Add TFRag (#9002)

* Create modeling_tf_dpr.py

* Add TFDPR

* Add back TFPegasus, TFMarian, TFMBart, TFBlenderBot

last commit accidentally deleted these 4 lines, so I recover them back

* Add TFDPR

* Add TFDPR

* clean up some comments, add TF input-style doc string

* Add TFDPR

* Make return_dict=False as default

* Fix return_dict bug (in .from_pretrained)

* Add get_input_embeddings()

* Create test_modeling_tf_dpr.py

The current version is already passed all 27 tests!
Please see the test run at : 
https://colab.research.google.com/drive/1czS_m9zy5k-iSJbzA_DP1k1xAAC_sdkf?usp=sharing

* fix quality

* delete init weights

* run fix copies

* fix repo consis

* del config_class, load_tf_weights

They shoud be 'pytorch only'

* add config_class back

after removing it, test failed ... so totally only removing "use_tf_weights = None" on Lysandre suggestion

* newline after .. note::

* import tf, np (Necessary for ModelIntegrationTest)

* slow_test from_pretrained with from_pt=True

At the moment we don't have TF weights (since we don't have official official TF model)
Previously, I did not run slow test, so I missed this bug

* Add simple TFDPRModelIntegrationTest

Note that this is just a test that TF and Pytorch gives approx. the same output.
However, I could not test with the official DPR repo's output yet

* upload correct tf model

* remove position_ids as missing keys

* create modeling_tf_rag

* add tests for tf

* add tf tests

* revert wrong pt commit

* further refactor

* further refactor

* refactor

* Update modeling_tf_rag.py

- input_processing
- fix prepare_input_for_generation (mostly fix generate bug)
- bring back from_pretrained hack in order to test generate

* delete colab pieces of code

* Show case of greedy "generate"

Temporarily change from beam_search test to greedy_search test to show case that TF and PT do get equivalent output.

* cosmetic update

* correct typos

* update

* push some progress

* make easy check

* fix rag save from pretrained

* Update src/transformers/modeling_tf_utils.py

* remove commented out lines

* delete unnecessary lines

* add simple test case for nq_checkpoint

Add nq_checkpoint test to show that current version without hack still fails

* temporarily put ugly hack back again

* Add TFRagSequenceForGeneration!!

* __init__.py , import TFRagSequenceForGeneration

* Add TFRagSequence tests!

* rag init.py - add TFRagSequenceForGeneration

* fix from_pretrained

* fix prepare_inputs_for_generation

* Beam search for RagToken!

* minor clean up

* add tf.cast in TFRagModel

* More tf.cast

* Add all remaining tests (still have issues)

* delete all T5 related

* make style

* fix load weight prefix

* fix bart

* fix return_dict for tf_rag

make all tests pass .. Hooray

* fix some tests

* fix code quality

* fix qualtiy check

* finish tests tf rag

* add tf rag to docs

* remove TFT5 from docstring

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

* remove TFT5 from docstring

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

* Delete outdated comments

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

* improve doc strings

* add generative model classes

* fix adjust token logic

* refactor generate for TFRag

* using shape_list, not _get_shape

Co-authored-by: Julien Plu <plu.julien@gmail.com>

* axis=[1]->axis=1

* delete NEED_HELP comment

* improve readability

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* improve readability

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* improve readability

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Indicating model is in a developing state in docstrings

As suggested by Julien

* small last changes

* apply sylvains suggestions

* finish tf rag

Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>
Co-authored-by: patrickvonplaten <patrick@huggingface.co>
Co-authored-by: Julien Plu <plu.julien@gmail.com>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

docs/source/index.rst

@@ -296,7 +296,7 @@ TensorFlow and/or Flax.
 +-----------------------------+----------------+----------------+-----------------+--------------------+--------------+
 |         ProphetNet          |       ✅       |       ❌       |       ✅        |         ❌         |      ❌      |
 +-----------------------------+----------------+----------------+-----------------+--------------------+--------------+
-|             RAG             |       ✅       |       ❌       |       ✅        |         ❌         |      ❌      |
+|             RAG             |       ✅       |       ❌       |       ✅        |         ✅         |      ❌      |
 +-----------------------------+----------------+----------------+-----------------+--------------------+--------------+
 |          Reformer           |       ✅       |       ✅       |       ✅        |         ❌         |      ❌      |
 +-----------------------------+----------------+----------------+-----------------+--------------------+--------------+

