bool XapianEngine::queryDatabase(Xapian::Database *pIndex, Xapian::Query &query)
{
bool completedQuery = false;
if (pIndex == NULL)
{
return false;
}
// Start an enquire session on the database
Xapian::Enquire enquire(*pIndex);
try
{
AbstractGenerator abstractGen(pIndex, 50);
vector<string> seedTerms;
// Give the query object to the enquire session
enquire.set_query(query);
// Get the top results of the query
Xapian::MSet matches = enquire.get_mset(0, m_maxResultsCount);
if (matches.empty() == false)
{
// Get the results
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: " << matches.get_matches_estimated()
<< "/" << m_maxResultsCount << " results found" << endl;
#endif
for (Xapian::MSetIterator mIter = matches.begin(); mIter != matches.end(); ++mIter)
{
Xapian::docid docId = *mIter;
Xapian::Document doc(mIter.get_document());
// What terms did this document match ?
seedTerms.clear();
for (Xapian::TermIterator termIter = enquire.get_matching_terms_begin(docId);
termIter != enquire.get_matching_terms_end(docId); ++termIter)
{
seedTerms.push_back(*termIter);
}
DocumentInfo thisResult;
thisResult.setExtract(abstractGen.generateAbstract(docId, seedTerms));
thisResult.setScore((float)mIter.get_percent());
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: found document ID " << docId << endl;
#endif
XapianDatabase::recordToProps(doc.get_data(), &thisResult);
string url(thisResult.getLocation());
if (url.empty() == true)
{
// Hmmm this shouldn't be empty...
// Use this instead, even though the document isn't cached in the index
thisResult.setLocation(XapianDatabase::buildUrl(m_databaseName, docId));
}
// We don't know the index ID, just the document ID
thisResult.setIsIndexed(0, docId);
// Add this result
m_resultsList.push_back(thisResult);
}
}
completedQuery = true;
}
catch (const Xapian::Error &error)
{
cerr << "XapianEngine::queryDatabase: " << error.get_type() << ": " << error.get_msg() << endl;
}
try
{
m_expandTerms.clear();
// Expand the query ?
if (m_relevantDocuments.empty() == false)
{
Xapian::RSet relevantDocs;
unsigned int count = 0;
for (set<unsigned int>::const_iterator docIter = m_relevantDocuments.begin();
docIter != m_relevantDocuments.end(); ++docIter)
{
relevantDocs.add_document(*docIter);
}
// Get 10 non-prefixed terms
Xapian::ESet expandTerms = enquire.get_eset(20, relevantDocs);
for (Xapian::ESetIterator termIter = expandTerms.begin();
(termIter != expandTerms.end()) && (count < 10); ++termIter)
{
if (isupper((int)((*termIter)[0])) == 0)
{
m_expandTerms.insert(*termIter);
++count;
}
}
}
}
catch (const Xapian::Error &error)
{
cerr << "XapianEngine::queryDatabase: " << error.get_type() << ": " << error.get_msg() << endl;
}
// Be tolerant of errors as long as we got some results
if ((completedQuery == true) ||
(m_resultsList.empty() == false))
{
return true;
}
return false;
}
bool XapianEngine::queryDatabase(Xapian::Database *pIndex, Xapian::Query &query,
const string &stemLanguage, unsigned int startDoc, const QueryProperties &queryProps)
{
Timer timer;
unsigned int maxResultsCount = queryProps.getMaximumResultsCount();
bool completedQuery = false;
if (pIndex == NULL)
{
return false;
}
// Start an enquire session on the database
Xapian::Enquire enquire(*pIndex);
timer.start();
try
{
AbstractGenerator abstractGen(pIndex, 50);
vector<string> seedTerms;
// Give the query object to the enquire session
enquire.set_query(query);
// How should results be sorted ?
if (queryProps.getSortOrder() == QueryProperties::RELEVANCE)
{
// By relevance, only
enquire.set_sort_by_relevance_then_value(4);
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: sorting by relevance first" << endl;
#endif
}
else if (queryProps.getSortOrder() == QueryProperties::DATE)
{
// By date, and then by relevance
enquire.set_sort_by_value_then_relevance(4);
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: sorting by date and time first" << endl;
#endif
}
// Get the top results of the query
Xapian::MSet matches = enquire.get_mset(startDoc, maxResultsCount, (2 * maxResultsCount) + 1);
m_resultsCountEstimate = matches.get_matches_estimated();
if (matches.empty() == false)
{
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: found " << matches.size() << "/" << maxResultsCount
<< " results found from position " << startDoc << endl;
cout << "XapianEngine::queryDatabase: estimated " << matches.get_matches_lower_bound()
<< "/" << m_resultsCountEstimate << "/" << matches.get_matches_upper_bound() << endl;
#endif
// Get the results
for (Xapian::MSetIterator mIter = matches.begin(); mIter != matches.end(); ++mIter)
{
Xapian::docid docId = *mIter;
Xapian::Document doc(mIter.get_document());
// What terms did this document match ?
