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# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
import ast
import collections
import contextlib
import inspect
import logging
import os
import re
import time
import traceback
from collections import OrderedDict
from pathlib import Path
from typing import Any, Dict, Optional, Union
import numpy as np
import torch
from fairseq.data import data_utils
from fairseq.dataclass.configs import CheckpointConfig
from fairseq.dataclass.utils import (
convert_namespace_to_omegaconf,
overwrite_args_by_name,
)
from fairseq.distributed.fully_sharded_data_parallel import FSDP, has_FSDP
from fairseq.file_io import PathManager
from fairseq.models import FairseqDecoder, FairseqEncoder
from omegaconf import DictConfig, OmegaConf, open_dict
logger = logging.getLogger(__name__)
def save_checkpoint(cfg: CheckpointConfig, trainer, epoch_itr, val_loss):
from fairseq import meters
# only one worker should attempt to create the required dir
if trainer.data_parallel_rank == 0:
os.makedirs(cfg.save_dir, exist_ok=True)
prev_best = getattr(save_checkpoint, "best", val_loss)
if val_loss is not None:
best_function = max if cfg.maximize_best_checkpoint_metric else min
save_checkpoint.best = best_function(val_loss, prev_best)
if cfg.no_save:
return None
trainer.consolidate_optimizer() # TODO(SS): do we need this if no_save_optimizer_state
if not trainer.should_save_checkpoint_on_current_rank:
if trainer.always_call_state_dict_during_save_checkpoint:
trainer.state_dict()
return None
write_timer = meters.StopwatchMeter()
write_timer.start()
epoch = epoch_itr.epoch
end_of_epoch = epoch_itr.end_of_epoch()
updates = trainer.get_num_updates()
logger.info(f"Preparing to save checkpoint for epoch {epoch} @ {updates} updates")
def is_better(a, b):
return a >= b if cfg.maximize_best_checkpoint_metric else a <= b
suffix = trainer.checkpoint_suffix
checkpoint_conds = collections.OrderedDict()
checkpoint_conds["checkpoint{}{}.pt".format(epoch, suffix)] = (
end_of_epoch and not cfg.no_epoch_checkpoints and epoch % cfg.save_interval == 0
)
checkpoint_conds["checkpoint_{}_{}{}.pt".format(epoch, updates, suffix)] = (
not end_of_epoch
and cfg.save_interval_updates > 0
and updates % cfg.save_interval_updates == 0
)
checkpoint_conds["checkpoint_best{}.pt".format(suffix)] = val_loss is not None and (
not hasattr(save_checkpoint, "best")
or is_better(val_loss, save_checkpoint.best)
)
if val_loss is not None and cfg.keep_best_checkpoints > 0:
worst_best = getattr(save_checkpoint, "best", None)
chkpts = checkpoint_paths(
cfg.save_dir,
pattern=r"checkpoint\.best_{}_(\d+\.?\d*){}\.pt".format(
cfg.best_checkpoint_metric, suffix
),
)
if len(chkpts) > 0:
p = chkpts[-1] if cfg.maximize_best_checkpoint_metric else chkpts[0]
worst_best = float(p.rsplit("_")[-1].replace("{}.pt".format(suffix), ""))
# add random digits to resolve ties
with data_utils.numpy_seed(epoch, updates, val_loss):
rand_sfx = np.random.randint(0, cfg.keep_best_checkpoints)
checkpoint_conds[
"checkpoint.best_{}_{:.3f}{}{}.pt".format(
cfg.best_checkpoint_metric, val_loss, rand_sfx, suffix
)
] = worst_best is None or is_better(val_loss, worst_best)
checkpoint_conds[
"checkpoint_last{}.pt".format(suffix)
] = not cfg.no_last_checkpoints
extra_state = {
"train_iterator": epoch_itr.state_dict(),
"val_loss": val_loss,
}
# Going forward, different tasks could expose an API like this to dump all
# the checkpoint worthy attributes in a dictionary which then will be
# merged with the parent dictionary to create the "extra_state". This
# allows for an extensible yet simple design to checkpoint task level
# attributes
if hasattr(trainer.task, "get_checkpoint_dict"):
extra_state = {**extra_state, **trainer.task.get_checkpoint_dict()}
logger.info(f"State of {trainer.task.__class__.__name__} is ready to be persisted with the checkpoint")
if hasattr(save_checkpoint, "best"):
extra_state.update({"best": save_checkpoint.best})
checkpoints = [
os.path.join(cfg.save_dir, fn) for fn, cond in checkpoint_conds.items() if cond
]
saved_cp = None
if len(checkpoints) > 0 and trainer.should_save_checkpoint_on_current_rank:
saved_cp = trainer.save_checkpoint(checkpoints[0], extra_state)
for cp in checkpoints[1:]:
if cfg.write_checkpoints_asynchronously:
