include/comphelper/backupfilehelper.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #ifndef INCLUDED_COMPHELPER_BACKUPFILEHELPER_HXX
  11 #define INCLUDED_COMPHELPER_BACKUPFILEHELPER_HXX
  12
  13 #include <sal/config.h>
  14
  15 #include <comphelper/comphelperdllapi.h>
  16 #include <rtl/ustring.hxx>
  17 #include <osl/file.hxx>
  18 #include <memory>
  19 #include <set>
  20 #include <vector>
  21
  22 namespace comphelper
  23 {
  24     /** Helper class to backup/restore a single file
  25      *
  26      *  This is a general class to manage backups/restore of the file
  27      *  given by the URL. The container holding the backups is created
  28      *  aside the original file, e.g for 'test.txt' a container
  29      *  called '.test.pack' will be used. If it was not yet backed-up
  30      *  this container file will be created at the 1st backup and deleted
  31      *  when the last gets removed. The container holds a stack with a
  32      *  maximum given number (in the constructor) of copies, these are by
  33      *  default compressed, but don't have to be (see tryPush).
  34      *
  35      *  Due to being on a low system level here, no UNO API and not much
  36      *  other tooling can be used, as a consequence for the container a
  37      *  own simple format is used and e.g. the zip lib directly.
  38      *
  39      *  You need to hand over the URL of the file to look at and
  40      *  a maximum number of allowed copies. That number is internally
  41      *  limited to a absolute max of 10 (see implementation). The number
  42      *  of allowed copies is limited to [1..max].
  43      *
  44      *  Calling tryPush() will check if there is no backup yet or if
  45      *  there is one that the file has changed. If yes, a new copy is
  46      *  created on a kind of 'stack' of copies. Tre return value can
  47      *  be used to see if a backup was indeed created.
  48      *
  49      *  Calling tryPop() will do the opposite: If a backup is available,
  50      *  delete the orig file and re-instantiate the backup. The backup
  51      *  is taken off the 'stack' of copies. The return value can be
  52      *  used to check if this was done.
  53      *
  54      *  isPopPossible can be called to see if there is a backup available
  55      *  before calling tryPop().
  56      *
  57      *  The 'stack' of copies works by using the same path, filename
  58      *  and extension, but adding a '_1' -> '_(num_of_copy)' to it.
  59      */
  60     class COMPHELPER_DLLPUBLIC BackupFileHelper
  61     {
  62     private:
  63         // internal data
  64         std::set< OUString >    maDirs;
  65         std::set< std::pair< OUString, OUString > > maFiles;
  66
  67         sal_uInt16              mnNumBackups;
  68         sal_uInt16              mnMode;
  69
  70         bool                    mbActive;
  71         bool                    mbExtensions;
  72         bool                    mbCompress;
  73
  74         // internal flag if _exit() was called already - a hint to evtl.
  75         // not create copies of potentially not well-defined data. This
  76         // may be used in destructors of static instances - which unfortunately
  77         // get called on WNT but not on linux. Thus I thought about encapsulating
  78         // in some '#ifdefs', but it's just more safe to always do it and
  79         // allows to add a SAL_WARN when one of these destructors is called
  80         // after _exit()
  81         static bool         mbExitWasCalled;
  82
  83         // internal detector if SafeModeName dir exists
  84         static bool         mbSafeModeDirExists;
  85
  86         // internal upper limit (max) of allowed backups
  87         static sal_uInt16   mnMaxAllowedBackups;
  88
  89         // path to User's configuration directory and derived strings
  90         static OUString     maInitialBaseURL;
  91         static OUString     maUserConfigBaseURL;
  92         static OUString     maUserConfigWorkURL;
  93         static OUString     maRegModName;
  94         static OUString     maExt;
  95
  96         // get path to User's configuration directory (created on-demand)
  97         static const OUString& getInitialBaseURL();
  98
  99         // the name of the SafeMode directory for temporary processing
 100         static const OUString& getSafeModeName();
 101
 102     public:
 103         /** Constructor to handle Backups of the given file, will internally
 104          *  detect configuration values and URL to initial registrymodifications
 105          *  and thus the User configuration directory
 106          */
 107         BackupFileHelper();
 108
 109         // allow to set static global flag when app had to call _exit()
 110         static void setExitWasCalled();
 111         static bool getExitWasCalled();
 112
 113         // This call initializes the state of the UserDirectory as needed, it may
 114         // initialize to SafeMode configuration or return from it by moving files
 115         // in that directory
 116         static void reactOnSafeMode(bool bSafeMode);
 117
 118         /** tries to create a new backup, if there is none yet, or if the
 119          *  last differs from the base file. It will then put a new version
 120          *  on the 'stack' of copies and evtl. delete the oldest backup.