seedTerms.clear();
for (Xapian::TermIterator termIter = enquire.get_matching_terms_begin(docId);
termIter != enquire.get_matching_terms_end(docId); ++termIter)
{
char firstChar = (*termIter)[0];
if (isupper(((int)firstChar)) == 0)
{
seedTerms.push_back(*termIter);
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: matched term " << *termIter << endl;
#endif
}
else if (firstChar == 'Z')
{
string stemmed((*termIter).substr(1));
string::size_type stemmedLen = stemmed.length();
// Which of this document's terms stem to this ?
Xapian::TermIterator docTermIter = pIndex->termlist_begin(docId);
if (docTermIter != pIndex->termlist_end(docId))
{
for (docTermIter.skip_to(stemmed);
docTermIter != pIndex->termlist_end(docId); ++docTermIter)
{
// Is this a potential unstem ?
if (strncasecmp((*docTermIter).c_str(), stemmed.c_str(), stemmedLen) != 0)
{
// No, no point looking at the next terms
break;
}
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: matched unstem " << *docTermIter << endl;
#endif
// FIXME: check this term stems to stemmed !
seedTerms.push_back(*docTermIter);
}
}
}
}
DocumentInfo thisResult;
thisResult.setExtract(abstractGen.generateAbstract(docId, seedTerms));
thisResult.setScore((float)mIter.get_percent());
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: found document ID " << docId << endl;
#endif
XapianDatabase::recordToProps(doc.get_data(), &thisResult);
// XapianDatabase stored the language in English
thisResult.setLanguage(Languages::toLocale(thisResult.getLanguage()));
string url(thisResult.getLocation());
if (url.empty() == true)
{
// Hmmm this shouldn't be empty...
// Use this instead, even though the document isn't cached in the index
thisResult.setLocation(XapianDatabase::buildUrl(m_databaseName, docId));
}
// We don't know the index ID, just the document ID
thisResult.setIsIndexed(0, docId);
// Add this result
m_resultsList.push_back(thisResult);
}
}
completedQuery = true;
}
catch (const Xapian::Error &error)
{
cerr << "Couldn't run query: " << error.get_type() << ": " << error.get_msg() << endl;
}
cout << "Ran query \"" << queryProps.getFreeQuery() << "\" in " << timer.stop() << " ms" << endl;
try
{
m_expandTerms.clear();
// Expand the query ?
if (m_expandDocuments.empty() == false)
{
Xapian::RSet expandDocs;
for (set<string>::const_iterator docIter = m_expandDocuments.begin();
docIter != m_expandDocuments.end(); ++docIter)
{
string uniqueTerm(string("U") + XapianDatabase::limitTermLength(Url::escapeUrl(Url::canonicalizeUrl(*docIter)), true));
// Only one document may have this term
Xapian::PostingIterator postingIter = pIndex->postlist_begin(uniqueTerm);
if (postingIter != pIndex->postlist_end(uniqueTerm))
{
expandDocs.add_document(*postingIter);
}
}
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: expand from " << expandDocs.size() << " documents" << endl;
#endif
// Get 10 non-prefixed terms
string allowedPrefixes("RS");
TermDecider expandDecider(pIndex, ((stemLanguage.empty() == true) ? NULL : &m_stemmer),
FileStopper::get_stopper(Languages::toCode(stemLanguage)),
allowedPrefixes, query);
Xapian::ESet expandTerms = enquire.get_eset(10, expandDocs, &expandDecider);
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: " << expandTerms.size() << " expand terms" << endl;
#endif
for (Xapian::ESetIterator termIter = expandTerms.begin();
termIter != expandTerms.end(); ++termIter)
{
string expandTerm(*termIter);
char firstChar = expandTerm[0];
// Is this prefixed ?
