chore: import upstream snapshot with attribution

paddle/phi/kernels/cpu/read_file_kernel.cc

@@ -0,0 +1,42 @@
+// Copyright (c) 2023 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 <fstream>
+#include <string>
+#include <vector>
+
+#include "paddle/phi/core/generator.h"
+#include "paddle/phi/core/kernel_registry.h"
+
+namespace phi {
+
+template <typename T, typename Context>
+void ReadFileKernel(const Context& dev_ctx,
+                    const std::string& filename,
+                    DenseTensor* out) {
+  std::ifstream input(filename.c_str(),
+                      std::ios::in | std::ios::binary | std::ios::ate);
+  std::streamsize file_size = input.tellg();
+
+  input.seekg(0, std::ios::beg);
+
+  out->Resize({file_size});
+  uint8_t* data = dev_ctx.template Alloc<T>(out);
+  input.read(reinterpret_cast<char*>(data), file_size);
+}
+}  // namespace phi
+
+PD_REGISTER_KERNEL(read_file, CPU, ALL_LAYOUT, phi::ReadFileKernel, uint8_t) {
+  kernel->OutputAt(0).SetDataType(phi::DataType::UINT8);
+}