 121          *  Also may cleanup older backups when NumBackups given in the
 122          *  constructor has changed.
 123          *
 124          *  @return bool
 125          *          returns true if a new backup was actually created
 126          *
 127          * tryPushExtensionInfo is the specialized version for ExtensionInfo
 128          */
 129         bool tryPush();
 130         bool tryPushExtensionInfo();
 131
 132         /** finds out if a restore is possible
 133          *
 134          *  @return bool
 135          *          returns true if a restore to an older backup is possible
 136          *
 137          * isPopPossibleExtensionInfo is the specialized version for ExtensionInfo
 138          */
 139         bool isPopPossible();
 140         bool isPopPossibleExtensionInfo();
 141
 142         /** tries to execute a restore. Will overwrite the base file
 143          *  in that case and take one version off the 'stack' of copies.
 144          *  Also may cleanup older backups when NumBackups given in the
 145          *  constructor has changed.
 146          *
 147          *  @return bool
 148          *          returns true if a restore was actually created
 149          *
 150          * tryPopExtensionInfo is the specialized version for ExtensionInfo
 151          */
 152         bool tryPop();
 153         bool tryPopExtensionInfo();
 154
 155         /** tries to iterate the extensions and to disable all of them
 156         */
 157         static bool isTryDisableAllExtensionsPossible();
 158         static void tryDisableAllExtensions();
 159
 160         /** Deinstall all User Extensions (installed for User only)
 161         */
 162         static bool isTryDeinstallUserExtensionsPossible();
 163         static void tryDeinstallUserExtensions();
 164
 165         /** Reset shared Extensions
 166         */
 167         static bool isTryResetSharedExtensionsPossible();
 168         static void tryResetSharedExtensions();
 169
 170         /** Reset bundled Extensions
 171         */
 172         static bool isTryResetBundledExtensionsPossible();
 173         static void tryResetBundledExtensions();
 174
 175         /// Disables OpenGL and OpenCL
 176         static void tryDisableHWAcceleration();
 177
 178         /** resets User-Customizations like Settings and UserInterface modifications
 179         */
 180         static bool isTryResetCustomizationsPossible();
 181         static void tryResetCustomizations();
 182
 183         /** resets the whole UserProfile
 184         */
 185         static void tryResetUserProfile();
 186
 187         /** Return the profile url */
 188         static const OUString& getUserProfileURL();
 189
 190         /** Return the url of the backed up profile (when in safe mode) */
 191         static const OUString& getUserProfileWorkURL();
 192
 193     private:
 194         // internal helper methods
 195         static const rtl::OUString getPackURL();
 196         static const std::vector< OUString >& getCustomizationDirNames();
 197         static const std::vector< OUString >& getCustomizationFileNames();
 198
 199         // file push helpers
 200         bool tryPush_Files(const std::set< OUString >& rDirs, const std::set< std::pair< OUString, OUString > >& rFiles, const OUString& rSourceURL, const OUString& rTargetURL);
 201         bool tryPush_file(const OUString& rSourceURL, const OUString& rTargetURL, const OUString& rName, const OUString& rExt);
 202
 203         // file pop possibilities helper
 204         bool isPopPossible_files(const std::set< OUString >& rDirs, const std::set< std::pair< OUString, OUString > >& rFiles, const OUString& rSourceURL, const OUString& rTargetURL);
 205         static bool isPopPossible_file(const OUString& rSourceURL, const OUString& rTargetURL, const OUString& rName, const OUString& rExt);
 206
 207         // file pop helpers
 208         bool tryPop_files(const std::set< OUString >& rDirs, const std::set< std::pair< OUString, OUString > >& rFiles, const OUString& rSourceURL, const OUString& rTargetURL);
 209         bool tryPop_file(const OUString& rSourceURL, const OUString& rTargetURL, const OUString& rName, const OUString& rExt);
 210
 211         // ExtensionInfo helpers
 212         bool tryPush_extensionInfo(const OUString& rTargetURL);
 213         static bool isPopPossible_extensionInfo(const OUString& rTargetURL);
 214         bool tryPop_extensionInfo(const OUString& rTargetURL);
 215
 216         // FileDirInfo helpers
 217         void fillDirFileInfo();
 218     };
 219 }
 220
 221 #endif
 222
 223 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */