# Copyright (c) 2021, NVIDIA CORPORATION. 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. import copy import hashlib import inspect import os import shutil import tarfile import tempfile import uuid from abc import abstractmethod from os import path from os.path import expanduser from typing import Callable, Dict, List, Optional, Union import hydra import torch from omegaconf import DictConfig, OmegaConf, open_dict from pytorch_lightning import LightningModule, Trainer from pytorch_lightning.utilities import rank_zero_only import nemo from nemo.core import optim from nemo.core.classes.common import Model from nemo.core.optim import prepare_lr_scheduler from nemo.utils import logging, model_utils from nemo.utils.app_state import AppState from nemo.utils.get_rank import is_global_rank_zero # Need to set them before EFF import as it is using them. _MODEL_CONFIG_YAML = "model_config.yaml" _MODEL_WEIGHTS = "model_weights.ckpt" __all__ = ['ModelPT'] """ Internal global flags that determine core functionality of ModelPT. _MODEL_IS_RESTORED: This flag determines the context of the model - whether the model is currently being restored or not. - When set, it can be assumed that the model's will disable all automatic methods - setup_training_data(), setup_validation/test_data() and their multi equivalents. - If a model is being restored from a archive file (tarfile), it can be assumed that under this context, the cwd is *inside* the tarfile itself. _MODEL_RESTORE_PATH: A string path to a a file from which the model is being restored. This file can either be a PyTorch Lightning Checkpoint, or a archive (tarfile) that contains artifact objects. If it is an archive file, during restoration, the cwd will be temporarily moved to inside the archive itself. """ _MODEL_IS_RESTORED = False _NEMO_FILE_FOLDER = None class ModelPT(LightningModule, Model): """ Interface for Pytorch-lightning based NeMo models """ def __init__(self, cfg: DictConfig, trainer: Trainer = None): """ Base class from which all NeMo models should inherit Args: cfg (DictConfig): configuration object. The cfg object should have (optionally) the following sub-configs: * train_ds - to instantiate training dataset * validation_ds - to instantiate validation dataset * test_ds - to instantiate testing dataset * optim - to instantiate optimizer with learning rate scheduler trainer (Optional): Pytorch Lightning Trainer instance """ if trainer is not None and not isinstance(trainer, Trainer): raise ValueError( f"trainer constructor argument must be either None or pytroch_lightning.Trainer. But got {type(trainer)} instead." ) super().__init__() # Convert config to a DictConfig cfg = model_utils.convert_model_config_to_dict_config(cfg) # Convert config to support Hydra 1.0+ instantiation cfg = model_utils.maybe_update_config_version(cfg) if 'target' not in cfg: # This is for Jarvis service. OmegaConf.set_struct(cfg, False) cfg.target = "{0}.{1}".format(self.__class__.__module__, self.__class__.__name__) OmegaConf.set_struct(cfg, True) self._cfg = cfg self.save_hyperparameters(self._cfg) self._train_dl = None self._validation_dl = None self._test_dl = None self._optimizer = None self._scheduler = None self.trainer = trainer # reference required for self.*_rank self._trainer = self.trainer # alias for backward compatibility self._set_model_guid() # Set device_id in AppState if torch.cuda.is_available() and torch.cuda.current_device() is not None: app_state = AppState() app_state.device_id = torch.cuda.current_device() if self._cfg is not None and not self._is_model_being_restored(): if 'train_ds' in self._cfg and self._cfg.train_ds is not None: self.setup_training_data(self._cfg.train_ds) if 'validation_ds' in self._cfg and self._cfg.validation_ds is not None: self.setup_multiple_validation_data(val_data_config=None) if 'test_ds' in self._cfg and self._cfg.test_ds is not None: self.setup_multiple_test_data(test_data_config=None) else: if 'train_ds' in self._cfg and self._cfg.train_ds is not None: logging.warning( f"If you intend to do training or fine-tuning, please call the ModelPT.setup_training_data() method " f"and provide a valid configuration file to setup the train data loader.\n" f"Train config : \n{OmegaConf.to_yaml(self._cfg.train_ds)}" ) if 'validation_ds' in self._cfg and self._cfg.validation_ds is not None: logging.warning( f"If you intend to do validation, please call the ModelPT.setup_validation_data() or ModelPT.setup_multiple_validation_data() method " f"and provide a valid configuration file to setup the validation data loader(s). \n" f"Validation config : \n{OmegaConf.to_yaml(self._cfg.validation_ds)}" ) if 'test_ds' in self._cfg and self._cfg.test_ds is not None: logging.warning( f"Please call the ModelPT.setup_test_data() or ModelPT.setup_multiple_test_data() method " f"and provide a valid configuration file to setup the test data loader(s).\n" f"Test config : \n{OmegaConf.to_yaml(self._cfg.test_ds)}" ) # ModelPT wrappers over subclass implementations self.training_step = model_utils.wrap_training_step(self.training_step) def register_artifact(self, config_path: str, src: str, verify_src_exists: bool = True): """ Register model artifacts with this function. These artifacts (files) will be included inside .nemo file when model.save_to("mymodel.nemo") is called. How it works: 1. It always returns existing absolute path which can be used during Model constructor call EXCEPTION: src is None or "" in which case nothing will be done and src will be returned 2. It will add (config_path, model_utils.ArtifactItem()) pair to self.artifacts If "src" is local existing path, then it will be returned in absolute path form. elif "src" starts with "nemo_file:unique_artifact_name": .nemo will be untarred to a temporary folder location and an actual existing path will be returned else an error will be raised. WARNING: use .register_artifact calls in your models' constructors. The