docs/source/model_doc/rag.rst

@@ -94,3 +94,24 @@ RagTokenForGeneration
 
 .. autoclass:: transformers.RagTokenForGeneration
     :members: forward, generate
+
+
+TFRagModel
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. autoclass:: transformers.TFRagModel
+    :members: call
+
+
+TFRagSequenceForGeneration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. autoclass:: transformers.TFRagSequenceForGeneration
+    :members: call, generate
+
+
+TFRagTokenForGeneration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. autoclass:: transformers.TFRagTokenForGeneration
+    :members: call, generate

src/transformers/__init__.py

@@ -1130,6 +1130,13 @@ if is_tf_available():
         ]
     )
     _import_structure["models.pegasus"].extend(["TFPegasusForConditionalGeneration", "TFPegasusModel"])
+    _import_structure["models.rag"].extend(
+        [
+            "TFRagModel",
+            "TFRagSequenceForGeneration",
+            "TFRagTokenForGeneration",
+        ]
+    )
     _import_structure["models.roberta"].extend(
         [
             "TF_ROBERTA_PRETRAINED_MODEL_ARCHIVE_LIST",
@@ -2166,6 +2173,7 @@ if TYPE_CHECKING:
             TFOpenAIGPTPreTrainedModel,
         )
         from .models.pegasus import TFPegasusForConditionalGeneration, TFPegasusModel
+        from .models.rag import TFRagModel, TFRagSequenceForGeneration, TFRagTokenForGeneration
         from .models.roberta import (
             TF_ROBERTA_PRETRAINED_MODEL_ARCHIVE_LIST,
             TFRobertaForMaskedLM,

src/transformers/generation_tf_utils.py

@@ -441,6 +441,7 @@ class TFGenerationMixin:
         encoder_outputs,
         attention_mask,
         use_cache,
+        **kwargs
     ):
         """
         Generate sequences for each example without beam search (num_beams == 1). All returned sequence are generated
@@ -455,7 +456,7 @@ class TFGenerationMixin:
 
         while cur_len < max_length:
             model_inputs = self.prepare_inputs_for_generation(
-                input_ids, past=past, attention_mask=attention_mask, use_cache=use_cache
+                input_ids, past=past, attention_mask=attention_mask, use_cache=use_cache, **kwargs
             )
             outputs = self(**model_inputs)
             next_token_logits = outputs[0][:, -1, :]
@@ -609,6 +610,7 @@ class TFGenerationMixin:
         use_cache,
         forced_bos_token_id,
         forced_eos_token_id,
+        **kwargs,
     ):
         """Generate sequences for each example with beam search."""
 
@@ -637,7 +639,7 @@ class TFGenerationMixin:
 
         while cur_len < max_length:
             model_inputs = self.prepare_inputs_for_generation(
-                input_ids, past=past, attention_mask=attention_mask, use_cache=use_cache
+                input_ids, past=past, attention_mask=attention_mask, use_cache=use_cache, **kwargs
             )
             outputs = self(**model_inputs)  # (batch_size * num_beams, cur_len, vocab_size)
             next_token_logits = outputs[0][:, -1, :]  # (batch_size * num_beams, vocab_size)

src/transformers/modeling_tf_utils.py

@@ -447,7 +447,7 @@ def input_processing(func, config, input_ids, **kwargs):
     return output
 
 
-def load_tf_weights(model, resolved_archive_file):
+def load_tf_weights(model, resolved_archive_file, _prefix=None):
     """
     Detect missing and unexpected layers and load the TF weights accordingly to their names and shapes.
 
