transactionalfilesystem.h

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/*
 * LibrePCB - Professional EDA for everyone!
 * Copyright (C) 2013 LibrePCB Developers, see AUTHORS.md for contributors.
 * https://librepcb.org/
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#ifndef LIBREPCB_CORE_TRANSACTIONALFILESYSTEM_H
#define LIBREPCB_CORE_TRANSACTIONALFILESYSTEM_H
 
/*******************************************************************************
 *  Includes
 ******************************************************************************/
#include "../exceptions.h"
#include "directorylock.h"
#include "filesystem.h"
 
#include <QtCore>
 
#include <memory>
 
/*******************************************************************************
 *  Namespace / Forward Declarations
 ******************************************************************************/
namespace librepcb {
 
class ZipWriter;
 
/*******************************************************************************
 *  Class TransactionalFileSystem
 ******************************************************************************/
 
class TransactionalFileSystem final : public FileSystem {
  Q_OBJECT
 
public:
  typedef std::function<bool(const QString& filePath)> FilterFunction;
 
  typedef std::function<bool(const FilePath& dir)> RestoreCallback;
 
  struct RestoreMode {
    static bool no(const FilePath& dir) {
      Q_UNUSED(dir);
      return false;
    }
 
    static bool yes(const FilePath& dir) {
      Q_UNUSED(dir);
      return true;
    }
 
    static bool abort(const FilePath& dir) {
      throw RuntimeError(__FILE__, __LINE__,
                         QString("Autosave backup detected in directory '%1'.")
                             .arg(dir.toNative()));
    }
  };
 
  struct State {
    QHash<QString, QByteArray> modifiedFiles;
    QSet<QString> removedFiles;
    QSet<QString> removedDirs;
  };
 
  // Constructors / Destructor
  TransactionalFileSystem() = delete;
  TransactionalFileSystem(
      const FilePath& filepath, bool writable = false,
      RestoreCallback restoreCallback = RestoreCallback(),
      DirectoryLock::LockHandlerCallback lockCallback = nullptr,
      QObject* parent = nullptr);
  TransactionalFileSystem(const TransactionalFileSystem& other) = delete;
  virtual ~TransactionalFileSystem() noexcept;
 
  // Getters
  const FilePath& getPath() const noexcept { return mFilePath; }
  bool isWritable() const noexcept { return mIsWritable; }
  bool isRestoredFromAutosave() const noexcept { return mRestoredFromAutosave; }
 
  // Inherited from FileSystem
  virtual FilePath getAbsPath(const QString& path = "") const noexcept override;
  virtual QStringList getDirs(const QString& path = "") const noexcept override;
  virtual QStringList getFiles(
      const QString& path = "") const noexcept override;
  virtual bool fileExists(const QString& path) const noexcept override;
  virtual QByteArray read(const QString& path) const override;
  virtual QByteArray readIfExists(const QString& path) const override;
  virtual void write(const QString& path, const QByteArray& content) override;
  virtual void renameFile(const QString& src, const QString& dst) override;
  virtual void removeFile(const QString& path) override;
  virtual void removeDirRecursively(const QString& path = "") override;
 
  // General Methods
  State saveState() const noexcept { return mState; }
  void restoreState(const State& state) noexcept { mState = state; }
  void loadFromZip(QByteArray content);
  void loadFromZip(const FilePath& fp);
  QByteArray exportToZip(FilterFunction filter = nullptr) const;
  void exportToZip(const FilePath& fp, FilterFunction filter = nullptr) const;
  void discardChanges() noexcept;
  QStringList checkForModifications() const;
  void autosave();
  void save();
  void releaseLock();
 
  // Static Methods
  static std::shared_ptr<TransactionalFileSystem> open(
      const FilePath& filepath, bool writable,
      RestoreCallback restoreCallback = &RestoreMode::no,
      DirectoryLock::LockHandlerCallback lockCallback = nullptr,
      QObject* parent = nullptr) {
    return std::make_shared<TransactionalFileSystem>(
        filepath, writable, restoreCallback, lockCallback, parent);
  }
  static std::shared_ptr<TransactionalFileSystem> openRO(
      const FilePath& filepath,
      RestoreCallback restoreCallback = &RestoreMode::no,
      QObject* parent = nullptr) {
    return open(filepath, false, restoreCallback, nullptr, parent);
  }
  static std::shared_ptr<TransactionalFileSystem> openRW(
      const FilePath& filepath,
      RestoreCallback restoreCallback = &RestoreMode::no,
      DirectoryLock::LockHandlerCallback lockCallback = nullptr,
      QObject* parent = nullptr) {
    return open(filepath, true, restoreCallback, lockCallback, parent);
  }
  static QString cleanPath(QString path) noexcept;
 
private:  // Methods
  bool isRemoved(const QString& path) const noexcept;
  void exportDirToZip(ZipWriter& zip, const FilePath& zipFp, const QString& dir,
                      FilterFunction filter) const;
  void saveDiff(const QString& type) const;
  void loadDiff(const FilePath& fp);
  void removeDiff(const QString& type);
  void sanitizePathOrThrow(const QString& cleanedPath) const;
  bool checkIfPathIsSafe(const QString& cleanedPath) const noexcept;
 
private:  // Data
  const FilePath mFilePath;
  bool mIsWritable;
  DirectoryLock mLock;
  bool mRestoredFromAutosave;
  mutable QRecursiveMutex mMutex;
 
  // File system modifications
  State mState;
};
 
/*******************************************************************************
 *  End of File
 ******************************************************************************/
 
}  // namespace librepcb
 
#endif