spaCy/spacy/pipeline/transition_parser.pyx
Sofie Van Landeghem ca491722ad
The Parser is now a Pipe (2) (#5844)
* moving syntax folder to _parser_internals

* moving nn_parser and transition_system

* move nn_parser and transition_system out of internals folder

* moving nn_parser code into transition_system file

* rename transition_system to transition_parser

* moving parser_model and _state to ml

* move _state back to internals

* The Parser now inherits from Pipe!

* small code fixes

* removing unnecessary imports

* remove link_vectors_to_models

* transition_system to internals folder

* little bit more cleanup

* newlines
2020-07-30 23:30:54 +02:00

555 lines
22 KiB
Cython

# cython: infer_types=True, cdivision=True, boundscheck=False
from __future__ import print_function
from cymem.cymem cimport Pool
cimport numpy as np
from itertools import islice
from libcpp.vector cimport vector
from libc.string cimport memset
from libc.stdlib cimport calloc, free
import srsly
from ._parser_internals.stateclass cimport StateClass
from ..ml.parser_model cimport alloc_activations, free_activations
from ..ml.parser_model cimport predict_states, arg_max_if_valid
from ..ml.parser_model cimport WeightsC, ActivationsC, SizesC, cpu_log_loss
from ..ml.parser_model cimport get_c_weights, get_c_sizes
from ..tokens.doc cimport Doc
from ..errors import Errors, Warnings
from .. import util
from ..util import create_default_optimizer
from thinc.api import set_dropout_rate
import numpy.random
import numpy
import warnings
cdef class Parser(Pipe):
"""
Base class of the DependencyParser and EntityRecognizer.
"""
def __init__(
self,
Vocab vocab,
model,
name="base_parser",
moves=None,
*,
update_with_oracle_cut_size,
multitasks=tuple(),
min_action_freq,
learn_tokens,
):
"""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
self.name = name
cfg = {
"moves": moves,
"update_with_oracle_cut_size": update_with_oracle_cut_size,
"multitasks": list(multitasks),
"min_action_freq": min_action_freq,
"learn_tokens": learn_tokens
}
if moves is None:
# defined by EntityRecognizer as a BiluoPushDown
moves = self.TransitionSystem(self.vocab.strings)
self.moves = moves
self.model = model
if self.moves.n_moves != 0:
self.set_output(self.moves.n_moves)
self.cfg = cfg
self._multitasks = []
for multitask in cfg["multitasks"]:
self.add_multitask_objective(multitask)
self._rehearsal_model = None
def __getnewargs_ex__(self):
"""This allows pickling the Parser and its keyword-only init arguments"""
args = (self.vocab, self.model, self.name, self.moves)
return args, self.cfg
@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()
return 1
return 0
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 use_params(self, params):
# Can't decorate cdef class :(. Workaround.
with self.model.use_params(params):
yield
def __call__(self, Doc doc):
"""Apply the parser or entity recognizer, setting the annotations onto
the `Doc` object.
doc (Doc): The document to be processed.
"""
states = self.predict([doc])
self.set_annotations([doc], states)
return doc
def pipe(self, docs, *, int batch_size=256):
"""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.
"""
cdef Doc doc
for batch in util.minibatch(docs, size=batch_size):
batch_in_order = list(batch)
by_length = sorted(batch, 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)
self.set_annotations(subbatch, parse_states)
yield from batch_in_order
def predict(self, docs):
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
return self.greedy_parse(docs, drop=0.0)
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)
model.clear_memory()
del model
return batch
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):
cdef StateClass state
cdef Doc doc
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)
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 update(self, examples, *, drop=0., set_annotations=False, sgd=None, losses=None):
cdef StateClass state
if losses is None:
losses = {}
losses.setdefault(self.name, 0.)
for multitask in self._multitasks:
multitask.update(examples, drop=drop, sgd=sgd)
n_examples = len([eg for eg in examples if self.moves.has_gold(eg)])
if n_examples == 0:
return losses
set_dropout_rate(self.model, drop)
# Prepare the stepwise model, and get the callback for finishing the batch
model, backprop_tok2vec = self.model.begin_update(
[eg.predicted for eg in examples])
if self.cfg["update_with_oracle_cut_size"] >= 1:
# Chop sequences into lengths of this many transitions, to make the
# batch uniform length.
# We used to randomize this, but it's not clear that actually helps?
cut_size = self.cfg["update_with_oracle_cut_size"]
states, golds, max_steps = self._init_gold_batch(
examples,
max_length=cut_size
)
else:
states, golds, _ = self.moves.init_gold_batch(examples)
max_steps = max([len(eg.x) for eg in examples])
if not states:
return losses
all_states = list(states)
states_golds = list(zip(states, golds))
