(2,), weights=w)
+    adv_model = adversarial_regularization.AdversarialRegularization(
+        model, label_keys=['label'], adv_config=adv_config)
+    adv_model.compile(optimizer=tf.keras.optimizers.SGD(lr), loss=['MAE'])
+
+    # Run the model before saving it. This is necessary for subclassed models.
+    inputs = {'feature': x0, 'label': y0}
+    adv_model.evaluate(inputs, steps=1)
+
+    saved_model_dir = os.path.join(self.get_temp_dir(), 'saved_model')
+    adv_model.save(saved_model_dir)
+
+    loaded_model = tf.keras.models.load_model(saved_model_dir)
+    self.assertEqual(
+        len(loaded_model.trainable_weights), len(adv_model.trainable_weights))
+    for w_loaded, w_adv in zip(loaded_model.trainable_weights,
+                               adv_model.trainable_weights):
+      self.assertAllClose(
+          tf.keras.backend.get_value(w_loaded),
+          tf.keras.backend.get_value(w_adv))
+
+  @parameterized.named_parameters([
+      ('sequential', build_linear_keras_sequential_model),
+      ('functional', build_linear_keras_functional_model),
+  ])
+  def test_adv_model_save(self, model_fn):
+    self._test_adv_model_save(model_fn)
+
+  # Saving subclassed models are only supported in TF v2.
+  @test_util.run_v2_only
+  def test_adv_model_save_subclassed(self):
+    self._test_adv_model_save(build_linear_keras_subclassed_model)
+
 
 if __name__ == '__main__':
   tf.test.main()

neural_structured_learning/keras/graph_regularization.py

@@ -139,3 +139,9 @@ def call(self, inputs, training=False, **kwargs):
     self.add_loss(scaled_graph_loss)
 
     return base_output
+
+  def save(self, *args, **kwargs):
+    """Saves the base model. See base class for details of the interface."""
+    # Graph regularization doesn't introduce new model variables, so saving the
+    # base model can capture all variables in the model.
+    self.base_model.save(*args, **kwargs)

neural_structured_learning/keras/graph_regularization_test.py

@@ -17,10 +17,11 @@
 from __future__ import division
 from __future__ import print_function
 
+import os
+
 from absl.testing import parameterized
 import neural_structured_learning.configs as configs
 from neural_structured_learning.keras import graph_regularization
-
 import numpy as np
 import tensorflow as tf
 
@@ -88,10 +89,12 @@ def build_linear_functional_model(input_shape, weights, num_output=1):
 def build_linear_subclass_model(input_shape, weights, num_output=1):
   del input_shape
 
-  class LinearModel(tf.keras.Model):
+  class CustomLinearModel(tf.keras.Model):
 
-    def __init__(self):
-      super(LinearModel, self).__init__()
+    def __init__(self, weights, num_output, name=None):
+      super(CustomLinearModel, self).__init__(name=name)
+      self.init_weights = weights
+      self.num_output = num_output
       self.dense = tf.keras.layers.Dense(
           num_output,
           use_bias=False,
@@ -101,7 +104,14 @@ def __init__(self):
     def call(self, inputs):
       return self.dense(inputs[FEATURE_NAME])
 
-  return LinearModel()
+    def get_config(self):
+      return {
+          'name': self.name,
+          'weights': self.init_weights,
+          'num_output': self.num_output
+      }
+
+  return CustomLinearModel(weights, num_output)
 
 
 def make_dataset(example_proto, input_shape, training, max_neighbors):
@@ -481,6 +491,47 @@ def test_graph_reg_model_evaluate(self, model_fn):
         weight=w,
         distributed_strategy=None)
 
+  def _test_graph_reg_model_save(self, model_fn):
+    """Template for testing model saving and loading."""
+    w = np.array([[4.0], [-3.0]])
+    base_model = model_fn((2,), w)
+    graph_reg_config = configs.make_graph_reg_config(
+        max_neighbors=1, multiplier=1)
+    graph_reg_model = graph_regularization.GraphRegularization(
+        base_model, graph_reg_config)
+    graph_reg_model.compile(
+        optimizer=tf.keras.optimizers.SGD(LEARNING_RATE),
+        loss='MSE',
+        metrics=['accuracy'])
+
+    # Run the model before saving it. This is necessary for subclassed models.
+    inputs = {FEATURE_NAME: tf.constant([[5.0, 3.0]])}
+    graph_reg_model.predict(inputs, steps=1, batch_size=1)
+    saved_model_dir = os.path.join(self.get_temp_dir(), 'saved_model')
+    graph_reg_model.save(saved_model_dir)
+
+    loaded_model = tf.keras.models.load_model(saved_model_dir)
+    self.assertEqual(
+        len(loaded_model.trainable_weights),
+        len(graph_reg_model.trainable_weights))
+    for w_loaded, w_graph_reg in zip(loaded_model.trainable_weights,
+                                     graph_reg_model.trainable_weights):
+      self.assertAllClose(
+          tf.keras.backend.get_value(w_loaded),
+          tf.keras.backend.get_value(w_graph_reg))
+
+  @parameterized.named_parameters([
+      ('_sequential', build_linear_sequential_model),
+      ('_functional', build_linear_functional_model),
+  ])
+  def test_graph_reg_model_save(self, model_fn):
+    self._test_graph_reg_model_save(model_fn)
+
+  # Saving subclassed models are only supported in TF v2.
+  @test_util.run_v2_only
+  def test_graph_reg_model_save_subclass(self):
+    self._test_graph_reg_model_save(build_linear_subclass_model)
+
 
 if __name__ == '__main__':
   tf.test.main()