if (allowedPrefixes.find(firstChar) != string::npos)
{
expandTerm.erase(0, 1);
}
m_expandTerms.insert(expandTerm);
}
}
}
catch (const Xapian::Error &error)
{
cerr << "Couldn't run query: " << error.get_type() << ": " << error.get_msg() << endl;
}
// Be tolerant of errors as long as we got some results
if ((completedQuery == true) ||
(m_resultsList.empty() == false))
{
return true;
}
return false;
}
bool XapianEngine::queryDatabase(Xapian::Query &query)
{
bool bStatus = false;
XapianDatabase *pDatabase = XapianDatabaseFactory::getDatabase(m_databaseName, true);
if (pDatabase == NULL)
{
return false;
}
// Get the latest revision...
pDatabase->reopen();
Xapian::Database *pIndex = pDatabase->readLock();
if (pIndex != NULL)
{
try
{
// Start an enquire session on the database
Xapian::Enquire enquire(*pIndex);
// Give the query object to the enquire session
enquire.set_query(query);
// Get the top results of the query
Xapian::MSet matches = enquire.get_mset(0, m_maxResultsCount);
if (matches.empty() == false)
{
multimap<Xapian::weight, string> queryTerms;
vector<string> seedTerms;
Xapian::weight maxWeight = matches.get_max_attained();
// Sort query terms by weight
for (Xapian::TermIterator termIter = query.get_terms_begin();
termIter != query.get_terms_end(); ++termIter)
{
string termName(*termIter);
Xapian::weight termWeight = maxWeight - matches.get_termweight(termName);
queryTerms.insert(pair<Xapian::weight, string>(termWeight, termName));
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: term " << termName
<< " has weight " << matches.get_termweight(termName) << "/" << maxWeight << endl;
#endif
}
for (multimap<Xapian::weight, string>::iterator weightIter = queryTerms.begin();
weightIter != queryTerms.end(); ++weightIter)
{
seedTerms.push_back(weightIter->second);
}
// Get the results
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: " << matches.get_matches_estimated() << "/" << m_maxResultsCount << " results found" << endl;
#endif
for (Xapian::MSetIterator mIter = matches.begin(); mIter != matches.end(); ++mIter)
{
Xapian::docid docId = *mIter;
Xapian::Document doc(mIter.get_document());
string record = doc.get_data();
// Get the title
string title = StringManip::extractField(record, "caption=", "\n");
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: found omindex title " << title << endl;
#endif
// Get the URL
string url = StringManip::extractField(record, "url=", "\n");
if (url.empty() == true)
{
// Hmmm this shouldn't be empty...
// Use this instead, even though the document isn't cached in the index
url = XapianDatabase::buildUrl(m_databaseName, *mIter);
}
else
{
#ifdef DEBUG
cout << "XapianEngine::queryDatabase: found omindex URL " << url << endl;
#endif
url = Url::canonicalizeUrl(url);
}
// Get the type
string type = StringManip::extractField(record, "type=", "\n");
// ...and the language, if available
string language = StringManip::extractField(record, "language=", "\n");
// Finally, get a summary
string summary = StringManip::extractField(record, "sample=", "\n");
if (summary.empty() == true)
{
AbstractGenerator abstractGen(pIndex, 50);
// Generate an abstract based on the query's terms
summary = abstractGen.generateAbstract(seedTerms, docId);
}
// Add this result
Result thisResult(url, title, summary, language, (float)mIter.get_percent());
m_resultsList.push_back(thisResult);
}
}
m_expandTerms.clear();
// Expand the query ?
if (m_relevantDocuments.empty() == false)
{
Xapian::RSet relevantDocs;
unsigned int count = 0;
for (set<unsigned int>::const_iterator docIter = m_relevantDocuments.begin();
docIter != m_relevantDocuments.end(); ++docIter)
{
relevantDocs.add_document(*docIter);
}
// Get 10 non-prefixed terms
Xapian::ESet expandTerms = enquire.get_eset(20, relevantDocs);
for (Xapian::ESetIterator termIter = expandTerms.begin();
(termIter != expandTerms.end()) && (count < 10); ++termIter)
{
if (isupper((int)((*termIter)[0])) == 0)
{
m_expandTerms.insert(*termIter);
++count;
}
}
}
bStatus = true;
}
catch (const Xapian::Error &error)
{
cerr << "XapianEngine::queryDatabase: " << error.get_type() << ": " << error.get_msg() << endl;
}
}
pDatabase->unlock();
return bStatus;
}