File indexing completed on 2024-05-05 16:18:05

 /*
     SPDX-FileCopyrightText: 2010-2018 Dominik Haumann <dhaumann@kde.org>
     SPDX-FileCopyrightText: 2010 Diana-Victoria Tiriplica <diana.tiriplica@gmail.com>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "config.h"
 
 #include "katebuffer.h"
 #include "kateconfig.h"
 #include "katedocument.h"
 #include "katepartdebug.h"
 #include "kateswapdiffcreator.h"
 #include "kateswapfile.h"
 #include "katetextbuffer.h"
 #include "kateundomanager.h"
 
 #include <ktexteditor/view.h>
 
 #include <KLocalizedString>
 #include <KStandardGuiItem>
 
 #include <QApplication>
 #include <QCryptographicHash>
 #include <QDir>
 #include <QFileInfo>
 
 #ifndef Q_OS_WIN
 #include <unistd.h>
 #endif
 
 // swap file version header
 const static char swapFileVersionString[] = "Kate Swap File 2.0";
 
 // tokens for swap files
 const static qint8 EA_StartEditing = 'S';
 const static qint8 EA_FinishEditing = 'E';
 const static qint8 EA_WrapLine = 'W';
 const static qint8 EA_UnwrapLine = 'U';
 const static qint8 EA_InsertText = 'I';
 const static qint8 EA_RemoveText = 'R';
 
 namespace Kate
 {
 QTimer *SwapFile::s_timer = nullptr;
 
 SwapFile::SwapFile(KTextEditor::DocumentPrivate *document)
     : QObject(document)
     , m_document(document)
     , m_trackingEnabled(false)
     , m_recovered(false)
     , m_needSync(false)
 {
     // fixed version of serialisation
     m_stream.setVersion(QDataStream::Qt_4_6);
 
     // connect the timer
     connect(syncTimer(), &QTimer::timeout, this, &Kate::SwapFile::writeFileToDisk, Qt::DirectConnection);
 
     // connecting the signals
     connect(&m_document->buffer(), &KateBuffer::saved, this, &Kate::SwapFile::fileSaved);
     connect(&m_document->buffer(), &KateBuffer::loaded, this, &Kate::SwapFile::fileLoaded);
     connect(m_document, &KTextEditor::Document::configChanged, this, &SwapFile::configChanged);
 
     // tracking on!
     setTrackingEnabled(true);
 }
 
 SwapFile::~SwapFile()
 {
     // only remove swap file after data recovery (bug #304576)
     if (!shouldRecover()) {
         removeSwapFile();
     }
 }
 
 void SwapFile::configChanged()
 {
 }
 
 void SwapFile::setTrackingEnabled(bool enable)
 {
     if (m_trackingEnabled == enable) {
         return;
     }
 
     m_trackingEnabled = enable;
 
     TextBuffer &buffer = m_document->buffer();
 
     if (m_trackingEnabled) {
         connect(&buffer, &Kate::TextBuffer::editingStarted, this, &Kate::SwapFile::startEditing);
         connect(&buffer, &Kate::TextBuffer::editingFinished, this, &Kate::SwapFile::finishEditing);
         connect(m_document, &KTextEditor::DocumentPrivate::modifiedChanged, this, &SwapFile::modifiedChanged);
 
         connect(&buffer, &Kate::TextBuffer::lineWrapped, this, &Kate::SwapFile::wrapLine);
         connect(&buffer, &Kate::TextBuffer::lineUnwrapped, this, &Kate::SwapFile::unwrapLine);
         connect(&buffer, &Kate::TextBuffer::textInserted, this, &Kate::SwapFile::insertText);
         connect(&buffer, &Kate::TextBuffer::textRemoved, this, &Kate::SwapFile::removeText);
     } else {
         disconnect(&buffer, &Kate::TextBuffer::editingStarted, this, &Kate::SwapFile::startEditing);
         disconnect(&buffer, &Kate::TextBuffer::editingFinished, this, &Kate::SwapFile::finishEditing);
         disconnect(m_document, &KTextEditor::DocumentPrivate::modifiedChanged, this, &SwapFile::modifiedChanged);
 
