transport/utils/file_reader.h

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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.
 */
#ifndef FILE_READER_H_
#define FILE_READER_H_

#include <string>
#include <vector>

namespace profiler {

// Class to read file and perform related tokenize util functions.
// TODO: Integrate into utils/fs/file.h?
class FileReader {
 public:
  // Real whole file and split it into lines.
  static bool Read(const std::string &file_path,
                   std::vector<std::string> *lines);

  // Reads whole file from beginning, and put output in a single string content.
  // Returns true on success.
  // The ownership of |content| is not transferred.
  // TODO(b/29111072): Provide an option to read the entire file in a single
  // access. Multiple reads may cause consistency issues, especially for virtual
  // files such as /proc.stat in Android/Linux.
  static bool Read(const std::string &file_path, std::string *content);

 private:
  // Single system call buffer size.
  // TODO: Make the buffer size configurable in a constructor.
  static const uint16_t kBufferSize_ = 4096;
};

}  // namespace profiler

#endif  // FILE_READER_H_