# TODO[ioPath]: Need to implement a delayed asynchronous
# file copying/moving feature.
logger.warning(
f"ioPath is not copying {checkpoints[0]} to {cp} "
"since async write mode is on."
)
else:
assert PathManager.copy(
checkpoints[0], cp, overwrite=True
), f"Failed to copy {checkpoints[0]} to {cp}"
write_timer.stop()
logger.info(
"Saved checkpoint {} (epoch {} @ {} updates, score {}) (writing took {} seconds)".format(
checkpoints[0], epoch, updates, val_loss, write_timer.sum
)
)
if (
not end_of_epoch
and cfg.keep_interval_updates > 0
and trainer.should_save_checkpoint_on_current_rank
):
# remove old checkpoints; checkpoints are sorted in descending order
if cfg.keep_interval_updates_pattern == -1:
checkpoints = checkpoint_paths(
cfg.save_dir, pattern=r"checkpoint_\d+_(\d+){}\.pt".format(suffix)
)
else:
checkpoints = checkpoint_paths(
cfg.save_dir,
pattern=r"checkpoint_\d+_(\d+){}\.pt".format(suffix),
keep_match=True,
)
checkpoints = [
x[0]
for x in checkpoints
if x[1] % cfg.keep_interval_updates_pattern != 0
]
for old_chk in checkpoints[cfg.keep_interval_updates :]:
if os.path.lexists(old_chk):
os.remove(old_chk)
elif PathManager.exists(old_chk):
PathManager.rm(old_chk)
if cfg.keep_last_epochs > 0 and trainer.should_save_checkpoint_on_current_rank:
# remove old epoch checkpoints; checkpoints are sorted in descending order
checkpoints = checkpoint_paths(
cfg.save_dir, pattern=r"checkpoint(\d+){}\.pt".format(suffix)
)
for old_chk in checkpoints[cfg.keep_last_epochs :]:
if os.path.lexists(old_chk):
os.remove(old_chk)
elif PathManager.exists(old_chk):
PathManager.rm(old_chk)
if cfg.keep_best_checkpoints > 0 and trainer.should_save_checkpoint_on_current_rank:
# only keep the best N checkpoints according to validation metric
checkpoints = checkpoint_paths(
cfg.save_dir,
pattern=r"checkpoint\.best_{}_(\d+\.?\d*){}\.pt".format(
cfg.best_checkpoint_metric, suffix
),
)
if not cfg.maximize_best_checkpoint_metric:
checkpoints = checkpoints[::-1]
for old_chk in checkpoints[cfg.keep_best_checkpoints :]:
if os.path.lexists(old_chk):
os.remove(old_chk)
elif PathManager.exists(old_chk):
PathManager.rm(old_chk)
return saved_cp
def load_checkpoint(cfg: CheckpointConfig, trainer, **passthrough_args):
"""
Load a checkpoint and restore the training iterator.
*passthrough_args* will be passed through to
``trainer.get_train_iterator``.
"""
reset_optimizer = cfg.reset_optimizer
reset_lr_scheduler = cfg.reset_lr_scheduler
optimizer_overrides = ast.literal_eval(cfg.optimizer_overrides)
reset_meters = cfg.reset_meters
reset_dataloader = cfg.reset_dataloader
if cfg.finetune_from_model is not None and (
reset_optimizer or reset_lr_scheduler or reset_meters or reset_dataloader
):
raise ValueError(
"--finetune-from-model can not be set together with either --reset-optimizer"
" or reset_lr_scheduler or reset_meters or reset_dataloader"
)
suffix = trainer.checkpoint_suffix
if (
cfg.restore_file == "checkpoint_last.pt"
): # default value of restore_file is 'checkpoint_last.pt'
checkpoint_path = os.path.join(
cfg.save_dir, "checkpoint_last{}.pt".format(suffix)
)
first_launch = not PathManager.exists(checkpoint_path)
if first_launch and getattr(cfg, "continue_once", None) is not None:
checkpoint_path = cfg.continue_once
elif cfg.finetune_from_model is not None and first_launch:
# if there is no last checkpoint to restore, start the finetune from pretrained model
# else just use usual logic to load checkpoint, e.g. restart from last checkpoint and etc.
if PathManager.exists(cfg.finetune_from_model):
checkpoint_path = cfg.finetune_from_model
reset_optimizer = True
reset_lr_scheduler = True
reset_meters = True
reset_dataloader = True
logger.info(
f"loading pretrained model from {checkpoint_path}: "
"optimizer, lr scheduler, meters, dataloader will be reset"
)
else:
raise ValueError(
f"--finetune-from-model {cfg.finetune_from_model} does not exist"
)
elif suffix is not None:
checkpoint_path = cfg.restore_file.replace(".pt", suffix + ".pt")
else:
checkpoint_path = cfg.restore_file
if cfg.restore_file != "checkpoint_last.pt" and cfg.finetune_from_model:
raise ValueError(
"--finetune-from-model and --restore-file (non-default value) "
"can not be specified together: " + str(cfg)
)
extra_state = trainer.load_checkpoint(
checkpoint_path,
reset_optimizer,
reset_lr_scheduler,
optimizer_overrides,
reset_meters=reset_meters,
)
if (
extra_state is not None
and "best" in extra_state
and not reset_optimizer
and not reset_meters
):
save_checkpoint.best = extra_state["best"]
if extra_state is not None and not reset_dataloader:
# restore iterator from checkpoint
itr_state = extra_state["train_iterator"]
epoch_itr = trainer.get_train_iterator(
epoch=itr_state["epoch"], load_dataset=True, **passthrough_args
)
epoch_itr.load_state_dict(itr_state)
# Preload the checkpoint for the task
task_cp_dict = extra_state.get(trainer.task.__class__.__name__, {})
if task_cp_dict and hasattr(trainer.task, "set_checkpoint_dict"):
trainer.task.set_checkpoint_dict(task_cp_dict)
else:
epoch_itr = trainer.get_train_iterator(
epoch=1, load_dataset=True, **passthrough_args
)
trainer.lr_step(epoch_itr.epoch)
return extra_state, epoch_itr
def load_checkpoint_to_cpu(path, arg_overrides=None, load_on_all_ranks=False):
"""Loads a checkpoint to CPU (with upgrading for backward compatibility).
If doing single-GPU training or if the checkpoint is only being loaded by at
most one process on each node (current default behavior is for only rank 0
to read the checkpoint from disk), load_on_all_ranks should be False to
avoid errors from torch.distributed not having been initialized or
torch.distributed.barrier() hanging.
If all processes on each node may be loading the checkpoint
simultaneously, load_on_all_ranks should be set to True to avoid I/O
conflicts.
There's currently no support for > 1 but < all processes loading the
checkpoint on each node.