         disconnect(&buffer, &Kate::TextBuffer::lineWrapped, this, &Kate::SwapFile::wrapLine);
         disconnect(&buffer, &Kate::TextBuffer::lineUnwrapped, this, &Kate::SwapFile::unwrapLine);
         disconnect(&buffer, &Kate::TextBuffer::textInserted, this, &Kate::SwapFile::insertText);
         disconnect(&buffer, &Kate::TextBuffer::textRemoved, this, &Kate::SwapFile::removeText);
     }
 }
 
 void SwapFile::fileClosed()
 {
     // remove old swap file, file is now closed
     if (!shouldRecover()) {
         removeSwapFile();
     } else {
         m_document->setReadWrite(true);
     }
 
     // purge filename
     updateFileName();
 }
 
 KTextEditor::DocumentPrivate *SwapFile::document()
 {
     return m_document;
 }
 
 bool SwapFile::isValidSwapFile(QDataStream &stream, bool checkDigest) const
 {
     // read and check header
     QByteArray header;
     stream >> header;
 
     if (header != swapFileVersionString) {
         qCWarning(LOG_KTE) << "Can't open swap file, wrong version";
         return false;
     }
 
     // read checksum
     QByteArray checksum;
     stream >> checksum;
     // qCDebug(LOG_KTE) << "DIGEST:" << checksum << m_document->checksum();
     if (checkDigest && checksum != m_document->checksum()) {
         qCWarning(LOG_KTE) << "Can't recover from swap file, checksum of document has changed";
         return false;
     }
 
     return true;
 }
 
 void SwapFile::fileLoaded(const QString &)
 {
     // look for swap file
     if (!updateFileName()) {
         return;
     }
 
     if (!m_swapfile.exists()) {
         // qCDebug(LOG_KTE) << "No swap file";
         return;
     }
 
     if (!QFileInfo(m_swapfile).isReadable()) {
         qCWarning(LOG_KTE) << "Can't open swap file (missing permissions)";
         return;
     }
 
     // sanity check
     QFile peekFile(fileName());
     if (peekFile.open(QIODevice::ReadOnly)) {
         QDataStream stream(&peekFile);
         if (!isValidSwapFile(stream, true)) {
             removeSwapFile();
             return;
         }
         peekFile.close();
     } else {
         qCWarning(LOG_KTE) << "Can't open swap file:" << fileName();
         return;
     }
 
     // show swap file message
     m_document->setReadWrite(false);
     showSwapFileMessage();
 }
 
 void SwapFile::modifiedChanged()
 {
     if (!m_document->isModified() && !shouldRecover()) {
         m_needSync = false;
         // the file is not modified and we are not in recover mode
         removeSwapFile();
     }
 }
 
 void SwapFile::recover()
 {
     m_document->setReadWrite(true);
 
     // if isOpen() returns true, the swap file likely changed already (appended data)
     // Example: The document was falsely marked as writable and the user changed
     // text even though the recover bar was visible. In this case, a replay of
     // the swap file across wrong document content would happen -> certainly wrong
     if (m_swapfile.isOpen()) {
         qCWarning(LOG_KTE) << "Attempt to recover an already modified document. Aborting";
         removeSwapFile();
         return;
     }
 
     // if the file doesn't exist, abort (user might have deleted it, or use two editor instances)
     if (!m_swapfile.open(QIODevice::ReadOnly)) {
         qCWarning(LOG_KTE) << "Can't open swap file";
         return;
     }
 
     // remember that the file has recovered
     m_recovered = true;
 
     // open data stream
     m_stream.setDevice(&m_swapfile);
 
     // replay the swap file
     bool success = recover(m_stream);
 
     // close swap file
     m_stream.setDevice(nullptr);
     m_swapfile.close();
 
     if (!success) {
         removeSwapFile();
     }
 
     // recover can also be called through the KTE::RecoveryInterface.
     // Make sure, the message is hidden in this case as well.
     if (m_swapMessage) {
         m_swapMessage->deleteLater();
     }
 }
 
 bool SwapFile::recover(QDataStream &stream, bool checkDigest)
 {
     if (!isValidSwapFile(stream, checkDigest)) {
         return false;
     }
 
