compressed_csv_reader

compressed_csv_reader.h

#pragma once
#include <iostream>
#include <sstream>
#include <vector>

#include <boost/algorithm/string.hpp>
#include <boost/iostreams/copy.hpp>
#include <boost/iostreams/filter/bzip2.hpp>
#include <boost/iostreams/filter/gzip.hpp>
#include <boost/iostreams/filtering_stream.hpp>
#include <boost/iostreams/filtering_streambuf.hpp>

using std::string;
using std::vector;

template <class RowData>
class CompressedCSVReader {
 public:
  CompressedCSVReader() {}

  CompressedCSVReader(std::string file_path, string delimiter = ",",
                      string compression = "gzip", bool header = true)
      : delimiter(delimiter), compression(compression), header(header) {
    file = std::ifstream(file_path, std::ios_base::in | std::ios_base::binary);
  }

  vector<RowData> read() {
    vector<RowData> row_data_list;
    try {
      boost::iostreams::filtering_istream in;
      if (compression == "gzip") {
        in.push(boost::iostreams::gzip_decompressor());
      } else if (compression == "bzip2") {
        in.push(boost::iostreams::bzip2_decompressor());
      }

      in.push(file);
      if (header) {
        string str;
        std::getline(in, str);
      }
      for (std::string str; std::getline(in, str);) {
        vector<string> tokens;
        boost::split(tokens, str, boost::is_any_of(delimiter));
        RowData row_data(tokens);
        row_data_list.push_back(row_data);
      }
    } catch (const boost::iostreams::gzip_error& e) {
      std::cout << e.what() << '\n';
    } catch (const boost::iostreams::bzip2_error& e) {
      std::cout << e.what() << '\n';
    }
    return row_data_list;
  }

 private:
  std::ifstream file;
  string delimiter;
  string compression = "gzip";
  bool header = true;
};