tsdb-kit/src/index.ts

import { DataTable } from './connectors';
import { QueryConfig } from './models/query_config';
import { BadRange } from './types';

export { QueryConfig } from './models/query_config';
export { Datasource, DatasourceType, DataTable } from './connectors'
export { DatasourceUnavailable } from './types';
export { GrafanaUnavailable } from './services/query_service/grafana';

const CHUNK_SIZE = 50000;


/**
 * @param queryConfig
 * @returns { values: [time, value][], columns: string[] }
 */
export async function queryByConfig(
  // TODO: check how did we wanna use `url` field
  queryConfig: QueryConfig, url: string, from: number, to: number,
  // TODO: we need an abstract DatasourceConfig class which will differ in direct and grafana queries
  apiKey?: string
): Promise<DataTable> {

  if(from > to) {
    throw new BadRange(
      `TSDB-kit got wrong range: from ${from} > to ${to}`,
      queryConfig.datasource.type,
      url
    );
  }

  if(from === to) {
    console.warn(`TSDB-kit got from === to`);
  }

  let data: DataTable = {
    values: [],
    columns: []
  };

  while(true) {
    let query = queryConfig.datasourceConnector.getQuery(from, to, CHUNK_SIZE, data.values.length);
    const res = await queryConfig.queryService.query(query, apiKey);
    let chunk = queryConfig.datasourceConnector.parseResponse(res);
    let values = chunk.values;
    data.values = data.values.concat(values);
    data.columns = chunk.columns;

    if(values.length < CHUNK_SIZE) {
      // because if we get less that we could, then there is nothing more
      break;
    }
  }
  return data;
}