"""
local_path = PathManager.get_local_path(path)
# The locally cached file returned by get_local_path() may be stale for
# remote files that are periodically updated/overwritten (ex:
# checkpoint_last.pt) - so we remove the local copy, sync across processes
# (if needed), and then download a fresh copy.
if local_path != path and PathManager.path_requires_pathmanager(path):
try:
os.remove(local_path)
except FileNotFoundError:
# With potentially multiple processes removing the same file, the
# file being missing is benign (missing_ok isn't available until
# Python 3.8).
pass
if load_on_all_ranks:
torch.distributed.barrier()
local_path = PathManager.get_local_path(path)
with open(local_path, "rb") as f:
state = torch.load(f, map_location=torch.device("cpu"))
if "args" in state and state["args"] is not None and arg_overrides is not None:
args = state["args"]
for arg_name, arg_val in arg_overrides.items():
setattr(args, arg_name, arg_val)
if "cfg" in state and state["cfg"] is not None:
# hack to be able to set Namespace in dict config. this should be removed when we update to newer
# omegaconf version that supports object flags, or when we migrate all existing models
from omegaconf import __version__ as oc_version
from omegaconf import _utils
if oc_version < "2.2":
old_primitive = _utils.is_primitive_type
_utils.is_primitive_type = lambda _: True
state["cfg"] = OmegaConf.create(state["cfg"])
_utils.is_primitive_type = old_primitive
OmegaConf.set_struct(state["cfg"], True)
else:
state["cfg"] = OmegaConf.create(state["cfg"], flags={"allow_objects": True})
if arg_overrides is not None:
overwrite_args_by_name(state["cfg"], arg_overrides)
state = _upgrade_state_dict(state)
return state
def load_model_ensemble(
filenames,
arg_overrides: Optional[Dict[str, Any]] = None,
task=None,
strict=True,
suffix="",
num_shards=1,
state=None,
):
"""Loads an ensemble of models.
Args:
filenames (List[str]): checkpoint files to load
arg_overrides (Dict[str,Any], optional): override model args that
were used during model training
task (fairseq.tasks.FairseqTask, optional): task to use for loading
"""
assert not (
strict and num_shards > 1
), "Cannot load state dict with strict=True and checkpoint shards > 1"
ensemble, args, _task = load_model_ensemble_and_task(
filenames,
arg_overrides,
task,
strict,
suffix,
num_shards,
state,
)
return ensemble, args
def get_maybe_sharded_checkpoint_filename(
filename: str, suffix: str, shard_idx: int, num_shards: int
) -> str:
orig_filename = filename
filename = filename.replace(".pt", suffix + ".pt")
fsdp_filename = filename[:-3] + f"-shard{shard_idx}.pt"
model_parallel_filename = orig_filename[:-3] + f"_part{shard_idx}.pt"
if PathManager.exists(fsdp_filename):
return fsdp_filename
elif num_shards > 1:
return model_parallel_filename
else:
return filename
def load_model_ensemble_and_task(
filenames,
arg_overrides: Optional[Dict[str, Any]] = None,
task=None,
strict=True,
suffix="",
num_shards=1,
state=None,
):
assert state is None or len(filenames) == 1
from fairseq import tasks
assert not (
strict and num_shards > 1
), "Cannot load state dict with strict=True and checkpoint shards > 1"
ensemble = []
cfg = None
for filename in filenames:
orig_filename = filename
model_shard_state = {"shard_weights": [], "shard_metadata": []}
assert num_shards > 0
st = time.time()
for shard_idx in range(num_shards):
filename = get_maybe_sharded_checkpoint_filename(
orig_filename, suffix, shard_idx, num_shards
)
if not PathManager.exists(filename):
raise IOError("Model file not found: {}".format(filename))
if state is None:
state = load_checkpoint_to_cpu(filename, arg_overrides)
if "args" in state and state["args"] is not None:
cfg = convert_namespace_to_omegaconf(state["args"])
elif "cfg" in state and state["cfg"] is not None:
cfg = state["cfg"]
else:
raise RuntimeError(
f"Neither args nor cfg exist in state keys = {state.keys()}"
)
if task is None:
task = tasks.setup_task(cfg.task, from_checkpoint=True)
if "task_state" in state:
task.load_state_dict(state["task_state"])
argspec = inspect.getfullargspec(task.build_model)