returned path is not guaranteed to exist after you have exited your model's constuctor. Args: config_path (str): Artifact key. Usually corresponds to the model config. src (str): Path to artifact. verify_src_exists (bool): If set to False, then the artifact is optional and register_artifact will return None even if src is not found. Defaults to True. Returns: str: If src is not None or empty it always returns absolute path which is guaranteed to exists during model instnce life """ app_state = AppState() if src is None or src == "": return src if not hasattr(self, 'artifacts'): self.artifacts = {} if self.artifacts is None: self.artifacts = {} if config_path in self.artifacts.keys(): logging.warning( f"You tried to register an artifact under config key={config_path} but an artifact for " f"it has already been registered." ) artifact_item = model_utils.ArtifactItem() # This is for backward compatibility, if the src objects exists simply inside of the tarfile # without its key having been overriden, this pathway will be used. src_obj_name = os.path.basename(src) if _NEMO_FILE_FOLDER is not None: src_obj_path = os.path.abspath(os.path.join(_NEMO_FILE_FOLDER, src_obj_name)) else: src_obj_path = src_obj_name # src is a local existing path - register artifact and return exact same path for usage by the model if os.path.exists(os.path.abspath(src)): return_path = os.path.abspath(src) artifact_item.path_type = model_utils.ArtifactPathType.LOCAL_PATH # this is the case when artifact must be retried from the nemo file # we are assuming that the location of the right nemo file is available from _MODEL_RESTORE_PATH elif src.startswith("nemo:"): return_path = os.path.abspath(os.path.join(_NEMO_FILE_FOLDER, src[5:])) artifact_item.path_type = model_utils.ArtifactPathType.TAR_PATH # backward compatibility implementation elif os.path.exists(src_obj_path): return_path = src_obj_path artifact_item.path_type = model_utils.ArtifactPathType.TAR_PATH else: if verify_src_exists: raise FileNotFoundError( f"src path does not exist or it is not a path in nemo file. src value I got was: {src}. Absolute: {os.path.abspath(src)}" ) else: # artifact is optional and we simply return None return None assert os.path.exists(return_path) artifact_item.path = os.path.abspath(src) self.artifacts[config_path] = artifact_item # we were called by ModelPT if hasattr(self, "cfg"): with open_dict(self._cfg): OmegaConf.update(self.cfg, config_path, return_path) return return_path def _handle_artifacts(self, nemo_file_folder): tarfile_artifacts = [] app_state = AppState() for conf_path, artiitem in self.artifacts.items(): if artiitem.path_type == model_utils.ArtifactPathType.LOCAL_PATH: if not os.path.exists(artiitem.path): raise FileNotFoundError(f"Artifact {conf_path} not found at location: {artiitem.path}") # Generate new uniq artifact name and copy it to nemo_file_folder # Note uuid.uuid4().hex is guaranteed to be 32 character long artifact_base_name = os.path.basename(artiitem.path) artifact_uniq_name = f"{uuid.uuid4().hex}_{artifact_base_name}" shutil.copy2(artiitem.path, os.path.join(nemo_file_folder, artifact_uniq_name)) # Update artifacts registry artiitem.hashed_path = "nemo:" + artifact_uniq_name self.artifacts[conf_path] = artiitem elif artiitem.path_type == model_utils.ArtifactPathType.TAR_PATH: # process all tarfile artifacts in one go, so preserve key-value pair tarfile_artifacts.append((conf_path, artiitem)) else: raise ValueError(f"Directly referencing artifacts from other nemo files isn't supported yet") # Process current tarfile artifacts by unpacking the previous tarfile and extract the artifacts # that are currently required. model_metadata = app_state.get_model_metadata_from_guid(self.model_guid) if len(tarfile_artifacts) > 0 and model_metadata.restoration_path is not None: # Need to step into nemo archive to extract file # Get path where the command is executed - the artifacts will be "retrieved" there # (original .nemo behavior) cwd = os.getcwd() try: # Step into the nemo archive to try and find the file with tempfile.TemporaryDirectory() as archive_dir: self._unpack_nemo_file(path2file=model_metadata.restoration_path, out_folder=archive_dir) os.chdir(archive_dir) for conf_path, artiitem in tarfile_artifacts: # Get basename and copy it to nemo_file_folder if 'nemo:' in artiitem.path: artifact_base_name = artiitem.path.split('nemo:')[1] else: artifact_base_name = os.path.basename(artiitem.path) # no need to hash here as we are in tarfile_artifacts which are already hashed artifact_uniq_name = artifact_base_name shutil.copy2(artifact_base_name, os.path.join(nemo_file_folder, artifact_uniq_name)) # Update artifacts registry new_artiitem = model_utils.ArtifactItem() new_artiitem.path = "nemo:" + artifact_uniq_name new_artiitem.path_type = model_utils.ArtifactPathType.TAR_PATH self.artifacts[conf_path] = new_artiitem finally: # change back working directory os.chdir(cwd) def _update_artifact_paths(self, path2yaml_file): if self.artifacts is not None and len(self.artifacts) > 0: conf = OmegaConf.load(path2yaml_file) for conf_path, item in self.artifacts.items(): if item.hashed_path is None: OmegaConf.update(conf, conf_path, item.path) else: OmegaConf.update(conf, conf_path, item.hashed_path) with open(path2yaml_file, 'w') as fout: OmegaConf.save(config=conf, f=fout, resolve=True) def _default_save_to(self, save_path: str): """ Saves model instance (weights and configuration) into .nemo file. You can use "restore_from" method to fully restore instance from .nemo file. .nemo file is an archive (tar.gz) with the following: model_config.yaml - model configuration in .yaml format. You can deserialize this into cfg argument for model's constructor model_wights.chpt - model checkpoint Args: save_path: Path to .nemo file where model instance should be saved """ with tempfile.TemporaryDirectory() as tmpdir: config_yaml = path.join(tmpdir, _MODEL_CONFIG_YAML) model_weights = path.join(tmpdir, _MODEL_WEIGHTS) self.to_config_file(path2yaml_file=config_yaml) if hasattr(self, 'artifacts') and self.artifacts is not None: self._handle_artifacts(nemo_file_folder=tmpdir) # We should not update self._cfg here - the model can still be in use self._update_artifact_paths(path2yaml_file=config_yaml) torch.save(self.state_dict(), model_weights) self._make_nemo_file_from_folder(filename=save_path, source_dir=tmpdir) @rank_zero_only def save_to(self, save_path: str): """ Saves model instance (weights and configuration) into .nemo file You can use "restore_from" method to fully restore instance from .nemo file. .nemo file is an archive (tar.gz) with the following: model_config.yaml - model configuration in .yaml format. You can deserialize this into cfg argument for model's constructor model_wights.chpt - model checkpoint Args: save_path: Path to .nemo file where model instance should be saved """ # Add NeMo rank check as well if not is_global_rank_zero(): return else: self._default_save_to(save_path) @classmethod def _default_restore_from( cls, restore_path: str, override_config_path: Optional[Union[OmegaConf, str]] = None, map_location: Optional[torch.device] = None, strict: bool = True, return_config: bool = False, ): """ Restores model instance (weights and configuration) into .nemo file Args: restore_path: path to .nemo file from which model should be instantiated override_config_path: path to a yaml config that will override the internal config file or an OmegaConf / DictConfig object representing the model config. map_location: Optional torch.device() to map the instantiated model to a device. By default (None), it will select a GPU if available, falling back to CPU otherwise. strict: Passed to load_state_dict. By default True return_config: If set to true, will return just the underlying config of the restored model as an OmegaConf DictConfig object without instantiating the model. Example: ``` model = nemo.collections.asr.models.EncDecCTCModel.restore_from('asr.nemo') assert isinstance(model, nemo.collections.asr.models.EncDecCTCModel) ``` Returns: An instance of type cls or its underlying config (if return_config is set). """ # Get path where the command is executed - the artifacts will be "retrieved" there # (original .nemo behavior) cwd = os.getcwd() if map_location is None: if torch.cuda.is_available(): map_location = torch.device('cuda') else: map_location = torch.device('cpu') with tempfile.TemporaryDirectory() as tmpdir: try: cls._set_model_restore_state(is_being_restored=True, folder=tmpdir) cls._unpack_nemo_file(path2file=restore_path, out_folder=tmpdir) os.chdir(tmpdir) if override_config_path is None: config_yaml = path.join(tmpdir, _MODEL_CONFIG_YAML) else: # can be str path or OmegaConf / DictConfig object config_yaml = override_config_path if not isinstance(config_yaml, (OmegaConf, DictConfig)): conf = OmegaConf.load(config_yaml) else: conf = config_yaml if override_config_path is not None: # Resolve the override config conf = OmegaConf.to_container(conf, resolve=True) conf = OmegaConf.create(conf) # If override is top level config, extract just `model` from it if 'model' in conf: conf = conf.model if return_config: instance = conf else: app_state = AppState() if app_state.model_parallel_rank is not None: model_weights = path.join( tmpdir, f'mp_rank_{app_state.model_parallel_rank:02}', _MODEL_WEIGHTS ) else: model_weights = path.join(tmpdir, _MODEL_WEIGHTS) OmegaConf.set_struct(conf, True) os.chdir(cwd) instance = cls.from_config_dict(config=conf) instance = instance.to(map_location) instance.load_state_dict(torch.load(model_weights, map_location=map_location), strict=strict) logging.info(f'Model {instance.__class__.__name__} was successfully restored from {restore_path}.') finally: cls._set_model_restore_state(is_being_restored=False) os.chdir(cwd) return instance @classmethod def restore_from( cls, restore_path: str, override_config_path: Optional[Union[OmegaConf, str]] = None, map_location: Optional[torch.device] = None, strict: bool = True, return_config: bool = False, ): """ Restores model instance (weights and configuration) from .nemo file. Args: restore_path: path to .nemo file from which model should be instantiated override_config_path: path to a yaml config that will override the internal config file or an OmegaConf / DictConfig object representing the model config. map_location: Optional torch.device() to map the instantiated model to a device. By default (None), it will select a GPU if available, falling back to CPU otherwise. strict: Passed to load_state_dict. By default True. return_config: If set to true, will return just the underlying config of the restored model as an OmegaConf DictConfig object without instantiating the model. Example: ``` model = nemo.collections.asr.models.EncDecCTCModel.restore_from('asr.nemo') assert isinstance(model, nemo.collections.asr.models.EncDecCTCModel) ``` Returns: An instance of type cls or its underlying config (if return_config is set). """ app_state = AppState() if not path.exists(restore_path): raise FileNotFoundError(f"Can't find {restore_path}") app_state.model_restore_path = os.path.abspath(os.path.expanduser(restore_path)) return cls._default_restore_from(restore_path, override_config_path, map_location, strict, return_config) @classmethod def load_from_checkpoint( cls, checkpoint_path: str, *args, map_location: Optional[Union[Dict[str, str], str, torch.device, int, Callable]] = None, hparams_file: Optional[str] = None, strict: bool = True, **kwargs, ): """ Loads ModelPT from checkpoint, with some maintenance of restoration. For documentation, please refer to LightningModule.load_from_checkpoin() documentation. """ checkpoint = None try: cls._set_model_restore_state(is_being_restored=True) checkpoint = super().load_from_checkpoint( checkpoint_path=checkpoint_path, *args, map_location=map_location, hparams_file=hparams_file, strict=strict, **kwargs, ) finally: cls._set_model_restore_state(is_being_restored=False) return checkpoint @abstractmethod def setup_training_data(self, train_data_config: Union[DictConfig, Dict]): """ Setups data loader to be used in training Args: train_data_layer_config: training data layer parameters. Returns: """ pass @abstractmethod def setup_validation_data(self, val_data_config: Union[DictConfig, Dict]): """ Setups data loader to be used in validation Args: val_data_layer_config: validation data layer parameters. Returns: """ pass def setup_test_data(self, test_data_config: Union[DictConfig, Dict]): """ (Optionally) Setups data loader to be used in test Args: test_data_layer_config: test data layer parameters. Returns: """ raise NotImplementedError() def setup_multiple_validation_data(self, val_data_config: Union[DictConfig, Dict]): """ (Optionally) Setups data loader to be used in validation, with support for multiple data loaders. Args: val_data_layer_config: validation data layer parameters. """ # Set some placeholder overriden by helper method self._val_dl_idx = 0 self._validation_names = None self._validation_dl = None # type: torch.utils.data.DataLoader # preserve config self._update_dataset_config(dataset_name='validation', config=val_data_config) try: self._multi_dataset_mode = True model_utils.resolve_validation_dataloaders(model=self) finally: self._multi_dataset_mode = False if self._validation_names is None: if self._validation_dl is not None and type(self._validation_dl) in [list, tuple]: self._validation_names = ['val_{}_'.format(idx) for idx in range(len(self._validation_dl))] def setup_multiple_test_data(self, test_data_config: Union[DictConfig, Dict]): """ (Optionally) Setups data loader to be used in test, with support for multiple data loaders. Args: test_data_layer_config: test data layer parameters. """ # Set some placeholder overriden by helper method self._test_dl_idx = 0 self._test_names = None self._test_dl = None # type: torch.utils.data.DataLoader # preserve config self._update_dataset_config(dataset_name='test', config=test_data_config) try: self._multi_dataset_mode = True model_utils.resolve_test_dataloaders(model=self) finally: self._multi_dataset_mode = False if self._test_names is None: if self._test_dl is not None and type(self._test_dl) in [list, tuple]: self._test_names = ['test_{}_'.format(idx) for idx in range(len(self._test_dl))] def setup_optimization(self, optim_config: Optional[Union[DictConfig, Dict]] = None): """ Prepares an optimizer from a string name and its optional config parameters. Args: optim_config: A dictionary containing the following keys: * "lr": mandatory key for learning rate. Will raise ValueError if not provided. * "optimizer": string name pointing to one of the available optimizers in the registry. \ If not provided, defaults to "adam". * "opt_args": Optional list of strings, in the format "arg_name=arg_value". \ The list of "arg_value" will be parsed and a dictionary of optimizer kwargs \ will be built and supplied to instantiate the optimizer. """ # If config was not explicitly passed to us if optim_config is None: # See if internal config has `optim` namespace if self._cfg is not None and hasattr(self._cfg, 'optim'): optim_config = self._cfg.optim # If config is still None, or internal config has no Optim, return without instantiation if optim_config is None: logging.info('No optimizer config provided, therefore no optimizer was created') return else: # Preserve the configuration if not isinstance(optim_config, DictConfig): optim_config = OmegaConf.create(optim_config) # See if internal config has `optim` namespace before preservation if self._cfg is not None and hasattr(self._cfg, 'optim'): if self._cfg.optim is None: self._cfg.optim = copy.deepcopy(optim_config) else: with open_dict(self._cfg.optim): self._cfg.optim = copy.deepcopy(optim_config) # Setup optimizer and scheduler if optim_config is not None and isinstance(optim_config, DictConfig): optim_config = OmegaConf.to_container(optim_config, resolve=True) if self._trainer is None: logging.warning(f"Trainer wasn't specified in model constructor. Make sure that you really wanted it.") if 'sched' in optim_config and self._trainer is not None: if not isinstance(self._trainer.accumulate_grad_batches, int): raise ValueError("We do not currently support gradient acculumation that is not an integer.") if self._trainer.max_steps is None: # Store information needed to calculate max_steps optim_config['sched']['t_max_epochs'] = self._trainer.max_epochs optim_config['sched']['t_accumulate_grad_batches'] = self._trainer.accumulate_grad_batches optim_config['sched']['t_limit_train_batches'] = self._trainer.limit_train_batches if self._trainer.distributed_backend is None: optim_config['sched']['t_num_workers'] = self._trainer.num_gpus or 1 elif self._trainer.distributed_backend == "ddp_cpu": optim_config['sched']['t_num_workers'] = self._trainer.num_processes * self._trainer.num_nodes elif self._trainer.distributed_backend == "ddp": optim_config['sched']['t_num_workers'] = self._trainer.num_gpus * self._trainer.num_nodes else: logging.warning( f"The lightning trainer received accelerator: {self._trainer.distributed_backend}. We " "recommend to use 'ddp' instead." ) optim_config['sched']['t_num_workers'] = self._trainer.num_gpus * self._trainer.num_nodes else: optim_config['sched']['max_steps'] = self._trainer.max_steps # Force into DictConfig from nested structure optim_config = OmegaConf.create(optim_config) # Get back nested dict so we its mutable optim_config = OmegaConf.to_container(optim_config, resolve=True) # Extract scheduler config if inside optimizer config if 'sched' in optim_config: scheduler_config = optim_config.pop('sched') else: scheduler_config = None # Check if caller provided optimizer name, default to Adam otherwise optimizer_cls = optim_config.get('_target_', None) if optimizer_cls is None: # Try to get optimizer name for dynamic resolution, defaulting to Adam optimizer_name = optim_config.get('name', 'adam') else: if inspect.isclass(optimizer_cls): optimizer_name = optimizer_cls.