     // disconnect current signals
     setTrackingEnabled(false);
 
     // needed to set undo/redo cursors in a sane way
     bool firstEditInGroup = false;
     KTextEditor::Cursor undoCursor = KTextEditor::Cursor::invalid();
     KTextEditor::Cursor redoCursor = KTextEditor::Cursor::invalid();
 
     // replay swapfile
     bool editRunning = false;
     bool brokenSwapFile = false;
     while (!stream.atEnd()) {
         if (brokenSwapFile) {
             break;
         }
 
         qint8 type;
         stream >> type;
         switch (type) {
         case EA_StartEditing: {
             m_document->editStart();
             editRunning = true;
             firstEditInGroup = true;
             undoCursor = KTextEditor::Cursor::invalid();
             redoCursor = KTextEditor::Cursor::invalid();
             break;
         }
         case EA_FinishEditing: {
             m_document->editEnd();
 
             // empty editStart() / editEnd() groups exist: only set cursor if required
             if (!firstEditInGroup) {
                 // set undo/redo cursor of last KateUndoGroup of the undo manager
                 m_document->undoManager()->setUndoRedoCursorsOfLastGroup(undoCursor, redoCursor);
                 m_document->undoManager()->undoSafePoint();
             }
             firstEditInGroup = false;
             editRunning = false;
             break;
         }
         case EA_WrapLine: {
             if (!editRunning) {
                 brokenSwapFile = true;
                 break;
             }
 
             int line = 0;
             int column = 0;
             stream >> line >> column;
 
             // emulate buffer unwrapLine with document
             m_document->editWrapLine(line, column, true);
 
             // track undo/redo cursor
             if (firstEditInGroup) {
                 firstEditInGroup = false;
                 undoCursor = KTextEditor::Cursor(line, column);
             }
             redoCursor = KTextEditor::Cursor(line + 1, 0);
 
             break;
         }
         case EA_UnwrapLine: {
             if (!editRunning) {
                 brokenSwapFile = true;
                 break;
             }
 
             int line = 0;
             stream >> line;
 
             // assert valid line
             Q_ASSERT(line > 0);
 
             const int undoColumn = m_document->lineLength(line - 1);
 
             // emulate buffer unwrapLine with document
             m_document->editUnWrapLine(line - 1, true, 0);
 
             // track undo/redo cursor
             if (firstEditInGroup) {
                 firstEditInGroup = false;
                 undoCursor = KTextEditor::Cursor(line, 0);
             }
             redoCursor = KTextEditor::Cursor(line - 1, undoColumn);
 
             break;
         }
         case EA_InsertText: {
             if (!editRunning) {
                 brokenSwapFile = true;
                 break;
             }
 
             int line;
             int column;
             QByteArray text;
             stream >> line >> column >> text;
             m_document->insertText(KTextEditor::Cursor(line, column), QString::fromUtf8(text.data(), text.size()));
 
             // track undo/redo cursor
             if (firstEditInGroup) {
                 firstEditInGroup = false;
                 undoCursor = KTextEditor::Cursor(line, column);
             }
             redoCursor = KTextEditor::Cursor(line, column + text.size());
 
             break;
         }
         case EA_RemoveText: {
             if (!editRunning) {
                 brokenSwapFile = true;
                 break;
             }
 
             int line;
             int startColumn;
             int endColumn;
             stream >> line >> startColumn >> endColumn;
             m_document->removeText(KTextEditor::Range(KTextEditor::Cursor(line, startColumn), KTextEditor::Cursor(line, endColumn)));
 
             // track undo/redo cursor
             if (firstEditInGroup) {
                 firstEditInGroup = false;
                 undoCursor = KTextEditor::Cursor(line, endColumn);
             }
             redoCursor = KTextEditor::Cursor(line, startColumn);
 
             break;
         }
         default: {
             qCWarning(LOG_KTE) << "Unknown type:" << type;
         }
         }
     }
 
     // balanced editStart and editEnd?
     if (editRunning) {
         brokenSwapFile = true;
         m_document->editEnd();
     }
 
