filesystem.h

/* Copyright (c) 2017 VisualDL Authors. All Rights Reserve.

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 VISUALDL_UTILS_FILESYSTEM_H
#define VISUALDL_UTILS_FILESYSTEM_H

#include <google/protobuf/text_format.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fstream>

#include "visualdl/utils/logging.h"

namespace visualdl {

namespace fs {

template <typename T>
std::string Serialize(const T& proto, bool human_readable = false) {
  if (human_readable) {
    std::string buffer;
    google::protobuf::TextFormat::PrintToString(proto, &buffer);
    return buffer;
  }
  return proto.SerializeAsString();
}

template <typename T>
bool DeSerialize(T* proto, const std::string buf, bool human_readable = false) {
  // NOTE human_readable not valid
  if (human_readable) {
    return google::protobuf::TextFormat::ParseFromString(buf, proto);
  }
  return proto->ParseFromString(buf);
}

template <typename T>
bool SerializeToFile(const T& proto, const std::string& path) {
  std::ofstream file(path, std::ios::binary);
  return proto.SerializeToOstream(&file);
}

template <typename T>
bool DeSerializeFromFile(T* proto, const std::string& path) {
  std::ifstream file(path, std::ios::binary);
  CHECK(file.is_open()) << "open " << path << " failed";
  return proto->ParseFromIstream(&file);
}

static void TryMkdir(const std::string& dir) {
  struct stat st = {0};
  if (stat(dir.c_str(), &st) == -1) {
    ::mkdir(dir.c_str(), 0700);
  }
}

// Create a path by recursively create directries
static void TryRecurMkdir(const std::string& path) {
  // split path by '/'
  for (int i = 1; i < path.size() - 1; i++) {
    if (path[i] == '/') {
      auto dir = path.substr(0, i + 1);
      TryMkdir(dir);
    }
  }
  // the last level
  TryMkdir(path);
}

inline void Write(const std::string& path,
                  const std::string& buffer,
                  std::ios::openmode open_mode = std::ios::binary) {
  std::ofstream file(path, open_mode);
  CHECK(file.is_open()) << "failed to open " << path;
  file.write(buffer.c_str(), buffer.size());
  file.close();
}

inline std::string Read(const std::string& path,
                        std::ios::openmode open_mode = std::ios::binary) {
  std::string buffer;
  std::ifstream file(path, open_mode | std::ios::ate);
  CHECK(file.is_open()) << "failed to open " << path;
  size_t size = file.tellg();
  file.seekg(0);
  buffer.resize(size);
  file.read(&buffer[0], size);
  return buffer;
}

}  // namespace fs

}  // namespace visualdl

#endif  // VISUALDL_BACKEND_UTILS_FILESYSTEM_H