spaCy/spacy/syntax/nn_parser.pyx
2020-05-21 18:39:06 +02:00

700 lines
29 KiB
Cython

# cython: infer_types=True, cdivision=True, boundscheck=False
cimport cython.parallel
cimport numpy as np
from cpython.ref cimport PyObject, Py_XDECREF
from cpython.exc cimport PyErr_CheckSignals, PyErr_SetFromErrno
from libc.math cimport exp
from libcpp.vector cimport vector
from libc.string cimport memset, memcpy
from libc.stdlib cimport calloc, free
from cymem.cymem cimport Pool
from thinc.extra.search cimport Beam
from thinc.backends.linalg cimport Vec, VecVec
from thinc.api import chain, clone, Linear, list2array, NumpyOps, CupyOps, use_ops
from thinc.api import get_array_module, zero_init, set_dropout_rate
from itertools import islice
import srsly
import numpy.random
import numpy
import warnings
from ..tokens.doc cimport Doc
from ..gold cimport GoldParse
from ..typedefs cimport weight_t, class_t, hash_t
from ._parser_model cimport alloc_activations, free_activations
from ._parser_model cimport predict_states, arg_max_if_valid
from ._parser_model cimport WeightsC, ActivationsC, SizesC, cpu_log_loss
from ._parser_model cimport get_c_weights, get_c_sizes
from .stateclass cimport StateClass
from ._state cimport StateC
from .transition_system cimport Transition
from . cimport _beam_utils
from ..gold import Example
from ..util import link_vectors_to_models, create_default_optimizer, registry
from ..compat import copy_array
from ..errors import Errors, Warnings
from .. import util
from . import _beam_utils
from . import nonproj
cdef class Parser:
"""
Base class of the DependencyParser and EntityRecognizer.
"""
name = 'base_parser'
def __init__(self, Vocab vocab, model, **cfg):
"""Create a Parser.
vocab (Vocab): The vocabulary object. Must be shared with documents
to be processed. The value is set to the `.vocab` attribute.
**cfg: Configuration parameters. Set to the `.cfg` attribute.
If it doesn't include a value for 'moves', a new instance is
created with `self.TransitionSystem()`. This defines how the
parse-state is created, updated and evaluated.
"""
self.vocab = vocab
moves = cfg.get("moves", None)
if moves is None:
# defined by EntityRecognizer as a BiluoPushDown
moves = self.TransitionSystem(self.vocab.strings)
self.moves = moves
cfg.setdefault('min_action_freq', 30)
cfg.setdefault('learn_tokens', False)
cfg.setdefault('beam_width', 1)
cfg.setdefault('beam_update_prob', 1.0) # or 0.5 (both defaults were previously used)
self.model = model
if self.moves.n_moves != 0:
self.set_output(self.moves.n_moves)
self.cfg = cfg
self._multitasks = []
self._rehearsal_model = None
@classmethod
def from_nlp(cls, nlp, model, **cfg):
return cls(nlp.vocab, model, **cfg)
def __reduce__(self):
return (Parser, (self.vocab, self.model), self.moves)
def __getstate__(self):
return self.moves
def __setstate__(self, moves):
self.moves = moves
@property
def move_names(self):
names = []
for i in range(self.moves.n_moves):
name = self.moves.move_name(self.moves.c[i].move, self.moves.c[i].label)
# Explicitly removing the internal "U-" token used for blocking entities
if name != "U-":
names.append(name)
return names
@property
def labels(self):
class_names = [self.moves.get_class_name(i) for i in range(self.moves.n_moves)]
return class_names
@property
def tok2vec(self):
'''Return the embedding and convolutional layer of the model.'''
return self.model.get_ref("tok2vec")
@property
def postprocesses(self):
# Available for subclasses, e.g. to deprojectivize
return []
def add_label(self, label):
resized = False
for action in self.moves.action_types:
added = self.moves.add_action(action, label)
if added:
resized = True
if resized:
self._resize()
def _resize(self):
self.model.attrs["resize_output"](self.model, self.moves.n_moves)
if self._rehearsal_model not in (True, False, None):
self._rehearsal_model.attrs["resize_output"](
self._rehearsal_model, self.moves.n_moves
)
def add_multitask_objective(self, target):
# Defined in subclasses, to avoid circular import
raise NotImplementedError
def init_multitask_objectives(self, get_examples, pipeline, **cfg):
'''Setup models for secondary objectives, to benefit from multi-task
learning. This method is intended to be overridden by subclasses.
