/// Renames a label.
bool XapianIndex::renameLabel(const string &name, const string &newName)
{
	bool renamedLabel = false;

	XapianDatabase *pDatabase = XapianDatabaseFactory::getDatabase(m_databaseName, false);
	if (pDatabase == NULL)
	{
		cerr << "Bad index " << m_databaseName << endl;
		return false;
	}

	try
	{
		Xapian::WritableDatabase *pIndex = pDatabase->writeLock();
		if (pIndex != NULL)
		{
			string term("XLABEL:");

			// Get documents that have this label
			term += name;
			for (Xapian::PostingIterator postingIter = pIndex->postlist_begin(term);
				postingIter != pIndex->postlist_end(term); ++postingIter)
			{
				Xapian::docid docId = *postingIter;

				// Get the document
				Xapian::Document doc = pIndex->get_document(docId);
				// Remove the term
				doc.remove_term(term);
				// ...add the new one
				doc.add_term(limitTermLength(string("XLABEL:") + newName));
				// ...and update the document
				pIndex->replace_document(docId, doc);
			}

			renamedLabel = true;
		}
	}
	catch (const Xapian::Error &error)
	{
		cerr << "Couldn't delete label: " << error.get_type() << ": " << error.get_msg() << endl;
	}
	catch (...)
	{
		cerr << "Couldn't delete label, unknown exception occured" << endl;
	}
	pDatabase->unlock();

	return renamedLabel;
}
/// Determines whether a document has a label.
bool XapianIndex::hasLabel(unsigned int docId, const string &name) const
{
	bool foundLabel = false;

	XapianDatabase *pDatabase = XapianDatabaseFactory::getDatabase(m_databaseName, false);
	if (pDatabase == NULL)
	{
		cerr << "Bad index " << m_databaseName << endl;
		return false;
	}

	try
	{
		Xapian::WritableDatabase *pIndex = pDatabase->writeLock();
		if (pIndex != NULL)
		{
			string term("XLABEL:");

			// Get documents that have this label
			// FIXME: would it be faster to get the document's terms ?
			term += name;
			Xapian::PostingIterator postingIter = pIndex->postlist_begin(term);
			if (postingIter != pIndex->postlist_end(term))
			{
				// Is this document in the list ?
				postingIter.skip_to(docId);
				if ((postingIter != pIndex->postlist_end(term)) &&
					(docId == (*postingIter)))
				{
					foundLabel = true;
				}
			}
		}
	}
	catch (const Xapian::Error &error)
	{
		cerr << "Couldn't check document labels: " << error.get_msg() << endl;
	}
	catch (...)
	{
		cerr << "Couldn't check document labels, unknown exception occured" << endl;
	}
	pDatabase->unlock();

	return foundLabel;
}