     // warn the user if the swap file is not complete
     if (brokenSwapFile) {
         qCWarning(LOG_KTE) << "Some data might be lost";
     } else {
         // set sane final cursor, if possible
         KTextEditor::View *view = m_document->activeView();
         redoCursor = m_document->undoManager()->lastRedoCursor();
         if (view && redoCursor.isValid()) {
             view->setCursorPosition(redoCursor);
         }
     }
 
     // reconnect the signals
     setTrackingEnabled(true);
 
     return true;
 }
 
 void SwapFile::fileSaved(const QString &)
 {
     m_needSync = false;
 
     // remove old swap file (e.g. if a file A was "saved as" B)
     removeSwapFile();
 
     // set the name for the new swap file
     updateFileName();
 }
 
 void SwapFile::startEditing()
 {
     // no swap file, no work
     if (m_swapfile.fileName().isEmpty()) {
         return;
     }
 
     // if swap file doesn't exists, open it in WriteOnly mode
     // if it does, append the data to the existing swap file,
     // in case you recover and start editing again
     if (!m_swapfile.exists()) {
         // create path if not there
         if (KateDocumentConfig::global()->swapFileMode() == KateDocumentConfig::SwapFilePresetDirectory
             && !QDir(KateDocumentConfig::global()->swapDirectory()).exists()) {
             QDir().mkpath(KateDocumentConfig::global()->swapDirectory());
         }
 
         m_swapfile.open(QIODevice::WriteOnly);
         m_swapfile.setPermissions(QFileDevice::ReadOwner | QFileDevice::WriteOwner);
         m_stream.setDevice(&m_swapfile);
 
         // write file header
         m_stream << QByteArray(swapFileVersionString);
 
         // write checksum
         m_stream << m_document->checksum();
     } else if (m_stream.device() == nullptr) {
         m_swapfile.open(QIODevice::Append);
         m_swapfile.setPermissions(QFileDevice::ReadOwner | QFileDevice::WriteOwner);
         m_stream.setDevice(&m_swapfile);
     }
 
     // format: qint8
     m_stream << EA_StartEditing;
 }
 
 void SwapFile::finishEditing()
 {
     // skip if not open
     if (!m_swapfile.isOpen()) {
         return;
     }
 
     // write the file to the disk every 15 seconds (default)
     // skip this if we disabled that
     if (m_document->config()->swapSyncInterval() != 0 && !syncTimer()->isActive()) {
         // important: we store the interval as seconds, start wants milliseconds!
         syncTimer()->start(m_document->config()->swapSyncInterval() * 1000);
     }
 
     // format: qint8
     m_stream << EA_FinishEditing;
     m_swapfile.flush();
 }
 
 void SwapFile::wrapLine(const KTextEditor::Cursor position)
 {
     // skip if not open
     if (!m_swapfile.isOpen()) {
         return;
     }
 
     // format: qint8, int, int
     m_stream << EA_WrapLine << position.line() << position.column();
 
     m_needSync = true;
 }
 
 void SwapFile::unwrapLine(int line)
 {
     // skip if not open
     if (!m_swapfile.isOpen()) {
         return;
     }
 
     // format: qint8, int
     m_stream << EA_UnwrapLine << line;
 
     m_needSync = true;
 }
 
 void SwapFile::insertText(const KTextEditor::Cursor position, const QString &text)
 {
     // skip if not open
     if (!m_swapfile.isOpen()) {
         return;
     }
 
     // format: qint8, int, int, bytearray
     m_stream << EA_InsertText << position.line() << position.column() << text.toUtf8();
 
     m_needSync = true;
 }
 
 void SwapFile::removeText(KTextEditor::Range range)
 {
     // skip if not open
     if (!m_swapfile.isOpen()) {
         return;
     }
 
     // format: qint8, int, int, int
     Q_ASSERT(range.start().line() == range.end().line());
     m_stream << EA_RemoveText << range.start().line() << range.start().column() << range.end().column();
 
     m_needSync = true;
 }
 
 bool SwapFile::shouldRecover() const
 {
     // should not recover if the file has already recovered in another view
     if (m_recovered) {
         return false;
     }
 
     return !m_swapfile.fileName().isEmpty() && m_swapfile.exists() && m_stream.device() == nullptr;
 }
 
 void SwapFile::discard()
 {
     m_document->setReadWrite(true);
     removeSwapFile();
 
