from typing import Optional, Callable, Iterable, Union, List from thinc.api import Config, fix_random_seed, set_gpu_allocator, Model, Optimizer from thinc.api import set_dropout_rate from pathlib import Path from collections import Counter import srsly import time import re from thinc.config import ConfigValidationError from wasabi import Printer from .example import Example from ..errors import Errors from ..tokens import Doc from ..schemas import ConfigSchemaPretrain from ..util import registry, load_model_from_config, dot_to_object def pretrain( config: Config, output_dir: Path, resume_path: Optional[Path] = None, epoch_resume: Optional[int] = None, use_gpu: int = -1, silent: bool = True, ): msg = Printer(no_print=silent) if config["training"]["seed"] is not None: fix_random_seed(config["training"]["seed"]) allocator = config["training"]["gpu_allocator"] if use_gpu >= 0 and allocator: set_gpu_allocator(allocator) nlp = load_model_from_config(config) _config = nlp.config.interpolate() P = registry.resolve(_config["pretraining"], schema=ConfigSchemaPretrain) corpus = dot_to_object(_config, P["corpus"]) corpus = registry.resolve({"corpus": corpus})["corpus"] batcher = P["batcher"] model = create_pretraining_model(nlp, P) optimizer = P["optimizer"] # Load in pretrained weights to resume from if resume_path is not None: epoch_resume = _resume_model(model, resume_path, epoch_resume, silent=silent) else: # Without '--resume-path' the '--epoch-resume' argument is ignored epoch_resume = 0 objective = model.attrs["loss"] # TODO: move this to logger function? tracker = ProgressTracker(frequency=10000) msg.divider(f"Pre-training tok2vec layer - starting at epoch {epoch_resume}") row_settings = {"widths": (3, 10, 10, 6, 4), "aligns": ("r", "r", "r", "r", "r")} msg.row(("#", "# Words", "Total Loss", "Loss", "w/s"), **row_settings) def _save_model(epoch, is_temp=False): is_temp_str = ".temp" if is_temp else "" with model.use_params(optimizer.averages): with (output_dir / f"model{epoch}{is_temp_str}.bin").open("wb") as file_: file_.write(model.get_ref("tok2vec").to_bytes()) log = { "nr_word": tracker.nr_word, "loss": tracker.loss, "epoch_loss": tracker.epoch_loss, "epoch": epoch, } with (output_dir / "log.jsonl").open("a") as file_: file_.write(srsly.json_dumps(log) + "\n") # TODO: I think we probably want this to look more like the # 'create_train_batches' function? for epoch in range(epoch_resume, P["max_epochs"]): for batch_id, batch in enumerate(batcher(corpus(nlp))): docs = ensure_docs(batch) loss = make_update(model, docs, optimizer, objective) progress = tracker.update(epoch, loss, docs) if progress: msg.row(progress, **row_settings) if P["n_save_every"] and (batch_id % P["n_save_every"] == 0): _save_model(epoch, is_temp=True) _save_model(epoch) tracker.epoch_loss = 0.0 def ensure_docs(examples_or_docs: Iterable[Union[Doc, Example]]) -> List[Doc]: docs = [] for eg_or_doc in examples_or_docs: if isinstance(eg_or_doc, Doc): docs.append(eg_or_doc) else: docs.append(eg_or_doc.reference) return docs def _resume_model( model: Model, resume_path: Path, epoch_resume: int, silent: bool = True ) -> int: msg = Printer(no_print=silent) msg.info(f"Resume training tok2vec from: {resume_path}") with resume_path.open("rb") as file_: weights_data = file_.read() model.get_ref("tok2vec").from_bytes(weights_data) if epoch_resume is None: # Parse the epoch number from the given weight file model_name = re.search(r"model\d+\.bin", str(resume_path)) if model_name: # Default weight file name so read epoch_start from it by cutting off 'model' and '.bin' epoch_resume = int(model_name.group(0)[5:][:-4]) + 1 else: # No epoch given and couldn't infer it raise ValueError(Errors.E1020) msg.info(f"Resuming from epoch: {epoch_resume}") return