Function ReadDatasetForSampler

catboost/libs/data/sampler.cpp:44–82

static TDataProviderPtr ReadDatasetForSampler(
    const TDataProviderSampleParams& params,
    bool loadSampleIds,
    THolder<ILineDataReader>&& lineDataReader
) {
    const auto& datasetReadingParams = params.DatasetReadingParams;

    TVector<TColumn> columnsDescription;
    TMaybe<size_t> sampleIdColumnIdx;

    ReadCDForSampler(
        datasetReadingParams.ColumnarPoolFormatParams.CdFilePath,
        params.OnlyFeaturesData,
        loadSampleIds,
        &columnsDescription,
        &sampleIdColumnIdx
    );

    TVector<NJson::TJsonValue> classLabels = datasetReadingParams.ClassLabels;

    return ReadDataset(
        std::move(lineDataReader),
        /*pairsFilePath*/ TPathWithScheme(),
        /*graphFilePath*/ TPathWithScheme(),
        /*groupWeightsFilePath*/ TPathWithScheme(),
        /*timestampsFilePath*/ TPathWithScheme(),
        /*baselineFilePath*/ TPathWithScheme(),
        datasetReadingParams.FeatureNamesPath,
        datasetReadingParams.PoolMetaInfoPath,
        datasetReadingParams.ColumnarPoolFormatParams.DsvFormat,
        columnsDescription,
        /*ignoredFeatures*/ {},  //TODO(akhropov): get unused features from the model
        EObjectsOrder::Ordered,
        loadSampleIds,
        /*forceUnitAutoPairWeights*/ false,
        &classLabels,
        params.LocalExecutor
    );
}

void DegroupDataset(TDataProvider* dataset) {
    auto& metaInfo = dataset->MetaInfo;