@@ -493,6 +493,10 @@ def load_tf_weights(model, resolved_archive_file):
                 for weight_name in hdf5_format.load_attributes_from_hdf5_group(h5_layer_object, "weight_names"):
                     # TF names always start with the model name so we ignore it
                     name = "/".join(weight_name.split("/")[1:])
+
+                    if _prefix is not None:
+                        name = _prefix + "/" + name
+
                     saved_weights[name] = np.asarray(h5_layer_object[weight_name])
 
                     # Add the updated name to the final list for computing missing/unexpected values
@@ -501,7 +505,14 @@ def load_tf_weights(model, resolved_archive_file):
                 # Loop over each weights from the instantiated model and compare with the weights from the H5 file
                 for symbolic_weight in symbolic_weights:
                     # TF names always start with the model name so we ignore it
-                    symbolic_weight_name = "/".join(symbolic_weight.name.split("/")[1:])
+                    if _prefix is not None:
+                        delimeter = len(_prefix.split("/"))
+                        symbolic_weight_name = "/".join(
+                            symbolic_weight.name.split("/")[:delimeter]
+                            + symbolic_weight.name.split("/")[delimeter + 1 :]
+                        )
+                    else:
+                        symbolic_weight_name = "/".join(symbolic_weight.name.split("/")[1:])
 
                     # here we check if the current weight is among the weights from the H5 file
                     # If yes, get the weight_value of the corresponding weight from the H5 file
@@ -603,6 +614,7 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin, TFGenerationMixin):
     # a list of re pattern of tensor names to ignore from the weights when loading the model weights
     # (and avoid unnecessary warnings).
     _keys_to_ignore_on_load_unexpected = None
+    _requires_load_weight_prefix = False
 
     @property
     def dummy_inputs(self) -> Dict[str, tf.Tensor]:
@@ -741,10 +753,10 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin, TFGenerationMixin):
 
     def get_prefix_bias_name(self) -> Union[None, str]:
         """
-        Get the concatenated prefix name of the bias from the model name to the parent layer
+        Get the concatenated _prefix name of the bias from the model name to the parent layer
 
         Return:
-            :obj:`str`: The prefix name of the bias.
+            :obj:`str`: The _prefix name of the bias.
         """
         warnings.warn("The method get_prefix_bias_name is deprecated. Please use `get_bias` instead.", FutureWarning)
         return None
@@ -1052,7 +1064,7 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin, TFGenerationMixin):
                       Valid model ids can be located at the root-level, like ``bert-base-uncased``, or namespaced under
                       a user or organization name, like ``dbmdz/bert-base-german-cased``.
                     - A path to a `directory` containing model weights saved using
-                      :func:`~transformersTF.PreTrainedModel.save_pretrained`, e.g., ``./my_model_directory/``.
+                      :func:`~transformers.TFPreTrainedModel.save_pretrained`, e.g., ``./my_model_directory/``.
                     - A path or url to a `PyTorch state_dict save file` (e.g, ``./pt_model/pytorch_model.bin``). In
                       this case, ``from_pt`` should be set to :obj:`True` and a configuration object should be provided
                       as ``config`` argument. This loading path is slower than converting the PyTorch model in a
@@ -1151,6 +1163,7 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin, TFGenerationMixin):
         use_auth_token = kwargs.pop("use_auth_token", None)
         revision = kwargs.pop("revision", None)
         mirror = kwargs.pop("mirror", None)
+        load_weight_prefix = kwargs.pop("load_weight_prefix", None)
 
         if is_offline_mode() and not local_files_only:
             logger.info("Offline mode: forcing local_files_only=True")
@@ -1230,6 +1243,11 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin, TFGenerationMixin):
 
         config.name_or_path = pretrained_model_name_or_path
 
+        # composed models, *e.g.* TFRag, require special treatment when it comes to loading
+        # pre-trained weights.
+        if cls._requires_load_weight_prefix and model_kwargs.get("name") is not None:
+            model_kwargs["load_weight_prefix"] = load_weight_prefix + "/" + model_kwargs.get("name")
+
         # Instantiate model.
         model = cls(config, *model_args, **model_kwargs)
 
@@ -1239,13 +1257,18 @@ class TFPreTrainedModel(tf.keras.Model, TFModelUtilsMixin, TFGenerationMixin):
             # Load from a PyTorch checkpoint
             return load_pytorch_checkpoint_in_tf2_model(model, resolved_archive_file, allow_missing_keys=True)
 
