未验证 提交 b5ab8979 编写于 作者: L liu zhengxi 提交者: GitHub

[remove fluid] Remove fluid APIs (#48641)

上级 b01f979b
......@@ -42,18 +42,12 @@ __all__ = [
'rnn',
'birnn',
'dynamic_decode',
'DecodeHelper',
'TrainingHelper',
'GreedyEmbeddingHelper',
'SampleEmbeddingHelper',
'dynamic_lstm',
'dynamic_lstmp',
'dynamic_gru',
'gru_unit',
'lstm_unit',
'lstm',
'beam_search',
'beam_search_decode',
]
......@@ -1234,447 +1228,6 @@ def dynamic_decode(
)
class DecodeHelper:
"""
DecodeHelper is the base class for any helper instance used in `BasicDecoder`.
It provides interface to implement sampling and produce inputs for the next
time step in dynamic decoding.
"""
def initialize(self):
r"""
DecodeHelper initialization to produce inputs for the first decoding step
and give the initial status telling whether each sequence in the batch
is finished. It is the partial of the initialization of `BasicDecoder`.
Returns:
tuple: A tuple( :code:`(initial_inputs, initial_finished)` ). \
`initial_inputs` is a (possibly nested structure of) tensor \
variable[s], and the tensor's shape is `[batch_size, ...]`. \
`initial_finished` is a bool tensor with shape `[batch_size]`.
"""
pass
def sample(self, time, outputs, states):
"""
Perform sampling with some strategies according to `outputs`. It is the
partial of `BasicDecoder.step`.
Parameters:
time(Variable): An `int64` tensor with shape `[1]` provided by the caller,
representing the current time step number of decoding.
outputs(Variable): A tensor variable. Usually it's data type is float32
or float64, and it's shape is `[batch_size, vocabulary_size]`,
representing the predicted logits of current step. It is same as
`outputs` returned by `BasicDecoder.output_fn(BasicDecoder.cell.call())`.
states(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `new_states` returned by `BasicDecoder.cell.call()`.
Returns:
Variable: An `int64` tensor representing the sampled ids.
"""
pass
def next_inputs(self, time, outputs, states, sample_ids):
r"""
Produce the inputs and states for next time step and give status telling
whether each minibatch entry is finished. It is called after `sample` in
`BasicDecoder.step`. It is the partial of `BasicDecoder.step`.
Parameters:
time(Variable): An `int64` tensor with shape `[1]` provided by the caller,
representing the current time step number of decoding.
outputs(Variable): A tensor variable. Usually it's data type is float32
or float64, and it's shape is `[batch_size, vocabulary_size]`,
representing the predicted logits of current step. It is same as
`outputs` returned by `BasicDecoder.output_fn(BasicDecoder.cell.call())`.
states(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `new_states` returned by `BasicDecoder.cell.call()`.
sample_ids(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `sample_ids` returned by `sample()`.
Returns:
tuple: A tuple( :code:`(finished, next_inputs, next_states)` ). \
`next_inputs` and `next_states` both are a (possibly nested \
structure of) tensor variable[s], and the structure, shape and \
data type of `next_states` must be same as the input argument \
`states`. `finished` is a bool tensor with shape `[batch_size]`.
"""
pass
class TrainingHelper(DecodeHelper):
"""
TrainingHelper is a subclass of DecodeHelper. It is a decoding helper
slicing from the full sequence inputs as the inputs for corresponding
step. And it uses `argmax` to sample from the outputs of `cell.call()`.
Since the needs of sequence inputs, it is used mostly for teach-forcing MLE
(maximum likelihood) training, and the sampled would not be used.
Examples:
.. code-block:: python
import paddle.fluid as fluid
import paddle.fluid.layers as layers
trg_emb = fluid.data(name="trg_emb",
shape=[None, None, 128],
dtype="float32")
trg_seq_length = fluid.data(name="trg_seq_length",
shape=[None],
dtype="int64")
helper = layers.TrainingHelper(trg_emb, trg_seq_length)
decoder_cell = layers.GRUCell(hidden_size=128)
decoder = layers.BasicDecoder(decoder_cell, helper)
outputs = layers.dynamic_decode(
decoder,
inits=decoder_cell.get_initial_states(trg_emb),
is_test=False)
"""
def __init__(self, inputs, sequence_length, time_major=False):
"""
Constructor of TrainingHelper.
Parameters:
inputs(Variable): A (possibly nested structure of) tensor variable[s].
The shape of tensor should be `[batch_size, sequence_length, ...]`
for `time_major == False` or `[sequence_length, batch_size, ...]`
for `time_major == True`. It represents the inputs to be sliced
from at every decoding step.
sequence_length(Variable): A tensor with shape `[batch_size]`.
