src/base/utils/io.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2020  Mike Tzou (Chocobo1)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  */
  28
  29 #include "io.h"
  30
  31 #include <limits>
  32 #include <utility>
  33
  34 #include <libtorrent/bencode.hpp>
  35 #include <libtorrent/entry.hpp>
  36
  37 #include <QCoreApplication>
  38 #include <QByteArray>
  39 #include <QFile>
  40 #include <QFileDevice>
  41 #include <QSaveFile>
  42 #include <QString>
  43 #include <QTemporaryFile>
  44
  45 #include "base/path.h"
  46 #include "base/utils/fs.h"
  47
  48 Utils::IO::FileDeviceOutputIterator::FileDeviceOutputIterator(QFileDevice &device, const int bufferSize)
  49     : m_device {&device}
  50     , m_buffer {std::make_shared<QByteArray>()}
  51     , m_bufferSize {bufferSize}
  52 {
  53     m_buffer->reserve(bufferSize);
  54 }
  55
  56 Utils::IO::FileDeviceOutputIterator::~FileDeviceOutputIterator()
  57 {
  58     if (m_buffer.use_count() == 1)
  59     {
  60         if (m_device->error() == QFileDevice::NoError)
  61             m_device->write(*m_buffer);
  62         m_buffer->clear();
  63     }
  64 }
  65
  66 Utils::IO::FileDeviceOutputIterator &Utils::IO::FileDeviceOutputIterator::operator=(const char c)
  67 {
  68     m_buffer->append(c);
  69     if (m_buffer->size() >= m_bufferSize)
  70     {
  71         if (m_device->error() == QFileDevice::NoError)
  72             m_device->write(*m_buffer);
  73         m_buffer->clear();
  74     }
  75     return *this;
  76 }
  77
  78 nonstd::expected<QByteArray, Utils::IO::ReadError> Utils::IO::readFile(const Path &path, const qint64 maxSize, const QIODevice::OpenMode additionalMode)
  79 {
  80     QFile file {path.data()};
  81     if (!file.open(QIODevice::ReadOnly | additionalMode))
  82     {
  83         const QString message = QCoreApplication::translate("Utils::IO", "File open error. File: \"%1\". Error: \"%2\"")
  84             .arg(file.fileName(), file.errorString());
  85         return nonstd::make_unexpected(ReadError {ReadError::NotExist, message});
  86     }
  87
  88     const qint64 fileSize = file.size();
  89     if ((maxSize >= 0) && (fileSize > maxSize))
  90     {
  91         const QString message = QCoreApplication::translate("Utils::IO", "File size exceeds limit. File: \"%1\". File size: %2. Size limit: %3")
  92             .arg(file.fileName(), QString::number(fileSize), QString::number(maxSize));
  93         return nonstd::make_unexpected(ReadError {ReadError::ExceedSize, message});
  94     }
  95     if (!std::in_range<qsizetype>(fileSize))
  96     {
  97         const QString message = QCoreApplication::translate("Utils::IO", "File size exceeds data size limit. File: \"%1\". File size: %2. Array limit: %3")
  98             .arg(file.fileName(), QString::number(fileSize), QString::number(std::numeric_limits<qsizetype>::max()));
  99         return nonstd::make_unexpected(ReadError {ReadError::ExceedSize, message});
 100     }
 101
 102     QByteArray ret {static_cast<qsizetype>(fileSize), Qt::Uninitialized};
 103     const qint64 actualSize = file.read(ret.data(), fileSize);
 104
 105     if (actualSize < 0)
 106     {
 107         const QString message = QCoreApplication::translate("Utils::IO", "File read error. File: \"%1\". Error: \"%2\"")
 108             .arg(file.fileName(), file.errorString());
 109         return nonstd::make_unexpected(ReadError {ReadError::Failed, message});
 110     }
 111
 112     if (actualSize < fileSize)
 113     {
 114         // `QIODevice::Text` will convert CRLF to LF on-the-fly and affects return value
 115         // of `qint64 QIODevice::read(char *data, qint64 maxSize)`
 116         if (additionalMode.testFlag(QIODevice::Text))
 117         {
 118             ret.truncate(actualSize);
 119         }
 120         else
 121         {
 122             const QString message = QCoreApplication::translate("Utils::IO", "Read size mismatch. File: \"%1\". Expected: %2. Actual: %3")
 123                 .arg(file.fileName(), QString::number(fileSize), QString::number(actualSize));
 124             return nonstd::make_unexpected(ReadError {ReadError::SizeMismatch, message});
 125         }
 126     }
 127
 128     return ret;
 129 }
 130
 131 nonstd::expected<void, QString> Utils::IO::saveToFile(const Path &path, const QByteArray &data)
 132 {
 133     if (const Path parentPath = path.parentPath(); !parentPath.isEmpty())
 134         Utils::Fs::mkpath(parentPath);
 135     QSaveFile file {path.data()};
 136     if (!file.open(QIODevice::WriteOnly) || (file.write(data) != data.size()) || !file.flush() || !file.commit())
 137         return nonstd::make_unexpected(file.errorString());
 138     return {};
 139 }
 140
 141 nonstd::expected<void, QString> Utils::IO::saveToFile(const Path &path, const lt::entry &data)
 142 {
 143     QSaveFile file {path.data()};
 144     if (!file.open(QIODevice::WriteOnly))
 145         return nonstd::make_unexpected(file.errorString());
 146
 147     const int bencodedDataSize = lt::bencode(Utils::IO::FileDeviceOutputIterator {file}, data);
 148     if ((file.size() != bencodedDataSize) || !file.flush() || !file.commit())
 149         return nonstd::make_unexpected(file.errorString());
 150
 151     return {};
 152 }
 153
 154 nonstd::expected<Path, QString> Utils::IO::saveToTempFile(const QByteArray &data)
 155 {
 156     QTemporaryFile file {(Utils::Fs::tempPath() / Path(u"file_"_s)).data()};
 157     if (!file.open() || (file.write(data) != data.length()) || !file.flush())
 158         return nonstd::make_unexpected(file.errorString());
 159
 160     file.setAutoRemove(false);
 161     return Path(file.fileName());
 162 }
 163
 164 nonstd::expected<Path, QString> Utils::IO::saveToTempFile(const lt::entry &data)
 165 {
 166     QTemporaryFile file {(Utils::Fs::tempPath() / Path(u"file_"_s)).data()};
 167     if (!file.open())
 168         return nonstd::make_unexpected(file.errorString());
 169
 170     const int bencodedDataSize = lt::bencode(Utils::IO::FileDeviceOutputIterator {file}, data);
 171     if ((file.size() != bencodedDataSize) || !file.flush())
 172         return nonstd::make_unexpected(file.errorString());
 173
 174     file.setAutoRemove(false);
 175     return Path(file.fileName());
 176 }