-        model(model.dummy_inputs)  # build the network with dummy inputs
+        # we might need to extend the variable scope for composite models
+        if load_weight_prefix is not None:
+            with tf.compat.v1.variable_scope(load_weight_prefix):
+                model(model.dummy_inputs)  # build the network with dummy inputs
+        else:
+            model(model.dummy_inputs)  # build the network with dummy inputs
 
         assert os.path.isfile(resolved_archive_file), "Error retrieving file {}".format(resolved_archive_file)
         # 'by_name' allow us to do transfer learning by skipping/adding layers
         # see https://github.com/tensorflow/tensorflow/blob/00fad90125b18b80fe054de1055770cfb8fe4ba3/tensorflow/python/keras/engine/network.py#L1339-L1357
         try:
-            missing_keys, unexpected_keys = load_tf_weights(model, resolved_archive_file)
+            missing_keys, unexpected_keys = load_tf_weights(model, resolved_archive_file, load_weight_prefix)
         except OSError:
             raise OSError(
                 "Unable to load weights from h5 file. "

src/transformers/models/auto/modeling_tf_auto.py

@@ -553,7 +553,7 @@ class TFAutoModel(object):
 
     @classmethod
     @replace_list_option_in_docstrings(TF_MODEL_MAPPING, use_model_types=False)
-    def from_config(cls, config):
+    def from_config(cls, config, **kwargs):
         r"""
         Instantiates one of the base model classes of the library from a configuration.
 
@@ -575,7 +575,7 @@ class TFAutoModel(object):
             >>> model = TFAutoModel.from_config(config)
         """
         if type(config) in TF_MODEL_MAPPING.keys():
-            return TF_MODEL_MAPPING[type(config)](config)
+            return TF_MODEL_MAPPING[type(config)](config, **kwargs)
         raise ValueError(
             "Unrecognized configuration class {} for this kind of TFAutoModel: {}.\n"
             "Model type should be one of {}.".format(
@@ -1037,7 +1037,7 @@ class TFAutoModelForSeq2SeqLM:
 
     @classmethod
     @replace_list_option_in_docstrings(TF_MODEL_FOR_SEQ_TO_SEQ_CAUSAL_LM_MAPPING, use_model_types=False)
-    def from_config(cls, config):
+    def from_config(cls, config, **kwargs):
         r"""
         Instantiates one of the model classes of the library---with a sequence-to-sequence language modeling
         head---from a configuration.
@@ -1061,7 +1061,7 @@ class TFAutoModelForSeq2SeqLM:
             >>> model = TFAutoModelForSeq2SeqLM.from_config(config)
         """
         if type(config) in TF_MODEL_FOR_SEQ_TO_SEQ_CAUSAL_LM_MAPPING.keys():
-            return TF_MODEL_FOR_SEQ_TO_SEQ_CAUSAL_LM_MAPPING[type(config)](config)
+            return TF_MODEL_FOR_SEQ_TO_SEQ_CAUSAL_LM_MAPPING[type(config)](config, **kwargs)
         raise ValueError(
             "Unrecognized configuration class {} for this kind of TFAutoModel: {}.\n"
             "Model type should be one of {}.".format(

src/transformers/models/bart/modeling_tf_bart.py

@@ -1015,13 +1015,16 @@ class TFBartDecoder(tf.keras.layers.Layer):
 class TFBartMainLayer(tf.keras.layers.Layer):
     config_class = BartConfig
 
-    def __init__(self, config: BartConfig, **kwargs):
+    def __init__(self, config: BartConfig, load_weight_prefix=None, **kwargs):
         super().__init__(**kwargs)
-
         self.config = config
         self.shared = TFSharedEmbeddings(config.vocab_size, config.d_model, config.pad_token_id, name="model.shared")
 
-        with tf.compat.v1.variable_scope("model.shared") as shared_abs_scope_name:
+        # set tf scope correctly
+        if load_weight_prefix is None:
+            load_weight_prefix = "model.shared"
+
+        with tf.compat.v1.variable_scope(load_weight_prefix) as shared_abs_scope_name:
             pass
 