It stores real length of each instance in `inputs`, by which we
can label the finished status of each instance at every decoding
step.
time_major(bool, optional): Indicate the data layout of Tensor included
in `inputs`. If `False`, the data layout would be batch major with
shape `[batch_size, sequence_length, ...]`. If `True`, the data
layout would be time major with shape `[sequence_length, batch_size, ...]`.
Default: `False`.
"""
self.inputs = inputs
self.sequence_length = sequence_length
self.time_major = time_major
# extend inputs to avoid to slice out of range in `next_inputs`
# may be easier and have better performance than condition_op
self.inputs_ = map_structure(
lambda x: paddle.nn.functional.pad(
x,
pad=([0, 1] + [0, 0] * (len(x.shape) - 1))
if time_major
else ([0, 0, 0, 1] + [0, 0] * (len(x.shape) - 2)),
),
self.inputs,
)
def initialize(self):
r"""
TrainingHelper initialization produces inputs for the first decoding
step by slicing at the first time step of full sequence inputs, and it
gives initial status telling whether each sequence in the batch is
finished. It is the partial of the initialization of `BasicDecoder`.
Returns:
tuple: A tuple( :code:`(initial_inputs, initial_finished)` ). \
`initial_inputs` is a (possibly nested structure of) tensor \
variable[s], and the tensor's shape is `[batch_size, ...]`. \
`initial_finished` is a bool tensor with shape `[batch_size]`.
"""
init_finished = paddle.equal(
self.sequence_length,
tensor.fill_constant(
shape=[1], dtype=self.sequence_length.dtype, value=0
),
)
# TODO: support zero length
init_inputs = map_structure(
lambda x: x[0] if self.time_major else x[:, 0], self.inputs
)
return init_inputs, init_finished
def sample(self, time, outputs, states):
r"""
Perform sampling by using `argmax` according to the `outputs`. Mostly
the sampled ids would not be used since the inputs for next decoding
step would be got by slicing.
Parameters:
time(Variable): An `int64` tensor with shape `[1]` provided by the
caller, representing the current time step number of decoding.
outputs(Variable): A tensor variable. Usually it's data type is float32
or float64, and it's shape is `[batch_size, vocabulary_size]`,
representing the predicted logits of current step. It is same as
`outputs` returned by `BasicDecoder.output_fn(BasicDecoder.cell.call())`.
states(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `new_states` returned by `BasicDecoder.cell.call()`.
Returns:
Variable: An `int64` tensor with shape `[batch_size]`, representing \
the sampled ids.
"""
sample_ids = tensor.argmax(outputs, axis=-1)
return sample_ids
def next_inputs(self, time, outputs, states, sample_ids):
r"""
Generate inputs for the next decoding step by slicing at corresponding
step of the full sequence inputs. Simultaneously, produce the states
for next time step by directly using the input `states` and emit status
telling whether each minibatch entry reaches to the corresponding length.
Parameters:
time(Variable): An `int64` tensor with shape `[1]` provided by the
caller, representing the current time step number of decoding.
outputs(Variable): A tensor variable. Usually it's data type is float32
or float64, and it's shape is `[batch_size, vocabulary_size]`,
representing the predicted logits of current step. It is same as
`outputs` returned by `BasicDecoder.output_fn(BasicDecoder.cell.call())`.
states(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `new_states` returned by `BasicDecoder.cell.call()`.
sample_ids(Variable): An `int64` tensor variable shaped `[batch_size]`.
It is same as `sample_ids` returned by `sample()`.
Returns:
tuple: A tuple( :code:`(finished, next_inputs, next_states)` ). \
`next_inputs` and `next_states` both are a (possibly nested \
structure of) tensor variable[s], and the tensor's shape is \
`[batch_size, ...]`. `next_states` is identical to the input \
argument `states`. `finished` is a `bool` Tensor with \
shape `[batch_size]`.
"""
# TODO: compatibility of int32 and int64
time = (
tensor.cast(time, "int32")
if convert_dtype(time.dtype) not in ["int32"]
else time
)
if self.sequence_length.dtype != time.dtype:
self.sequence_length = tensor.cast(self.sequence_length, time.dtype)
next_time = time + 1
finished = paddle.less_equal(self.sequence_length, next_time)
def _slice(x): # TODO: use Variable.__getitem__
axes = [0 if self.time_major else 1]
return paddle.squeeze(
paddle.slice(
x, axes=axes, starts=[next_time], ends=[next_time + 1]
),
axis=axes,
)
next_inputs = map_structure(_slice, self.inputs_)
return finished, next_inputs, states
class GreedyEmbeddingHelper(DecodeHelper):
"""
GreedyEmbeddingHelper is a subclass of DecodeHelper. It is a decoding helper
uses the argmax of the output (treated as logits) and passes the results
through an embedding layer to get inputs for the next decoding step.