__name__.lower() else: # resolve the class name (lowercase) from the class path if not provided optimizer_name = optimizer_cls.split(".")[-1].lower() # We are guarenteed to have lr since it is required by the argparser # But maybe user forgot to pass it to this function lr = optim_config.get('lr', None) # Check if caller has optimizer kwargs, default to empty dictionary if 'args' in optim_config: optimizer_args = optim_config.pop('args') optimizer_args = optim.parse_optimizer_args(optimizer_name, optimizer_args) else: optimizer_args = copy.deepcopy(optim_config) # Remove extra parameters from optimizer_args nest # Assume all other parameters are to be passed into optimizer constructor optimizer_args.pop('name', None) optimizer_args.pop('cls', None) optimizer_args.pop('lr', None) # Adaptive schedulers don't need `lr` if lr is not None: optimizer_args['lr'] = lr # Actually instantiate the optimizer if optimizer_cls is not None: if inspect.isclass(optimizer_cls): optimizer = optimizer_cls(self.parameters(), **optimizer_args) logging.info("Optimizer config = %s", str(optimizer)) self._optimizer = optimizer else: # Attempt class path resolution try: optimizer_cls = OmegaConf.create({'_target_': optimizer_cls}) if lr is not None: optimizer_config = {'lr': lr} else: optimizer_config = {} optimizer_config.update(optimizer_args) optimizer_instance = hydra.utils.instantiate( optimizer_cls, self.parameters(), **optimizer_config ) # type: DictConfig logging.info("Optimizer config = %s", str(optimizer_instance)) self._optimizer = optimizer_instance except Exception as e: logging.error( "Could not instantiate class path - {} with kwargs {}".format( optimizer_cls, str(optimizer_config) ) ) raise e else: optimizer = optim.get_optimizer(optimizer_name) optimizer = optimizer(self.parameters(), **optimizer_args) logging.info("Optimizer config = %s", str(optimizer)) self._optimizer = optimizer # Try to instantiate scheduler for optimizer self._scheduler = prepare_lr_scheduler( optimizer=self._optimizer, scheduler_config=scheduler_config, train_dataloader=self._train_dl ) # Return the optimizer with/without scheduler # This return allows multiple optimizers or schedulers to be created return self._optimizer, self._scheduler def configure_optimizers(self): self.setup_optimization() if self._scheduler is None: return self._optimizer else: return [self._optimizer], [self._scheduler] def train_dataloader(self): if self._train_dl is not None: return self._train_dl def val_dataloader(self): if self._validation_dl is not None: return self._validation_dl def test_dataloader(self): if self._test_dl is not None: return self._test_dl def validation_epoch_end( self, outputs: Union[List[Dict[str, torch.Tensor]], List[List[Dict[str, torch.Tensor]]]] ) -> Optional[Dict[str, Dict[str, torch.Tensor]]]: """ Default DataLoader for Validation set which automatically supports multiple data loaders via `multi_validation_epoch_end`. If multi dataset support is not required, override this method entirely in base class. In such a case, there is no need to implement `multi_validation_epoch_end` either. .. note:: If more than one data loader exists, and they all provide `val_loss`, only the `val_loss` of the first data loader will be used by default. This default can be changed by passing the special key `val_dl_idx: int` inside the `validation_ds` config. Args: outputs: Single or nested list of tensor outputs from one or more data loaders. Returns: A dictionary containing the union of all items from individual data_loaders, along with merged logs from all data loaders. """ # Case where we dont provide data loaders if outputs is not None and len(outputs) == 0: return {} # Case where we provide exactly 1 data loader if type(outputs[0]) == dict: output_dict = self.multi_validation_epoch_end(outputs, dataloader_idx=0) if output_dict is not None and 'log' in output_dict: self.log_dict(output_dict.pop('log'), on_epoch=True) return output_dict else: # Case where we provide more than 1 data loader output_dict = {'log': {}} # The output is a list of list of dicts, outer list corresponds to dataloader idx for dataloader_idx, val_outputs in enumerate(outputs): # Get prefix and dispatch call to multi epoch end dataloader_prefix = self.get_validation_dataloader_prefix(dataloader_idx) dataloader_logs = self.multi_validation_epoch_end(val_outputs, dataloader_idx=dataloader_idx) # If result was not provided, generate empty dict dataloader_logs = dataloader_logs or {} # Perform `val_loss` resolution first (if provided outside logs) if 'val_loss' in dataloader_logs: if 'val_loss' not in output_dict and dataloader_idx == self._val_dl_idx: output_dict['val_loss'] = dataloader_logs['val_loss'] # For every item in the result dictionary for k, v in dataloader_logs.items(): # If the key is `log` if k == 'log': # Parse every element of the log, and attach the prefix name of the data loader log_dict = {} for k_log, v_log in v.items(): # If we are logging the metric, but dont provide it at result level, # store it twice - once in log and once in result level. # Also mark log with prefix name to avoid log level clash with other data loaders if k_log not in output_dict['log'] and dataloader_idx == self._val_dl_idx: new_k_log = k_log # Also insert duplicate key with prefix for ease of comparison / avoid name clash log_dict[dataloader_prefix + k_log] = v_log else: # Simply prepend prefix to key and save new_k_log = dataloader_prefix + k_log # Store log value log_dict[new_k_log] = v_log # Update log storage of individual data loader output_logs = output_dict['log'] output_logs.update(log_dict) # Update global log storage output_dict['log'] = output_logs else: # If any values are stored