Merge pull request #13856 from kuke/seq_unpad_op

Add sequence unpad op

paddle/fluid/API.spec

@@ -75,7 +75,8 @@ paddle.fluid.layers.conv2d_transpose ArgSpec(args=['input', 'num_filters', 'outp
 paddle.fluid.layers.conv3d_transpose ArgSpec(args=['input', 'num_filters', 'output_size', 'filter_size', 'padding', 'stride', 'dilation', 'groups', 'param_attr', 'bias_attr', 'use_cudnn', 'act', 'name'], varargs=None, keywords=None, defaults=(None, None, 0, 1, 1, None, None, None, True, None, None))
 paddle.fluid.layers.sequence_expand ArgSpec(args=['x', 'y', 'ref_level', 'name'], varargs=None, keywords=None, defaults=(-1, None))
 paddle.fluid.layers.sequence_expand_as ArgSpec(args=['x', 'y', 'name'], varargs=None, keywords=None, defaults=(None,))
-paddle.fluid.layers.sequence_pad ArgSpec(args=['x', 'pad_value', 'maxlen'], varargs=None, keywords=None, defaults=(None,))
+paddle.fluid.layers.sequence_pad ArgSpec(args=['x', 'pad_value', 'maxlen', 'name'], varargs=None, keywords=None, defaults=(None, None))
+paddle.fluid.layers.sequence_unpad ArgSpec(args=['x', 'length', 'name'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.layers.lstm_unit ArgSpec(args=['x_t', 'hidden_t_prev', 'cell_t_prev', 'forget_bias', 'param_attr', 'bias_attr', 'name'], varargs=None, keywords=None, defaults=(0.0, None, None, None))
 paddle.fluid.layers.reduce_sum ArgSpec(args=['input', 'dim', 'keep_dim', 'name'], varargs=None, keywords=None, defaults=(None, False, None))
 paddle.fluid.layers.reduce_mean ArgSpec(args=['input', 'dim', 'keep_dim', 'name'], varargs=None, keywords=None, defaults=(None, False, None))