For instance, the dependency parser can benefit from sharing
an input representation with a label prediction model. These auxiliary
models are discarded after training.
'''
pass
def preprocess_gold(self, examples):
for ex in examples:
yield ex
def use_params(self, params):
# Can't decorate cdef class :(. Workaround.
with self.model.use_params(params):
yield
def __call__(self, Doc doc, beam_width=None):
"""Apply the parser or entity recognizer, setting the annotations onto
the `Doc` object.
doc (Doc): The document to be processed.
"""
if beam_width is None:
beam_width = self.cfg['beam_width']
beam_density = self.cfg.get('beam_density', 0.)
states = self.predict([doc], beam_width=beam_width,
beam_density=beam_density)
self.set_annotations([doc], states, tensors=None)
return doc
def pipe(self, docs, int batch_size=256, int n_threads=-1, beam_width=None,
as_example=False):
"""Process a stream of documents.
stream: The sequence of documents to process.
batch_size (int): Number of documents to accumulate into a working set.
YIELDS (Doc): Documents, in order.
"""
if beam_width is None:
beam_width = self.cfg['beam_width']
beam_density = self.cfg.get('beam_density', 0.)
cdef Doc doc
for batch in util.minibatch(docs, size=batch_size):
batch_in_order = list(batch)
docs = [self._get_doc(ex) for ex in batch_in_order]
by_length = sorted(docs, key=lambda doc: len(doc))
for subbatch in util.minibatch(by_length, size=max(batch_size//4, 2)):
subbatch = list(subbatch)
parse_states = self.predict(subbatch, beam_width=beam_width,
beam_density=beam_density)
self.set_annotations(subbatch, parse_states, tensors=None)
if as_example:
annotated_examples = []
for ex, doc in zip(batch_in_order, docs):
ex.doc = doc
annotated_examples.append(ex)
yield from annotated_examples
else:
yield from batch_in_order
def predict(self, docs, beam_width=1, beam_density=0.0, drop=0.):
if isinstance(docs, Doc):
docs = [docs]
if not any(len(doc) for doc in docs):
result = self.moves.init_batch(docs)
self._resize()
return result
if beam_width < 2:
return self.greedy_parse(docs, drop=drop)
else:
return self.beam_parse(docs, beam_width=beam_width,
beam_density=beam_density, drop=drop)
def greedy_parse(self, docs, drop=0.):
cdef vector[StateC*] states
cdef StateClass state
set_dropout_rate(self.model, drop)
batch = self.moves.init_batch(docs)
# This is pretty dirty, but the NER can resize itself in init_batch,
# if labels are missing. We therefore have to check whether we need to
# expand our model output.
self._resize()
model = self.model.predict(docs)
weights = get_c_weights(model)
for state in batch:
if not state.is_final():
states.push_back(state.c)
sizes = get_c_sizes(model, states.size())
with nogil:
self._parseC(&states[0],
weights, sizes)
return batch
def beam_parse(self, docs, int beam_width, float drop=0., beam_density=0.):
cdef Beam beam
cdef Doc doc
cdef np.ndarray token_ids
set_dropout_rate(self.model, drop)
beams = self.moves.init_beams(docs, beam_width, beam_density=beam_density)
