Method dropGraph

src/main/database_manager.cpp:209–267

}

void DatabaseManager::dropGraph(const std::string& graphName, main::ClientContext* clientContext) {
    if (StringUtils::caseInsensitiveEquals(graphName, "main")) {
        throw BinderException{"Cannot drop the main graph."};
    }

    auto upperCaseName = StringUtils::getUpper(graphName);

    // Check if graph exists in system catalog first
    auto mainCatalog = clientContext->getDatabase()->getCatalog();
    auto transaction = TransactionContext::Get(*clientContext)->getActiveTransaction();
    if (!mainCatalog->containsGraph(transaction, graphName)) {
        throw RuntimeException{std::format("No graph named {}.", graphName)};
    }

    // Remove from system catalog
    mainCatalog->dropGraph(transaction, graphName);

    for (auto it = graphs.begin(); it != graphs.end(); ++it) {
        auto graphNameUpper = StringUtils::getUpper((*it)->getCatalogName());
        if (graphNameUpper == upperCaseName) {
            if (defaultGraph != "" && StringUtils::getUpper(defaultGraph) == upperCaseName) {
                defaultGraph = "";
            }
            auto storageManager = (*it)->getStorageManager();
            std::string graphPath;
            if (storageManager != nullptr) {
                graphPath = storageManager->getDatabasePath();
                storageManager->closeFileHandle();
            }
            if (hasAttachedDatabase(graphName)) {
                detachDatabase(graphName);
            }
            graphs.erase(it);

            // Delete the physical graph files
            if (!graphPath.empty() &&
                !DBConfig::isDBPathInMemory(clientContext->getDatabasePath())) {
                auto vfs = common::VirtualFileSystem::GetUnsafe(*clientContext);
                vfs->removeFileIfExists(graphPath, clientContext);
                vfs->removeFileIfExists(storage::StorageUtils::getWALFilePath(graphPath),
                    clientContext);
                vfs->removeFileIfExists(storage::StorageUtils::getShadowFilePath(graphPath),
                    clientContext);
                vfs->removeFileIfExists(storage::StorageUtils::getTmpFilePath(graphPath),
                    clientContext);
            }

            auto dbStorageManager = clientContext->getDatabase()->getStorageManager();
            auto databaseHeader = dbStorageManager->getOrInitDatabaseHeader(*clientContext);
            auto newHeader = std::make_unique<storage::DatabaseHeader>(*databaseHeader);
            newHeader->catalogPageRange.startPageIdx = common::INVALID_PAGE_IDX;
            newHeader->catalogPageRange.numPages = 0;
            newHeader->metadataPageRange.startPageIdx = common::INVALID_PAGE_IDX;
            newHeader->metadataPageRange.numPages = 0;
            dbStorageManager->setDatabaseHeader(std::move(newHeader));
            return;
        }
    }