add_nets (#3416)

PaddleNLP/Research/MRQA2019-D-NET/server/bert_server/pdnlp/nets/bert.py

+#   Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""BERT model."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import six
+import json
+import numpy as np
+import paddle.fluid as fluid
+
+from palm.nets.transformer_encoder import encoder as encoder
+from palm.nets.transformer_encoder import pre_process_layer as pre_process_layer
+
+
+class BertModel(object):
+    def __init__(self,
+                 src_ids,
+                 position_ids,
+                 sentence_ids,
+                 input_mask,
+                 config,
+                 weight_sharing=True,
+                 use_fp16=False,
+                 model_name=''):
+
+        self._emb_size = config["hidden_size"]
+        self._n_layer = config["num_hidden_layers"]
+        self._n_head = config["num_attention_heads"]
+        self._voc_size = config["vocab_size"]
+        self._max_position_seq_len = config["max_position_embeddings"]
+        self._sent_types = config["type_vocab_size"]
+        self._hidden_act = config["hidden_act"]
+        self._prepostprocess_dropout = config["hidden_dropout_prob"]
+        self._attention_dropout = config["attention_probs_dropout_prob"]
+        self._weight_sharing = weight_sharing
+
+        self.model_name = model_name
+
+        self._word_emb_name = self.model_name + "word_embedding"
+        self._pos_emb_name = self.model_name + "pos_embedding"
+        self._sent_emb_name = self.model_name + "sent_embedding"
+        self._dtype = "float16" if use_fp16 else "float32"
+
+        # Initialize all weigths by truncated normal initializer, and all biases 
+        # will be initialized by constant zero by default.
+        self._param_initializer = fluid.initializer.TruncatedNormal(
+            scale=config["initializer_range"])
+
+        self._build_model(src_ids, position_ids, sentence_ids, input_mask,
+                          config)
+
+    def _build_model(self, src_ids, position_ids, sentence_ids, input_mask,
+                     config):
+        # padding id in vocabulary must be set to 0
+        emb_out = fluid.layers.embedding(
+            input=src_ids,
+            size=[self._voc_size, self._emb_size],
+            dtype=self._dtype,
+            param_attr=fluid.ParamAttr(
+                name=self._word_emb_name, initializer=self._param_initializer),
+            is_sparse=False)
+
+        self.emb_out = emb_out
+
+        position_emb_out = fluid.layers.embedding(
+            input=position_ids,
+            size=[self._max_position_seq_len, self._emb_size],
+            dtype=self._dtype,
+            param_attr=fluid.ParamAttr(
+                name=self._pos_emb_name, initializer=self._param_initializer))
+
+        self.position_emb_out = position_emb_out
+
+        sent_emb_out = fluid.layers.embedding(
+            sentence_ids,
+            size=[self._sent_types, self._emb_size],
+            dtype=self._dtype,
+            param_attr=fluid.ParamAttr(
+                name=self._sent_emb_name, initializer=self._param_initializer))
+
+        self.sent_emb_out = sent_emb_out
+
+        emb_out = emb_out + position_emb_out
+        emb_out = emb_out + sent_emb_out
+
+        emb_out = pre_process_layer(
+            emb_out, 'nd', self._prepostprocess_dropout, name='pre_encoder')
+
+        if self._dtype == "float16":
+            input_mask = fluid.layers.cast(x=input_mask, dtype=self._dtype)
+
+        self_attn_mask = fluid.layers.matmul(
+            x=input_mask, y=input_mask, transpose_y=True)
+
+        self_attn_mask = fluid.layers.scale(
+            x=self_attn_mask,
+            scale=config["self_att_scale"],
+            bias=-1.0,
+            bias_after_scale=False)
+
+        n_head_self_attn_mask = fluid.layers.stack(
+            x=[self_attn_mask] * self._n_head, axis=1)
+
+        n_head_self_attn_mask.stop_gradient = True
+
+        self._enc_out = encoder(
+            enc_input=emb_out,
+            attn_bias=n_head_self_attn_mask,
+            n_layer=self._n_layer,
+            n_head=self._n_head,
+            d_key=self._emb_size // self._n_head,
+            d_value=self._emb_size // self._n_head,