while states_golds:
states, golds = zip(*states_golds)
scores, backprop = model.begin_update(states)
d_scores = self.get_batch_loss(states, golds, scores, losses)
# Note that the gradient isn't normalized by the batch size
# here, because our "samples" are really the states...But we
# can't normalize by the number of states either, as then we'd
# be getting smaller gradients for states in long sequences.
backprop(d_scores)
# Follow the predicted action
self.transition_states(states, scores)
states_golds = [(s, g) for (s, g) in zip(states, golds) if not s.is_final()]
backprop_tok2vec(golds)
if sgd not in (None, False):
self.model.finish_update(sgd)
if set_annotations:
docs = [eg.predicted for eg in examples]
self.set_annotations(docs, all_states)
# Ugh, this is annoying. If we're working on GPU, we want to free the
# memory ASAP. It seems that Python doesn't necessarily get around to
# removing these in time if we don't explicitly delete? It's confusing.
del backprop
del backprop_tok2vec
model.clear_memory()
del model
return losses
def rehearse(self, examples, sgd=None, losses=None, **cfg):
"""Perform a "rehearsal" update, to prevent catastrophic forgetting."""
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 = [eg.predicted for eg 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, backprop_tok2vec = 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
backprop_tok2vec(docs)
if sgd is not None:
self.model.finish_update(sgd)
losses[self.name] += loss / n_scores
del backprop
del backprop_tok2vec
model.clear_memory()
tutor.clear_memory()
del model
del tutor
return losses
def get_batch_loss(self, states, golds, float[:, ::1] scores, losses):
cdef StateClass state
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]
# Note that we don't normalize this. See comment in update() for why.
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)
lexeme_norms = self.vocab.lookups.get_table("lexeme_norm", {})
if len(lexeme_norms) == 0 and self.vocab.lang in util.LEXEME_NORM_LANGS:
langs = ", ".join(util.LEXEME_NORM_LANGS)
warnings.warn(Warnings.W033.format(model="parser or NER", langs=langs))
if not hasattr(get_examples, '__call__'):
gold_tuples = get_examples
get_examples = lambda: gold_tuples
actions = self.moves.get_actions(
examples=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 = []
for example in islice(get_examples(), 10):
doc_sample.append(example.predicted)
if pipeline is not None:
for name, component in pipeline:
if component is self:
break
if hasattr(component, "pipe"):
doc_sample = list(component.pipe(doc_sample, batch_size=8))
else:
doc_sample = [component(doc) for doc in doc_sample]
if doc_sample:
self.model.initialize(doc_sample)
else:
self.model.initialize()
if pipeline is not None:
self.init_multitask_objectives(get_examples, pipeline, sgd=sgd, **self.cfg)
return sgd
def to_disk(self, path, exclude=tuple()):
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)
}
util.to_disk(path, serializers, exclude)
def from_disk(self, path, exclude=tuple()):
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,
}
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()):
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)
}
return util.to_bytes(serializers, exclude)
def from_bytes(self, bytes_data, exclude=tuple()):
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,
}
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
def _init_gold_batch(self, examples, min_length=5, max_length=500):
"""Make a square batch, of length equal to the shortest transition
sequence or a cap. 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 start_state
StateClass state
Transition action
all_states = self.moves.init_batch([eg.predicted for eg in examples])
states = []
golds = []
kept = []
max_length_seen = 0
for state, eg in zip(all_states, examples):
if self.moves.has_gold(eg) and not state.is_final():
gold = self.moves.init_gold(state, eg)
if len(eg.x) < max_length:
states.append(state)
golds.append(gold)
else:
oracle_actions = self.moves.get_oracle_sequence_from_state(
state.copy(), gold)
kept.append((eg, state, gold, oracle_actions))
min_length = min(min_length, len(oracle_actions))
max_length_seen = max(max_length, len(oracle_actions))
if not kept:
return states, golds, 0
max_length = max(min_length, min(max_length, max_length_seen))
cdef int clas
max_moves = 0
for eg, state, gold, oracle_actions in kept:
for i in range(0, len(oracle_actions), max_length):
start_state = state.copy()
n_moves = 0
for clas in oracle_actions[i:i+max_length]:
action = self.moves.c[clas]
action.do(state.c, action.label)
state.c.push_hist(action.clas)
n_moves += 1
if state.is_final():
break
max_moves = max(max_moves, n_moves)
if self.moves.has_gold(eg, start_state.B(0), state.B(0)):
states.append(start_state)
golds.append(gold)
max_moves = max(max_moves, n_moves)
if state.is_final():
break
return states, golds, max_moves