# This is pretty dirty, but the NER can resize itself in init_batch,
# if labels are missing. We therefore have to check whether we need to
# expand our model output.
self._resize()
cdef int nr_feature = self.model.get_ref("lower").get_dim("nF")
model = self.model.predict(docs)
token_ids = numpy.zeros((len(docs) * beam_width, nr_feature),
dtype='i', order='C')
cdef int* c_ids
cdef int n_states
model = self.model.predict(docs)
todo = [beam for beam in beams if not beam.is_done]
while todo:
token_ids.fill(-1)
c_ids = <int*>token_ids.data
n_states = 0
for beam in todo:
for i in range(beam.size):
state = <StateC*>beam.at(i)
# This way we avoid having to score finalized states
# We do have to take care to keep indexes aligned, though
if not state.is_final():
state.set_context_tokens(c_ids, nr_feature)
c_ids += nr_feature
n_states += 1
if n_states == 0:
break
vectors = model.state2vec.predict(token_ids[:n_states])
scores = model.vec2scores.predict(vectors)
todo = self.transition_beams(todo, scores)
return beams
cdef void _parseC(self, StateC** states,
WeightsC weights, SizesC sizes) nogil:
cdef int i, j
cdef vector[StateC*] unfinished
cdef ActivationsC activations = alloc_activations(sizes)
while sizes.states >= 1:
predict_states(&activations,
states, &weights, sizes)
# Validate actions, argmax, take action.
self.c_transition_batch(states,
activations.scores, sizes.classes, sizes.states)
for i in range(sizes.states):
if not states[i].is_final():
unfinished.push_back(states[i])
for i in range(unfinished.size()):
states[i] = unfinished[i]
sizes.states = unfinished.size()
unfinished.clear()
free_activations(&activations)
def set_annotations(self, docs, states_or_beams, tensors=None):
cdef StateClass state
cdef Beam beam
cdef Doc doc
states = []
beams = []
for state_or_beam in states_or_beams:
if isinstance(state_or_beam, StateClass):
states.append(state_or_beam)
else:
beam = state_or_beam
state = StateClass.borrow(<StateC*>beam.at(0))
states.append(state)
beams.append(beam)
for i, (state, doc) in enumerate(zip(states, docs)):
self.moves.finalize_state(state.c)
for j in range(doc.length):
doc.c[j] = state.c._sent[j]
self.moves.finalize_doc(doc)
for hook in self.postprocesses:
hook(doc)
for beam in beams:
_beam_utils.cleanup_beam(beam)
def transition_states(self, states, float[:, ::1] scores):
cdef StateClass state
cdef float* c_scores = &scores[0, 0]
cdef vector[StateC*] c_states
for state in states:
c_states.push_back(state.c)
self.c_transition_batch(&c_states[0], c_scores, scores.shape[1], scores.shape[0])
return [state for state in states if not state.c.is_final()]
cdef void c_transition_batch(self, StateC** states, const float* scores,
int nr_class, int batch_size) nogil:
# n_moves should not be zero at this point, but make sure to avoid zero-length mem alloc
with gil:
assert self.moves.n_moves > 0
is_valid = <int*>calloc(self.moves.n_moves, sizeof(int))
cdef int i, guess
cdef Transition action
for i in range(batch_size):
self.moves.set_valid(is_valid, states[i])
guess = arg_max_if_valid(&scores[i*nr_class], is_valid, nr_class)
if guess == -1:
# This shouldn't happen, but it's hard to raise an error here,
# and we don't want to infinite loop. So, force to end state.
states[i].force_final()
else:
action = self.moves.c[guess]
action.do(states[i], action.label)
states[i].push_hist(guess)
free(is_valid)
def transition_beams(self, beams, float[:, ::1] scores):
cdef Beam beam
cdef float* c_scores = &scores[0, 0]
for beam in beams:
for i in range(beam.size):
state = <StateC*>beam.at(i)
if not state.is_final():
self.moves.set_valid(beam.is_valid[i], state)
memcpy(beam.scores[i], c_scores, scores.shape[1] * sizeof(float))
c_scores += scores.shape[1]
beam.advance(_beam_utils.transition_state, _beam_utils.hash_state, <void*>self.moves.c)
beam.check_done(_beam_utils.check_final_state, NULL)
return [b for b in beams if not b.is_done]
def update(self, examples, drop=0., set_annotations=False, sgd=None, losses=None):
examples = Example.to_example_objects(examples)
if losses is None:
losses = {}
losses.setdefault(self.name, 0.)