+            d_model=self._emb_size,
+            d_inner_hid=self._emb_size * 4,
+            prepostprocess_dropout=self._prepostprocess_dropout,
+            attention_dropout=self._attention_dropout,
+            relu_dropout=0,
+            hidden_act=self._hidden_act,
+            preprocess_cmd="",
+            postprocess_cmd="dan",
+            param_initializer=self._param_initializer,
+            name=self.model_name + 'encoder')
+
+    def get_sequence_output(self):
+        return self._enc_out
+
+    def get_pooled_output(self):
+        """Get the first feature of each sequence for classification"""
+
+        next_sent_feat = fluid.layers.slice(
+            input=self._enc_out, axes=[1], starts=[0], ends=[1])
+        next_sent_feat = fluid.layers.fc(
+            input=next_sent_feat,
+            size=self._emb_size,
+            act="tanh",
+            param_attr=fluid.ParamAttr(
+                name=self.model_name + "pooled_fc.w_0",
+                initializer=self._param_initializer),
+            bias_attr="pooled_fc.b_0")
+        return next_sent_feat
+
+    def get_pretraining_output(self, mask_label, mask_pos, labels):
+        """Get the loss & accuracy for pretraining"""
+
+        mask_pos = fluid.layers.cast(x=mask_pos, dtype='int32')
+
+        # extract the first token feature in each sentence
+        next_sent_feat = self.get_pooled_output()
+        reshaped_emb_out = fluid.layers.reshape(
+            x=self._enc_out, shape=[-1, self._emb_size])
+        # extract masked tokens' feature
+        mask_feat = fluid.layers.gather(input=reshaped_emb_out, index=mask_pos)
+
+        # transform: fc
+        mask_trans_feat = fluid.layers.fc(
+            input=mask_feat,
+            size=self._emb_size,
+            act=self._hidden_act,
+            param_attr=fluid.ParamAttr(
+                name=self.model_name + 'mask_lm_trans_fc.w_0',
+                initializer=self._param_initializer),
+            bias_attr=fluid.ParamAttr(
+                name=self.model_name + 'mask_lm_trans_fc.b_0'))
+        # transform: layer norm 
+        mask_trans_feat = pre_process_layer(
+            mask_trans_feat, 'n', name=self.model_name + 'mask_lm_trans')
+
+        mask_lm_out_bias_attr = fluid.ParamAttr(
+            name=self.model_name + "mask_lm_out_fc.b_0",
+            initializer=fluid.initializer.Constant(value=0.0))
+        if self._weight_sharing:
+            fc_out = fluid.layers.matmul(
+                x=mask_trans_feat,
+                y=fluid.default_main_program().global_block().var(
+                    self._word_emb_name),
+                transpose_y=True)
+            fc_out += fluid.layers.create_parameter(
+                shape=[self._voc_size],
+                dtype=self._dtype,
+                attr=mask_lm_out_bias_attr,
+                is_bias=True)
+
+        else:
+            fc_out = fluid.layers.fc(
+                input=mask_trans_feat,
+                size=self._voc_size,
+                param_attr=fluid.ParamAttr(
+                    name=self.model_name + "mask_lm_out_fc.w_0",
+                    initializer=self._param_initializer),
+                bias_attr=mask_lm_out_bias_attr)
+
+        mask_lm_loss = fluid.layers.softmax_with_cross_entropy(
+            logits=fc_out, label=mask_label)
+        mean_mask_lm_loss = fluid.layers.mean(mask_lm_loss)
+
+        next_sent_fc_out = fluid.layers.fc(
+            input=next_sent_feat,
+            size=2,
+            param_attr=fluid.ParamAttr(
+                name=self.model_name + "next_sent_fc.w_0",
+                initializer=self._param_initializer),
+            bias_attr=self.model_name + "next_sent_fc.b_0")
+
+        next_sent_loss, next_sent_softmax = fluid.layers.softmax_with_cross_entropy(
+            logits=next_sent_fc_out, label=labels, return_softmax=True)
+
+        next_sent_acc = fluid.layers.accuracy(
+            input=next_sent_softmax, label=labels)
+
+        mean_next_sent_loss = fluid.layers.mean(next_sent_loss)
+
+        loss = mean_next_sent_loss + mean_mask_lm_loss
+        return next_sent_acc, mean_mask_lm_loss, loss
+
+
+if __name__ == "__main__":
+    print("hello wolrd!")

PaddleNLP/Research/MRQA2019-D-NET/server/bert_server/pdnlp/nets/transformer_encoder.py

+#   Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Transformer encoder."""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from functools import partial
+import numpy as np
+
+import paddle.fluid as fluid
+import paddle.fluid.layers as layers
+
+
+def multi_head_attention(queries,
+                         keys,
+                         values,
+                         attn_bias,
+                         d_key,
+                         d_value,
+                         d_model,
+                         n_head=1,
+                         dropout_rate=0.,
+                         cache=None,
+                         param_initializer=None,
+                         name='multi_head_att'):
+    """
+    Multi-Head Attention. Note that attn_bias is added to the logit before
+    computing softmax activiation to mask certain selected positions so that
+    they will not considered in attention weights.
+    """
+    keys = queries if keys is None else keys
+    values = keys if values is None else values
+
+    if not (len(queries.shape) == len(keys.shape) == len(values.shape) == 3):
+        raise ValueError(
+            "Inputs: quries, keys and values should all be 3-D tensors.")
+
+    def __compute_qkv(queries, keys, values, n_head, d_key, d_value):
+        """
+        Add linear projection to queries, keys, and values.
+        """
+        q = layers.fc(input=queries,
+                      size=d_key * n_head,
+                      num_flatten_dims=2,
+                      param_attr=fluid.ParamAttr(
+                          name=name + '_query_fc.w_0',
+                          initializer=param_initializer),
+                      bias_attr=name + '_query_fc.b_0')
+        k = layers.fc(input=keys,
+                      size=d_key * n_head,
+                      num_flatten_dims=2,
+                      param_attr=fluid.ParamAttr(
+                          name=name + '_key_fc.w_0',
+                          initializer=param_initializer),
+                      bias_attr=name + '_key_fc.b_0')
+        v = layers.fc(input=values,
+                      size=d_value * n_head,
+                      num_flatten_dims=2,
+                      param_attr=fluid.ParamAttr(
+                          name=name + '_value_fc.w_0',
+                          initializer=param_initializer),
+                      bias_attr=name + '_value_fc.b_0')
+        return q, k, v
+
+    def __split_heads(x, n_head):
+        """
+        Reshape the last dimension of inpunt tensor x so that it becomes two
+        dimensions and then transpose. Specifically, input a tensor with shape
+        [bs, max_sequence_length, n_head * hidden_dim] then output a tensor
+        with shape [bs, n_head, max_sequence_length, hidden_dim].
+        """
+        hidden_size = x.shape[-1]
+        # The value 0 in shape attr means copying the corresponding dimension
+        # size of the input as the output dimension size.
+        reshaped = layers.reshape(
+            x=x, shape=[0, 0, n_head, hidden_size // n_head], inplace=True)
+
+        # permuate the dimensions into:
+        # [batch_size, n_head, max_sequence_len, hidden_size_per_head]
+        return layers.transpose(x=reshaped, perm=[0, 2, 1, 3])
+
+    def __combine_heads(x):
+        """
+        Transpose and then reshape the last two dimensions of inpunt tensor x
+        so that it becomes one dimension, which is reverse to __split_heads.
+        """
+        if len(x.shape) == 3: return x
+        if len(x.shape) != 4:
+            raise ValueError("Input(x) should be a 4-D Tensor.")
+
+        trans_x = layers.transpose(x, perm=[0, 2, 1, 3])
+        # The value 0 in shape attr means copying the corresponding dimension
+        # size of the input as the output dimension size.
+        return layers.reshape(
+            x=trans_x,
+            shape=[0, 0, trans_x.shape[2] * trans_x.shape[3]],
+            inplace=True)
+
+    def scaled_dot_product_attention(q, k, v, attn_bias, d_key, dropout_rate):
+        """
+        Scaled Dot-Product Attention
+        """
+        scaled_q = layers.scale(x=q, scale=d_key**-0.5)
+        product = layers.matmul(x=scaled_q, y=k, transpose_y=True)
+        if attn_bias:
+            product += attn_bias
+        weights = layers.softmax(product)
+        if dropout_rate:
+            weights = layers.dropout(
+                weights,
+                dropout_prob=dropout_rate,
+                dropout_implementation="upscale_in_train",
+                is_test=False)
+        out = layers.matmul(weights, v)
+        return out
+
+    q, k, v = __compute_qkv(queries, keys, values, n_head, d_key, d_value)
+
+    if cache is not None:  # use cache and concat time steps
+        # Since the inplace reshape in __split_heads changes the shape of k and
+        # v, which is the cache input for next time step, reshape the cache
+        # input from the previous time step first.
+        k = cache["k"] = layers.concat(
+            [layers.reshape(
+                cache["k"], shape=[0, 0, d_model]), k], axis=1)
+        v = cache["v"] = layers.concat(
+            [layers.reshape(
+                cache["v"], shape=[0, 0, d_model]), v], axis=1)
+
+    q = __split_heads(q, n_head)
+    k = __split_heads(k, n_head)
+    v = __split_heads(v, n_head)
+
+    ctx_multiheads = scaled_dot_product_attention(q, k, v, attn_bias, d_key,
+                                                  dropout_rate)
+
+    out = __combine_heads(ctx_multiheads)
+
+    # Project back to the model size.
+    proj_out = layers.fc(input=out,
+                         size=d_model,
+                         num_flatten_dims=2,
+                         param_attr=fluid.ParamAttr(
+                             name=name + '_output_fc.w_0',
+                             initializer=param_initializer),
+                         bias_attr=name + '_output_fc.b_0')
+    return proj_out
+
+
+def positionwise_feed_forward(x,
+                              d_inner_hid,
+                              d_hid,
+                              dropout_rate,
+                              hidden_act,
+                              param_initializer=None,
+                              name='ffn'):
+    """
+    Position-wise Feed-Forward Networks.
+    This module consists of two linear transformations with a ReLU activation
+    in between, which is applied to each position separately and identically.
+    """
+    hidden = layers.fc(input=x,
+                       size=d_inner_hid,
+                       num_flatten_dims=2,
+                       act=hidden_act,
+                       param_attr=fluid.ParamAttr(
+                           name=name + '_fc_0.w_0',
+                           initializer=param_initializer),
+                       bias_attr=name + '_fc_0.b_0')
+    if dropout_rate:
+        hidden = layers.dropout(
+            hidden,
+            dropout_prob=dropout_rate,
+            dropout_implementation="upscale_in_train",
+            is_test=False)
+
+    out = layers.fc(input=hidden,
+                    size=d_hid,
+                    num_flatten_dims=2,
+                    param_attr=fluid.ParamAttr(
+                        name=name + '_fc_1.w_0', initializer=param_initializer),
+                    bias_attr=name + '_fc_1.b_0')
+    return out
+
+
+def pre_post_process_layer(prev_out, out, process_cmd, dropout_rate=0.,
+                           name=''):
+    """
+    Add residual connection, layer normalization and droput to the out tensor
+    optionally according to the value of process_cmd.
+    This will be used before or after multi-head attention and position-wise
+    feed-forward networks.
+    """
+    for cmd in process_cmd:
+        if cmd == "a":  # add residual connection
+            out = out + prev_out if prev_out else out
+        elif cmd == "n":  # add layer normalization
+            out_dtype = out.dtype
+            if out_dtype == fluid.core.VarDesc.VarType.FP16:
+                out = layers.cast(x=out, dtype="float32")
+            out = layers.layer_norm(
+                out,
+                begin_norm_axis=len(out.shape) - 1,
+                param_attr=fluid.ParamAttr(
+                    name=name + '_layer_norm_scale',
+                    initializer=fluid.initializer.Constant(1.)),
+                bias_attr=fluid.ParamAttr(
+                    name=name + '_layer_norm_bias',
+                    initializer=fluid.initializer.Constant(0.)))