paddle/fluid/operators/sequence_unpad_op.cc

+/* Copyright (c) 2018 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. */
+
+#include "paddle/fluid/operators/sequence_unpad_op.h"
+
+namespace paddle {
+namespace operators {
+
+class SequenceUnpadOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+ protected:
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"),
+                   "Input(X) of SequenceUnpadOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasInput("Length"),
+                   "Input(Length) of SequenceUnpadOp should not be null.");
+    PADDLE_ENFORCE(ctx->HasOutput("Out"),
+                   "Output(Out) of SequenceUnpadOp should not be null.");
+
+    auto x_dims = ctx->GetInputDim("X");
+    PADDLE_ENFORCE_GE(x_dims.size(), 2,
+                      "The rank of Input(X) can't be less than 2.");
+
+    auto len_dims = ctx->GetInputDim("Length");
+    PADDLE_ENFORCE(len_dims.size() == 2 && len_dims[1] == 1,
+                   "The shape of Input(Length) should be [batch_size, 1].");
+    PADDLE_ENFORCE(
+        len_dims[0] == x_dims[0],
+        "Input(X) and Input(Length) should have the same first dimension.");
+
+    int64_t out_dim_0 = -1;
+    if (ctx->IsRuntime()) {
+      out_dim_0 = x_dims[0] * x_dims[1];
+    }
+
+    std::vector<int64_t> out_dims_vec{out_dim_0};
+    if (x_dims.size() == 2) {
+      out_dims_vec.push_back(1);
+    } else {
+      for (size_t i = 2; i < x_dims.size(); ++i) {
+        out_dims_vec.push_back(x_dims[i]);
+      }
+    }
+    ctx->SetOutputDim("Out", framework::make_ddim(out_dims_vec));
+  }
+
+ protected:
+  framework::OpKernelType GetExpectedKernelType(
+      const framework::ExecutionContext& ctx) const override {
+    auto data_type = framework::GetDataTypeOfVar(ctx.InputVar("X"));
+    return framework::OpKernelType(data_type, ctx.device_context());
+  }
+};
+
+class SequenceUnpadOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() override {
+    AddInput("X",
+             "(LoDTensor, default LoDTensor<float>) Input tensor which "
+             "contains the padded sequences with equal length.");
+    AddInput("Length",
+             "(LoDTensor) The input tensor which specifies the actual ength of "
+             "sequences after unpadding.");
+    AddOutput(
+        "Out",
+        "(LoDTensor) The output tensor which contains unpadded sequences.");
+    AddComment(R"DOC(
+      Sequence Unpad Operator
+
+      This operator removes the padding data in the input sequences and convert 
+      them into sequences with actual length as output, identitied by lod 
+      information.
+
+      Example:
+
+      Given input tensor Input(X):
+          X.data = [[ 1.0,  2.0,  3.0,  4.0,  5.0],
+                    [ 6.0,  7.0,  8.0,  9.0, 10.0],
+                    [11.0, 12.0, 13.0, 14.0, 15.0]], 
+`     
+      in which there are 3 sequences padded to length 5, and the acutal length 
+      specified by Input(Length):
+
+          Length.data = [[2], [3], [4]],
+
+      after unpadding, Output(Out) will be:
+
+          Out.data = [[1.0, 2.0, 6.0, 7.0, 8.0, 11.0, 12.0, 13.0, 14.0]]
+          Out.lod = [[0, 2, 5, 9]]      
+
+    )DOC");
+  }
+};
+
+class SequenceUnpadGradOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"),
+                   "Input(X) of SequenceUnpadGradOp should not be null.");
+    PADDLE_ENFORCE(
+        ctx->HasInput(framework::GradVarName("Out")),
+        "Input(Out@GRAD) of SequenceUnpadGradOp should not be null.");
+
+    if (ctx->HasOutput(framework::GradVarName("X"))) {
+      ctx->SetOutputDim(framework::GradVarName("X"), ctx->GetInputDim("X"));
+      ctx->ShareLoD("X", /*->*/ framework::GradVarName("X"));
+    }
+  }
+
+ protected:
+  framework::OpKernelType GetExpectedKernelType(
+      const framework::ExecutionContext& ctx) const override {
+    auto data_type = framework::GetDataTypeOfVar(ctx.InputVar("X"));
+    return framework::OpKernelType(data_type, ctx.device_context());
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OPERATOR(sequence_unpad, ops::SequenceUnpadOp,
+                  ops::SequenceUnpadOpMaker,
+                  paddle::framework::DefaultGradOpDescMaker<true>);
+REGISTER_OPERATOR(sequence_unpad_grad, ops::SequenceUnpadGradOp);
+REGISTER_OP_CPU_KERNEL(
+    sequence_unpad,
+    ops::SequenceUnpadOpKernel<paddle::platform::CPUDeviceContext, float>,
+    ops::SequenceUnpadOpKernel<paddle::platform::CPUDeviceContext, double>,
+    ops::SequenceUnpadOpKernel<paddle::platform::CPUDeviceContext, int>,
+    ops::SequenceUnpadOpKernel<paddle::platform::CPUDeviceContext, int64_t>);
+REGISTER_OP_CPU_KERNEL(
+    sequence_unpad_grad,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CPUDeviceContext, float>,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CPUDeviceContext, double>,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CPUDeviceContext, int>,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CPUDeviceContext,
+                                   int64_t>);

paddle/fluid/operators/sequence_unpad_op.cu

+/* Copyright (c) 2018 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. */
+
+#include "paddle/fluid/operators/sequence_unpad_op.h"
+
+namespace ops = paddle::operators;
+REGISTER_OP_CUDA_KERNEL(
+    sequence_unpad,
+    ops::SequenceUnpadOpKernel<paddle::platform::CUDADeviceContext, float>,
+    ops::SequenceUnpadOpKernel<paddle::platform::CUDADeviceContext, double>,
+    ops::SequenceUnpadOpKernel<paddle::platform::CUDADeviceContext, int>,
+    ops::SequenceUnpadOpKernel<paddle::platform::CUDADeviceContext, int64_t>);
+REGISTER_OP_CUDA_KERNEL(
+    sequence_unpad_grad,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CUDADeviceContext, float>,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CUDADeviceContext, double>,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CUDADeviceContext, int>,
+    ops::SequenceUnpadGradOpKernel<paddle::platform::CUDADeviceContext,
+                                   int64_t>);

