add split ids op (#9370)

* add split_ids_op

* add TestSplitIdsOp

* fix comment

* add test for empty tensor

* clean code

* rm unused code

paddle/fluid/operators/split_ids_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/split_ids_op.h"
+
+namespace paddle {
+namespace operators {
+
+class SplitIdsOpMaker : public framework::OpProtoAndCheckerMaker {
+ public:
+  SplitIdsOpMaker(OpProto *proto, OpAttrChecker *op_checker)
+      : OpProtoAndCheckerMaker(proto, op_checker) {
+    AddInput("Ids", "(LoDTensor) the input ids with shape{batch_num, 1}");
+    AddOutput("Out", "(LoDTensor) The outputs of the input Ids.")
+        .AsDuplicable();
+
+    AddComment(R"DOC(
+Split a LoDTensor of Ids into multi LoDTensors, the number is pserver's number
+Example:
+  Input:
+    X = [1,2,3,4,5,6]
+
+  Out(3 output):
+    out0 = [3, 6]
+    out1 = [1, 4]
+    out2 = [2, 5]
+)DOC");
+  }
+};
+
+class SplitIdsOp : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext *ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("Ids"), "SplitIdsOp must has input Ids.");
+    PADDLE_ENFORCE(ctx->HasOutputs("Out"), "SplitIdsOp must has output Out.");
+
+    auto ids_var_type = ctx->GetInputsVarType("Ids").front();
+    PADDLE_ENFORCE_EQ(ids_var_type, framework::proto::VarType::LOD_TENSOR);
+
+    auto ids_dims = ctx->GetInputDim("Ids");
+    PADDLE_ENFORCE_EQ(ids_dims.size(), 2);
+    PADDLE_ENFORCE_EQ(ids_dims[1], 1);
+  }
+};
+
+class SplitIdsOpInferVarType : public framework::VarTypeInference {
+ public:
+  void operator()(const framework::OpDesc &op_desc,
+                  framework::BlockDesc *block) const override {
+    for (auto &out_var : op_desc.Output("Out")) {
+      block->Var(out_var)->SetType(framework::proto::VarType::LOD_TENSOR);
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+REGISTER_OPERATOR(split_ids, ops::SplitIdsOp, ops::SplitIdsOpMaker,
+                  ops::SplitIdsOpInferVarType);
+REGISTER_OP_CPU_KERNEL(
+    split_ids, ops::SplitIdsOpKernel<paddle::platform::CPUPlace, int64_t>);

paddle/fluid/operators/split_ids_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/operators/math/selected_rows_functor.h"
+
+namespace paddle {
+namespace operators {
+
+template <typename DeviceContext, typename T>
+class SplitIdsOpKernel : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext& ctx) const override {
+    auto place = ctx.GetPlace();
+    if (!platform::is_cpu_place(place)) {
+      PADDLE_THROW("SplitIds do not support GPU kernel");
+    }
+
+    const auto* ids_t = ctx.Input<framework::LoDTensor>("Ids");
+    auto& ids_dims = ids_t->dims();
+    auto outs = ctx.MultiOutput<framework::LoDTensor>("Out");
+
+    const T* ids = ids_t->data<T>();
+
+    const size_t shard_num = outs.size();
+
+    std::vector<std::vector<T>> out_ids;
+    out_ids.resize(outs.size());
+
+    // split id by their shard_num.
+    for (size_t i = 0; i < ids_dims[0]; ++i) {
+      T id = ids[i];
+      size_t shard_id = static_cast<size_t>(id) % shard_num;
+      out_ids[shard_id].push_back(id);
+    }
+
+    // create tensor for each shard and send to parameter server
+    for (size_t i = 0; i < out_ids.size(); ++i) {
+      auto* shard_t = outs[i];
+      std::vector<T> ids = out_ids[i];
+      auto* shard_data = shard_t->mutable_data<T>(
+          framework::make_ddim({static_cast<int64_t>(ids.size()), 1}), place);
+      for (size_t i = 0; i < ids.size(); ++i) {
+        shard_data[i] = ids[i];
+      }
+    }
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/tests/unittests/test_split_ids_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 numpy as np
+from op_test import OpTest
+
+
+class TestSplitIdsOp(OpTest):
+    def setUp(self):
+        self.op_type = "split_ids"
+        ids = np.array([[0], [2], [2], [3], [5], [5], [6]]).astype('int64')
+        out0 = np.array([[0], [3], [6]]).astype('int64')
+        out1 = np.array([[]]).astype('int64')
+        out2 = np.array([[2], [2], [5], [5]]).astype('int64')
+        self.inputs = {'Ids': ids}
+        self.outputs = {'Out': [('out0', out0), ('out1', out1), ('out2', out2)]}
+
+    def test_check_output(self):
+        self.check_output()
+
+
+if __name__ == '__main__':
+    unittest.main()