source/modules/water/files/TemporaryFile.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the Water library.
   5    Copyright (c) 2016 ROLI Ltd.
   6    Copyright (C) 2017-2023 Filipe Coelho <falktx@falktx.com>
   7
   8    Permission is granted to use this software under the terms of the ISC license
   9    http://www.isc.org/downloads/software-support-policy/isc-license/
  10
  11    Permission to use, copy, modify, and/or distribute this software for any
  12    purpose with or without fee is hereby granted, provided that the above
  13    copyright notice and this permission notice appear in all copies.
  14
  15    THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
  16    TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  17    FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
  18    OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  19    USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  20    TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  21    OF THIS SOFTWARE.
  22
  23   ==============================================================================
  24 */
  25
  26 #include "TemporaryFile.h"
  27 #include "../maths/Random.h"
  28
  29 #include "CarlaTimeUtils.hpp"
  30
  31 namespace water {
  32
  33 static File createTempFile (const File& parentDirectory, String name,
  34                             const String& suffix, const int optionFlags)
  35 {
  36     if ((optionFlags & TemporaryFile::useHiddenFile) != 0)
  37         name = "." + name;
  38
  39     return parentDirectory.getNonexistentChildFile (name, suffix, (optionFlags & TemporaryFile::putNumbersInBrackets) != 0);
  40 }
  41
  42 TemporaryFile::TemporaryFile (const String& suffix, const int optionFlags)
  43     : temporaryFile (createTempFile (File::getSpecialLocation (File::tempDirectory),
  44                                      "temp_" + String::toHexString (Random::getSystemRandom().nextInt()),
  45                                      suffix, optionFlags))
  46 {
  47 }
  48
  49 TemporaryFile::TemporaryFile (const File& target, const int optionFlags)
  50     : temporaryFile (createTempFile (target.getParentDirectory(),
  51                                      target.getFileNameWithoutExtension()
  52                                        + "_temp" + String::toHexString (Random::getSystemRandom().nextInt()),
  53                                      target.getFileExtension(), optionFlags)),
  54       targetFile (target)
  55 {
  56     // If you use this constructor, you need to give it a valid target file!
  57     wassert (targetFile != File());
  58 }
  59
  60 TemporaryFile::TemporaryFile (const File& target, const File& temporary)
  61     : temporaryFile (temporary), targetFile (target)
  62 {
  63 }
  64
  65 TemporaryFile::~TemporaryFile()
  66 {
  67     if (! deleteTemporaryFile())
  68     {
  69         /* Failed to delete our temporary file! The most likely reason for this would be
  70            that you've not closed an output stream that was being used to write to file.
  71
  72            If you find that something beyond your control is changing permissions on
  73            your temporary files and preventing them from being deleted, you may want to
  74            call TemporaryFile::deleteTemporaryFile() to detect those error cases and
  75            handle them appropriately.
  76         */
  77         wassertfalse;
  78     }
  79 }
  80
  81 //==============================================================================
  82 bool TemporaryFile::overwriteTargetFileWithTemporary() const
  83 {
  84     // This method only works if you created this object with the constructor
  85     // that takes a target file!
  86     wassert (targetFile != File());
  87
  88     if (temporaryFile.exists())
  89     {
  90         // Have a few attempts at overwriting the file before giving up..
  91         for (int i = 5; --i >= 0;)
  92         {
  93             if (temporaryFile.replaceFileIn (targetFile))
  94                 return true;
  95
  96             carla_msleep (100);
  97         }
  98     }
  99     else
 100     {
 101         // There's no temporary file to use. If your write failed, you should
 102         // probably check, and not bother calling this method.
 103         wassertfalse;
 104     }
 105
 106     return false;
 107 }
 108
 109 bool TemporaryFile::deleteTemporaryFile() const
 110 {
 111     // Have a few attempts at deleting the file before giving up..
 112     for (int i = 5; --i >= 0;)
 113     {
 114         if (temporaryFile.deleteFile())
 115             return true;
 116
 117         carla_msleep (50);
 118     }
 119
 120     return false;
 121 }
 122
 123 }