+            if out_dtype == fluid.core.VarDesc.VarType.FP16:
+                out = layers.cast(x=out, dtype="float16")
+        elif cmd == "d":  # add dropout
+            if dropout_rate:
+                out = layers.dropout(
+                    out,
+                    dropout_prob=dropout_rate,
+                    dropout_implementation="upscale_in_train",
+                    is_test=False)
+    return out
+
+
+pre_process_layer = partial(pre_post_process_layer, None)
+post_process_layer = pre_post_process_layer
+
+
+def encoder_layer(enc_input,
+                  attn_bias,
+                  n_head,
+                  d_key,
+                  d_value,
+                  d_model,
+                  d_inner_hid,
+                  prepostprocess_dropout,
+                  attention_dropout,
+                  relu_dropout,
+                  hidden_act,
+                  preprocess_cmd="n",
+                  postprocess_cmd="da",
+                  param_initializer=None,
+                  name=''):
+    """
+    The encoder layers that can be stacked to form a deep encoder.
+    This module consits of a multi-head (self) attention followed by
+    position-wise feed-forward networks and both the two components companied
+    with the post_process_layer to add residual connection, layer normalization
+    and droput.
+    """
+    attn_output = multi_head_attention(
+        pre_process_layer(
+            enc_input,
+            preprocess_cmd,
+            prepostprocess_dropout,
+            name=name + '_pre_att'),
+        None,
+        None,
+        attn_bias,
+        d_key,
+        d_value,
+        d_model,
+        n_head,
+        attention_dropout,
+        param_initializer=param_initializer,
+        name=name + '_multi_head_att')
+    attn_output = post_process_layer(
+        enc_input,
+        attn_output,
+        postprocess_cmd,
+        prepostprocess_dropout,
+        name=name + '_post_att')
+    ffd_output = positionwise_feed_forward(
+        pre_process_layer(
+            attn_output,
+            preprocess_cmd,
+            prepostprocess_dropout,
+            name=name + '_pre_ffn'),
+        d_inner_hid,
+        d_model,
+        relu_dropout,
+        hidden_act,
+        param_initializer=param_initializer,
+        name=name + '_ffn')
+    return post_process_layer(
+        attn_output,
+        ffd_output,
+        postprocess_cmd,
+        prepostprocess_dropout,
+        name=name + '_post_ffn')
+
+
+def encoder(enc_input,
+            attn_bias,
+            n_layer,
+            n_head,
+            d_key,
+            d_value,
+            d_model,
+            d_inner_hid,
+            prepostprocess_dropout,
+            attention_dropout,
+            relu_dropout,
+            hidden_act,
+            preprocess_cmd="n",
+            postprocess_cmd="da",
+            param_initializer=None,
+            name='',
+            return_all=False):
+    """
+    The encoder is composed of a stack of identical layers returned by calling
+    encoder_layer.
+    """
+    enc_outputs = []
+    for i in range(n_layer):
+        enc_output = encoder_layer(
+            enc_input,
+            attn_bias,
+            n_head,
+            d_key,
+            d_value,
+            d_model,
+            d_inner_hid,
+            prepostprocess_dropout,
+            attention_dropout,
+            relu_dropout,
+            hidden_act,
+            preprocess_cmd,
+            postprocess_cmd,
+            param_initializer=param_initializer,
+            name=name + '_layer_' + str(i))
+        enc_input = enc_output
+        if i < n_layer - 1:
+            enc_outputs.append(enc_output)
+
+    enc_output = pre_process_layer(
+        enc_output, preprocess_cmd, prepostprocess_dropout, name="post_encoder")
+    enc_outputs.append(enc_output)
+
+    if not return_all:
+        return enc_output
+    else:
+        return enc_output, enc_outputs