Extend fill_zeros_like_op for zero-filling an LoDTensorArray (#11496)

* Add fill_zeros_array op. This op is used for zero-filling an LoDTensorArray.

* merge fill_zeros_array_op with fill_zeros_like_op

* add unit_test for fill_zeros_like for array

paddle/fluid/framework/operator.cc

@@ -713,6 +713,10 @@ proto::VarType::Type OperatorWithKernel::IndicateDataType(
           t = &var->Get<LoDTensor>();
         } else if (var->IsType<SelectedRows>()) {
           t = &(var->Get<SelectedRows>().value());
+        } else if (var->IsType<LoDTensorArray>()) {
+          const LoDTensorArray& arr = var->Get<LoDTensorArray>();
+          PADDLE_ENFORCE(arr.size() > 0);
+          t = &(arr[0]);
         }
         if (t != nullptr) {
           int tmp = static_cast<int>(ToDataType(t->type()));

paddle/fluid/operators/fill_zeros_like_op.cc

@@ -26,8 +26,12 @@ class FillZerosLikeOp : public framework::OperatorWithKernel {
                    "Input(X) of FillZerosLikeOp should not be null.");
     PADDLE_ENFORCE(ctx->HasOutput("Out"),
                    "Output(Out) of FillZerosLikeOp should not be null.");
-    ctx->SetOutputDim("Out", ctx->GetInputDim("X"));
-    ctx->ShareLoD("X", /*->*/ "Out");
+
+    if (ctx->IsRuntime() &&
+        ctx->GetOutputsVarType("Out")[0] ==
+            framework::proto::VarType::LOD_TENSOR_ARRAY) {
+      return;  // skip runtime infershape when is tensor array;
+    }
   }
 };
 
@@ -39,7 +43,7 @@ class FillZerosLikeOpMaker : public framework::OpProtoAndCheckerMaker {
     AddComment(R"DOC(
 FillZerosLike Operator.
 
-Fill up a variable with zeros.
+Fill up a variable with zeros, supporting both LoDTensor and LoDTensorArray.
 The output will have the same size as the input.
 
 )DOC");

paddle/fluid/operators/fill_zeros_like_op.h

@@ -13,6 +13,7 @@ See the License for the specific language governing permissions and
 limitations under the License. */
 
 #pragma once
+#include "paddle/fluid/framework/lod_tensor_array.h"
 #include "paddle/fluid/framework/op_registry.h"
 #include "paddle/fluid/operators/math/math_function.h"
 
@@ -23,12 +24,29 @@ template <typename DeviceContext, typename T>
 class FillZerosLikeKernel : public framework::OpKernel<T> {
  public:
   void Compute(const framework::ExecutionContext& context) const override {
-    auto* out = context.Output<framework::Tensor>("Out");
-    out->mutable_data<T>(context.GetPlace());
-
-    math::SetConstant<DeviceContext, T> setter;
-    setter(context.template device_context<DeviceContext>(), out,
-           static_cast<T>(0));
+    auto var = context.InputVar("X");
+    if (var->IsType<framework::LoDTensor>()) {
+      auto& input = *context.Input<framework::LoDTensor>("X");
+      auto& output = *context.Output<framework::LoDTensor>("Out");
+      output.Resize(input.dims());
+      output.set_lod(input.lod());
+      output.mutable_data<T>(context.GetPlace());
+      math::SetConstant<DeviceContext, T> setter;
+      setter(context.template device_context<DeviceContext>(), &(output),
+             static_cast<T>(0));
+    } else if (var->IsType<framework::LoDTensorArray>()) {
+      auto& input = *context.Input<framework::LoDTensorArray>("X");
+      auto& output = *context.Output<framework::LoDTensorArray>("Out");
+      output.resize(input.size());
+      for (auto i = 0; i < input.size(); i++) {
+        output[i].Resize(input[i].dims());
+        output[i].set_lod(input[i].lod());
+        output[i].mutable_data<T>(context.GetPlace());
+        math::SetConstant<DeviceContext, T> setter;
+        setter(context.template device_context<DeviceContext>(), &(output[i]),
+               static_cast<T>(0));
+      }
+    }
   }
 };
 

python/paddle/fluid/layers/nn.py

@@ -95,6 +95,7 @@ __all__ = [
     'relu',
     'log',
     'crop',
+    'fill_zeros_like',
 ]
 
