Method loadInformation

kdevplatform/language/duchain/duchain.cpp:1028–1067

Loads/gets the environment-information for the given top-context index, or returns zero if none exists @warning m_chainsMutex should NOT be locked when this is called, because it triggers I/O @warning no other mutexes should be locked, as that may lead to a dedalock

    ///@warning m_chainsMutex should NOT be locked when this is called, because it triggers I/O
    ///@warning no other mutexes should be locked, as that may lead to a dedalock
    ParsingEnvironmentFile* loadInformation(uint topContextIndex)
    {
        ParsingEnvironmentFile* alreadyLoaded = findInformation(topContextIndex);
        if (alreadyLoaded)
            return alreadyLoaded;

        // Step two: Check if it is on disk, and if is, load it
        //  TODO: this looks pretty dubious, shouldn't we keep the repo locked while operating on the item?
        const auto item = LockedItemRepository::read<EnvironmentInformation>(
            [req = EnvironmentInformationRequest(topContextIndex)](const EnvironmentInformationRepo& repo) {
                return repo.findItem(req);
            });
        if (!item) {
            //No environment-information stored for this top-context
            return nullptr;
        }

        QMutexLocker lock(&m_chainsMutex);

        //Due to multi-threading, we must do this check after locking the mutex, so we can be sure we don't create the same item twice at the same time
        alreadyLoaded = findInformation(topContextIndex);
        if (alreadyLoaded)
            return alreadyLoaded;

        ///FIXME: ugly, and remove const_cast
        auto* ret = dynamic_cast<ParsingEnvironmentFile*>(
            DUChainItemSystem::self().create(const_cast<DUChainBaseData*>(reinterpret_cast<const DUChainBaseData*>(
                reinterpret_cast<const char*>(item) + sizeof(EnvironmentInformationItem)))));
        if (ret) {
            Q_ASSERT(ret->d_func()->classId);
            Q_ASSERT(ret->indexedTopContext().index() == topContextIndex);
            ParsingEnvironmentFilePointer retPtr(ret);

            m_fileEnvironmentInformations.insert(ret->url(), retPtr);

            Q_ASSERT(!m_indexEnvironmentInformations.contains(ret->indexedTopContext().index()));
            m_indexEnvironmentInformations.insert(ret->indexedTopContext().index(), retPtr);
        }
        return ret;
    }

    struct CleanupListVisitor
    {