Examples:
.. code-block:: python
import paddle.fluid as fluid
import paddle.fluid.layers as layers
trg_emb = fluid.data(name="trg_emb",
shape=[None, None, 128],
dtype="float32")
trg_embeder = lambda x: fluid.embedding(
x, size=[10000, 128], param_attr=fluid.ParamAttr(name="trg_embedding"))
output_layer = lambda x: layers.fc(x,
size=10000,
num_flatten_dims=len(x.shape) - 1,
param_attr=fluid.ParamAttr(name=
"output_w"),
bias_attr=False)
helper = layers.GreedyEmbeddingHelper(trg_embeder, start_tokens=0, end_token=1)
decoder_cell = layers.GRUCell(hidden_size=128)
decoder = layers.BasicDecoder(decoder_cell, helper, output_fn=output_layer)
outputs = layers.dynamic_decode(
decoder=decoder, inits=decoder_cell.get_initial_states(encoder_output))
"""
def __init__(self, embedding_fn, start_tokens, end_token):
r"""
Constructor of GreedyEmbeddingHelper.
Parameters:
embedding_fn(callable): A functor to apply on the argmax results.
Mostly it is an embedding layer to transform ids to embeddings.
**Note that fluid.embedding should be used here rather than
fluid.layers.embedding, since shape of ids is [batch_size].
when using fluid.layers.embedding, must unsqueeze in embedding_fn.**
start_tokens(Variable): A `int64` tensor shaped `[batch_size]`,
representing the start tokens.
end_token(int): The end token id.
Returns:
tuple: A tuple( :code:`(initial_inputs, initial_states, finished)` ). \
`initial_inputs` and `initial_states` both are a (possibly nested \
structure of) tensor variable[s], and `finished` is a tensor with \
bool data type.
"""
self.embedding_fn = embedding_fn
self.start_tokens = start_tokens
self.end_token = tensor.fill_constant(
shape=[1], dtype="int64", value=end_token
)
def initialize(self):
r"""
GreedyEmbeddingHelper initialization produces inputs for the first decoding
step by using `start_tokens` of the constructor, and gives initial
status telling whether each sequence in the batch is finished.
It is the partial of the initialization of `BasicDecoder`.
Returns:
tuple: A tuple( :code:`(initial_inputs, initial_finished)` ). \
`initial_inputs` is same as `start_tokens` of the constructor. \
`initial_finished` is a `bool` tensor filled by False and has \
the same shape as `start_tokens`.
"""
# TODO: remove the restriction of force_cpu
init_finished = tensor.fill_constant_batch_size_like(
input=self.start_tokens,
shape=[-1],
dtype="bool",
value=False,
force_cpu=True,
)
init_inputs = self.embedding_fn(self.start_tokens)
return init_inputs, init_finished
def sample(self, time, outputs, states):
r"""
Perform sampling by using `argmax` according to the `outputs`.
Parameters:
time(Variable): An `int64` tensor with shape `[1]` provided by the
caller, representing the current time step number of decoding.
outputs(Variable): A tensor variable. Usually it's data type is float32
or float64, and it's shape is `[batch_size, vocabulary_size]`,
representing the predicted logits of current step. It is same as
`outputs` returned by `BasicDecoder.output_fn(BasicDecoder.cell.call())`.
states(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `new_states` returned by `BasicDecoder.cell.call()`.
Returns:
Variable: An `int64` tensor with shape `[batch_size]`, representing \
the sampled ids.
"""
sample_ids = tensor.argmax(outputs, axis=-1)
return sample_ids
def next_inputs(self, time, outputs, states, sample_ids):
r"""
Generate inputs for the next decoding step by applying `embedding_fn`
to `sample_ids`. Simultaneously, produce the states for next time step
by directly using the input `states` and emit status telling whether
each minibatch entry gets an `end_token` sample.
Parameters:
time(Variable): An `int64` tensor with shape `[1]` provided by the
caller, representing the current time step number of decoding.
outputs(Variable): A tensor variable. Usually it's data type is float32
or float64, and it's shape is `[batch_size, vocabulary_size]`,
representing the predicted logits of current step. It is same as
`outputs` returned by `BasicDecoder.output_fn(BasicDecoder.cell.call())`.
states(Variable): A (possibly nested structure of) tensor variable[s].
It is same as `new_states` returned by `BasicDecoder.cell.call()`.
sample_ids(Variable): An `int64` tensor variable shaped `[batch_size]`.
It is same as `sample_ids` returned by `sample()`.
Returns:
tuple: A tuple( :code:`(finished, next_inputs, next_states)` ). \
`next_inputs` and `next_states` both are a (possibly nested \
structure of) tensor variable[s], and the tensor's shape is \
`[batch_size, ...]`. `next_states` is identical to the input \
argument `states`. `finished` is a `bool` Tensor with \
shape `[batch_size]`.
