/**

 * This file is part of the CernVM File System

 *

 * This file defines a class which derives `SyncUnion` to provide support for

 * overlayfs

 *

 */

#ifndef CVMFS_SYNC_UNION_OVERLAYFS_H_

#define CVMFS_SYNC_UNION_OVERLAYFS_H_

#include "sync_union.h"

#include <set>

#include <string>

#include "util/shared_ptr.h"

namespace publish {

/**

 * Syncing a cvmfs repository by the help of an overlayed overlayfs

 * read-write volume.

 */

 public:

  SyncUnionOverlayfs(SyncMediator *mediator, const std::string &rdonly_path,

                     const std::string &union_path,

                     const std::string &scratch_path);

  bool Initialize();

  void Traverse();

  static bool ReadlinkEquals(std::string const &path,

                             std::string const &compare_value);

  static bool HasXattr(std::string const &path, std::string const &attr_name);

 protected:

  void PreprocessSyncItem(SharedPtr<SyncItem> entry) const;

  bool IsWhiteoutEntry(SharedPtr<SyncItem> entry) const;

  bool IsOpaqueDirectory(SharedPtr<SyncItem> directory) const;

  bool IsWhiteoutSymlinkPath(const std::string &path) const;

  std::string UnwindWhiteoutFilename(SharedPtr<SyncItem> entry) const;

  std::set<std::string> GetIgnoreFilenames() const;

  void CheckForBrokenHardlink(SharedPtr<SyncItem> entry) const;

  void MaskFileHardlinks(SharedPtr<SyncItem> entry) const;

  bool ObtainSysAdminCapability() const;

 private:

  bool IsOpaqueDirPath(const std::string &path) const;

  std::set<std::string> hardlink_lower_files_;

  uint64_t hardlink_lower_inode_;

};  // class SyncUnionOverlayfs

}  // namespace publish

#endif  // CVMFS_SYNC_UNION_OVERLAYFS_H_