File indexing completed on 2024-06-23 04:30:52

 /*
     Kchmviewer - a CHM and EPUB file viewer with broad language support
     SPDX-FileCopyrightText: 2004-2014 George Yunaev gyunaev@ulduzsoft.com
 
     SPDX-License-Identifier: GPL-3.0-or-later
 */
 
 #include <QApplication>
 
 #include "ebook.h"
 #include "ebook_search.h"
 
 // Helper class to simplicity state management and data keeping
 class SearchDataKeeper
 {
 public:
     SearchDataKeeper()
     {
         m_inPhrase = false;
     }
 
     void beginPhrase()
     {
         phrase_terms.clear();
         m_inPhrase = true;
     }
 
     void endPhrase()
     {
         m_inPhrase = false;
         phrasewords += phrase_terms;
         phrases.push_back(phrase_terms.join(QStringLiteral(" ")));
     }
 
     bool isInPhrase() const
     {
         return m_inPhrase;
     }
 
     void addTerm(const QString &term)
     {
         if (!term.isEmpty()) {
             terms.push_back(term);
 
             if (m_inPhrase) {
                 phrase_terms.push_back(term);
             }
         }
     }
 
     // Should contain all the search terms present in query, includind those from phrases. One element - one term .
     QStringList terms;
 
     // Should contain phrases present in query without quotes. One element - one phrase.
     QStringList phrases;
 
     // Should contain all the terms present in all the phrases (but not outside).
     QStringList phrasewords;
 
 private:
     bool m_inPhrase;
     QStringList phrase_terms;
 };
 
 EBookSearch::EBookSearch()
 {
     m_Index = nullptr;
 }
 
 EBookSearch::~EBookSearch()
 {
     delete m_Index;
 }
 
 bool EBookSearch::loadIndex(QDataStream &stream)
 {
     delete m_Index;
 
     m_Index = new QtAs::Index();
     return m_Index->readDict(stream);
 }
 
 bool EBookSearch::generateIndex(EBook *ebookFile, QDataStream &stream)
 {
     QList<QUrl> documents;
     QList<QUrl> alldocuments;
 
     Q_EMIT progressStep(0, QStringLiteral("Generating the list of documents"));
     processEvents();
 
     // Enumerate the documents
     if (!ebookFile->enumerateFiles(alldocuments)) {
         return false;
     }
 
     if (m_Index) {
         delete m_Index;
     }
 
     m_Index = new QtAs::Index();
     connect(m_Index, &QtAs::Index::indexingProgress, this, &EBookSearch::updateProgress);
 
     // Process the list of files in CHM archive and keep only HTML document files from there
     for (const QUrl &allDocumentsI : std::as_const(alldocuments)) {
         const QString docpath = allDocumentsI.path();
 
         if (docpath.endsWith(QLatin1String(".html"), Qt::CaseInsensitive) || docpath.endsWith(QLatin1String(".htm"), Qt::CaseInsensitive) || docpath.endsWith(QLatin1String(".xhtml"), Qt::CaseInsensitive)) {
             documents.push_back(allDocumentsI);
         }
     }
 
     if (!m_Index->makeIndex(documents, ebookFile)) {
         delete m_Index;
         m_Index = nullptr;
         return false;
     }
 
     m_Index->writeDict(stream);
     m_keywordDocuments.clear();
 
     return true;
 }
 
 void EBookSearch::cancelIndexGeneration()
 {
     m_Index->setLastWinClosed();
 }
 
 void EBookSearch::updateProgress(int value, const QString &stepName)
 {
     Q_EMIT progressStep(value, stepName);
 }
 
 void EBookSearch::processEvents()
 {
     // Do it up to ten times; some events generate other events
     for (int i = 0; i < 10; i++) {
         qApp->processEvents(QEventLoop::ExcludeUserInputEvents);
     }
 }
 
 bool EBookSearch::searchQuery(const QString &query, QList<QUrl> *results, EBook *ebookFile, unsigned int limit)
 {
     // We should have index
     if (!m_Index) {
         return false;
     }
 
     // Characters which split the words. We need to make them separate tokens
     QString splitChars = m_Index->getCharsSplit();
 
     // Characters which are part of the word. We should keep them apart.
     QString partOfWordChars = m_Index->getCharsPartOfWord();
 
     // Variables to store current state
     SearchDataKeeper keeper;
     QString term;
 
     for (const QChar &iChar : query) {
         const QChar ch = iChar.toLower();
 
         // a quote either begins or ends the phrase
         if (ch == QLatin1Char('"')) {
             keeper.addTerm(term);
 
             if (keeper.isInPhrase()) {
                 keeper.endPhrase();
             } else {
                 keeper.beginPhrase();
             }
 
             continue;
         }
 
         // If new char does not stop the word, add ot and continue
         if (ch.isLetterOrNumber() || partOfWordChars.indexOf(ch) != -1) {
             term.append(ch);
             continue;
         }
 
         // If it is a split char, add this term and split char as separate term
         if (splitChars.indexOf(ch) != -1) {
             // Add existing term if present
             keeper.addTerm(term);
 
             // Change the term variable, so it will be added when we exit this block
             term = ch;
         }
 
         // Just add the word; it is most likely a space or terminated by tokenizer.
         keeper.addTerm(term);
         term = QString();
     }
 
     keeper.addTerm(term);
 
     if (keeper.isInPhrase()) {
         return false;
     }
 
     QList<QUrl> foundDocs = m_Index->query(keeper.terms, keeper.phrases, keeper.phrasewords, ebookFile);
 
     for (QList<QUrl>::iterator it = foundDocs.begin(); it != foundDocs.end() && limit > 0; ++it, limit--) {
         results->push_back(*it);
     }
 
     return true;
 }
 
 bool EBookSearch::hasIndex() const
 {
     return m_Index != nullptr;
 }