"""
finished = paddle.equal(sample_ids, self.end_token)
next_inputs = self.embedding_fn(sample_ids)
return finished, next_inputs, states
class SampleEmbeddingHelper(GreedyEmbeddingHelper):
"""
SampleEmbeddingHelper is a subclass of GreedyEmbeddingHelper. It is a decoding
helper uses sampling (from a distribution) instead of argmax of the output
(treated as logits) and passes the results through an embedding layer to get
inputs for the next decoding step.
Examples:
.. code-block:: python
import paddle.fluid as fluid
import paddle.fluid.layers as layers
trg_emb = fluid.data(name="trg_emb",
shape=[None, None, 128],
dtype="float32")
trg_embeder = lambda x: fluid.embedding(
x, size=[10000, 128], param_attr=fluid.ParamAttr(name="trg_embedding"))
output_layer = lambda x: layers.fc(x,
size=10000,
num_flatten_dims=len(x.shape) - 1,
param_attr=fluid.ParamAttr(name=
"output_w"),
bias_attr=False)
helper = layers.SampleEmbeddingHelper(trg_embeder, start_tokens=0, end_token=1)
decoder_cell = layers.GRUCell(hidden_size=128)
decoder = layers.BasicDecoder(decoder_cell, helper, output_fn=output_layer)
outputs = layers.dynamic_decode(
decoder=decoder, inits=decoder_cell.get_initial_states(encoder_output))
"""
def __init__(
self,
embedding_fn,
start_tokens,
end_token,
softmax_temperature=None,
seed=None,
):
r"""
Constructor of SampleEmbeddingHelper.
Parameters:
embedding_fn(callable): A functor to apply on the argmax results.
Mostly it is an embedding layer to transform ids to embeddings.
**Note that fluid.embedding should be used here rather than
fluid.layers.embedding, since shape of ids is [batch_size].
when using fluid.layers.embedding, must unsqueeze in embedding_fn.**
start_tokens(Variable): A `int64` tensor shaped `[batch_size]`,
representing the start tokens.
end_token(int): The end token id.
softmax_temperature(float, optional): the value to divide the logits
by before computing the softmax. Higher temperatures (above 1.0)
lead to more random, while lower temperatures push the sampling
distribution towards the argmax. It must be strictly greater than
0. Defaults to None, meaning using a temperature valued 1.0.
seed: (int, optional) The sampling seed. Defaults to None, meaning not
to use fixed seed.
Returns:
tuple: A tuple( :code:`(initial_inputs, initial_states, finished)` ). \
`initial_inputs` and `initial_states` both are a (possibly nested \
structure of) tensor variable[s], and `finished` is a tensor with \
bool data type.
"""
super().__init__(embedding_fn, start_tokens, end_token)
self.softmax_temperature = (
tensor.fill_constant(
shape=[1], dtype="float32", value=softmax_temperature
)
if softmax_temperature is not None
else None
)
self.seed = seed
def dynamic_lstm(
input,
size,
......@@ -2619,251 +2172,6 @@ def gru_unit(
return updated_hidden, reset_hidden_pre, gate
def beam_search(
pre_ids,
pre_scores,
ids,
scores,
beam_size,
end_id,
level=0,
is_accumulated=True,
name=None,
return_parent_idx=False,
):
r"""
Beam search is a classical algorithm for selecting candidate words in a
machine translation task.
Refer to `Beam search <https://en.wikipedia.org/wiki/Beam_search>`_
for more details.
**This operator only supports LoDTensor.** It is used after finishing
scores calculation to perform beam search for one time step. Specifically,
after ``ids`` and ``scores`` have been produced, it selects the top-K
( `k` is ``beam_size`` ) candidate word ids of current step from ``ids``
according to the corresponding ``scores``. Additionally, ``pre_id`` and
``pre_scores`` are the output of `beam_search` at previous step, they
are needed for special use to handle ended candidate translations.
Note that if ``is_accumulated`` is True, the ``scores`` passed in should
be accumulated scores. Otherwise, the ``scores`` are
considered as the probabilities of single step and would be transformed to
the log field and added up with ``pre_scores`` for final scores in this
operator. Length penalty should be done with extra operators before calculating
the accumulated scores if needed.
Please see the following demo for a fully beam search usage example:
fluid/tests/book/test_machine_translation.py
Args:
pre_ids(Variable): A LodTensor variable (lod level is 2), representing
the selected ids of previous step. It is the output of beam_search
at previous step. Its shape is `[batch_size, 1]` and its lod is
`[[0, 1, ... , batch_size], [0, 1, ..., batch_size]]` at the
first step. The data type should be int64.
pre_scores(Variable): A LodTensor variable has the same shape and lod
with ``pre_ids`` , representing the accumulated scores corresponding
to the selected ids of previous step. It is the output of
beam_search at previous step. The data type should be float32 or float64.
ids(Variable|None): A LodTensor variable containing the candidates ids.
It has the same lod with ``pre_ids`` and its shape should be
`[batch_size * beam_size, K]`, where `K` supposed to be greater than
``beam_size`` and the first dimension size (decrease as samples reach
to the end) should be same as that of ``pre_ids`` . The data type
should be int64. It can be None, which use index in ``scores`` as
ids.
scores(Variable): A LodTensor variable containing the accumulated
scores corresponding to ``ids`` . Both its shape and lod are same as
those of ``ids`` . The data type should be float32 or float64.
beam_size(int): The beam width used in beam search.
end_id(int): The id of end token.
level(int): **It can be ignored and mustn't change currently.**
The 2 level lod used in this operator has the following
meaning: The first level describes how many beams each sample has,
which would change to 0 when beams of the sample all end (batch reduce);
The second level describes how many times each beam is selected.
Default 0, which shouldn't be changed currently.
is_accumulated(bool): Whether the input ``score`` is accumulated scores.
Default True.
name(str, optional): For detailed information, please refer
to :ref:`api_guide_Name`. Usually name is no need to set and
None by default.
return_parent_idx(bool, optional): Whether to return an extra Tensor variable
in output, which stores the selected ids' parent index in
``pre_ids`` and can be used to update RNN's states by gather operator.
Default False.
Returns:
tuple: The tuple contains two or three LodTensor variables. The two LodTensor, \
representing the selected ids and the corresponding accumulated scores of \
current step, have the same shape `[batch_size, beam_size]` and lod with 2 levels, \
and have data types int64 and float32. If ``return_parent_idx`` is True, \
an extra Tensor variable preserving the selected ids' parent index \
is included, whose shape is `[batch_size * beam_size]` and data type \
is int64.
Examples:
.. code-block:: python
import paddle.fluid as fluid
import paddle
paddle.enable_static()
# Suppose `probs` contains predicted results from the computation
# cell and `pre_ids` and `pre_scores` is the output of beam_search
# at previous step.
beam_size = 4
end_id = 1
pre_ids = fluid.data(
name='pre_id', shape=[None, 1], lod_level=2, dtype='int64')
pre_scores = fluid.data(
name='pre_scores', shape=[None, 1], lod_level=2, dtype='float32')
probs = fluid.data(
name='probs', shape=[None, 10000], dtype='float32')
topk_scores, topk_indices = fluid.layers.topk(probs, k=beam_size)
accu_scores = fluid.layers.elementwise_add(
x=paddle.log(x=topk_scores),
y=paddle.reshape(pre_scores, shape=[-1]),
axis=0)
selected_ids, selected_scores = fluid.layers.beam_search(
pre_ids=pre_ids,
pre_scores=pre_scores,
ids=topk_indices,
scores=accu_scores,
beam_size=beam_size,
end_id=end_id)
"""
check_variable_and_dtype(pre_ids, 'pre_ids', ['int64'], 'beam_search')
check_variable_and_dtype(
pre_scores, 'pre_scores', ['float32', 'float64'], 'beam_search'
)
check_type(ids, 'ids', (Variable, type(None)), 'beam_search')
check_variable_and_dtype(
scores, 'scores', ['float32', 'float64'], 'beam_search'
)
helper = LayerHelper('beam_search', **locals())
score_type = pre_scores.dtype
id_type = pre_ids.dtype
inputs = {"pre_ids": pre_ids, "pre_scores": pre_scores, "scores": scores}
if ids is not None:
inputs["ids"] = ids
selected_scores = helper.create_variable_for_type_inference(
dtype=score_type
)
selected_ids = helper.create_variable_for_type_inference(dtype=id_type)
# parent_idx is a tensor used to gather cell states at the next time
# step. Though lod in selected_ids can also be used to gather by
# sequence_expand, it is not efficient.
# gather_op's index input only supports int32 dtype currently
parent_idx = helper.create_variable_for_type_inference(dtype="int32")
helper.append_op(
type='beam_search',
inputs=inputs,
outputs={
'selected_ids': selected_ids,
'selected_scores': selected_scores,
'parent_idx': parent_idx,
},
attrs={
# TODO(ChunweiYan) to assure other value support
'level': level,
'beam_size': beam_size,
'end_id': end_id,
'is_accumulated': is_accumulated,
},
)
if return_parent_idx:
return selected_ids, selected_scores, parent_idx
else:
return selected_ids, selected_scores
def beam_search_decode(ids, scores, beam_size, end_id, name=None):
r"""
This operator is used after beam search has completed. It constructs the
full predicted sequences for each sample by walking back along the search
paths stored in lod of ``ids`` . The result sequences are stored in a
LoDTensor, which uses the following way to parse:
.. code-block:: text
If lod = [[0, 3, 6], [0, 12, 24, 40, 54, 67, 82]]
The first level of lod stands for: There are 2 samples each having 3
(beam width) predicted sequence.