paddle/fluid/operators/sequence_unpad_op.h

+/* Copyright (c) 2018 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. */
+
+#pragma once
+
+#include <vector>
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/memory/memcpy.h"
+#include "paddle/fluid/operators/math/math_function.h"
+#include "paddle/fluid/operators/math/sequence_padding.h"
+
+namespace paddle {
+namespace operators {
+
+using LoDTensor = framework::LoDTensor;
+using LoD = framework::LoD;
+
+template <typename DeviceContext, typename T>
+class SequenceUnpadOpKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    auto* x_t = ctx.Input<LoDTensor>("X");
+    auto* len_t = ctx.Input<LoDTensor>("Length");
+    auto* out_t = ctx.Output<LoDTensor>("Out");
+    out_t->mutable_data<T>(ctx.GetPlace());
+
+    const int64_t* seq_len_ptr = nullptr;
+    if (platform::is_gpu_place(ctx.GetPlace())) {
+      LoDTensor seq_len_cpu;
+      seq_len_cpu.Resize(len_t->dims());
+      seq_len_ptr = seq_len_cpu.mutable_data<int64_t>(platform::CPUPlace());
+      framework::TensorCopy(*len_t, platform::CPUPlace(),
+                            ctx.template device_context<DeviceContext>(),
+                            &seq_len_cpu);
+    } else {
+      seq_len_ptr = len_t->data<int64_t>();
+    }
+
+    size_t batch_size = x_t->dims()[0];
+    std::vector<size_t> out_lod0(batch_size + 1, 0);
+    for (size_t i = 0; i < batch_size; ++i) {
+      out_lod0[i + 1] = out_lod0[i] + seq_len_ptr[i];
+    }
+
+    framework::LoD out_lod;
+    out_lod.push_back(out_lod0);
+    out_t->set_lod(out_lod);
+
+    std::vector<int64_t> out_dims_vec{static_cast<int64_t>(out_lod0.back())};
+    if (x_t->dims().size() == 2) {
+      out_dims_vec.push_back(1);
+    } else {
+      for (size_t i = 2; i < x_t->dims().size(); ++i) {
+        out_dims_vec.push_back(x_t->dims()[i]);
+      }
+    }
+    out_t->Resize(framework::make_ddim(out_dims_vec));
+
+    int64_t padded_length = x_t->dims()[1];
+    math::UnpaddingLoDTensorFunctor<DeviceContext, T>()(
+        ctx.template device_context<DeviceContext>(), *x_t, out_t,
+        padded_length, 0, false, math::kBatchLengthWidth);
+  }
+};
+
+template <typename DeviceContext, typename T>
+class SequenceUnpadGradOpKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    auto* d_x = ctx.Output<LoDTensor>(framework::GradVarName("X"));
+    if (d_x) {
+      const auto* d_out = ctx.Input<LoDTensor>(framework::GradVarName("Out"));
+      const auto* x_t = ctx.Input<LoDTensor>("X");
+      d_x->mutable_data<T>(ctx.GetPlace());
+
+      int padded_length = x_t->dims()[1];
+
+      LoDTensor zero_pads;
+      zero_pads.Resize({1, 1});
+      zero_pads.mutable_data<T>(ctx.GetPlace());
+      math::SetConstant<DeviceContext, T> set_zero;
+      auto& dev_ctx = ctx.template device_context<DeviceContext>();
+      set_zero(dev_ctx, &zero_pads, static_cast<T>(0));
+
+      math::PaddingLoDTensorFunctor<DeviceContext, T>()(
+          ctx.template device_context<DeviceContext>(), *d_out, d_x, zero_pads,
+          padded_length, 0, false, math::kBatchLengthWidth);
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/layers/nn.py

@@ -56,6 +56,7 @@ __all__ = [
     'sequence_expand',
     'sequence_expand_as',
     'sequence_pad',
+    'sequence_unpad',
     'lstm_unit',
     'reduce_sum',
     'reduce_mean',
@@ -2793,7 +2794,7 @@ def sequence_expand_as(x, y, name=None):
 
 
 @templatedoc()
-def sequence_pad(x, pad_value, maxlen=None):
+def sequence_pad(x, pad_value, maxlen=None, name=None):
     """
     ${comment}
 
@@ -2807,7 +2808,9 @@ def sequence_pad(x, pad_value, maxlen=None):
             None or any positive int. When it is None, all sequences will be
             padded up to the length of the longest one among them; when it a
             certain positive value, it must be greater than the length of the
-            longest original sequence."
+            longest original sequence.
+        name(str|None): A name for this layer(optional). If set None, the layer
+            will be named automatically.
 