epoch_resume def make_update( model: Model, docs: Iterable[Doc], optimizer: Optimizer, objective_func: Callable ) -> float: """Perform an update over a single batch of documents. docs (iterable): A batch of `Doc` objects. optimizer (callable): An optimizer. RETURNS loss: A float for the loss. """ predictions, backprop = model.begin_update(docs) loss, gradients = objective_func(model.ops, docs, predictions) backprop(gradients) model.finish_update(optimizer) # Don't want to return a cupy object here # The gradients are modified in-place by the BERT MLM, # so we get an accurate loss return float(loss) def create_pretraining_model(nlp, pretrain_config): """Define a network for the pretraining. We simply add an output layer onto the tok2vec input model. The tok2vec input model needs to be a model that takes a batch of Doc objects (as a list), and returns a list of arrays. Each array in the output needs to have one row per token in the doc. The actual tok2vec layer is stored as a reference, and only this bit will be serialized to file and read back in when calling the 'train' command. """ with nlp.select_pipes(enable=[]): nlp.initialize() tok2vec = get_tok2vec_ref(nlp, pretrain_config) # If the config referred to a Tok2VecListener, grab the original model instead if type(tok2vec).__name__ == "Tok2VecListener": original_tok2vec = ( tok2vec.upstream_name if tok2vec.upstream_name != "*" else "tok2vec" ) tok2vec = nlp.get_pipe(original_tok2vec).model try: tok2vec.initialize(X=[nlp.make_doc("Give it a doc to infer shapes")]) except ValueError: component = pretrain_config["component"] layer = pretrain_config["layer"] raise ValueError(Errors.E874.format(component=component, layer=layer)) create_function = pretrain_config["objective"] model = create_function(nlp.vocab, tok2vec) model.initialize(X=[nlp.make_doc("Give it a doc to infer shapes")]) set_dropout_rate(model, pretrain_config["dropout"]) return model def get_tok2vec_ref(nlp, pretrain_config): tok2vec_component = pretrain_config["component"] if tok2vec_component is None: desc = ( f"To use pretrained tok2vec weights, [pretraining.component] " f"needs to specify the component that should load them." ) err = "component can't be null" errors = [{"loc": ["pretraining", "component"], "msg": err}] raise ConfigValidationError( config=nlp.config["pretraining"], errors=errors, desc=desc ) layer = nlp.get_pipe(tok2vec_component).model if pretrain_config["layer"]: layer = layer.get_ref(pretrain_config["layer"]) return layer class ProgressTracker: def __init__(self, frequency=1000000): self.loss = 0.0 self.prev_loss = 0.0 self.nr_word = 0 self.words_per_epoch = Counter() self.frequency = frequency self.last_time = time.time() self.last_update = 0 self.epoch_loss = 0.0 def update(self, epoch, loss, docs): self.loss += loss self.epoch_loss += loss words_in_batch = sum(len(doc) for doc in docs) self.words_per_epoch[epoch] += words_in_batch self.nr_word += words_in_batch words_since_update = self.nr_word - self.last_update if words_since_update >= self.frequency: wps = words_since_update / (time.time() - self.last_time) self.last_update = self.nr_word self.last_time = time.time() loss_per_word = self.loss - self.prev_loss status = ( epoch, self.nr_word, _smart_round(self.loss, width=10), _smart_round(loss_per_word, width=6), int(wps), ) self.prev_loss = float(self.loss) return status else: return None def _smart_round( figure: Union[float, int], width: int = 10, max_decimal: int = 4 ) -> str: """Round large numbers as integers, smaller numbers as decimals.""" n_digits = len(str(int(figure))) n_decimal = width - (n_digits + 1) if n_decimal <= 1: return str(int(figure)) else: n_decimal = min(n_decimal, max_decimal) format_str = "%." + str(n_decimal) + "f" return format_str % figure