if "fsdp_metadata" in state and num_shards > 1:
model_shard_state["shard_weights"].append(state["model"])
model_shard_state["shard_metadata"].append(state["fsdp_metadata"])
# check FSDP import before the code goes too far
if not has_FSDP:
raise ImportError(
"Cannot find FullyShardedDataParallel. "
"Please install fairscale with: pip install fairscale"
)
if shard_idx == num_shards - 1:
consolidated_model_state = FSDP.consolidate_shard_weights(
shard_weights=model_shard_state["shard_weights"],
shard_metadata=model_shard_state["shard_metadata"],
)
if "from_checkpoint" in argspec.args:
model = task.build_model(cfg.model, from_checkpoint=True)
else:
model = task.build_model(cfg.model)
if (
"optimizer_history" in state
and len(state["optimizer_history"]) > 0
and "num_updates" in state["optimizer_history"][-1]
):
model.set_num_updates(
state["optimizer_history"][-1]["num_updates"]
)
model.load_state_dict(
consolidated_model_state, strict=strict, model_cfg=cfg.model
)
else:
# model parallel checkpoint or unsharded checkpoint
# support old external tasks
if "from_checkpoint" in argspec.args:
model = task.build_model(cfg.model, from_checkpoint=True)
else:
model = task.build_model(cfg.model)
if (
"optimizer_history" in state
and len(state["optimizer_history"]) > 0
and "num_updates" in state["optimizer_history"][-1]
):
model.set_num_updates(state["optimizer_history"][-1]["num_updates"])
model.load_state_dict(
state["model"], strict=strict, model_cfg=cfg.model
)
# reset state so it gets loaded for the next model in ensemble
state = None
if shard_idx % 10 == 0 and shard_idx > 0:
elapsed = time.time() - st
logger.info(
f"Loaded {shard_idx} shards in {elapsed:.2f}s, {elapsed / (shard_idx+1):.2f}s/shard"
)
# build model for ensemble
ensemble.append(model)
return ensemble, cfg, task
def load_model_ensemble_and_task_from_hf_hub(
model_id,
cache_dir: Optional[str] = None,
arg_overrides: Optional[Dict[str, Any]] = None,
**kwargs: Any,
):
try:
from huggingface_hub import snapshot_download
except ImportError:
raise ImportError(
"You need to install huggingface_hub to use `load_from_hf_hub`. "
"See https://pypi.org/project/huggingface-hub/ for installation."
)
library_name = "fairseq"
cache_dir = cache_dir or (Path.home() / ".cache" / library_name).as_posix()
cache_dir = snapshot_download(
model_id, cache_dir=cache_dir, library_name=library_name, **kwargs
)
_arg_overrides = arg_overrides or {}
_arg_overrides["data"] = cache_dir
return load_model_ensemble_and_task(
[p.as_posix() for p in Path(cache_dir).glob("*.pt")],
arg_overrides=_arg_overrides,
)
def checkpoint_paths(path, pattern=r"checkpoint(\d+)\.pt", keep_match=False):
"""Retrieves all checkpoints found in `path` directory.
Checkpoints are identified by matching filename to the specified pattern. If
the pattern contains groups, the result will be sorted by the first group in
descending order.
"""
pt_regexp = re.compile(pattern)
files = PathManager.ls(path)
entries = []
for i, f in enumerate(files):
m = pt_regexp.fullmatch(f)
if m is not None:
idx = float(m.group(1)) if len(m.groups()) > 0 else i
entries.append((idx, m.group(0)))
if keep_match:
return [(os.path.join(path, x[1]), x[0]) for x in sorted(entries, reverse=True)]
else:
return [os.path.join(path, x[1]) for x in sorted(entries, reverse=True)]
def torch_persistent_save(obj, filename, async_write: bool = False):
if async_write:
with PathManager.opena(filename, "wb") as f:
_torch_persistent_save(obj, f)
else:
if PathManager.supports_rename(filename):
# do atomic save
with PathManager.open(filename + ".tmp", "wb") as f:
_torch_persistent_save(obj, f)
PathManager.rename(filename + ".tmp", filename)
else:
# fallback to non-atomic save
with PathManager.open(filename, "wb") as f:
_torch_persistent_save(obj, f)
def _torch_persistent_save(obj, f):
if isinstance(f, str):
with PathManager.open(f, "wb") as h:
torch_persistent_save(obj, h)
return
for i in range(3):
try:
return torch.save(obj, f)
except Exception:
if i == 2:
logger.error(traceback.format_exc())
raise
else:
time.sleep(2.5)
def _upgrade_state_dict(state):
"""Helper for upgrading old model checkpoints."""