 
@@ -5184,3 +5185,40 @@ def crop(x, shape=None, offsets=None, name=None):
         outputs={'Out': out},
         attrs=None if len(attrs) == 0 else attrs)
     return out
+
+
+def fill_zeros_like(x):
+    """
+    This layer takes an input and outputs a variable that has the same structure as
+    the input and with all the element values as zero. The variable can be a Tensor
+    or TensorArray.
+
+    .. code-block:: text
+
+
+       Given
+          X = [[0, 1, 2, 0],
+               [0, 3, 4, 0],
+               [0, 0, 0, 0]],
+       output is:
+          Out = [[0, 0, 0, 0],
+                 [0, 0, 0, 0],
+                 [0, 0, 0, 0]].
+
+    Args:
+        x (Variable): The input variable, which could be a tensor or tensor array
+
+    Returns:
+        Variable: The zero-filled variable, which has the same type and shape as
+                  the input variable.
+
+    Examples:
+
+        .. code-block:: python
+            y = fluid.layers.fill_zeros_like(x)
+    """
+    helper = LayerHelper('fill_zeros_like', **locals())
+    out = helper.create_tmp_variable(dtype=x.dtype)
+    helper.append_op(
+        type='fill_zeros_like', inputs={'X': [x]}, outputs={'Out': [out]})
+    return out

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

@@ -0,0 +1,88 @@
+#   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 paddle.fluid.core as core
+import numpy
+import paddle.fluid.layers as layers
+from paddle.fluid.framework import Program, program_guard
+from paddle.fluid.executor import Executor
+
+import paddle.fluid as fluid
+import paddle.fluid.core as core
+
+
+class TestFillZerosLikeOpForTensorArray(unittest.TestCase):
+    def place(self):
+        return core.CPUPlace()
+
+    def test_zero_filling_lod_tensor_array(self):
+        tensor = core.LoDTensor()
+        tensor.set(
+            numpy.arange(20).reshape(20, 1).astype('int32'), self.place())
+        tensor.set_lod([[0, 2, 5], [0, 3, 9, 11, 17, 20]])
+
+        expect = [
+            numpy.array(
+                [0, 0, 0, 0, 0], dtype='int32'), numpy.array(
+                    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], dtype='int32'),
+            numpy.array(
+                [0, 0, 0], dtype='int32')
+        ]
+
+        lod = [[[0, 2, 5]], [[0, 6, 12]], [[0, 3]]]
+        self.main(
+            tensor=tensor,
+            expect_array=expect,
+            expect_lod=lod,
+            expect_max_len=3)
+
+    def main(self, tensor, expect_array, expect_lod, expect_max_len, level=0):
+        place = self.place()
+        program = Program()
+        with program_guard(program):
+            x = layers.data(name='x', shape=[10])
+            x.persistable = True
+            table = layers.lod_rank_table(x, level=level)
+            max_len = layers.max_sequence_len(table)
+            max_len.persistable = True
+            array = layers.lod_tensor_to_array(x, table)
+            array = layers.fill_zeros_like(array)
+            array.persistable = True
+
+            result = layers.array_to_lod_tensor(array, table)
+            result.persistable = True
+        exe = Executor(place)
+        scope = core.Scope()
+        exe.run(program, feed={'x': tensor}, scope=scope)
+        var = scope.find_var(array.name)
+        array = var.get_lod_tensor_array()
+        if expect_array is not None and expect_lod is not None:
+            self.check_array_same(array, expect_array, expect_lod)
+
+        self.assertEqual(
+            numpy.array(scope.find_var(max_len.name).get_tensor())[0],
+            expect_max_len)
+
+    def check_array_same(self, array, expect_tensor, expect_lod):
+        self.assertEqual(len(expect_tensor), len(array))
+        for i, exp in enumerate(zip(expect_tensor, expect_lod)):
+            exp_tensor, exp_lod = exp
+            exp_tensor = numpy.expand_dims(exp_tensor, axis=1)
+            self.assertTrue(numpy.allclose(exp_tensor, numpy.array(array[i])))
+            self.assertEqual(exp_lod, array[i].lod())
+
+
+if __name__ == '__main__':
+    unittest.main()