The second level of lod stands for: The lengths of the first sample's
3 predicted sequences are 12, 12, 16; The lengths of the second sample's
3 predicted sequences are 14, 13, 15.
Please see the following demo for a fully beam search usage example:
fluid/tests/book/test_machine_translation.py
Args:
ids(Variable): The LoDTensorArray variable containing the selected ids
of all steps. Each LoDTensor in it has int64 data type and 2 level
lod which can be used to get the search paths.
scores(Variable): The LodTensorArray variable containing the accumulated
scores corresponding to selected ids of all steps. It has the same size
as ``ids`` . Each LoDTensor in it has the same shape and lod as the
counterpart in ``ids`` , and has a float32 data type.
beam_size(int): The beam width used in beam search.
end_id(int): The id of end token.
name(str, optional): For detailed information, please refer
to :ref:`api_guide_Name`. Usually name is no need to set and
None by default.
Returns:
tuple: The tuple contains two LodTensor variables. The two LodTensor, \
containing the full sequences of ids and the corresponding accumulated \
scores, have the same shape flattened to 1D and have the same 2 level \
lod. The lod can be used to get how many predicted sequences each sample \
has and how many ids each predicted sequence has.
Examples:
.. code-block:: python
import paddle.fluid as fluid
import paddle
paddle.enable_static()
# Suppose `ids` and `scores` are LodTensorArray variables reserving
# the selected ids and scores of all steps
ids = fluid.layers.create_array(dtype='int64')
scores = fluid.layers.create_array(dtype='float32')
finished_ids, finished_scores = fluid.layers.beam_search_decode(
ids, scores, beam_size=5, end_id=0)
"""
check_variable_and_dtype(ids, 'ids', ['int64'], 'beam_search_encode')
check_variable_and_dtype(
scores, 'scores', ['float32'], 'beam_search_encode'
)
helper = LayerHelper('beam_search_decode', **locals())
sentence_ids = helper.create_variable_for_type_inference(dtype=ids.dtype)
sentence_scores = helper.create_variable_for_type_inference(
dtype=scores.dtype
)
helper.append_op(
type="beam_search_decode",
inputs={"Ids": ids, "Scores": scores},
outputs={
"SentenceIds": sentence_ids,
"SentenceScores": sentence_scores,
},
attrs={"beam_size": beam_size, "end_id": end_id},
)
return sentence_ids, sentence_scores
def lstm_unit(
x_t,
hidden_t_prev,
......
......@@ -1719,161 +1719,6 @@ def wrap_decoder(
return predict
def fast_decode(
src_vocab_size,
trg_vocab_size,
max_in_len,
n_layer,
n_head,
d_key,
d_value,
d_model,
d_inner_hid,
dropout_rate,
weight_sharing,
beam_size,
max_out_len,
eos_idx,
):
"""
Use beam search to decode. Caches will be used to store states of history
steps which can make the decoding faster.
"""
enc_output = wrap_encoder(
src_vocab_size,
max_in_len,
n_layer,
n_head,
d_key,
d_value,
d_model,
d_inner_hid,
dropout_rate,
weight_sharing,
)
start_tokens, init_scores, trg_src_attn_bias = make_all_inputs(
fast_decoder_data_input_fields
)
def beam_search():
max_len = layers.fill_constant(
shape=[1], dtype=start_tokens.dtype, value=max_out_len
)
step_idx = layers.fill_constant(
shape=[1], dtype=start_tokens.dtype, value=0
)
cond = paddle.less_than(x=step_idx, y=max_len)
while_op = paddle.static.nn.control_flow.While(cond)
# array states will be stored for each step.
ids = layers.array_write(
paddle.reshape(start_tokens, (-1, 1)), step_idx
)
scores = layers.array_write(init_scores, step_idx)
# cell states will be overwrited at each step.
# caches contains states of history steps to reduce redundant
# computation in decoder.
caches = [
{
"k": layers.fill_constant_batch_size_like(
input=start_tokens,
shape=[-1, 0, d_model],
dtype=enc_output.dtype,
value=0,
),
"v": layers.fill_constant_batch_size_like(
input=start_tokens,
shape=[-1, 0, d_model],
dtype=enc_output.dtype,
value=0,
),
}
for i in range(n_layer)
]
with while_op.block():
pre_ids = layers.array_read(array=ids, i=step_idx)
pre_ids = paddle.reshape(pre_ids, (-1, 1, 1))
pre_scores = layers.array_read(array=scores, i=step_idx)