# add optimizer_history
if "optimizer_history" not in state:
state["optimizer_history"] = [
{"criterion_name": "CrossEntropyCriterion", "best_loss": state["best_loss"]}
]
state["last_optimizer_state"] = state["optimizer"]
del state["optimizer"]
del state["best_loss"]
# move extra_state into sub-dictionary
if "epoch" in state and "extra_state" not in state:
state["extra_state"] = {
"epoch": state["epoch"],
"batch_offset": state["batch_offset"],
"val_loss": state["val_loss"],
}
del state["epoch"]
del state["batch_offset"]
del state["val_loss"]
# reduce optimizer history's memory usage (only keep the last state)
if "optimizer" in state["optimizer_history"][-1]:
state["last_optimizer_state"] = state["optimizer_history"][-1]["optimizer"]
for optim_hist in state["optimizer_history"]:
del optim_hist["optimizer"]
# record the optimizer class name
if "optimizer_name" not in state["optimizer_history"][-1]:
state["optimizer_history"][-1]["optimizer_name"] = "FairseqNAG"
# move best_loss into lr_scheduler_state
if "lr_scheduler_state" not in state["optimizer_history"][-1]:
state["optimizer_history"][-1]["lr_scheduler_state"] = {
"best": state["optimizer_history"][-1]["best_loss"]
}
del state["optimizer_history"][-1]["best_loss"]
# keep track of number of updates
if "num_updates" not in state["optimizer_history"][-1]:
state["optimizer_history"][-1]["num_updates"] = 0
# use stateful training data iterator
if "train_iterator" not in state["extra_state"]:
state["extra_state"]["train_iterator"] = {
"epoch": state["extra_state"].get("epoch", 0),
"iterations_in_epoch": state["extra_state"].get("batch_offset", 0),
}
# backward compatibility, cfg updates
if "args" in state and state["args"] is not None:
# old model checkpoints may not have separate source/target positions
if hasattr(state["args"], "max_positions") and not hasattr(
state["args"], "max_source_positions"
):
state["args"].max_source_positions = state["args"].max_positions
state["args"].max_target_positions = state["args"].max_positions
# default to translation task
if not hasattr(state["args"], "task"):
state["args"].task = "translation"
# --raw-text and --lazy-load are deprecated
if getattr(state["args"], "raw_text", False):
state["args"].dataset_impl = "raw"
elif getattr(state["args"], "lazy_load", False):
state["args"].dataset_impl = "lazy"
# epochs start at 1
if state["extra_state"]["train_iterator"] is not None:
state["extra_state"]["train_iterator"]["epoch"] = max(
state["extra_state"]["train_iterator"].get("epoch", 1), 1
)
# --remove-bpe ==> --postprocess
if hasattr(state["args"], "remove_bpe"):
state["args"].post_process = state["args"].remove_bpe
# --min-lr ==> --stop-min-lr
if hasattr(state["args"], "min_lr"):
state["args"].stop_min_lr = state["args"].min_lr
del state["args"].min_lr
# binary_cross_entropy / kd_binary_cross_entropy => wav2vec criterion
if hasattr(state["args"], "criterion") and state["args"].criterion in [
"binary_cross_entropy",
"kd_binary_cross_entropy",
]:
state["args"].criterion = "wav2vec"
# remove log_keys if it's None (criteria will supply a default value of [])
if hasattr(state["args"], "log_keys") and state["args"].log_keys is None:
delattr(state["args"], "log_keys")
# speech_pretraining => audio pretraining
if (
hasattr(state["args"], "task")
and state["args"].task == "speech_pretraining"
):
state["args"].task = "audio_pretraining"
# audio_cpc => wav2vec
if hasattr(state["args"], "arch") and state["args"].arch == "audio_cpc":
state["args"].arch = "wav2vec"
# convert legacy float learning rate to List[float]
if hasattr(state["args"], "lr") and isinstance(state["args"].lr, float):
state["args"].lr = [state["args"].lr]
# convert task data arg to a string instead of List[string]
if (
hasattr(state["args"], "data")
and isinstance(state["args"].data, list)
and len(state["args"].data) > 0
):
state["args"].data = state["args"].data[0]
state["cfg"] = convert_namespace_to_omegaconf(state["args"])
if "cfg" in state and state["cfg"] is not None:
cfg = state["cfg"]
with open_dict(cfg):
# any upgrades for Hydra-based configs
if (
"task" in cfg
and "eval_wer_config" in cfg.task
and isinstance(cfg.task.eval_wer_config.print_alignment, bool)
):
cfg.task.eval_wer_config.print_alignment = "hard"
if "generation" in cfg and isinstance(cfg.generation.print_alignment, bool):
cfg.generation.print_alignment = (
"hard" if cfg.generation.print_alignment else None
)
if (
"model" in cfg
and "w2v_args" in cfg.model
and cfg.model.w2v_args is not None
and (
hasattr(cfg.model.w2v_args, "task") or "task" in cfg.model.w2v_args
)
and hasattr(cfg.model.w2v_args.task, "eval_wer_config")
and cfg.model.w2v_args.task.eval_wer_config is not None
and isinstance(
cfg.model.w2v_args.task.eval_wer_config.print_alignment, bool
)
):
cfg.model.w2v_args.task.eval_wer_config.print_alignment = "hard"
return state
def prune_state_dict(state_dict, model_cfg: Optional[DictConfig]):
"""Prune the given state_dict if desired for LayerDrop
(https://arxiv.org/abs/1909.11556).
Training with LayerDrop allows models to be robust to pruning at inference
time. This function prunes state_dict to allow smaller models to be loaded
from a larger model and re-maps the existing state_dict for this to occur.
It's called by functions that load models from checkpoints and does not
need to be called directly.
"""
arch = None
if model_cfg is not None:
arch = (
model_cfg._name
if isinstance(model_cfg, DictConfig)
else getattr(model_cfg, "arch", None)
)
if not model_cfg or arch is None or arch == "ptt_transformer":
# args should not be none, but don't crash if it is.
return state_dict
encoder_layers_to_keep = getattr(model_cfg, "encoder_layers_to_keep", None)
decoder_layers_to_keep = getattr(model_cfg, "decoder_layers_to_keep", None)
if not encoder_layers_to_keep and not decoder_layers_to_keep:
return state_dict
# apply pruning
logger.info(
"Pruning model to specified layer configuration - this works best if the model was trained with LayerDrop"
)
def create_pruning_pass(layers_to_keep, layer_name):
keep_layers = sorted(
int(layer_string) for layer_string in layers_to_keep.split(",")
)
mapping_dict = {}
for i in range(len(keep_layers)):
mapping_dict[str(keep_layers[i])] = str(i)
regex = re.compile(r"^{layer}.*\.layers\.(\d+)".format(layer=layer_name))
return {"substitution_regex": regex, "mapping_dict": mapping_dict}
pruning_passes = []
if encoder_layers_to_keep:
pruning_passes.append(create_pruning_pass(encoder_layers_to_keep, "encoder"))
if decoder_layers_to_keep:
pruning_passes.append(create_pruning_pass(decoder_layers_to_keep, "decoder"))
new_state_dict = {}
for layer_name in state_dict.keys():
match = re.search(r"\.layers\.(\d+)\.", layer_name)
# if layer has no number in it, it is a supporting layer, such as an
# embedding
if not match:
new_state_dict[layer_name] = state_dict[layer_name]
continue
# otherwise, layer should be pruned.
original_layer_number = match.group(1)
# figure out which mapping dict to replace from
for pruning_pass in pruning_passes:
if original_layer_number in pruning_pass["mapping_dict"] and pruning_pass[
"substitution_regex"
].search(layer_name):
new_layer_number = pruning_pass["mapping_dict"][original_layer_number]
substitution_match = pruning_pass["substitution_regex"].search(
layer_name
)
new_state_key = (
layer_name[: substitution_match.start(1)]
+ new_layer_number
+ layer_name[substitution_match.end(1) :]
)
new_state_dict[new_state_key] = state_dict[layer_name]
# Since layers are now pruned, *_layers_to_keep are no longer needed.
# This is more of "It would make it work fix" rather than a proper fix.
if isinstance(model_cfg, DictConfig):
context = open_dict(model_cfg)
else:
context = contextlib.ExitStack()
with context:
if hasattr(model_cfg, "encoder_layers_to_keep"):
model_cfg.encoder_layers_to_keep = None
if hasattr(model_cfg, "decoder_layers_to_keep"):
model_cfg.decoder_layers_to_keep = None
return new_state_dict
def load_pretrained_component_from_model(
component: Union[FairseqEncoder, FairseqDecoder],
checkpoint: str,
strict: bool = True,
):
"""
Load a pretrained FairseqEncoder or FairseqDecoder from checkpoint into the
provided `component` object. If state_dict fails to load, there may be a
mismatch in the architecture of the corresponding `component` found in the
`checkpoint` file.
"""
if not PathManager.exists(checkpoint):
raise IOError("Model file not found: {}".format(checkpoint))
state = load_checkpoint_to_cpu(checkpoint)
if isinstance(component, FairseqEncoder):
component_type = "encoder"
elif isinstance(component, FairseqDecoder):
component_type = "decoder"
else:
raise ValueError(
"component to load must be either a FairseqEncoder or "
"FairseqDecoder. Loading other component types are not supported."
)
component_state_dict = OrderedDict()
for key in state["model"].keys():
if key.startswith(component_type):
# encoder.input_layers.0.0.weight --> input_layers.0.0.weight
component_subkey = key[len(component_type) + 1 :]
component_state_dict[component_subkey] = state["model"][key]
component.load_state_dict(component_state_dict, strict=strict)
return component
def verify_checkpoint_directory(save_dir: str) -> None:
if not os.path.exists(save_dir):
os.makedirs(save_dir, exist_ok=True)
temp_file_path = os.path.join(save_dir, "dummy")
try:
with open(temp_file_path, "w"):
pass
except OSError as e:
logger.warning(
"Unable to access checkpoint save directory: {}".format(save_dir)
)
raise e
else:
os.remove(temp_file_path)
def save_ema_as_checkpoint(src_path, dst_path):
state = load_ema_from_checkpoint(src_path)
torch_persistent_save(state, dst_path)
def load_ema_from_checkpoint(fpath):
"""Loads exponential moving averaged (EMA) checkpoint from input and
returns a model with ema weights.
Args:
fpath: A string path of checkpoint to load from.
Returns:
A dict of string keys mapping to various values. The 'model' key
from the returned dict should correspond to an OrderedDict mapping
string parameter names to torch Tensors.
"""
params_dict = collections.OrderedDict()
new_state = None
with PathManager.open(fpath, "rb") as f:
new_state = torch.load(
f,
map_location=(
lambda s, _: torch.serialization.default_restore_location(s, "cpu")
),
)
# EMA model is stored in a separate "extra state"
model_params = new_state["extra_state"]["ema"]
for key in list(model_params.keys()):
p = model_params[key]
if isinstance(p, torch.HalfTensor):
p = p.float()
if key not in params_dict:
params_dict[key] = p.clone()
# NOTE: clone() is needed in case of p is a shared parameter
else:
raise ValueError("Key {} is repeated in EMA model params.".format(key))
if len(params_dict) == 0:
raise ValueError(
f"Input checkpoint path '{fpath}' does not contain "
"ema model weights, is this model trained with EMA?"
)
new_state["model"] = params_dict
return new_state