for multitask in self._multitasks:
multitask.update(examples, drop=drop, sgd=sgd)
# The probability we use beam update, instead of falling back to
# a greedy update
beam_update_prob = self.cfg['beam_update_prob']
if self.cfg['beam_width'] >= 2 and numpy.random.random() < beam_update_prob:
return self.update_beam(examples, self.cfg['beam_width'],
drop=drop, sgd=sgd, losses=losses, set_annotations=set_annotations,
beam_density=self.cfg.get('beam_density', 0.001))
set_dropout_rate(self.model, drop)
cut_gold = True
if cut_gold:
# Chop sequences into lengths of this many transitions, to make the
# batch uniform length.
cut_gold = numpy.random.choice(range(20, 100))
states, golds, max_steps = self._init_gold_batch(examples, max_length=cut_gold)
else:
states, golds, max_steps = self._init_gold_batch_no_cut(examples)
states_golds = [(s, g) for (s, g) in zip(states, golds)
if not s.is_final() and g is not None]
# Prepare the stepwise model, and get the callback for finishing the batch
model, backprop_tok2vec = self.model.begin_update([ex.doc for ex in examples])
all_states = list(states)
for _ in range(max_steps):
if not states_golds:
break
states, golds = zip(*states_golds)
scores, backprop = model.begin_update(states)
d_scores = self.get_batch_loss(states, golds, scores, losses)
backprop(d_scores)
# Follow the predicted action
self.transition_states(states, scores)
states_golds = [eg for eg in states_golds if not eg[0].is_final()]
backprop_tok2vec(golds)
if sgd is not None:
self.model.finish_update(sgd)
if set_annotations:
docs = [ex.doc for ex in examples]
self.set_annotations(docs, all_states)
return losses
def rehearse(self, examples, sgd=None, losses=None, **cfg):
"""Perform a "rehearsal" update, to prevent catastrophic forgetting."""
examples = Example.to_example_objects(examples)
if losses is None:
losses = {}
for multitask in self._multitasks:
if hasattr(multitask, 'rehearse'):
multitask.rehearse(examples, losses=losses, sgd=sgd)
if self._rehearsal_model is None:
return None
losses.setdefault(self.name, 0.)
docs = [ex.doc for ex in examples]
states = self.moves.init_batch(docs)
# This is pretty dirty, but the NER can resize itself in init_batch,
# if labels are missing. We therefore have to check whether we need to
# expand our model output.
self._resize()
# Prepare the stepwise model, and get the callback for finishing the batch
set_dropout_rate(self._rehearsal_model, 0.0)
set_dropout_rate(self.model, 0.0)
tutor, _ = self._rehearsal_model.begin_update(docs)
model, finish_update = self.model.begin_update(docs)
n_scores = 0.
loss = 0.
while states:
targets, _ = tutor.begin_update(states)
guesses, backprop = model.begin_update(states)
d_scores = (guesses - targets) / targets.shape[0]
# If all weights for an output are 0 in the original model, don't
# supervise that output. This allows us to add classes.
loss += (d_scores**2).sum()
backprop(d_scores, sgd=sgd)
# Follow the predicted action
self.transition_states(states, guesses)
states = [state for state in states if not state.is_final()]
n_scores += d_scores.size
# Do the backprop
finish_update(docs)
if sgd is not None:
self.model.finish_update(sgd)
losses[self.name] += loss / n_scores
return losses
def update_beam(self, examples, width, drop=0., sgd=None, losses=None,
set_annotations=False, beam_density=0.0):
examples = Example.to_example_objects(examples)
docs = [ex.doc for ex in examples]
golds = [ex.gold for ex in examples]
new_golds = []
lengths = [len(d) for d in docs]
states = self.moves.init_batch(docs)
for gold in golds:
self.moves.preprocess_gold(gold)
new_golds.append(gold)
set_dropout_rate(self.model, drop)
model, backprop_tok2vec = self.model.begin_update(docs)
states_d_scores, backprops, beams = _beam_utils.update_beam(
self.moves,
self.model.get_ref("lower").get_dim("nF"),
10000,
states,
golds,
model.state2vec,
model.vec2scores,
width,
losses=losses,
beam_density=beam_density
)
for i, d_scores in enumerate(states_d_scores):
losses[self.name] += (d_scores**2).mean()
ids, bp_vectors, bp_scores = backprops[i]
d_vector = bp_scores(d_scores)
if isinstance(model.ops, CupyOps) \
and not isinstance(ids, model.state2vec.ops.xp.ndarray):
model.backprops.append((
util.get_async(model.cuda_stream, ids),
util.get_async(model.cuda_stream, d_vector),
bp_vectors))
else:
model.backprops.append((ids, d_vector, bp_vectors))
backprop_tok2vec(golds)
if sgd is not None:
self.model.finish_update(sgd)
if set_annotations:
self.set_annotations(docs, beams)
cdef Beam beam
for beam in beams:
_beam_utils.cleanup_beam(beam)
def get_gradients(self):
"""Get non-zero gradients of the model's parameters, as a dictionary
keyed by the parameter ID. The values are (weights, gradients) tuples.
"""
gradients = {}
queue = [self.model]
seen = set()
for node in queue:
if node.id in seen:
continue
seen.add(node.id)
if hasattr(node, "_mem") and node._mem.gradient.any():
gradients[node.id] = [node._mem.weights, node._mem.gradient]
if hasattr(node, "_layers"):
queue.extend(node._layers)
return gradients
def _init_gold_batch_no_cut(self, whole_examples):
states = self.moves.init_batch([eg.doc for eg in whole_examples])
good_docs = []
good_golds = []
good_states = []
for i, eg in enumerate(whole_examples):
doc = eg.doc
gold = self.moves.preprocess_gold(eg.gold)
if gold is not None and self.moves.has_gold(gold):
good_docs.append(doc)
good_golds.append(gold)
good_states.append(states[i])
n_moves = []
for doc, gold in zip(good_docs, good_golds):
oracle_actions = self.moves.get_oracle_sequence(doc, gold)
n_moves.append(len(oracle_actions))
return good_states, good_golds, max(n_moves, default=0) * 2
def _init_gold_batch(self, whole_examples, min_length=5, max_length=500):
"""Make a square batch, of length equal to the shortest doc. A long
doc will get multiple states. Let's say we have a doc of length 2*N,
where N is the shortest doc. We'll make two states, one representing
long_doc[:N], and another representing long_doc[N:]."""
cdef:
StateClass state
Transition action
whole_docs = [ex.doc for ex in whole_examples]
whole_golds = [ex.gold for ex in whole_examples]
whole_states = self.moves.init_batch(whole_docs)
max_length = max(min_length, min(max_length, min([len(doc) for doc in whole_docs])))
max_moves = 0
states = []
golds = []
for doc, state, gold in zip(whole_docs, whole_states, whole_golds):
gold = self.moves.preprocess_gold(gold)
if gold is None:
continue
oracle_actions = self.moves.get_oracle_sequence(doc, gold)
start = 0
while start < len(doc):
state = state.copy()
n_moves = 0
while state.B(0) < start and not state.is_final():
action = self.moves.c[oracle_actions.pop(0)]
action.do(state.c, action.label)
state.c.push_hist(action.clas)
n_moves += 1
has_gold = self.moves.has_gold(gold, start=start,
end=start+max_length)
if not state.is_final() and has_gold:
states.append(state)
golds.append(gold)
max_moves = max(max_moves, n_moves)
start += min(max_length, len(doc)-start)
max_moves = max(max_moves, len(oracle_actions))
return states, golds, max_moves
def get_batch_loss(self, states, golds, float[:, ::1] scores, losses):
cdef StateClass state
cdef GoldParse gold
cdef Pool mem = Pool()
cdef int i
# n_moves should not be zero at this point, but make sure to avoid zero-length mem alloc
assert self.moves.n_moves > 0
is_valid = <int*>mem.alloc(self.moves.n_moves, sizeof(int))
costs = <float*>mem.alloc(self.moves.n_moves, sizeof(float))
cdef np.ndarray d_scores = numpy.zeros((len(states), self.moves.n_moves),
dtype='f', order='C')
c_d_scores = <float*>d_scores.data
unseen_classes = self.model.attrs["unseen_classes"]
for i, (state, gold) in enumerate(zip(states, golds)):
memset(is_valid, 0, self.moves.n_moves * sizeof(int))
memset(costs, 0, self.moves.n_moves * sizeof(float))
self.moves.set_costs(is_valid, costs, state, gold)
for j in range(self.moves.n_moves):
if costs[j] <= 0.0 and j in unseen_classes:
unseen_classes.remove(j)
cpu_log_loss(c_d_scores,
costs, is_valid, &scores[i, 0], d_scores.shape[1])
c_d_scores += d_scores.shape[1]
if len(states):
d_scores /= len(states)
if losses is not None:
losses.setdefault(self.name, 0.)