# sequence_expand can gather sequences according to lod thus can be
# used in beam search to sift states corresponding to selected ids.
pre_src_attn_bias = layers.sequence_expand(
x=trg_src_attn_bias, y=pre_scores
)
pre_enc_output = layers.sequence_expand(x=enc_output, y=pre_scores)
pre_caches = [
{
"k": layers.sequence_expand(x=cache["k"], y=pre_scores),
"v": layers.sequence_expand(x=cache["v"], y=pre_scores),
}
for cache in caches
]
pre_pos = layers.elementwise_mul(
x=layers.fill_constant_batch_size_like(
input=pre_enc_output, # can't use pre_ids here since it has lod
value=1,
shape=[-1, 1, 1],
dtype=pre_ids.dtype,
),
y=layers.increment(x=step_idx, value=1.0, in_place=False),
axis=0,
)
logits = wrap_decoder(
trg_vocab_size,
max_in_len,
n_layer,
n_head,
d_key,
d_value,
d_model,
d_inner_hid,
dropout_rate,
weight_sharing,
dec_inputs=(pre_ids, pre_pos, None, pre_src_attn_bias),
enc_output=pre_enc_output,
caches=pre_caches,
)
logits = paddle.reshape(logits, (-1, trg_vocab_size))
topk_scores, topk_indices = paddle.topk(
x=paddle.nn.functional.softmax(logits), k=beam_size
)
accu_scores = layers.elementwise_add(
x=paddle.log(topk_scores),
y=paddle.reshape(pre_scores, shape=[-1]),
axis=0,
)
# beam_search op uses lod to distinguish branches.
topk_indices = layers.lod_reset(topk_indices, pre_ids)
selected_ids, selected_scores = layers.beam_search(
pre_ids=pre_ids,
pre_scores=pre_scores,
ids=topk_indices,
scores=accu_scores,
beam_size=beam_size,
end_id=eos_idx,
)
layers.increment(x=step_idx, value=1.0, in_place=True)
# update states
layers.array_write(selected_ids, i=step_idx, array=ids)
layers.array_write(selected_scores, i=step_idx, array=scores)
layers.assign(pre_src_attn_bias, trg_src_attn_bias)
layers.assign(pre_enc_output, enc_output)
for i in range(n_layer):
layers.assign(pre_caches[i]["k"], caches[i]["k"])
layers.assign(pre_caches[i]["v"], caches[i]["v"])
length_cond = paddle.less_than(x=step_idx, y=max_len)
finish_cond = paddle.logical_not(layers.is_empty(x=selected_ids))
paddle.logical_and(x=length_cond, y=finish_cond, out=cond)
finished_ids, finished_scores = layers.beam_search_decode(
ids, scores, beam_size=beam_size, end_id=eos_idx
)
return finished_ids, finished_scores
finished_ids, finished_scores = beam_search()
return finished_ids, finished_scores
def get_model(is_dist, is_async):
sum_cost, avg_cost, predict, token_num = transformer(
ModelHyperParams.src_vocab_size,
......
......@@ -16,10 +16,7 @@ import unittest
import numpy as np
import paddle
import paddle.fluid as fluid
import paddle.fluid.core as core
from paddle.fluid.framework import Program, program_guard
from paddle.fluid.op import Operator
......@@ -118,50 +115,5 @@ class TestBeamSearchDecodeOpGPU(TestBeamSearchDecodeOp):
self.place = core.CUDAPlace(0)
class TestBeamSearchDecodeOpError(unittest.TestCase):
def test_errors(self):
with program_guard(Program(), Program()):
def test_id_Variable():
# the input pre_ids must be Variable
test_ids = np.random.randint(1, 5, [5, 1]).astype("int64")
scores = paddle.tensor.create_array(dtype='float32')
fluid.layers.beam_search_decode(
test_ids, scores, beam_size=5, end_id=0
)
self.assertRaises(TypeError, test_id_Variable)
def test_score_Variable():
# the input pre_scores must be Variable
ids = paddle.tensor.create_array(dtype='int64')
test_scores = np.random.uniform(1, 5, [5, 1]).astype("float32")
fluid.layers.beam_search_decode(
ids, test_scores, beam_size=5, end_id=0
)
self.assertRaises(TypeError, test_score_Variable)
def test_id_dtype():
# the dtype of input pre_ids must be int64
type_ids = paddle.tensor.create_array(dtype='float32')
scores = paddle.tensor.create_array(dtype='float32')
fluid.layers.beam_search_decode(
type_ids, scores, beam_size=5, end_id=0
)
self.assertRaises(TypeError, test_id_dtype)
def test_score_dtype():
# the dtype of input pre_scores must be float32
ids = paddle.tensor.create_array(dtype='int64')
type_scores = paddle.tensor.create_array(dtype='int64')
fluid.layers.beam_search_decode(
ids, type_scores, beam_size=5, end_id=0
)
self.assertRaises(TypeError, test_score_dtype)