outside 'log', simply prefix name and store new_k = dataloader_prefix + k output_dict[new_k] = v if 'log' in output_dict: self.log_dict(output_dict.pop('log'), on_epoch=True) # return everything else return output_dict def test_epoch_end( self, outputs: Union[List[Dict[str, torch.Tensor]], List[List[Dict[str, torch.Tensor]]]] ) -> Optional[Dict[str, Dict[str, torch.Tensor]]]: """ Default DataLoader for Test set which automatically supports multiple data loaders via `multi_test_epoch_end`. If multi dataset support is not required, override this method entirely in base class. In such a case, there is no need to implement `multi_test_epoch_end` either. .. note:: If more than one data loader exists, and they all provide `test_loss`, only the `test_loss` of the first data loader will be used by default. This default can be changed by passing the special key `test_dl_idx: int` inside the `test_ds` config. Args: outputs: Single or nested list of tensor outputs from one or more data loaders. Returns: A dictionary containing the union of all items from individual data_loaders, along with merged logs from all data loaders. """ # Case where we dont provide data loaders if outputs is not None and len(outputs) == 0: return {} # Case where we provide exactly 1 data loader if type(outputs[0]) == dict: output_dict = self.multi_test_epoch_end(outputs, dataloader_idx=0) if output_dict is not None and 'log' in output_dict: self.log_dict(output_dict.pop('log'), on_epoch=True) return output_dict else: # Case where we provide more than 1 data loader output_dict = {'log': {}} # The output is a list of list of dicts, outer list corresponds to dataloader idx for dataloader_idx, test_outputs in enumerate(outputs): # Get prefix and dispatch call to multi epoch end dataloader_prefix = self.get_test_dataloader_prefix(dataloader_idx) dataloader_logs = self.multi_test_epoch_end(test_outputs, dataloader_idx=dataloader_idx) # If result was not provided, generate empty dict dataloader_logs = dataloader_logs or {} # Perform `test_loss` resolution first (if provided outside logs) if 'test_loss' in dataloader_logs: if 'test_loss' not in output_dict and dataloader_idx == self._test_dl_idx: output_dict['test_loss'] = dataloader_logs['test_loss'] # For every item in the result dictionary for k, v in dataloader_logs.items(): # If the key is `log` if k == 'log': # Parse every element of the log, and attach the prefix name of the data loader log_dict = {} for k_log, v_log in v.items(): # If we are logging the loss, but dont provide it at result level, # store it twice - once in log and once in result level. # Also mark log with prefix name to avoid log level clash with other data loaders if k_log not in output_dict['log'] and dataloader_idx == self._test_dl_idx: new_k_log = k_log # Also insert duplicate key with prefix for ease of comparison / avoid name clash log_dict[dataloader_prefix + k_log] = v_log else: # Simply prepend prefix to key and save new_k_log = dataloader_prefix + k_log log_dict[new_k_log] = v_log # Update log storage of individual data loader output_logs = output_dict.get('log', {}) output_logs.update(log_dict) # Update global log storage output_dict['log'] = output_logs else: # If any values are stored outside 'log', simply prefix name and store new_k = dataloader_prefix + k output_dict[new_k] = v if 'log' in output_dict: self.log_dict(output_dict.pop('log'), on_epoch=True) # return everything else return output_dict def multi_validation_epoch_end( self, outputs: List[Dict[str, torch.Tensor]], dataloader_idx: int = 0 ) -> Optional[Dict[str, Dict[str, torch.Tensor]]]: """ Adds support for multiple validation datasets. Should be overriden by subclass, so as to obtain appropriate logs for each of the dataloaders. Args: outputs: Same as that provided by LightningModule.validation_epoch_end() for a single dataloader. dataloader_idx: int representing the index of the dataloader. Returns: A dictionary of values, optionally containing a sub-dict `log`, such that the values in the log will be pre-pended by the dataloader prefix. """ logging.warning( "Multi data loader support has been enabled, but " "`multi_validation_epoch_end(outputs, dataloader_idx) has not been implemented.\n" "If you require multi data loader support for validation sets, please override this method.\n" "If you do not require multi data loader support, please instead override " "`validation_epoch_end(outputs)." ) def multi_test_epoch_end( self, outputs: List[Dict[str, torch.Tensor]], dataloader_idx: int = 0 ) -> Optional[Dict[str, Dict[str, torch.Tensor]]]: """ Adds support for multiple test datasets. Should be overriden by subclass, so as to obtain appropriate logs for each of the dataloaders. Args: outputs: Same as that provided by LightningModule.validation_epoch_end() for a single dataloader. dataloader_idx: int representing the index of the dataloader. Returns: A dictionary of values, optionally containing a sub-dict `log`, such that the values in the log will be pre-pended by the dataloader prefix. """ logging.warning( "Multi data loader support has been enabled, but " "`multi_test_epoch_end(outputs, dataloader_idx) has not been implemented.\n" "If you require multi data loader support for validation sets, please override this method.