losses[self.name] += (d_scores**2).sum()
return d_scores
def create_optimizer(self):
return create_default_optimizer()
def set_output(self, nO):
self.model.attrs["resize_output"](self.model, nO)
def begin_training(self, get_examples, pipeline=None, sgd=None, **kwargs):
self.cfg.update(kwargs)
if not hasattr(get_examples, '__call__'):
gold_tuples = get_examples
get_examples = lambda: gold_tuples
actions = self.moves.get_actions(gold_parses=get_examples(),
min_freq=self.cfg['min_action_freq'],
learn_tokens=self.cfg["learn_tokens"])
for action, labels in self.moves.labels.items():
actions.setdefault(action, {})
for label, freq in labels.items():
if label not in actions[action]:
actions[action][label] = freq
self.moves.initialize_actions(actions)
# make sure we resize so we have an appropriate upper layer
self._resize()
if sgd is None:
sgd = self.create_optimizer()
doc_sample = []
gold_sample = []
for example in islice(get_examples(), 1000):
parses = example.get_gold_parses(merge=False, vocab=self.vocab)
for doc, gold in parses:
doc_sample.append(doc)
gold_sample.append(gold)
self.model.initialize(doc_sample, gold_sample)
if pipeline is not None:
self.init_multitask_objectives(get_examples, pipeline, sgd=sgd, **self.cfg)
link_vectors_to_models(self.vocab)
return sgd
def _get_doc(self, example):
""" Use this method if the `example` can be both a Doc or an Example """
if isinstance(example, Doc):
return example
return example.doc
def to_disk(self, path, exclude=tuple(), **kwargs):
serializers = {
'model': lambda p: (self.model.to_disk(p) if self.model is not True else True),
'vocab': lambda p: self.vocab.to_disk(p),
'moves': lambda p: self.moves.to_disk(p, exclude=["strings"]),
'cfg': lambda p: srsly.write_json(p, self.cfg)
}
exclude = util.get_serialization_exclude(serializers, exclude, kwargs)
util.to_disk(path, serializers, exclude)
def from_disk(self, path, exclude=tuple(), **kwargs):
deserializers = {
'vocab': lambda p: self.vocab.from_disk(p),
'moves': lambda p: self.moves.from_disk(p, exclude=["strings"]),
'cfg': lambda p: self.cfg.update(srsly.read_json(p)),
'model': lambda p: None,
}
exclude = util.get_serialization_exclude(deserializers, exclude, kwargs)
util.from_disk(path, deserializers, exclude)
if 'model' not in exclude:
path = util.ensure_path(path)
with (path / 'model').open('rb') as file_:
bytes_data = file_.read()
try:
self._resize()
self.model.from_bytes(bytes_data)
except AttributeError:
raise ValueError(Errors.E149)
return self
def to_bytes(self, exclude=tuple(), **kwargs):
serializers = {
"model": lambda: (self.model.to_bytes()),
"vocab": lambda: self.vocab.to_bytes(),
"moves": lambda: self.moves.to_bytes(exclude=["strings"]),
"cfg": lambda: srsly.json_dumps(self.cfg, indent=2, sort_keys=True)
}
exclude = util.get_serialization_exclude(serializers, exclude, kwargs)
return util.to_bytes(serializers, exclude)
def from_bytes(self, bytes_data, exclude=tuple(), **kwargs):
deserializers = {
"vocab": lambda b: self.vocab.from_bytes(b),
"moves": lambda b: self.moves.from_bytes(b, exclude=["strings"]),
"cfg": lambda b: self.cfg.update(srsly.json_loads(b)),
"model": lambda b: None,
}
exclude = util.get_serialization_exclude(deserializers, exclude, kwargs)
msg = util.from_bytes(bytes_data, deserializers, exclude)
if 'model' not in exclude:
if 'model' in msg:
try:
self.model.from_bytes(msg['model'])
except AttributeError:
raise ValueError(Errors.E149)
return self