if __name__ == '__main__':
unittest.main()
......@@ -16,10 +16,7 @@ import unittest
import numpy as np
import paddle
import paddle.fluid as fluid
import paddle.fluid.core as core
from paddle.fluid.framework import Program, program_guard
from paddle.fluid.op import Operator
......@@ -302,119 +299,5 @@ class BeamSearchOpTester6(BeamSearchOpTester):
self.output_parent_idx = np.array([0, 1, 2, 3])
class TestBeamSearchOpError(unittest.TestCase):
def test_errors(self):
with program_guard(Program(), Program()):
pre_ids = fluid.data(
name='pre_id', shape=[1], lod_level=2, dtype='int64'
)
pre_scores = fluid.data(
name='pre_scores', shape=[1], lod_level=2, dtype='float32'
)
probs = fluid.data(name='probs', shape=[10000], dtype='float32')
topk_scores, topk_indices = paddle.topk(probs, k=4)
accu_scores = fluid.layers.elementwise_add(
x=paddle.log(x=topk_scores),
y=paddle.reshape(pre_scores, shape=[-1]),
axis=0,
)
def test_preids_Variable():
# the input pre_ids must be Variable
preids_data = np.random.randint(1, 5, [5, 1]).astype("int64")
fluid.layers.beam_search(
pre_ids=preids_data,
pre_scores=pre_scores,
ids=topk_indices,
scores=accu_scores,
beam_size=4,
end_id=1,
)
self.assertRaises(TypeError, test_preids_Variable)
def test_prescores_Variable():
# the input pre_scores must be Variable
prescores_data = np.random.uniform(1, 5, [5, 1]).astype(
"float32"
)
fluid.layers.beam_search(
pre_ids=pre_ids,
pre_scores=prescores_data,
ids=topk_indices,
scores=accu_scores,
beam_size=4,
end_id=1,
)
self.assertRaises(TypeError, test_prescores_Variable)
def test_ids_Variable():
# the input ids must be Variable or None
ids_data = np.random.randint(1, 5, [5, 1]).astype("int64")
fluid.layers.beam_search(
pre_ids=pre_ids,
pre_scores=pre_scores,
ids=ids_data,
scores=accu_scores,
beam_size=4,
end_id=1,
)
self.assertRaises(TypeError, test_ids_Variable)
def test_scores_Variable():
# the input scores must be Variable
scores_data = np.random.uniform(1, 5, [5, 1]).astype("float32")
fluid.layers.beam_search(
pre_ids=pre_ids,
pre_scores=pre_scores,
ids=topk_indices,
scores=scores_data,
beam_size=4,
end_id=1,
)
self.assertRaises(TypeError, test_scores_Variable)
def test_preids_dtype():
# the dtype of input pre_ids must be int64
preids_type_data = fluid.data(
name='preids_type_data',
shape=[1],
lod_level=2,
dtype='float32',
)
fluid.layers.beam_search(
pre_ids=preids_type_data,
pre_scores=pre_scores,
ids=topk_indices,
scores=accu_scores,
beam_size=4,
end_id=1,
)
self.assertRaises(TypeError, test_preids_dtype)
def test_prescores_dtype():
# the dtype of input pre_scores must be float32
prescores_type_data = fluid.data(
name='prescores_type_data',
shape=[1],
lod_level=2,
dtype='int64',
)
fluid.layers.beam_search(
pre_ids=pre_ids,
pre_scores=prescores_type_data,
ids=topk_indices,
scores=accu_scores,
beam_size=4,
end_id=1,
)
self.assertRaises(TypeError, test_prescores_dtype)
if __name__ == '__main__':
unittest.main()
......@@ -141,25 +141,17 @@ class Decoder:
**kwargs
):
output_layer = kwargs.pop("output_layer", None)
if self.decoding_strategy == "train_greedy":
# for teach-forcing MLE pre-training
helper = layers.TrainingHelper(**kwargs)
elif self.decoding_strategy == "infer_sample":
helper = layers.SampleEmbeddingHelper(**kwargs)
elif self.decoding_strategy == "infer_greedy":
helper = layers.GreedyEmbeddingHelper(**kwargs)
if self.decoding_strategy == "beam_search":
beam_size = kwargs.get("beam_size", 4)
encoder_output = BeamSearchDecoder.tile_beam_merge_with_batch(
encoder_output, beam_size
)
encoder_padding_mask = BeamSearchDecoder.tile_beam_merge_with_batch(
encoder_padding_mask, beam_size
)
decoder = BeamSearchDecoder(
cell=self.decoder_cell, output_fn=output_layer, **kwargs
)
beam_size = kwargs.get("beam_size", 4)
encoder_output = BeamSearchDecoder.tile_beam_merge_with_batch(
encoder_output, beam_size
)
encoder_padding_mask = BeamSearchDecoder.tile_beam_merge_with_batch(
encoder_padding_mask, beam_size
)
decoder = BeamSearchDecoder(
cell=self.decoder_cell, output_fn=output_layer, **kwargs
)
(
decoder_output,
......
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