\n" "If you do not require multi data loader support, please instead override " "`test_epoch_end(outputs)." ) def get_validation_dataloader_prefix(self, dataloader_idx: int = 0) -> str: """ Get the name of one or more data loaders, which will be prepended to all logs. Args: dataloader_idx: Index of the data loader. Returns: str name of the data loader at index provided. """ return self._validation_names[dataloader_idx] def get_test_dataloader_prefix(self, dataloader_idx: int = 0) -> str: """ Get the name of one or more data loaders, which will be prepended to all logs. Args: dataloader_idx: Index of the data loader. Returns: str name of the data loader at index provided. """ return self._test_names[dataloader_idx] @rank_zero_only def maybe_init_from_pretrained_checkpoint(self, cfg: OmegaConf, map_location: str = 'cpu'): """ Initializes a given model with the parameters obtained via specific config arguments. The state dict of the provided model will be updated with `strict=False` setting so as to prevent requirement of exact model parameters matching. Initializations: init_from_nemo_model: Str path to a .nemo model, which will be instantiated in order to extract the state dict. init_from_pretrained_model: Str name of a pretrained model checkpoint (obtained via cloud). The model will be downloaded (or a cached copy will be used), instantiated and then its state dict will be extracted. init_from_ptl_ckpt: Str name of a Pytorch Lightning checkpoint file. It will be loaded and the state dict will extracted. Args: cfg: The config used to instantiate the model. It need only contain one of the above keys. map_location: str or torch.device() which represents where the intermediate state dict (from the pretrained model or checkpoint) will be loaded. """ args = ['init_from_nemo_model', 'init_from_pretrained_model', 'init_from_ptl_ckpt'] arg_matches = [(1 if arg in cfg and arg is not None else 0) for arg in args] if sum(arg_matches) == 0: # model weights do not need to be restored return if sum(arg_matches) > 1: raise ValueError( f"Cannot pass more than one model initialization arguments to config!\n" f"Found : {[args[idx] for idx, arg_present in enumerate(arg_matches) if arg_present]}" ) if 'init_from_nemo_model' in cfg and cfg.init_from_nemo_model is not None: with open_dict(cfg): # Restore model model_path = cfg.pop('init_from_nemo_model') restored_model = self.restore_from(model_path, map_location=map_location, strict=True) # Restore checkpoint into current model self.load_state_dict(restored_model.state_dict(), strict=False) logging.info(f'Model checkpoint restored from nemo file with path : `{model_path}`') del restored_model if 'init_from_pretrained_model' in cfg and cfg.init_from_pretrained_model is not None: with open_dict(cfg): # Restore model model_name = cfg.pop('init_from_pretrained_model') # Check if model is being resumed or not - only works if `Trainer` is attached to model if hasattr(self, 'trainer') and self.trainer is not None: trainer = self.trainer if hasattr(trainer, 'resume_from_checkpoint') and trainer.resume_from_checkpoint is not None: logging.info( "Model training is being resumed via Pytorch Lightning.\n" "Initialization from pretrained model (via cloud) will be skipped." ) return restored_model = self.from_pretrained(model_name, map_location=map_location, strict=True) # Restore checkpoint into current model self.load_state_dict(restored_model.state_dict(), strict=False) logging.info(f'Model checkpoint restored from pretrained chackpoint with name : `{model_name}`') del restored_model if 'init_from_ptl_ckpt' in cfg and cfg.init_from_ptl_ckpt is not None: with open_dict(cfg): # Restore checkpoint ckpt_path = cfg.pop('init_from_ptl_ckpt') ckpt = torch.load(ckpt_path, map_location=map_location) # Restore checkpoint into current model self.load_state_dict(ckpt['state_dict'], strict=False) logging.info(f'Model checkpoint restored from pytorch lightning chackpoint with path : `{ckpt_path}`') del ckpt def teardown(self, stage: str): """ Called at the end of fit and test. Args: stage: either 'fit' or 'test' """ if stage == 'fit': # Update env variable to bypass multi gpu issue after training # This fix affects usage of trainer.test() after trainer.train() # If trainer.train() was done on multiple GPUs, then trainer.test() # will try to do ddp, even if its a new Trainer object with just 1 GPU. # Temporary patch to fix that if 'PL_TRAINER_GPUS' in os.environ: os.environ.pop('PL_TRAINER_GPUS') super().teardown(stage) @classmethod def extract_state_dict_from(cls, restore_path: str, save_dir: str, split_by_module: bool = False): """ Extract the state dict(s) from a provided .nemo tarfile and save it to a directory. Args: restore_path: path to .nemo file from which state dict(s) should be extracted save_dir: directory in which the saved state dict(s) should be stored split_by_module: bool flag, which determins whether the output checkpoint should be for the entire Model, or the individual module's that comprise the Model Example: To convert the .nemo tarfile into a single Model level PyTorch checkpoint :: state_dict = nemo.collections.asr.models.EncDecCTCModel.extract_state_dict_from('asr.nemo', './asr_ckpts') To restore a model from a Model level checkpoint :: model = nemo.collections.asr.models.EncDecCTCModel(cfg) # or any other method of restoration model.load_state_dict(torch.load("./asr_ckpts/model_weights.ckpt")) To convert the .nemo tarfile into multiple Module level PyTorch checkpoints :: state_dict = nemo.collections.asr.models.EncDecCTCModel.extract_state_dict_from('asr.nemo', './asr_ckpts', split_by_module=True) To restore a module from a Module level checkpoint :: model = nemo.collections.asr.models.EncDecCTCModel(cfg) # or any other method of restoration # load the individual components model.preprocessor.load_state_dict(torch.load("./asr_ckpts/preprocessor.ckpt")) model.encoder.load_state_dict(torch.load("./asr_ckpts/encoder.ckpt")) model.decoder.load_state_dict(torch.load("./asr_ckpts/decoder.ckpt")) Returns: The state dict that was loaded from the original .nemo checkpoint """ if not path.exists(restore_path): raise FileExistsError(f"Can't find {restore_path}") cwd = os.getcwd() save_dir = os.path.abspath(save_dir) if not os.path.exists(save_dir): os.makedirs(save_dir, exist_ok=True) with tempfile.TemporaryDirectory() as tmpdir: try: cls._unpack_nemo_file(path2file=restore_path, out_folder=tmpdir) os.chdir(tmpdir) model_weights = path.join(tmpdir, _MODEL_WEIGHTS) state_dict = torch.load(model_weights) if not split_by_module: filepath = os.path.join(save_dir, _MODEL_WEIGHTS) torch.save(state_dict, filepath) else: key_set = set([key.split(".")