         # Wraps layer to avoid problems with weight restoring and ensuring we're in the correct TF scope.
@@ -1157,10 +1160,13 @@ class TFBartMainLayer(tf.keras.layers.Layer):
     BART_START_DOCSTRING,
 )
 class TFBartModel(TFBartPretrainedModel):
-    def __init__(self, config: BartConfig, *inputs, **kwargs):
+
+    _requires_load_weight_prefix = True
+
+    def __init__(self, config: BartConfig, load_weight_prefix=None, *inputs, **kwargs):
         super().__init__(config, *inputs, **kwargs)
 
-        self.model = TFBartMainLayer(config, name="model")
+        self.model = TFBartMainLayer(config, load_weight_prefix=load_weight_prefix, name="model")
 
     def get_encoder(self):
         return self.model.encoder
@@ -1263,9 +1269,11 @@ class TFBartForConditionalGeneration(TFBartPretrainedModel, TFCausalLanguageMode
         r"model.decoder.embed_tokens.weight",
     ]
 
-    def __init__(self, config, *inputs, **kwargs):
+    _requires_load_weight_prefix = True
+
+    def __init__(self, config, load_weight_prefix=None, *inputs, **kwargs):
         super().__init__(config, *inputs, **kwargs)
-        self.model = TFBartMainLayer(config, name="model")
+        self.model = TFBartMainLayer(config, load_weight_prefix=load_weight_prefix, name="model")
         self.use_cache = config.use_cache
         # final_bias_logits is registered as a buffer in pytorch, so not trainable for the the sake of consistency.
         self.final_logits_bias = self.add_weight(

src/transformers/models/rag/__init__.py

@@ -18,7 +18,7 @@
 
 from typing import TYPE_CHECKING
 
-from ...file_utils import _BaseLazyModule, is_torch_available
+from ...file_utils import _BaseLazyModule, is_tf_available, is_torch_available
 
 
 _import_structure = {
@@ -30,6 +30,9 @@ _import_structure = {
 if is_torch_available():
     _import_structure["modeling_rag"] = ["RagModel", "RagSequenceForGeneration", "RagTokenForGeneration"]
 
+if is_tf_available():
+    _import_structure["modeling_tf_rag"] = ["TFRagModel", "TFRagSequenceForGeneration", "TFRagTokenForGeneration"]
+
 
 if TYPE_CHECKING:
     from .configuration_rag import RagConfig
@@ -39,6 +42,9 @@ if TYPE_CHECKING:
     if is_torch_available():
         from .modeling_rag import RagModel, RagSequenceForGeneration, RagTokenForGeneration
 
+    if is_tf_available():
+        from .modeling_tf_rag import TFRagModel, TFRagSequenceForGeneration, TFRagTokenForGeneration
+
 else:
     import importlib
     import os

src/transformers/utils/dummy_tf_objects.py

@@ -1332,6 +1332,25 @@ class TFPegasusModel:
         requires_tf(self)
 
 
+class TFRagModel:
+    def __init__(self, *args, **kwargs):
+        requires_tf(self)
+
+    @classmethod
+    def from_pretrained(self, *args, **kwargs):
+        requires_tf(self)
+
+
+class TFRagSequenceForGeneration:
+    def __init__(self, *args, **kwargs):
+        requires_tf(self)
+
+
+class TFRagTokenForGeneration:
+    def __init__(self, *args, **kwargs):
+        requires_tf(self)
+
+
 TF_ROBERTA_PRETRAINED_MODEL_ARCHIVE_LIST = None
 
 

utils/check_repo.py

@@ -121,6 +121,9 @@ IGNORE_NON_AUTO_CONFIGURED = [
     "TFGPT2DoubleHeadsModel",
     "TFMT5EncoderModel",
     "TFOpenAIGPTDoubleHeadsModel",
+    "TFRagModel",
+    "TFRagSequenceForGeneration",
+    "TFRagTokenForGeneration",
     "TFT5EncoderModel",
     "Wav2Vec2ForCTC",
     "XLMForQuestionAnswering",