     Returns:
         Variable: The padded sequence batch and the original lengths before
@@ -2844,6 +2847,66 @@ def sequence_pad(x, pad_value, maxlen=None):
     return out, length
 
 
+def sequence_unpad(x, length, name=None):
+    """
+    **Sequence Unpad Layer**
+
+    This layer removes the padding data in the input sequences and convert 
+    them into sequences with actual length as output, identitied by lod 
+    information.
+
+    .. code-block:: text
+
+	Example:
+
+	Given input Variable **x**:
+	    x.data = [[ 1.0,  2.0,  3.0,  4.0,  5.0],
+		      [ 6.0,  7.0,  8.0,  9.0, 10.0],
+		      [11.0, 12.0, 13.0, 14.0, 15.0]], 
+     
+	in which there are 3 sequences padded to length 5, and the acutal length 
+	specified by input Variable **length**:
+
+	    length.data = [[2], [3], [4]],
+
+	after unpadding, the output Variable will be:
+
+	    out.data = [[1.0, 2.0, 6.0, 7.0, 8.0, 11.0, 12.0, 13.0, 14.0]]
+	    out.lod = [[2, 3, 4]]      
+
+    Args:
+        x(Variable): Input Variable which contains the padded sequences with
+            equal length.
+        length(Variable): The Variable that specifies the actual ength of
+            sequences after unpadding.
+        name(str|None): A name for this layer(optional). If set None, the layer
+            will be named automatically.
+
+    Returns:
+        Variable: The Variable contains the unpadded sequences.
+
+    Examples:
+        .. code-block:: python
+
+            x = fluid.layers.data(name='x', shape=[10, 5], dtype='float32')
+            len = fluid.layers.data(name='length', shape=[1], dtype='int64')
+            out = fluid.layers.sequence_unpad(x=x, length=len)
+    """
+
+    helper = LayerHelper('sequence_unpad', input=x, **locals())
+    dtype = helper.input_dtype()
+    out = helper.create_tmp_variable(dtype)
+
+    length.stop_gradient = True
+
+    helper.append_op(
+        type='sequence_unpad',
+        inputs={'X': x,
+                'Length': length},
+        outputs={'Out': out})
+    return out
+
+
 def beam_search(pre_ids,
                 pre_scores,
                 ids,

python/paddle/fluid/tests/unittests/test_layers.py

@@ -194,6 +194,14 @@ class TestBook(unittest.TestCase):
             self.assertIsNotNone(layers.sequence_expand(x=x, y=y, ref_level=1))
         print(str(program))
 
+    def test_sequence_unpad(self):
+        program = Program()
+        with program_guard(program):
+            x = layers.data(name='x', shape=[10, 5], dtype='float32')
+            length = layers.data(name='length', shape=[1], dtype='int64')
+            self.assertIsNotNone(layers.sequence_unpad(x=x, length=length))
+        print(str(program))
+
     def test_lstm_unit(self):
         program = Program()
         with program_guard(program):

python/paddle/fluid/tests/unittests/test_sequence_unpad_op.py

+# Copyright (c) 2018 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.
+
+import unittest
+import six
+import numpy as np
+from op_test import OpTest
+
+
+class TestSequenceUnpadOp(OpTest):
+    def init(self):
+        self.length = [2, 3, 4]
+        self.x_shape = (3, 5)
+        self.dtype = "float32"
+
+    def compute(self):
+        assert len(self.length) == self.x_shape[0]
+        x = np.random.random(self.x_shape).astype(self.dtype)
+        out_lod = [self.length]
+
+        out = x[0, 0:self.length[0]]
+        for i in six.moves.xrange(1, x.shape[0]):
+            out = np.append(out, x[i, 0:self.length[i]], axis=0)
+
+        out_shape = (sum(self.length), )
+        if len(self.x_shape) == 2:
+            out_shape = out_shape + (1, )
+        else:
+            out_shape = out_shape + self.x_shape[2:]
+
+        self.inputs = {
+            'X': x,
+            'Length': np.array(self.length).astype('int64').reshape(-1, 1)
+        }
+        self.outputs = {'Out': (out.reshape(out_shape), out_lod)}
+
+    def setUp(self):
+        self.op_type = 'sequence_unpad'
+        self.init()
+        self.compute()
+
+    def test_check_output(self):
+        self.check_output()
+
+    def test_check_grad(self):
+        self.check_grad(["X"], "Out")
+
+
+class TestSequenceUnpadOp2(TestSequenceUnpadOp):
+    def init(self):
+        self.length = [2, 3, 4]
+        self.x_shape = (3, 5, 4, 3)
+        self.dtype = "float32"
+
+
+class TestSequenceUnpadOp3(TestSequenceUnpadOp):
+    def init(self):
+        self.length = [5, 2, 3, 4]
+        self.x_shape = (4, 5, 3, 3, 6)
+        self.dtype = "float64"
+
+
+if __name__ == '__main__':
+    unittest.main()