[0] for key in state_dict.keys()]) for primary_key in key_set: inner_keys = [key for key in state_dict.keys() if key.split(".")[0] == primary_key] state_dict_subset = { ".".join(inner_key.split(".")[1:]): state_dict[inner_key] for inner_key in inner_keys } filepath = os.path.join(save_dir, f"{primary_key}.ckpt") torch.save(state_dict_subset, filepath) logging.info(f'Checkpoints from {restore_path} were successfully extracted into {save_dir}.') finally: os.chdir(cwd) return state_dict def prepare_test(self, trainer: 'Trainer') -> bool: """ Helper method to check whether the model can safely be tested on a dataset after training (or loading a checkpoint). :: trainer = Trainer() if model.prepare_test(trainer): trainer.test(model) Returns: bool which declares the model safe to test. Provides warnings if it has to return False to guide the user. """ if not hasattr(self._cfg, 'test_ds'): logging.info("No `test_ds` config found within the manifest.") return False # Replace ddp multi-gpu until PTL has a fix DDP_WARN = """\n\nDuring testing, it is currently advisable to construct a new Trainer " "with single GPU and no DDP to obtain accurate results. "Following pattern should be used: " "gpu = 1 if cfg.trainer.gpus != 0 else 0" "trainer = Trainer(gpus=gpu)" "if model.prepare_test(trainer):" " trainer.test(model)\n\n""" if trainer is not None: if trainer.num_gpus > 1: logging.warning(DDP_WARN) return False # Assign trainer to the model self.set_trainer(trainer) return True def set_trainer(self, trainer: Trainer): """ Set an instance of Trainer object. Args: trainer: PyTorch Lightning Trainer object. """ self.trainer = trainer self._trainer = trainer self.set_world_size(self._trainer) def set_world_size(self, trainer: Trainer): """ Determines the world size from the PyTorch Lightning Trainer. And then updates AppState. Args: trainer (Trainer): PyTorch Lightning Trainer object """ # Update AppState with world information from trainer if isinstance(trainer, Trainer): app_state = AppState() if self._trainer.num_gpus and self._trainer.num_nodes: app_state.world_size = self._trainer.num_gpus * self._trainer.num_nodes else: logging.warning(f'World size can only be set by PyTorch Lightning Trainer.') def _update_dataset_config(self, dataset_name: str, config: Optional[Union[DictConfig, Dict]]): """ Update the config (if not None) of the dataset by given name. Preserves said config after updating. Args: dataset_name: str name of the dataset whose config is being updated. Can be one of `train`, `validation` and `test`. config: Optional DictConfig or dict. If None is passed, this method simply returns. If dict is passed, it is cast into a DictConfig. The internal config is updated with the passed config. """ if hasattr(self, '_multi_dataset_mode') and self._multi_dataset_mode is True: return if config is not None: if not isinstance(config, DictConfig): config = OmegaConf.create(config) if dataset_name in ['train', 'validation', 'test']: OmegaConf.set_struct(self.cfg, False) key_name = dataset_name + "_ds" self.cfg[key_name] = config OmegaConf.set_struct(self.cfg, True) # Update hyper parameters by calling property setter self.cfg = self._cfg else: raise ValueError("`dataset_name` when updating config must be one of [train, validation, test]") @property def num_weights(self): """ Utility property that returns the total number of parameters of the Model. """ num: int = 0 for p in self.parameters(): if p.requires_grad: num += p.numel() return num @property def cfg(self): """ Property that holds the finalized internal config of the model. Note: Changes to this config are not reflected in the state of the model. Please create a new model using an updated config to properly update the model. """ return self._cfg @cfg.setter def cfg(self, cfg): """ Property that holds the finalized internal config of the model. Note: Changes to this config are not reflected in the state of the model. Please create a new model using an updated config to properly update the model. """ self._cfg = cfg self._set_hparams(self._cfg) self._hparams_initial = copy.deepcopy(self._hparams) @staticmethod def _make_nemo_file_from_folder(filename, source_dir): with tarfile.open(filename, "w:gz") as tar: tar.add(source_dir, arcname=".") @staticmethod def _unpack_nemo_file(path2file: str, out_folder: str) -> str: if not path.exists(path2file): raise FileNotFoundError(f"{path2file} does not exist") tar = tarfile.open(path2file, "r:gz") tar.extractall(path=out_folder) tar.close() return out_folder @staticmethod def _is_model_being_restored() -> bool: global _MODEL_IS_RESTORED return _MODEL_IS_RESTORED @staticmethod def _set_model_restore_state(is_being_restored: bool, folder: str = None): global _MODEL_IS_RESTORED global _NEMO_FILE_FOLDER _MODEL_IS_RESTORED = is_being_restored _NEMO_FILE_FOLDER = folder def _set_model_guid(self): if not hasattr(self, 'model_guid'): appstate = AppState() # Generate a unique uuid for the instance # also determine if the model is being restored or not, and preserve the path self.model_guid = str(uuid.uuid4()) if self._is_model_being_restored(): restore_path = appstate.model_restore_path else: restore_path = None appstate.register_model_guid(self.model_guid, restoration_path=restore_path) @staticmethod def _is_restore_type_tarfile() -> bool: """ Utility method that checks if the restore path of the underlying Model is a tarfile (can be any valid archive)._MODEL_EFF_SAVE """ app_state = AppState() if app_state.model_restore_path is None: return False else: if app_state.model_restore_path: if tarfile.is_tarfile(app_state.model_restore_path): return True else: return False @staticmethod def set_eff_save(use_eff_save: bool): global _MODEL_EFF_SAVE _MODEL_EFF_SAVE = use_eff_save @staticmethod def use_eff_save() -> bool: global _MODEL_EFF_SAVE return _MODEL_EFF_SAVE