Method printBody

tools/shell/printer/json_printer.cpp:29–64

TODO(Ziyi): I'm inclined to move this as a QueryResult interface.

// TODO(Ziyi): I'm inclined to move this as a QueryResult interface.
std::string JsonPrinter::printBody(QueryResult& queryResult, MemoryManager& mm) const {
    std::string result;
    std::vector<std::shared_ptr<ValueVector>> resultVectors;
    std::vector<ValueVector*> scanVectors;
    for (auto& type : queryResult.getColumnDataTypes()) {
        auto resultVector = std::make_shared<ValueVector>(type.copy(), &mm, resultVectorState);
        resultVectors.push_back(resultVector);
        scanVectors.push_back(resultVector.get());
    }
    std::span<ValueVector*> vectorsToScan{scanVectors};
    DASSERT(queryResult.getType() == QueryResultType::FTABLE);
    auto& table = queryResult.constCast<MaterializedQueryResult>().getFactorizedTable();
    uint64_t numTuplesScanned = 0;
    auto maxNumTuplesToScanInBatch = table.hasUnflatCol() ? 1 : DEFAULT_VECTOR_CAPACITY;
    auto totalNumTuplesToScan = table.getNumTuples();
    while (numTuplesScanned < totalNumTuplesToScan) {
        auto numTuplesToScanInBatch =
            std::min<uint64_t>(maxNumTuplesToScanInBatch, totalNumTuplesToScan - numTuplesScanned);
        table.scan(vectorsToScan, numTuplesScanned, numTuplesToScanInBatch);
        numTuplesScanned += numTuplesToScanInBatch;
        auto queryResultsInJson =
            json_extension::jsonifyQueryResult(resultVectors, queryResult.getColumnNames());
        for (auto i = 0u; i < queryResultsInJson.size() - 1; i++) {
            result += jsonToString(queryResultsInJson[i]);
            result += printDelim();
            result += JsonPrinter::NEW_LINE;
        }
        // Only print the delimiter when it is not the last record.
        result += jsonToString(queryResultsInJson[queryResultsInJson.size() - 1]);
        if (numTuplesScanned != totalNumTuplesToScan) {
            result += printDelim();
        }
        result += JsonPrinter::NEW_LINE;
    }
    return result;
}

} // namespace main
} // namespace lbug