     // discard can also be called through the KTE::RecoveryInterface.
     // Make sure, the message is hidden in this case as well.
     if (m_swapMessage) {
         m_swapMessage->deleteLater();
     }
 }
 
 void SwapFile::removeSwapFile()
 {
     if (!m_swapfile.fileName().isEmpty() && m_swapfile.exists()) {
         m_stream.setDevice(nullptr);
         m_swapfile.close();
         m_swapfile.remove();
     }
 }
 
 bool SwapFile::updateFileName()
 {
     // first clear filename
     m_swapfile.setFileName(QString());
 
     // get the new path
     QString path = fileName();
     if (path.isNull()) {
         return false;
     }
 
     m_swapfile.setFileName(path);
     return true;
 }
 
 QString SwapFile::fileName()
 {
     const QUrl &url = m_document->url();
     if (url.isEmpty() || !url.isLocalFile()) {
         return QString();
     }
 
     const QString fullLocalPath(url.toLocalFile());
     QString path;
     if (KateDocumentConfig::global()->swapFileMode() == KateDocumentConfig::SwapFilePresetDirectory) {
         path = KateDocumentConfig::global()->swapDirectory();
         path.append(QLatin1Char('/'));
 
         // append the sha1 sum of the full path + filename, to avoid "too long" paths created
         path.append(QString::fromLatin1(QCryptographicHash::hash(fullLocalPath.toUtf8(), QCryptographicHash::Sha1).toHex()));
         path.append(QLatin1Char('-'));
         path.append(QFileInfo(fullLocalPath).fileName());
 
         path.append(QLatin1String(".kate-swp"));
     } else {
         path = fullLocalPath;
         int poz = path.lastIndexOf(QLatin1Char('/'));
         path.insert(poz + 1, QLatin1Char('.'));
         path.append(QLatin1String(".kate-swp"));
     }
 
     return path;
 }
 
 QTimer *SwapFile::syncTimer()
 {
     if (s_timer == nullptr) {
         s_timer = new QTimer(QApplication::instance());
         s_timer->setSingleShot(true);
     }
 
     return s_timer;
 }
 
 void SwapFile::writeFileToDisk()
 {
     if (m_needSync) {
         m_needSync = false;
 
 #ifndef Q_OS_WIN
         // ensure that the file is written to disk
 #if HAVE_FDATASYNC
         fdatasync(m_swapfile.handle());
 #else
         fsync(m_swapfile.handle());
 #endif
 #endif
     }
 }
 
 void SwapFile::showSwapFileMessage()
 {
     m_swapMessage = new KTextEditor::Message(i18n("The file was not closed properly."), KTextEditor::Message::Warning);
     m_swapMessage->setWordWrap(true);
 
     QAction *diffAction = new QAction(QIcon::fromTheme(QStringLiteral("split")), i18n("View Changes"), nullptr);
     QAction *recoverAction = new QAction(QIcon::fromTheme(QStringLiteral("edit-redo")), i18n("Recover Data"), nullptr);
     QAction *discardAction = new QAction(KStandardGuiItem::discard().icon(), i18n("Discard"), nullptr);
 
     m_swapMessage->addAction(diffAction, false);
     m_swapMessage->addAction(recoverAction);
     m_swapMessage->addAction(discardAction);
 
     connect(diffAction, &QAction::triggered, this, &SwapFile::showDiff);
     connect(recoverAction, &QAction::triggered, this, qOverload<>(&Kate::SwapFile::recover), Qt::QueuedConnection);
     connect(discardAction, &QAction::triggered, this, &SwapFile::discard, Qt::QueuedConnection);
 
     m_document->postMessage(m_swapMessage);
 }
 
 void SwapFile::showDiff()
 {
     // the diff creator deletes itself through deleteLater() when it's done
     SwapDiffCreator *diffCreator = new SwapDiffCreator(this);
     diffCreator->viewDiff();
 }
 
 }
 
 #include "moc_kateswapfile.cpp"