feat: universal method `destroy` in `Component` class

Created by: varenick

fixes #713 (closed)

deeppavlov/core/common/chainer.py

@@ -200,11 +200,14 @@ class Chainer(Component):
                 component.reset()
 
     def destroy(self):
-        for in_params, out_params, component in self.train_pipe:
-            if callable(getattr(component, 'destroy', None)):
-                component.destroy()
-        self.pipe.clear()
-        self.train_pipe.clear()
+        if hasattr(self, 'train_pipe'):
+            for in_params, out_params, component in self.train_pipe:
+                if callable(getattr(component, 'destroy', None)):
+                    component.destroy()
+            self.train_pipe.clear()
+        if hasattr(self, 'pipe'):
+            self.pipe.clear()
+        super().destroy()
 
     def serialize(self) -> bytes:
         data = []

deeppavlov/core/models/component.py

@@ -30,7 +30,12 @@ class Component(metaclass=ABCMeta):
         pass
 
     def destroy(self):
-        pass
+        attr_list = list(self.__dict__.keys())
+        for attr_name in attr_list:
+            attr = getattr(self, attr_name)
+            if hasattr(attr, 'destroy'):
+                attr.destroy()
+            delattr(self, attr_name)
 
     def serialize(self):
         from deeppavlov.core.models.serializable import Serializable

deeppavlov/core/models/tf_model.py

@@ -162,5 +162,7 @@ class TFModel(NNModel, metaclass=TfModelMeta):
         log.info('Total number of parameters equal {}'.format(total_num_parameters))
 
     def destroy(self):
-        for k in list(self.sess.graph.get_all_collection_keys()):
-            self.sess.graph.clear_collection(k)
+        if hasattr(self, 'sess'):
+            for k in list(self.sess.graph.get_all_collection_keys()):
+                self.sess.graph.clear_collection(k)
+        super().destroy()

deeppavlov/models/elmo/elmo.py

@@ -598,3 +598,4 @@ class ELMo(NNModel):
         if hasattr(self, 'sess'):
             for k in list(self.sess.graph.get_all_collection_keys()):
                 self.sess.graph.clear_collection(k)
+        super().destroy()

deeppavlov/models/embedders/abstract_embedder.py

@@ -55,9 +55,6 @@ class Embedder(Component, Serializable, metaclass=ABCMeta):
         self.model = None
         self.load()
 
-    def destroy(self):
-        del self.model
-
     @overrides
     def save(self) -> None:
         """