lokinet/llarp/util/fs.hpp

#pragma once

#include <functional>

#if defined(WIN32) || defined(_WIN32)
#define PATH_SEP "\\"
#else
#define PATH_SEP "/"
#endif

#ifdef USE_GHC_FILESYSTEM
#include <ghc/filesystem.hpp>
namespace fs = ghc::filesystem;
#else
#include <filesystem>
namespace fs
{
  using namespace std::filesystem;
  using ifstream = std::ifstream;
  using ofstream = std::ofstream;
  using fstream = std::fstream;
}  // namespace fs

#endif

#ifndef _MSC_VER
#include <dirent.h>
#endif

#include <optional>

namespace llarp
{
  namespace util
  {
    struct FileHash
    {
      size_t
      operator()(const fs::path& f) const
      {
        std::hash<std::string> h;
        return h(f.string());
      }
    };

    using error_code_t = std::error_code;

    /// Ensure that a file exists and has correct permissions
    /// return any error code or success
    error_code_t
    EnsurePrivateFile(fs::path pathname);

    /// open a stream to a file and ensure it exists before open
    /// sets any permissions on creation
    template <typename T>
    std::optional<T>
    OpenFileStream(fs::path pathname, std::ios::openmode mode)
    {
      if (EnsurePrivateFile(pathname))
        return {};

      std::string f = pathname.string();
      return T{pathname, mode};
    }

    using PathVisitor = std::function<bool(const fs::path&)>;
    using PathIter = std::function<void(const fs::path&, PathVisitor)>;

    static PathIter IterDir = [](const fs::path& path, PathVisitor visit) {
#ifdef _MSC_VER
      for (auto& p : fs::directory_iterator(path))
      {
        if (!visit(p.path()))
        {
          break;
        }
      }
#else
      DIR* d = opendir(path.string().c_str());
      if (d == nullptr)
        return;
      struct dirent* ent = nullptr;
      do
      {
        ent = readdir(d);
        if (!ent)
          break;
        if (ent->d_name[0] == '.')
          continue;
        fs::path p = path / fs::path(ent->d_name);
        if (!visit(p))
          break;
      } while (ent);
      closedir(d);
#endif
    };
  }  // namespace util
}  // namespace llarp